It contains citations and abstracts to approximately 60 malaria studies published in August 2009.

Below are titles to some of the studies in this issue:

Acta Trop. 2009 Aug 13.
- Plasmodium falciparum parasite infection prevalence from a household survey in Zambia using
- Distribution and larval habitat characterization of Anopheles moucheti, Anopheles nili, and
- Species B of Anopheles culicifacies (Diptera: Culicidae) is reproductively less fit than species A and C
AIDS. 2009 Aug 1.
- Impact of HIV infection on severity of imported malaria is restricted to patients with CD4 cell counts

Am J Trop Med Hyg. 2009 Aug;81(2):366-9.
- Quantitative determination of Plasmodium vivax gametocytes by real-time quantitative nucleic acid
- Common genotypic polymorphisms in glutathione S-transferases in mild and severe falciparum malaria
- Use of a histidine-rich protein 2-based rapid diagnostic test for malaria by health personnel during
Ann Bot (Lond). 2009 Aug;104(2):315-23.
- Enhancement of artemisinin concentration and yield in response to optimization of nitrogen and potassium supply to Artemisia annua.

Interdiscip Perspect Infect Dis. 2009;2009:617954.
- The Impact of HIV and Malaria Coinfection: What Is Known and Suggested Venues for Further Study.

J Community Health. 2009 Aug;34(4):288-94.
- Malaria prevention in Sub-Saharan Africa: a field study in rural Uganda.

1: BMC Infect Dis. 2009 May 10;9:59.

Shifting suitability for malaria vectors across Africa with warming climates.

Peterson AT.

Biodiversity Research Center, The University of Kansas, Lawrence, Kansas 66045, USA. town@ku.edu.

BACKGROUND: Climates are changing rapidly, producing warm climate conditions globally not previously observed in modern history. Malaria is of great concern as a cause of human mortality and morbidity, particularly across Africa, thanks in large part to the presence there of a particularly competent suite of mosquito vector species. METHODS: I derive spatially explicit estimates of human populations living in regions newly suitable climatically for populations of two key Anopheles gambiae vector complex species in Africa over the coming 50 years, based on ecological niche model projections over two global climate models, two
scenarios of climate change, and detailed spatial summaries of human population distributions. RESULTS: For both species, under all scenarios, given the changing spatial distribution of appropriate conditions and the current population distribution, the models predict a reduction of 11.3-30.2% in the percentage of the overall population living in areas climatically suitable for these vector species in coming decades, but reductions and increases are focused in different regions: malaria vector suitability is likely to decrease in West Africa, but
increase in eastern and southern Africa. CONCLUSION: Climate change effects on African malaria vectors shift their distributional potential from west to east and south, which has implications for overall numbers of people exposed to these vector species. Although the total is reduced, malaria is likely to pose novel public health problems in areas where it has not previously been common.

2: Ecohealth. 2009 May 16. [Epub ahead of print]

Risk of Malaria Reemergence in Southern France: Testing Scenarios with a Multiagent Simulation Model.

Linard C, Ponçon N, Fontenille D, Lambin EF.

Department of Geography, Université Catholique de Louvain, Place Pasteur 3, 1348, Louvain-la-Neuve, Belgium, catherine.linard@zoo.ox.ac.uk.

The Camargue, a region in southern France, is considered a potential site for malaria reemergence. All the suitable factors of the disease transmission system are present-competent mosquito vectors, habitats for their breeding, and susceptible people-except for the parasite. The objective of this study was to test potential drivers of malaria reemergence in this system after possible changes in biological attributes of vectors, agricultural practices, land use, tourism activities, and climate. Scenarios of plausible futures were formulated and then simulated using a spatially explicit and dynamic multiagent simulation: the MALCAM model. Scenarios were developed by varying the value of model inputs. Model outputs were compared based on the contact rate between people and potential malaria vectors, and the number of new infections in case of reintroduction of the parasite in the region. Model simulations showed that the risk of malaria reemergence is low in the Camargue. If the disease would reemerge, it would be the result of a combination of unfavorable conditions: introduction of a large population of infectious people or mosquitoes, combined with high levels of people-vector contacts resulting from significant changes in land use, tourism activities, agricultural policies, biological evolution of mosquitoes, and climate changes. The representation in the MALCAM model of interactions and feedbacks between different agents, and between agents and their environment, led in some cases to counterintuitive results. Results from scenario analyses can help local public health authorities in policy formulation.

3: Ecohealth. 2009 May 6. [Epub ahead of print]

Climate Change and Health in Sub-Saharan Africa: A Case-Based Perspective.

Ramin BM, McMichael AJ.

Faculty of Medicine, University of Toronto, Toronto, Canada, brodie.ramin@utoronto.ca.

Over the coming decades, sub-Saharan Africa will face profound stresses and challenges from global climate change. Many of these will manifest as adverse health outcomes. This article uses a series of five hypothetical cases to review the climate impacts on the health and well-being of individuals and populations
in sub-Saharan Africa. This approach fosters insights into the human dimensions of the risks to health, their interaction with local human ecology, and awareness of the diverse health ramifications of external environmental changes. Each case illustrates the health impact resulting from a specific environmental or social consequence of climate change, including impacts on agriculture and food security, droughts, floods, malaria, and population displacement. Whereas the article focuses on discrete manifestations of climate change, individuals will, in practice, face multiple stresses from climate change (i.e., floods and
malaria) concomitant with other non-climate stressors (i.e., HIV/AIDS, globalization, etc.). These multiple sources of vulnerability must be considered when designing climate change and socioeconomic development interventions.

4: Environ Manage. 2009 May;43(5):765-78. Epub 2009 Feb 18.

Development and climate change: a mainstreaming approach for assessing economic, social, and environmental impacts of adaptation measures.

Halsnaes K, Traerup S.

DTU Climate Centre, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, Roskilde, Denmark. kirsten.halsnaes@risoe.dk

The paper introduces the so-called climate change mainstreaming approach, where vulnerability and adaptation measures are assessed in the context of general development policy objectives. The approach is based on the application of a limited set of indicators. These indicators are selected as representatives of
focal development policy objectives, and a stepwise approach for addressing climate change impacts, development linkages, and the economic, social and environmental dimensions related to vulnerability and adaptation are introduced. Within this context it is illustrated using three case studies how development
policy indicators in practice can be used to assess climate change impacts and adaptation measures based on three case studies, namely a road project in flood prone areas of Mozambique, rainwater harvesting in the agricultural sector in Tanzania and malaria protection in Tanzania. The conclusions of the paper confirm
that climate risks can be reduced at relatively low costs, but the uncertainty is still remaining about some of the wider development impacts of implementing climate change adaptation measures.

5: Environ Manage. 2009 May;43(5):779-89. Epub 2009 Jan 6.

Development, malaria and adaptation to climate change: a case study from India.

Garg A, Dhiman RC, Bhattacharya S, Shukla PR.

Indian Institute of Management Ahmedabad, Vastrapur, Ahmedabad, India.
amitgarg@iimahd.ernet.in

India has reasons to be concerned about climate change. Over 650 million people depend on climate-sensitive sectors, such as rain-fed agriculture and forestry, for livelihood and over 973 million people are exposed to vector borne malarial parasites. Projection of climatic factors indicates a wider exposure to malaria
for the Indian population in the future. If precautionary measures are not taken and development processes are not managed properly some developmental activities, such as hydro-electric dams and irrigation canal systems, may also exacerbate breeding grounds for malaria. This article integrates climate change and
developmental variables in articulating a framework for integrated impact assessment and adaptation responses, with malaria incidence in India as a case study. The climate change variables include temperature, rainfall, humidity, extreme events, and other secondary variables. Development variables are income levels, institutional mechanisms to implement preventive measures, infrastructure development that could promote malarial breeding grounds, and other policies. The case study indicates that sustainable development variables may sometimes reduce the adverse impacts on the system due to climate change alone, while it may sometimes also exacerbate these impacts if the development variables are not
managed well and therefore they produce a negative impact on the system. The study concludes that well crafted and well managed developmental policies could result in enhanced resilience of communities and systems, and lower health impacts due to climate change.

6: Eur J Immunol. 2009 May;39(5):1288-300.

Homeostatic regulation of T effector to Treg ratios in an area of seasonal malaria transmission.

Finney OC, Nwakanma D, Conway DJ, Walther M, Riley EM.

Malaria Programme, MRC Laboratories, Fajara, Banjul, The Gambia.

An important aspect of clinical immunity to malaria is the ability to down-regulate inflammatory responses, once parasitaemia is under control, in order to avoid immune-mediated pathology. The role of classical
(CD4(+)CD25(+)CD127(lo/-)FOXP3(+)) Treg in this process, however, remains controversial. Thus, we have characterized the frequency, phenotype and function of Treg populations, over time, in healthy individuals in The Gambia. We observed that both the percentage and the absolute number of CD4(+)FOXP3(+)CD127(lo/-) T cells were higher among individuals living in a rural village with highly seasonal malaria transmission than among individuals living in an urban area where malaria rarely occurs. These CD4(+)FOXP3(+)CD127(lo/-) T cells exhibited an effector memory and apoptosis-prone phenotype and suppressed cytokine production
in response to malaria antigen. Cells from individuals exposed to malaria expressed significantly higher levels of mRNA for forkhead box P3 and T-box 21 (T-BET) at the end of the malaria transmission season than at the end of the non-transmission season. Importantly, the ratio of T-BET to forkhead box P3 was remarkably consistent between populations and over time, indicating that in healthy individuals, a transient increase in Th1 responses during the malaria transmission season is balanced by a commensurate Treg response, ensuring that immune homeostasis is maintained.

7: Int J Biometeorol. 2009 May;53(3):299-304. Epub 2009 Mar 5.

Malaria morbidity and temperature variation in a low risk Kenyan district: a case of overdiagnosis?

Njuguna J, Muita J, Mundia G.

Nyandarua District Public Health Office, P.O. Box 86-20300, Nyahururu, Kenya.
jowanju2002@yahoo.com

Diagnosis of malaria using only clinical means leads to overdiagnosis. This has implications due to safety concerns and the recent introduction of more expensive drugs. Temperature is a major climatic factor influencing the transmission dynamics of malaria. This study looked at trends in malaria morbidity in the low
risk Kenyan district of Nyandarua, coupled with data on temperature and precipitation for the years 2003-2006. July had the highest number of cases (12.2% of all cases) followed by August (10.2% of all cases). July and August also had the lowest mean maximum temperatures, 20.1 and 20.2 degrees C respectively. April, July and August had the highest rainfall, with daily means of 4.0, 4.3 and 4.9 mm, respectively. Observation showed that the coldest months experienced the highest number of cases of malaria. Despite the high rainfall, transmission of malaria tends to be limited by low temperatures due to the long duration required for sporogony, with fewer vectors surviving. These cold months also tend to have the highest number of cases of respiratory infections. There is a possibility that some of these were misdiagnosed as malaria based on the fact that only a small proportion of malaria cases were diagnosed using microscopy or
rapid diagnostic tests. We conclude that overdiagnosis may be prevalent in this district and there may be a need to design an intervention to minimise it.

8: J R Soc Interface. 2009 Jul 1. [Epub ahead of print]

The interaction of seasonal forcing and immunity and the resonance dynamics of malaria.

Childs DZ, Boots M.

Department of Animal and Plant Sciences, University of Sheffield, , Alfred Denny Building, Western Bank, Sheffield S10 2TN, UK.

Theory has emphasized the importance of both intrinsic factors such as host immunity and extrinsic drivers such as climate in determining disease dynamics. In particular, seasonality may lead to multi-annual cycles in prevalence, but the likelihood of this depends on the role of acquired immunity. Some diseases including malaria have immunity that falls between the classic susceptible-infectious-removed and susceptible-infectious-susceptible models. Here, we investigate the general conditions promoting the subharmonic resonance behaviour that may lead to multi-annual cycles in a general malaria dynamical model. Utilizing two complementary approaches to bifurcation analyses, we show that resonance is promoted by processes shortening the length of the infectious period and that subharmonic cycles are favoured in situations with strong seasonality in transmission but at intermediate levels of endemicity. We discuss the implications of our results for understanding prevalence patterns in long-term malaria datasets from Kenya that show multi-annual cycles and one from Thailand that does not and discuss the possible implications of treatment.

9: Malar J. 2009 Jun 7;8:123.

Spatial and temporal distribution of the malaria mosquito Anopheles arabiensis in northern Sudan: influence of environmental factors and implications for vector control.

Ageep TB, Cox J, Hassan MM, Knols BG, Benedict MQ, Malcolm CA, Babiker A, El
Sayed BB.

Epidemiology Department, Tropical Medicine Research Institute, Khartoum, Sudan.
tellalageep@yahoo.com

BACKGROUND: Malaria is an important public health problem in northern Sudan, but little is known about the dynamics of its transmission. Given the characteristic low densities of Anopheles arabiensis and the difficult terrain in this area, future vector control strategies are likely to be based on area-wide integrated
pest management (AW-IPM) that may include the sterile insect technique (SIT). To support the planning and implementation of future AW-IPM activities, larval surveys were carried out to provide key data on spatial and seasonal dynamics of local vector populations. METHODS: Monthly cross-sectional larval surveys were
carried out between March 2005 and May 2007 in two localities (Dongola and Merowe) adjacent to the river Nile. A stratified random sampling strategy based on the use of Remote Sensing (RS), Geographical Information Systems (GIS) and the Global Positioning System (GPS) was used to select survey locations. Breeding sites were mapped using GPS and data on larval density and breeding site characteristics were recorded using handheld computers. Bivariate and multivariate logistic regression models were used to identify breeding site characteristics associated with increased risk of presence of larvae. Seasonal
patterns in the proportion of breeding sites positive for larvae were compared visually to contemporaneous data on climate and river height. RESULTS: Of a total of 3,349 aquatic habitats sampled, 321 (9.6%) contained An. arabiensis larvae. The frequency with which larvae were found varied markedly by habitat type.
Although most positive sites were associated with temporary standing water around the margins of the main Nile channel, larvae were also found at brickworks and in areas of leaking pipes and canals – often far from the river. Close to the Nile channel, a distinct seasonal pattern in larval populations was evident and
appeared to be linked to the rise and fall of the river level. These patterns were not evident in vector populations breeding in artificial water sources away from the river. CONCLUSION: The GIS-based survey strategy developed in this study provides key data on the population dynamics of An. arabiensis in Northern State. Quantitative estimates of the contributions of various habitat types and their proximity to settlements provide a basis for planning a strategy for reducing malaria risk by elimination of the vector population.

10: Malar J. 2009 May 7;8:94.

The decline of malaria in Finland–the impact of the vector and social variables.

Hulden L, Hulden L. Department of Forest Ecology, PO Box 26, FIN-00014 Helsinki University, Helsinki,
Finland. lena.hulden@helsinki.fi

BACKGROUND: Malaria was prevalent in Finland in the 18th century. It declined slowly without deliberate counter-measures and the last indigenous case was reported in 1954. In the present analysis of indigenous malaria in Finland, an effort was made to construct a data set on annual malaria cases of maximum
temporal length to be able to evaluate the significance of different factors assumed to affect malaria trends. METHODS: To analyse the long-term trend malaria statistics were collected from 1750-2008. During that time, malaria frequency decreased from about 20,000-50,000 per 1,000,000 people to less than 1 per
1,000,000 people. To assess the cause of the decline, a correlation analysis was performed between malaria frequency per million people and temperature data, animal husbandry, consolidation of land by redistribution and household size. RESULTS: Anopheles messeae and Anopheles beklemishevi exist only as larvae in
June and most of July. The females seek an overwintering place in August. Those that overwinter together with humans may act as vectors. They have to stay in their overwintering place from September to May because of the cold climate. The temperatures between June and July determine the number of malaria cases during the following transmission season. This did not, however, have an impact on the long-term trend of malaria. The change in animal husbandry and reclamation of wetlands may also be excluded as a possible cause for the decline of malaria. The long-term social changes, such as land consolidation and decreasing household size, showed a strong correlation with the decline of Plasmodium. CONCLUSION: The
indigenous malaria in Finland faded out evenly in the whole country during 200 years with limited or no counter-measures or medication. It appears that malaria in Finland was basically a social disease and that malaria trends were strongly linked to changes in human behaviour. Decreasing household size caused fewer
interactions between families and accordingly decreasing recolonization possibilities for Plasmodium. The permanent drop of the household size was the precondition for a permanent eradication of malaria.

11: Malar J. 2009 May 5;8:92.

Preliminary study of malaria incidence in Nouakchott, Mauritania.

Lekweiry KM, Abdallahi MO, Ba H, Arnathau C, Durand P, Trape JF, Salem AO.

Laboratoire de Biotechnologie, Faculté des Sciences et Techniques, Université de Nouakchott, Nouakchott, Mauritania. k.lekweiry@ucam.ac.ma

BACKGROUND: Malaria is one of the main motives for outpatient consultation and hospitalization in Mauritania. However, its incidence remains unclear because of diagnostic problems and insufficient epidemiological data. METHODS: Between April and August 2007, a study on malaria incidence was carried out in Nouakchott city. A total of 237 febrile outpatients, from all Nouakchott districts, attending the
two main hospitals of the city were investigated. Finger prick and blood dried filter paper samples were performed to prepare thick and thin films and nested-PCR for malaria parasite species identification and density. The accuracy of diagnosis of ‘presumptive malaria’, assigned by clinicians and based on fever
and other malaria suggestive symptoms, was assessed. Entomological investigations based on morphological and molecular characterization of Anopheline species were conducted in Dar Naïm district. RESULTS: Malaria prevalence rate was 25.7% (61/237), the majority of positive blood slides as well as nested-PCR products
were due to Plasmodium vivax 70.5% (43/61) and Plasmodium ovale 24.6% (15/61). Two malaria patients, both with P. vivax, have never travelled out of Nouakchott and seem likely to have been autochthonous (3.3%). Of the 237 individuals included in the survey, 231(97.5%) were clinically diagnosed and treated as
malaria cases. 26.4% of clinically diagnosed cases were positive for Plasmodium using microscopic examination and PCR. Thus, false positive cases constituted 73.6% (170/231) of the clinically diagnosed malaria cases. The search for mosquito vectors in Dar Naïm district allowed morphological and molecular
identification of Anopheles arabiensis and Anopheles pharoensis. CONCLUSION: This study demonstrates that, during the hot and dry season, Plasmodium species responsible of recurrent malaria (P. vivax and P. ovale) are the dominant species in Nouakchott city and autochthonous malaria cases exist but are rare. Clinical diagnosis of malaria has a very low positive predicted value. The systematic use of microscopy-based diagnosis and/or rapid diagnostic tests should be considered to appropriately manage malaria and non-malaria cases.

1: Immunol Cell Biol. 2009 Jul;87(5):366-70. Epub 2009 May 12.

Moving candidate vaccines into development from research: lessons from HIV.

Sullivan M.

Medicines Development Limited, Melbourne, Victoria, Australia.

There is a logarithmic increase in the cost and complexity of the research and
development process when transitioning a promising candidate vaccine from the
laboratory into the clinic. Managing complex development programs involving
people from diverse technical, cultural and geographical backgrounds is a
specialised skill. It is essential that the group is clear on their objectives
and how their activities affect others, that communication is open, inclusive and
effective, and that the most rigorous, scientific approach based on statistical
principles in compliance with regulatory requirements is used. Applying these
standards to all vaccine development programs will filter out inappropriate
candidates more readily and enhance the efficiency of vaccine development. The
challenges of developing a new vaccine are illustrated in human immunodeficiency
virus (HIV) vaccinology. Selecting vaccine candidates for HIV requires the
ability to evaluate the large number of potential antigens in imperfect and
non-standardised animal models. Further, using these models to evaluate questions
such as dose scaling to humans, optimal route of administration, the use of
adjuvants and potential formulation improvements adds variable to variable,
making the interpretation of results particularly challenging. This may lead to
the promotion of a poor candidate or the elimination of a good one. The absence
of precise immunological correlates of protection and the prohibitive cost of
confirmatory clinical trials are further significant barriers. However, there are
practical steps that can be taken to standardise early vaccine evaluation, which
would result in more efficient development of new vaccines for HIV and other
disease areas with similarly challenging development issues (such as hepatitis C
virus, influenza, Mycobacterium tuberculosis and malaria).Immunology and Cell
Biology (2009) 87, 366-370; doi:10.1038/icb.2009.30; published online 12 May
2009.

2: Immunol Cell Biol. 2009 Jul;87(5):377-90. Epub 2009 May 5.

The future for blood-stage vaccines against malaria.

Richards JS, Beeson JG.

Infection and Immunity Division, Walter and Eliza Hall Institute of Medical
Research, Parkville, Victoria, Australia.

Malaria is a leading cause of mortality and morbidity globally, and effective
vaccines are urgently needed. Malaria vaccine approaches can be broadly grouped
as pre-erythrocytic, blood stage and transmission blocking. This review focuses
on blood-stage vaccines, and considers the evidence supporting the development of
blood-stage vaccines, the advantages and challenges of this approach, potential
targets, human vaccine studies and future directions. There is a strong rationale
for the development of vaccines based on antigens of blood-stage parasites.
Symptomatic malaria is caused by blood-stage parasitemia and acquired immunity in
humans largely targets blood-stage antigens. Several candidate vaccines have
proved efficacious in animal models and at least one vaccine showed partial
efficacy in a clinical trial. At present, all leading candidate blood-stage
antigens are merozoite proteins, located on the merozoite surface or within the
apical organelles. Major challenges and priorities include overcoming antigenic
diversity, identification of protective epitopes, understanding the nature and
targets of protective immune responses, and defining antigen combinations that
give the greatest efficacy. Additionally, objective criteria and approaches are
needed to prioritize the large number of candidate antigens, and strong
candidates need to be tested in clinical trials as quickly as possible.Immunology
and Cell Biology (2009) 87, 377-390; doi:10.1038/icb.2009.27; published online 5
May 2009.

3: Infect Immun. 2009 Jul 6. [Epub ahead of print]

Towards the rational design of a malaria vaccine construct: example of the MSP3
family. Part I: Immunogenicity studies in models.

Daher LJ, Demanga CG, Prieur E, Pérignon JL, Bouharoun-Tayoun H, Druilhe P.

Biomedical Parasitology Unit, Institut Pasteur, Paris, France; Laboratory of
Immunology, Faculty of Public Health, Lebanese University, Fanar, Lebanon.

P. falciparum Merozoite Surface Protein 3 (MSP3), being the target of antibodies
which mediate parasite killing in cooperation with blood monocytes, and are
associated with protection in exposed populations, is a vaccine candidate under
development. It belongs to a family of six structurally related genes. To
optimize immunogenicity we attempted to improve its design based on knowledge of
antigenicity of various regions from the conserved C-terminus of the six proteins
and an analysis of the immunogenicity of “tailored” constructs. The
immunogenicity studies were conducted in BALB/c and C57BL/6J mice, using MSP3
(referred to as MSP3-1) as a model. Four constructs were designed in order to
assess the effect of sequences flanking the 69 amino acid region of MSP3-1
previously shown to be the target of biologically active antibodies. The results
indicate major beneficial effects of removing i) the sub-region downstream from
the 69aa sequence, as antibody titers increased by two orders of magnitude, and
ii) the upstream sub-region which although it defines a T helper cell epitope, is
not the target of antibodies. The construct excluding both flanking sequences was
able to induce Th1 like responses, with a dominance of cytophilic antibodies.
This led to design a multigenic construct based on those results, combining the
six members of the MSP3 family. This new construction was immunogenic in mice,
induced antibodies which recognized the parasite native proteins and inhibited
parasite growth in the functional ADCI assay, thus satisfying the preclinical
criteria for a valuable vaccine candidate.

4: Infect Immun. 2009 Jul;77(7):3033-43. Epub 2009 Apr 20.

Cellular tumor necrosis factor, gamma interferon, and interleukin-6 responses as
correlates of immunity and risk of clinical Plasmodium falciparum malaria in
children from Papua New Guinea.

Robinson LJ, D’Ombrain MC, Stanisic DI, Taraika J, Bernard N, Richards JS, Beeson
JG, Tavul L, Michon P, Mueller I, Schofield L.

The Walter & Eliza Hall Institute of Medical Research, 1G Royal Parade,
Parkville, Victoria, Australia.

The role of early to intermediate Plasmodium falciparum-induced cellular
responses in the development of clinical immunity to malaria is not well
understood, and such responses have been proposed to contribute to both immunity
and risk of clinical malaria episodes. To investigate whether P.
falciparum-induced cellular responses are able to function as predictive
correlates of parasitological and clinical outcomes, we conducted a prospective
cohort study of children (5 to 14 years of age) residing in a region of Papua New
Guinea where malaria is endemic Live, intact P. falciparum-infected red blood
cells were applied to isolated peripheral blood mononuclear cells obtained at
baseline. Cellular cytokine production, including production of interleukin-2
(IL-2), IL-4, IL-6, IL-10, tumor necrosis factor (TNF) (formerly tumor necrosis
factor alpha), and gamma interferon (IFN-gamma), was measured, and the cellular
source of key cytokines was investigated. Multicytokine models revealed that
increasing P. falciparum-induced IL-6 production was associated with an increased
incidence of P. falciparum clinical episodes (incidence rate ratio [IRR], 1.75;
95% confidence interval [CI], 1.20 to 2.53), while increasing P.
falciparum-induced TNF and IFN-gamma production was associated with a reduced
incidence of clinical episodes (IRR for TNF, 0.55 [95% CI, 0.38 to 0.80]; IRR for
IFN-gamma, 0.71 [95% CI, 0.55 to 0.90]). Furthermore, we found that
monocytes/macrophages and gammadelta-T cells are important for the P.
falciparum-induced production of IL-6 and TNF. Early to intermediate cellular
cytokine responses to P. falciparum may therefore be important correlates of
immunity and risk of symptomatic malaria episodes and thus warrant detailed
investigation in relation to the development and implementation of effective
vaccines.

5: Infect Immun. 2009 Jun 29. [Epub ahead of print]

Strain-Specific Duffy Binding Protein Antibodies Correlate with Protection
Against Infection with Homologous Compared to Heterologous Plasmodium vivax
Strains in Papua New Guinean Children.

Cole-Tobian JL, Michon P, Biasor M, Richards JS, Beeson JG, Mueller I, King CL.

Center for Global Health and Diseases, Case Western Reserve University,
Cleveland, OH, USA; Veterans Affairs Research Service, Cleveland, OH; Papua New
Guinea Institute for Medical Research, Goroka, Papua New Guinea; The Walter and
Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia.

Individuals repeatedly infected with malaria acquire protection from infection
and disease; immunity is thought to be primarily antibody-mediated and directed
to blood stage infection. Merozoite surface proteins involved in invasion of host
erythrocytes are likely targets of protective antibodies. We hypothesized that
Papua New Guinean children (N=206) who acquire high antibody levels to two
Plasmodium vivax merozoite proteins, Duffy binding protein region II (PvDBPII)
and the 19-kD C-terminal region of P. vivax merozoite surface protein 1
(PvMSP119) would have a delay in time to re-infection following treatment to
clear all blood stage malaria infections. 94% of the children were re-infected
with P. vivax during biweekly follow-up for 6 months. Since PvDBPII is
polymorphic, we examined whether individuals acquired strain-specific immunity to
PvDBPII. Children with high antibody levels to a prevalent PvDBPII allele (O)
were associated with a delay in time to re-infection with the same variant of P.
vivax by 25% compared to parasites expressing other PvDBPII alleles (age Adjusted
Hazard Ratio = 0.75 (0.56-1.00, 95% CI, Cox Regression) and 39% lower incidence
density parasitema (P=0.01). Two other prevalent alleles (AH and P) showed a
similar trend of 16% and 18% protection against parasites with same PvDBPII
allele and reduced incidence-density parasitemia. Antibodies directed to PvDBPII
PNG-P and O were both associated with a 21-26% reduction in risk of P. vivax
infections with higher parasitemia (>150 parasites/microl), respectively. There
was no association with high antibody levels to PvMSP119 and delay in time to P.
vivax re-infection. Thus, anti-PvDBPII antibodies are associated with
strain-specific immunity to P. vivax and support use of PvDBPII for a vaccine
against P. vivax.

6: Infect Immun. 2009 Jun 22. [Epub ahead of print]

Functional and immunological characterization of a Duffy Binding-Like alpha
domain from Plasmodium falciparum-erythrocyte membrane protein-1 that mediates
rosetting.

Mayor A, Rovira-Vallbona E, Srivastava A, Sharma SK, Pati SS, Puyol L, Quinto L,
Bassat Q, Machevo S, Mandomando I, Chauhan VS, Alonso PL, Chitnis CE.

Barcelona Centre for International Health Research (CRESIB), Hospital
Clínic/Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS),
Universitat de Barcelona, Barcelona, Spain; International Centre for Genetic
Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India; Manhiça
Health Research Centre (CISM), Maputo, Mozambique; National Institute of Malaria
Research (formerly Malaria Research Centre), Field Station, Sector-5, Rourkela,
District Sundargarh, Orissa, India; Ispat General Hospital, Rourkela, District
Sundargarh, Orissa, India.

The Duffy-Binding-Like (DBL) domains are common adhesion modules present in
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variants, which are
responsible for immune evasion and cytoadherence. Knowledge about how immune
responses are acquired against polymorphic DBL domains of PfEMP-1 can aid in the
development of vaccines for malaria. A recombinant DBLalpha domain from R29var1,
which binds complement receptor-1 to mediate rosetting by the P. falciparum
laboratory strain R29, was expressed in Escherichia coli, renatured by oxidative
refolding to its native form and purified to homogeneity. Antibody levels in 704
plasmas obtained from residents of areas of different malaria endemicity in
Orissa (India) and Manhiça (Mozambique) were assessed by ELISA. Refolded DBLalpha
was pure, homogeneous and functional in that it binds human erythrocytes with
specificity and is capable of inhibiting rosetting. Proportion of individuals who
had measurable anti-DBLalpha IgG responses was low in areas of low malaria
endemicity from Orissa (6.7%), but high in areas of high endemicity from Orissa
(87.5%) and Manhiça (74.5%). Seroprevalence and antibody levels against the
recombinant protein increased with age of inhabitants from high transmission
areas (p<0.001). Half of the children in these areas had seroconverted by the age
of five years. These findings suggest that, in spite of the extreme polymorphism
of PfEMP1-DBLalpha domains, acquisition of specific antibodies is rapid,
age-related, and reflects the reduced risk of malaria in high transmission areas.
Further studies are required to elucidate the role of these antibodies in
protection from malaria.

7: Malar J. 2009 Jul 15;8(1):161. [Epub ahead of print]

Assessment of the relative success of sporozoite inoculations in individuals
exposed to moderate seasonal transmission.

Tall A, Sokhna C, Perrault R, Fontenille D, Marrama L, Ly AB, Sarr FD, Toure A,
Trape JF, Spiegel A, Rogier C, Druilhe P.

ABSTRACT: BACKGROUND: The time necessary for malaria parasite to re-appear in the
blood following treatment (re-infection time) is an indirect method for
evaluating the immune defences operating against pre-erythrocytic and early
erythrocytic malaria stages. Few longitudinal data are available in populations
in whom malaria transmission level had also been measured. METHODS: One hundred
and ten individuals from the village of Ndiop (Senegal), aged between one and 72
years, were cured of malaria by quinine (25 mg/day oral Quinimax(R) in three
equal daily doses, for seven days). Thereafter, thick blood films were examined
to detect the reappearance of Plasmodium falciparum every week, for 11 weeks
after treatment. Malaria transmission was simultaneously measured weekly by night
collection of indoor mosquitoes. RESULTS: Malaria transmission was on average
15.3 infective bites per person during the 77 days follow up leading to an EIR
wich was 72.3 infective bites per person per year. The median reappearance time
for the whole study population was 46.8 days, whereas individuals would have
received an average one infective bite every 5 days. At the end of the follow-up,
after 77 days, 103 of the 110 individuals (93.6%; CI 95% [89.0-98.2]) had been
re-infected with P. falciparum. The median reappearance time (‘re-positivation’)
was longer in subjects with patent parasitaemia at enrolment than in
parasitologically-negative individuals (58 days vs. 45.9; p=0.03) and in adults >
30 years than in younger subjects (58.6 days vs. 42.7; p=0.0002). In a
multivariate Cox PH model controlling for the sickle cell trait, G6PD deficiency
and the type of habitat, the presence of parasitaemia at enrolment and age
[greater than or equal to]30 years were independently predictive of a reduced
risk of re-infection (PH=0.5 [95% CI: 0.3-0.9] and 0.4; [95% CI: 0.2-0.6]
respectively). CONCLUSIONS: Results indicate the existence of a substantial
resistance to sporozoites inoculations, but which was ultimately overcome in
almost every individual after 2 1/2 months of natural challenges. Such a study
design and the results obtained suggest that, despite a small sample size, this
approach can contribute to assess the impact of intervention methods, such as the
efficacy vector-control measures or of malaria pre-erythrocytic stages vaccines.

8: Malar J. 2009 Jun 29;8(1):143. [Epub ahead of print]

Optimizing expression of the pregnancy malaria vaccine candidate, VAR2CSA in
Pichia pastoris.

Avril M, Hathaway MJ, Cartwright MM, Gose SO, Narum DL, Smith JD.

ABSTRACT: BACKGROUND: VAR2CSA is the main candidate for a vaccine against
pregnancy-associated malaria, but vaccine development is complicated by the large
size and complex disulfide bonding pattern of the protein. Recent X-ray
crystallographic information suggests that domain boundaries of VAR2CSA Duffy
binding-like (DBL) domains may be larger than previously predicted and include
two additional cysteine residues. This study investigated whether longer
constructs would improve VAR2CSA recombinant protein secretion from Pichia
pastoris and if domain boundaries were applicable across different VAR2CSA
alleles. METHODS: VAR2CSA sequences were bioinformatically analysed to identify
the predicted C11 and C12 cysteine residues at the C-termini of DBL domains and
revised N- and C-termimal domain boundaries were predicted in VAR2CSA. Multiple
construct boundaries were systematically evaluated for protein secretion in P.
pastoris and secreted proteins were tested as immunogens. RESULTS: From a total
of 42 different VAR2CSA constructs, 15 proteins (36%) were secreted. Longer
construct boundaries, including the predicted C11 and C12 cysteine residues,
generally improved expression of poorly or non-secreted domains and permitted
expression of all six VAR2CSA DBL domains. However, protein secretion was still
highly empiric and affected by subtle differences in domain boundaries and
allelic variation between VAR2CSA sequences. Eleven of the secreted proteins were
used to immunize rabbits. Antibodies reacted with CSA-binding infected
erythrocytes, indicating that P. pastoris recombinant proteins possessed native
protein epitopes. CONCLUSIONS: These findings strengthen emerging data for a
revision of DBL domain boundaries in var-encoded proteins and may facilitate
pregnancy malaria vaccine development.

9: Vaccine. 2009 Jul 8. [Epub ahead of print]

Plasmodium berghei HAP2 induces strong malaria transmission-blocking immunity in
vivo and in vitro.

Blagborough AM, Sinden RE.

Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial
College London, Imperial College Road, South Kensington, London SW7 2AZ, UK.

Fertilization in Plasmodium is a complex process that occurs in the gut of the
female Anopheles mosquito upon uptake of a bloodmeal. It requires the emergence
of the gametocyte from the RBC and release of eight flagellate male gametes from
each male cell, and subsequent fertilization of a similarly emerged immotile
extracellular female macrogamete. Previous studies have demonstrated that
antibodies against male gamete surface proteins ingested from the blood of an
infected and immunized host inhibit parasite transmission. Gene disruption
studies in Plasmodium berghei and complimentary studies on the green alga
Chlamydomonas have shown that a conserved male gamete sterility gene, HAP2, is
essential for fusion of male and female gametes. Genetic disruption of the HAP2
locus revealed that parasite fertilization is prevented, yet hap2 KO male gametes
still retained the ability to form tight pre-fusion membrane attachments with
females.We demonstrate that heterologous expression of the P. berghei HAP2
protein in Escherichia coli, and subsequent immunization of rabbits, has produced
anti-sera that react specifically with recombinant HAP2, and with the native
protein on the male gamete. Additionally, anti-HAP2 sera reduces in vitro
formation of ookinetes by up to 81%, and, using standard membrane feeding assays,
reduces oocyst burden within the mosquito host by up to 81.1%, and prevalence of
in vivo infection by up to 34%. Inhibition is dose dependent. These results
indicate that HAP2 should be considered as a potential target for any future
anti-malarial transmission-blocking vaccine.

10: Vaccine. 2009 Jul 7. [Epub ahead of print]

Plasmodium falciparum apical membrane antigen 1 vaccine elicits multifunctional
CD4 cytokine-producing and memory T cells.

Huaman MC, Mullen GE, Long CA, Mahanty S.

Laboratory of Malaria and Vector Research and Malaria Vaccine Development Branch,
National Institute of Allergy and Infectious Diseases, National Institutes of
Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA.

The Plasmodium falciparum apical membrane antigen 1 (AMA1) is a leading vaccine
candidate and was tested for safety and immunogenicity in human Phase I Clinical
Trials. PBMC from vaccine recipients were analyzed by flow cytometric methods to
determine the nature of T-cell responses and AMA1-reactive memory T cells. Both
CD4 and CD8 T cells produced a number of cytokines following AMA1 re-stimulation,
with IL-5-producing cells at the highest frequency, consistent with a Th2 bias.
The relative frequency of multifunctional cells synthesizing Th1 cytokines
IFN-gamma, IL-2 and TNF-alpha changed after each vaccination. Interestingly,
median fluorescence intensity measurements revealed that cells producing more
than one cytokine contributed greater quantities of each cytokine than cell
populations that produced each of the cytokines alone. AMA1 vaccination also
elicited the development of memory cell populations, and both central and
effector memory T cells were identified concurrently after the AMA1 vaccination.
The detailed profile of multifunctional T-cell responses to AMA1 presented here
will advance our ability to assess the immunogenicity of human malarial vaccines.

11: Vaccine. 2009 Jul 1. [Epub ahead of print]

Molecular adjuvants for malaria DNA vaccines based on the modulation of host-cell
apoptosis.

Bergmann-Leitner ES, Leitner WW, Duncan E, Savranskaya T, Angov E.

Department of Molecular Parasitology, US Military Malaria Vaccine Program, Walter
Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD 20910,
USA.

Malaria represents a major global health problem but despite extensive efforts,
no effective vaccine is available. Various vaccine candidates have been developed
that provide protection in animal models, such as a gene gun-delivered DNA
vaccine encoding the circumsporozoite protein (CSP) of Plasmodium berghei. A
common shortcoming of most malaria vaccines is the requirement for multiple
immunizations leaving room for improvement even for established vaccine
candidates such as the CSP-DNA vaccine. In this study, we explored whether
regulating apoptosis in DNA vaccine transfected host cells could accelerate the
onset of protective immunity and provide significant protection after a single
immunization. A pro-apoptotic gene (Bax) was used as a molecular adjuvant in an
attempt to mimic the immunostimulatory apoptosis triggered by viral or
virus-derived vaccines, while anti-apoptotic genes such as Bcl-XL may increase
the life span of transfected cells thus prolonging antigen production.
Surprisingly, co-delivery of either Bax or Bcl-XL greatly reduced CSP-DNA vaccine
efficacy after a single immunization. Co-delivery of Bax for three immunizations
still had a detrimental effect on protective immunity, while repeated co-delivery
of Bcl-XL had no negative impact. The fine characterization of humoral and
cellular immune response modulated by these two molecular adjuvants revealed a
previously unknown effect, i.e., a shift in the Th-profile. These results
demonstrate that pro- or anti-apoptotic molecules should not be used as molecular
adjuvants without careful evaluation of the resulting immune response. This
finding represents yet another example that strategies to enhance vaccine
efficacy developed for other model systems such as viral diseases cannot easily
be applied to any vaccine.

12: Vaccine. 2009 Jun 24;27(31):4104-9. Epub 2009 May 15.

A Phase 1 study of the blood-stage malaria vaccine candidate AMA1-C1/Alhydrogel
with CPG 7909, using two different formulations and dosing intervals.

Ellis RD, Mullen GE, Pierce M, Martin LB, Miura K, Fay MP, Long CA, Shaffer D,
Saul A, Miller LH, Durbin AP.

Malaria Vaccine Development Branch, National Institute of Allergy and Infectious
Diseases, National Institutes of Health, Twinbrook I, MD 20852, USA.
ellisru@niaid.nih.gov

A Phase 1 study was conducted in 24 malaria naïve adults to assess the safety and
immunogenicity of the recombinant protein vaccine apical membrane antigen
1-Combination 1 (AMA1-C1)/Alhydrogel with CPG 7909 in two different formulations
(phosphate buffer and saline), and given at two different dosing schedules, 0 and
1 month or 0 and 2 months. Both formulations were well tolerated and frequency of
local reactions and solicited adverse events was similar among the groups. Peak
antibody levels in the groups receiving CPG 7909 in saline were not significantly
different than those receiving CPG 7909 in phosphate. Peak antibody levels in the
groups vaccinated at a 0,2 month interval were 2.52-fold higher than those
vaccinated at a 0,1 month interval (p=0.037, 95% CI 1.03, 4.28). In vitro growth
inhibition followed the antibody level: median inhibition was 51% (0,1 month
interval) versus 85% (0,2 month interval) in antibody from samples taken 2 weeks
post-second vaccination (p=0.056).

13: Vaccine. 2009 Jun 21. [Epub ahead of print]

Age-dependent systemic antibody responses and immunisation-associated changes in
mice orally and nasally immunised with Lactococcus lactis expressing a malaria
parasite protein.

Moorthy SA, Yasawardena SG, Ramasamy R.

National Science Foundation, Sri Lanka.

Gram positive food-grade bacteria such as lactococci have significant advantages
over attenuated pathogens as vaccine delivery vehicles because of their
inherently greater safety. Plasmodium falciparum merozoite surface antigen 2
(MSA2) was expressed in recombinant Lactococcus lactis both intracellularly and
covalently anchored to the peptidoglycan of the cell wall (MSA2cP). Balb/c mice
of different ages were immunised with the MSA2cP expressing L. lactis in a
combined oral and nasal immunisation procedure. Serum IgG antibody responses to
MSA2 were higher in young adult Balb/c mice compared to old mice and neonates.
The elicited serum IgG antibodies reacted with native MSA2 on the surface of P.
falciparum merozoites in an immunofluorescence assay. The serum IgG antibody
isotypes in young adult mice were mainly IgG1, IgG2a and IgG2b, while IgG3 tended
to be higher in old mice. IgA antibodies to MSA2 were also produced in young
mice. Enlarged mesenteric lymph nodes, and more prominent lymphoid tissue in the
lamina propria of the ileum and lymphoid follicles in the spleen, were observed
in mice fed L. lactis. These findings are relevant for developing L. lactis as a
vector to deliver vaccines in human populations.

1: Cad Saude Publica. 2009 Jul;25(7):1486-92.

[Malaria and hematological aspects among residents to be impacted by reservoirs for the Santo Antônio and Jirau Hydroelectric Power Stations, Rondônia State, Brazil] [Article in Portuguese]

Katsuragawa TH, Cunha RP, de Souza DC, Gil LH, Cruz RB, Silva Ade A, Tada MS, da Silva LH.

Instituto de Pesquisa em Patologias Tropicais, Porto Velho, Brasil.
tonykatsuragawa@yahoo.com.br

In Rondônia State, Brazil, two new hydroelectric plants, Santo Antônio and Jirau, are scheduled for construction on the Madeira River, upriver from the State capital, Porto Velho. The current study analyzes malaria prevalence before the construction and provides information on the possible impacts of malaria burden
related to the influx of thousands of persons attracted by direct and indirect employment opportunities. According to the findings, malaria is present throughout the region, with varying prevalence rates. The existence of potential asymptomatic malaria carriers among the local population may be epidemiologically
relevant and should be considered in the malaria control programs organized by public authorities and companies responsible for building the power plants, aimed at early diagnosis and treatment, vector control, water supply, and infrastructure in the urban areas.

2: Diagn Microbiol Infect Dis. 2009 May;64(1):20-6.

Malaria overdiagnosis and burden of malaria misdiagnosis in the suburbs of central Sudan: special emphasis on artemisinin-based combination therapy era.

A-Elgayoum SM, El-Feki Ael-K, Mahgoub BA, El-Rayah el-A, Giha HA.

Faculty of Science, Department of Zoology, University of Khartoum, P.O. Box 321,
Khartoum, Sudan 11111.

Accuracy of diagnosis is central for malaria control. Although microscopy is gold standard in malaria diagnosis, its reliability is largely dependent on user skill. In this study, we evaluated practitioners’ clinical and microscopists’ technical skills in diagnosis of malaria in central Sudan. In a retrospective study, 3203 blood smears from 95 peripheral health facilities (each represented by a general practitioner [GP] and general microscopist [GM]) were reexamined by expert microscopist. Furthermore, in a prospective study, 410 patients had their malaria diagnosis rechecked by rapid diagnostic test for validation of the microscopic diagnosis. Results showed that the rate of false-positive diagnosis of malaria was 75.6% and false-negative diagnosis was 0.01%. The study disclosed poor skills of the GPs and GMs in malaria diagnosis because 43% of the GPs and 44% of the GMs failed to make a single true-positive malaria diagnosis. The false-positive malaria diagnosis showed bias toward adult females. Economically, the calculated cost of diagnosis and treatment of malaria in Sudan in year 2000 is US$100 million, whereas the calculated cost of true malaria is approximately US$14 million. In conclusion, malaria overdiagnosis was widely recognized in central Sudan, with high economic burden during the era of artemisinin-based combination therapy. Finally, different scenarios were suggested for improvement of malaria diagnosis.

3: Geospat Health. 2009 May;3(2):189-210.

Urban agriculture and Anopheles habitats in Dar es Salaam, Tanzania.

Dongus S, Nyika D, Kannady K, Mtasiwa D, Mshinda H, Gosoniu L, Drescher AW, Fillinger U, Tanner M, Killeen GF, Castro MC.

Department of Public Health and Epidemiology, Swiss Tropical Institute, University of Basel, P.O. Box, CH-4002 Basel, Switzerland. stefan.dongus@unibas.ch

A cross-sectional survey of agricultural areas, combined with routinely monitored mosquito larval information, was conducted in urban Dar es Salaam, Tanzania, to investigate how agricultural and geographical features may influence the presence of Anopheles larvae. Data were integrated into a geographical information systems framework, and predictors of the presence of Anopheles larvae in farming areas were assessed using multivariate logistic regression with independent random effects. It was found that more than 5% of the study area (total size 16.8 km2) was used for farming in backyard gardens and larger open spaces. The proportion of habitats containing Anopheles larvae was 1.7 times higher in agricultural areas compared to other areas (95% confidence interval = 1.56-1.92). Significant geographic predictors of the presence of Anopheles larvae in gardens included location in lowland areas, proximity to river, and relatively impermeable soils. Agriculture-related predictors comprised specific seedbed types, mid-sized gardens, irrigation by wells, as well as cultivation of sugar cane or leafy vegetables. Negative predictors included small garden size, irrigation by tap water, rainfed production and cultivation of leguminous crops or fruit trees. Although there was an increased chance of finding Anopheles larvae in agricultural sites, it was found that breeding sites originated by urban agriculture account for less than a fifth of all breeding sites of malaria vectors in Dar es Salaam. It is suggested that strategies comprising an integrated malaria control effort in malaria-endemic African cities include participatory involvement of farmers by planting shade trees near larval habitats.

4: J Am Pharm Assoc (2003). 2009 May-Jun;49(3):432-5.

Advertising of OTC products in a Nigerian urban setting: content analysis for indications, targets, and advertising appeal.

Yusuff KB, Yusuf A.

Department of Clinical Pharmacy & Pharmacy Administration, Faculty of Pharmacy, University of Ibadan, Nigeria. yusuffkby@yahoo.co.uk

OBJECTIVE: To identify the indications for which treatments were promoted, the segments of population targeted, and the type and extent of advertising appeal used for over-the-counter (OTC) products in a Nigerian urban setting. METHODS: Using a cross-sectional design, the content of advertisements for OTC products on radio, television, and billboards in a city in southwestern Nigeria were assessed during a 3-month period. Two coders independently assessed 1,492 advertisements for 49 brands of OTC products (interrater reliability [Cohen's kappa] = 0.83 [95% CI 0.80-0.90]). RESULTS: The most frequent indications for OTC products were aches and pain (42.9%), anemia/malnutrition (34.8%), and malaria (22.2%). Of advertisements, 92% were targeted at the primary end user. Use of appeal related to efficacy (100%), psychosocial enhancement (80%), and ease of use (40%) in visual, written, and audio messages was highest in ads on billboards. Efficacy appeal had the highest frequency across the three advertising media (100%);
ease-of-use and safety appeal had the lowest frequency (40% and 7.4%, respectively). Nigerian movie stars were used as brand icons in advertisements of OTC products on radio (59.5%), television (52.9%), and billboards (49.6%). CONCLUSION: The majority of advertisements for OTC products in a Nigerian urban setting used advertising appeal related to efficacy and psychosocial enhancement. Promotional efforts by pharmaceutical manufacturers appear to focus on positive emotional appeal to influence drug purchase and use decisions.

5: Lancet. 2009 May 9;373(9675):1582-4.

Home management of malaria with artemether-lumefantrine compared with standard care in urban Ugandan children: a randomised controlled trial.

Staedke SG, Mwebaza N, Kamya MR, Clark TD, Dorsey G, Rosenthal PJ, Whitty CJ.

London School of Hygiene and Tropical Medicine, London, UK.
sarah.staedke@lshtm.ac.uk

BACKGROUND: Home management of malaria-the presumptive treatment of febrile children with antimalarial drugs-is advocated to ensure prompt effective treatment of the disease. We assessed the effect of home delivery of artemether-lumefantrine on the incidence of antimalarial treatment and on clinical outcomes in children from an urban setting with fairly low malaria transmission. METHODS: In Kampala, Uganda, 437 children aged between 1 and 6 years from 325 households were randomly assigned by a computer-generated sequence to receive home delivery of prepackaged artemether-lumefantrine for presumptive treatment of febrile illnesses (n=225) or current standard of care (n=212). Randomisation was done by household after a pilot period of 1 month. After randomisation, study participants were followed up for an additional 12 months
and information on their health and treatment of illnesses was obtained by use of monthly questionnaires and household diaries, which were completed by the participants’ carers. The primary outcome was treatment incidence density per person-year. Analysis of the primary outcome was done on the modified intention-to-treat population, which included all participants apart from those excluded before data collection. This trial is registered with ClinicalTrials.gov, number NCT00115921. FINDINGS: Eight participants in the home management group and four in the standard care group were excluded before data collection; therefore, the primary analysis was done in 217 and 208 participants, respectively. The home management group received nearly twice the number of antimalarial treatments as the standard care group (4.66 per person-year vs 2.53
per person-year; incidence rate ratio [IRR] 1.72, 95% CI 1.43-2.06, p<0.0001), and nearly five times the number given to children with microscopically confirmed malaria in a comparable cohort of children (4.66 per person-year vs 1.03 per person-year, IRR 5.19, 95% CI 4.24-6.35, p<0.0001). Clinical data were available
for 189 children in the home management group and 176 in the control group at study end; the main reasons for exclusion were movement out of the study area or loss to follow-up. The proportion of participants with parasitaemia at final assessment in the intervention group was lower than in the control group (four [2%] vs 17 [10%], p=0.006), but there were no other differences in standard malariometric indices, including anaemia. Serious adverse events were captured retrospectively. One child died in each group (home management-severe pneumonia and possible septicaemia; standard care-presumed respiratory failure).
INTERPRETATION: Although home management of malaria led to prompt treatment of fever, there was little effect on clinical outcomes. The substantial over-treatment suggests that artemether-lumefantrine provided in the home might not be appropriate for large urban areas or settings with fairly low malaria transmission. FUNDING: Gates Malaria Partnership.

6: Malar J. 2009 Jul 15;8(1):160. [Epub ahead of print]

Fever treatment in the absence of malaria transmission in an urban informal settlement in Nairobi, Kenya.

Ye Y, Madise N, Ndugwa R, Ochola S, Snow RW.

ABSTRACT: BACKGROUND: In sub-Saharan Africa, knowledge of malaria transmission across rapidly proliferating urban centres and recommendations for its prevention or management remain poorly defined. This paper presents the results of an investigation into infection prevalence and treatment of recent febrile events among a slum population in Nairobi, Kenya. METHODS: In July 2008, a community-based malaria parasite prevalence survey was conducted in Korogocho slum, which forms part of the Nairobi Urban Health and Demographic Surveillance system. Interviewers visited 1,069 participants at home and collected data on
reported fevers experienced over the preceding 14 days and details on the treatment of these episodes. Each participant was tested for malaria parasite presence with Rapid Diagnostic Test (RDT) and microscopy. Descriptive analyses were performed to assess the period prevalence of reported fever episodes and treatment behaviour. RESULTS: Of the 1,069 participants visited, 983 (92%) consented to be tested. Three were positive for Plasmodium falciparum using RDT; however, all were confirmed negative on microscopy. Microscopic examination of all 953 readable slides showed zero prevalence. Overall, from the 1,004
participants who have data on fever, 170 fever episodes were reported giving a relatively high period prevalence (16.9%, 95% CI:13.9%-20.5%) and higher among children below five years (20.1%, 95%CI:13.8%-27.8%). Of the fever episodes with treatment information 54.3% (95%CI:46.3%-62.2%) were treated as malaria using mainly sulphadoxine-pyrimethamine or amodiaquine, including those managed at a
formal health facility. Only four episodes were managed using the nationally recommended first-line treatment, artemether-lumefantrine. CONCLUSION: The study could not demonstrate any evidence of malaria in Korogocho, a slum in the centre of Nairobi. Fever was a common complaint and often treated as malaria with anti-malarial drugs. Strategies, including testing for malaria parasites to reduce the inappropriate exposure of poor communities to expensive anti-malarial drugs provided by clinical services and drug vendors, should be a priority for district planners.

7: Malar J. 2009 Jul 14;8(1):157. [Epub ahead of print]

A new tent trap for sampling exophagic and endophagic members of the Anopheles gambiae complex.

Govella NJ, Chaki PP, Geissbuehler Y, Kannady K, Okumu F, Charlwood JD, Anderson RA, Killeen GF.

ABSTRACT: BACKGROUND: Mosquito sampling methods are essential for monitoring and evaluating malaria vector control interventions. In urban Dar es Salaam, human landing catch (HLC) is the only method sufficiently sensitive for monitoring malaria-transmitting Anopheles. HLC is labour intensive, cumbersome, hazardous, and requires such intense supervision that is difficulty to sustain on large scales. METHODS: Novel tent traps were developed as alternatives to HLC. The Furvella tent, designed in Mozambique, incorporates a CDC Light trap (LT) components, while two others from Ifakara, Tanzania (designs A and B) require no electricity or moving parts. Their sensitivity for sampling malaria vectors was compared with LT and HLC over a wide range of vector abundances in rural and urban settings in Tanzania, with endophagic and exophagic populations, respectively, using randomised Latin-square and cross- over experimental designs.
RESULTS: The sensitivity of LTs was greater than HLC while the opposite was true of Ifakara tent traps (crude mean catch of An. gambiae sensu lato relative to HLC = 0.28, 0.65 and 1.30 for designs A, B and LT in a rural setting and 0.32 for design B in an urban setting). However, Ifakara B catches correlated far better
to HLC (r2 = 0.73, P <0.001) than any other method tested (r2 = 0.04, P = 0.426 and r2 = 0.19, P = 0.006 for Ifakara A and LTs respectively). Only Ifakara B in a rural setting with high vector density exhibited onstant sampling efficiency relative to HLC. The relative sensitivity of Ifakara B increased as vector densities decreased in the urban setting and exceeded that of HLC at the lowest densities. None of the tent traps differed from HLC in terms of the proportions of parous mosquitoes (P [greater than or equal to]0.849) or An. gambiae s.l. sibling species (P [greater than or equal to]0.280) they sampled but both Ifakara A and B designs failed to reduce the proportion of blood-fed mosquitoes caught (Odds ratio [95% Confidence Interval] = 1.6 [1.2, 2.1] and 1.0 [0.8, 1.2], P = 0.002 and 0.998, respectively), probably because of operator exposure while emptying the trap each morning. CONCLUSION: The Ifakara B trap may have potential for monitoring and evaluating a variety of endophagic and exophagic Afrotropical
malaria vectors, particularly at low but epidemiologically relevant population densities. However, operator exposure to mosquito bites remains a concern so additional modifications or protective measures will be required before this design can be considered for widespread, routine use.

8: Malar J. 2009 Jun 24;8(1):138. [Epub ahead of print]

Highly focused anopheline breeding sites and malaria transmission in Dakar.

Machault V, Gadiaga L, Vignolles C, Jarjaval F, Bouzid S, Sokhna C, Lacaux JP, Trape JF, Rogier C, Pages F.

ABSTRACT: BBackground Urbanization has a great impact on the composition of the vector system and malaria transmission dynamics. In Dakar, some malaria cases are autochthonous but parasite rates and incidences of clinical malaria attacks have been recorded at low levels. Ecological heterogeneity of malaria transmission was investigated in Dakar, in order to characterize the Anopheles breeding sites in the city and to study the dynamics of larval density and adult aggressiveness in ten characteristically different urban areas. METHODS: Ten study areas were sampled in Dakar and Pikine. Mosquitoes were collected by human landing collection during four nights in each area (120 person-nights). The Plasmodium falciparum circumsporozoite (CSP) index was measured by ELISA and the entomological inoculation rates (EIR) were calculated. Open water collections in the study areas were monitored weekly for physico-chemical characterization and the presence of anopheline larvae. Adult mosquitoes and hatched larvae were identified morphologically and by molecular methods. RESULTS: In September-October 2007, 19,451 adult mosquitoes were caught among which, 1,101 were Anopheles gambiae s.l. The Human Biting Rate ranged from 0.1 bites per person per night in Yoff Village to 43.7 in Almadies. Seven out of 1,101 An. gambiae s.l. were found to be positive for P. falciparum (CSP index = 0.64%). EIR ranged from 0 infected bites per person per year in Yoff Village to 16.8 in Almadies. The An. gambiae complex population was composed of Anopheles arabiensis (94.8%) and Anopheles melas (5.2%). None of the An. melas were infected with P. falciparum. Of the 54 water collection sites monitored, 33 (61.1%) served as anopheline breeding sites on at least one observation. No An. melas was identified among the larval samples. Some physico-chemical characteristics of
water bodies were associated with the presence/absence of anopheline larvae and with larval density. A very close parallel between larval and adult densities was found in six of the ten study areas. CONCLUSIONS: The results provide evidence of malaria transmission in downtown Dakar and its surrounding suburbs. Spatial
heterogeneity of human biting rates was very marked and malaria transmission was highly focal. In Dakar, mean figures for transmission would not provide a comprehensive picture of the entomological situation; risk evaluation should therefore be undertaken on a small scale.

9: Malar J. 2009 Jun 20;8:135.

Plasmodium falciparum genotypes diversity in symptomatic malaria of children living in an urban and a rural setting in Burkina Faso.

Soulama I, Nébié I, Ouédraogo A, Gansane A, Diarra A, Tiono AB, Bougouma EC, Konaté AT, Kabré GB, Taylor WR, Sirima SB.

Centre National de Recherche et de Formation sur le Paludisme, 01 BP 2208 Ouagadougou 01, Burkina Faso. a.soulama.cnrfp@fasonet.bf

BACKGROUND: The clinical presentation of malaria, considered as the result of a complex interaction between parasite and human genetics, is described to be different between rural and urban areas. The analysis of the Plasmodium falciparum genetic diversity in children with uncomplicated malaria, living in these two different areas, may help to understand the effect of urbanization on the distribution of P. falciparum genotypes. METHODS: Isolates collected from 75 and 89 children with uncomplicated malaria infection living in a rural and an urban area of Burkina Faso, respectively, were analysed by a nested PCR amplification of msp1 and msp2 genes to compare P. falciparum diversity. RESULTS: The K1 allelic family was widespread in children living in the two sites, compared to other msp1 allelic families (frequency >90%). The MAD 20 allelic family of msp1 was more prevalent (p = 0.0001) in the urban (85.3%) than the rural area (63.2%). In the urban area, the 3D7 alleles of msp2 were more prevalent compared to FC27 alleles, with a high frequency for the 3D7 300bp allele (>30%). The multiplicity of infection was in the range of one to six in the urban area and of one to seven in the rural area. There was no difference in the frequency of multiple infections (p = 0.6): 96.0% (95% C.I: 91.6-100) in urban versus 93.1% (95%C.I: 87.6-98.6) in rural areas. The complexity of
infection increased with age [p = 0.04 (rural area), p = 0.06 (urban area)]. CONCLUSION: Urban-rural area differences were observed in some allelic families (MAD20, FC27, 3D7), suggesting a probable impact of urbanization on genetic variability of P. falciparum. This should be taken into account in the implementation of malaria control measures.

10: Malar J. 2009 May 21;8:109.

How equitable is bed net ownership and utilisation in Tanzania? A practical application of the principles of horizontal and vertical equity.

Matovu F, Goodman C, Wiseman V, Mwengee W.

Faculty of Economics and Management, Makerere University, PO Box, 7062 Kampala, Uganda. frmatov2000@yahoo.co.uk

BACKGROUND: Studies show that the burden of malaria remains huge particularly in low-income settings. Although effective malaria control measures such as insecticide-treated nets (ITNs) have been promoted, relatively little is known about their equity dimension. Understanding variations in their use in low-income
settings is important for scaling up malaria control programmes particularly ITNs. The objective of this paper is to measure the extent and causes of inequalities in the ownership and utilisation of bed nets across socioeconomic groups (SEGs) and age groups in Tanga District, north-eastern Tanzania. METHODS: A questionnaire was administered to heads of 1,603 households from rural and urban areas. Households were categorized into SEGs using both an asset-based wealth index and education level of the household head. Concentration indices and regression-based measures of inequality were computed to analyse both vertical
and horizontal inequalities in ownership and utilisation of bed nets. Focus Group Discussions (FGDs) were used to explore community perspectives on the causes of inequalities. RESULTS: Use of ITNs remained appallingly low compared to the RBM target of 80% coverage. Inequalities in ownership of ITNs and all nets combined were significantly pro-rich and were much more pronounced in rural areas. FGDs revealed that lack of money was the key factor for not using ITNs followed by negative perceptions about the effect of insecticides on the health of users. Household SES, living within the urban areas and being under-five were positively associated with bed net ownership and/or utilisation. CONCLUSION: The results highlight the need for mass distribution of ITN; a community-wide programme to treat all untreated nets and to promote the use of Long-Lasting Insecticidal nets (LLINs) or longer-lasting treatment of nets. The rural population and under-fives should be targeted through highly subsidized schemes and mass distribution of free nets. Public campaigns are also needed to encourage people to use treated nets and mitigate negative perceptions about insecticides.

11: Malar J. 2009 May 14;8:103.

Development of vegetable farming: a cause of the emergence of insecticide resistance in populations of Anopheles gambiae in urban areas of Benin.

Yadouleton AW, Asidi A, Djouaka RF, Braïma J, Agossou CD, Akogbeto MC.

Centre de Recherche Entomologique de Cotonou, Benin. anges33@yahoo.fr

BACKGROUND: A fast development of urban agriculture has recently taken place in many areas in the Republic of Benin. This study aims to assess the rapid expansion of urban agriculture especially, its contribution to the emergence of insecticide resistance in populations of Anopheles gambiae. METHODS: The protocol was based on the collection of sociological data by interviewing vegetable farmers regarding various agricultural practices and the types of pesticides used. Bioassay tests were performed to assess the susceptibility of malaria vectors to various agricultural insecticides and biochemical analysis were done
to characterize molecular status of population of An. gambiae. RESULTS: This research showed that:(1) The rapid development of urban agriculture is related to unemployment observed in cities, rural exodus and the search for a balanced diet by urban populations;(2) Urban agriculture increases the farmers’ household
income and their living standard;(3) At a molecular level, PCR revealed the presence of three sub-species of An. gambiae (An. gambiae s.s., Anopheles melas and Anopheles arabiensis) and two molecular forms (M and S). The kdr west mutation recorded in samples from the three sites and more specifically on the M forms seems to be one of the major resistance mechanisms found in An. gambiae from agricultural areas. Insecticide susceptibility tests conducted during this research revealed a clear pattern of resistance to permethrin (76% mortality rate at Parakou; 23.5% at Porto-Novo and 17% at Cotonou). CONCLUSION: This study confirmed an increase activity of the vegetable farming in urban areas of Benin. This has led to the use of insecticide in an improper manner to control vegetable pests, thus exerting a huge selection pressure on mosquito larval population, which resulted to the emergence of insecticide resistance in malaria vectors.

12: Parasitol Res. 2009 Jun;104(6):1289-93. Epub 2009 Jan 16.

Larvicidal activity of oak Quercus infectoria Oliv. (Fagaceae) gall extracts against Anopheles stephensi Liston.

Aivazi AA, Vijayan VA.

Department of Studies in Zoology, University of Mysore, Manasagangotri, Mysore, India.

There is a growing interest in the use of botanical insecticides to reduce the use of synthetic pesticides in order to avoid environmental side effects. Anopheles stephensi is the primary vector of urban malaria, an endemic disease in India. So, an effort to assay An. stephensi larvae with gall extracts of Quercus infectoria was made under laboratory conditions at Mysore. Ethyl-acetate extract was found to be the most effective of all the five extracts tested for larvicidal activity against the fourth instar larvae, with LC(50) of 116.92 ppm followed by gallotannin, n-butanol, acetone, and methanol with LC(50) values of 124.62, 174.76, 299.26, and 364.61 ppm, respectively. The efficacy in killing mosquito larvae may make this plant promising for the development of new botanical larvicide.

1: Acta Trop. 2009 Aug;111(2):197-9. Epub 2009 Apr 11.

The suitability of clay pots for indoor sampling of mosquitoes in an arid area in
northern Tanzania.

van den Bijllaardt W, ter Braak R, Shekalaghe S, Otieno S, Mahande A, Sauerwein
R, Takken W, Bousema T.

Department of Medical Microbiology 268, Radboud University Nijmegen Medical
Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. wvandenbijl@hotmail.com

Water storage clay pots have been recently explored as method for outdoor
mosquito sampling and as novel device for administrating insect-pathogenic fungi
to mosquitoes. Their suitability for indoor mosquito sampling in natural
conditions is unknown. We tested clay pots as indoor resting sites alongside
catches by CDC light trap in an area of low malaria endemicity in northern
Tanzania. Mosquitoes were caught by clay pots although the rate of female
Anopheles mosquito catches was 22.64 (95% CI 11.26-45.52) times greater for CDC
light traps. The proportion of fed female Anophelines was significantly higher
for clay pots compared to CDC light trap (p<0.001), indicating these methods
sample different populations of mosquitoes. Although we were able to identify
households with a consistently higher exposure to mosquitoes by CDC light trap,
there was no apparent heterogeneity in mosquito catches by clay pots. We conclude
that clay pots are not a reliable tool to sample mosquitoes in the dry season in
an area of low transmission intensity with Anopheles arabiensis as principle
vector.

2: Acta Trop. 2009 Jun 17. [Epub ahead of print]

Field investigation on the repellent activity of some aromatic plants by
traditional means against Anopheles arabiensis and An. pharoensis (Diptera:
Culicidae) around Koka, central Ethiopia.

Dugassa S, Medhin G, Balkew M, Seyoum A, Gebre-Michael T.

Department of Biology, Faculty of Science, Addis Ababa University, P.O. Box 1176,
Addis Ababa, Ethiopia.

A study was undertaken to evaluate the impact of traditional application methods
of mosquito repellent plants in the reduction of the human-vector contact of
malaria vectors in central Ethiopia. The plants (Corymbia citriodora, Eucalyptus
camaldulensis, Ocimum suave and Ocimum basilicum) were tested by thermal
expulsion and direct burning on traditional stoves in the field against two
important malaria vectors in Ethiopia (Anopheles arabiensis and An. pharoensis).
A Latin-square design was applied for randomly assigning the treatment plants and
control to experimental houses over different nights. The percentage repellency
of each candidate plant by both application methods was estimated from the
catches of mosquitoes in the treatment and control houses. On direct burning of
the plants, O. basilicum showed the highest percentage repellency (73.11%,
P<0.001) and E. camaldulensis the least repellency (65.29%, P<0.001) against An.
arabiensis. By the same method of application, C. citriodora on the other hand
gave the highest repellency (72.87%, P<0.001) while E. camaldulensis was still
the least repellent plant (66.60%, P<0.001) against An. pharoensis. On thermal
expulsion, C. citriodora exhibited the highest repellency (78.69%, P<0.001) while
E. camaldulensis was the lowest repellent plant (71.91%, P<0.001) against An.
arabiensis. Against An. pharoensis, C. citriodora gave the highest repellency
(72.9%, P<0.001) while E. camaldulensis still gave the least repellency (72.2%,
P65%) against the
house-entry and biting of two important malaria vectors in Ethiopia, and thus
have a potential to be used at least as supplements to other control methods.
However, feasibility and actual impact on disease transmission need to be known
on these and other potentially useful plants.

3: Acta Trop. 2009 Jun 16. [Epub ahead of print]

Plasmodium falciparum GPI toxin: a common foe for man and mosquito.

Arrighi RB, Faye I.

Swedish Institute for Infectious Disease, SE-171 82 Stockholm, Sweden.

The glycosylphosphatidylinositol (GPI) anchor of the malaria parasite, Plasmodium
falciparum, which can be regarded as an endotoxin, plays a role in the induced
pathology associated with severe malaria in humans. However, it is unclear
whether the main mosquito vector, Anopheles gambiae, can specifically recognize,
and respond to GPI from the malaria parasite. Recent data suggests that the
malaria vector does mount a specific response against malaria GPI. In addition,
following the strong immune response, mosquito fecundity is severely affected,
resulting in a significant reduction in viable eggs produced. In this mini-review
we look at the increased interest in understanding the way that malaria antigens
are recognized in the mosquito, and how this relates to a better understanding of
the interactions between the malaria parasite and both human and vector.

4: Acta Trop. 2009 Jun 16. [Epub ahead of print]

Is K-O Tab 1-2-3((R)); long-lasting on non-polyester mosquito nets?

Oxborough RM, Weir V, Irish S, Kaur H, N’guessan R, Boko P, Odjo A, Metonnou C,
Yates A, Akogbeto M, Rowland MW.

London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT,
UK; Pan-African Malaria Vector Research Consortium (PAMVERC) www.pamverc.org.

Many societies use locally sourced mosquito nets made from a variety of
materials. For protecting against malaria these require regular re-treatment with
insecticide. K-O Tab 1-2-3 is a ‘dip-it-yourself’ long lasting formulation with
time limited interim recommendation from WHO for treatment of washed white and
coloured polyester nets for up to 15 washes. To determine wash resistance on
different fabrics, nets made of polyester, polyethylene, cotton or nylon were
treated with K-O Tab 1-2-3 and washed up to 20 times using standard WHO washing
procedures. Efficacy was assessed using cone and cylinder bioassays and tunnel
tests, and deltamethrin content using high-pressure liquid chromatography.
Polyethylene and cotton nets treated with K-O Tab 1-2-3 and washed 20 times
achieved the WHO threshold of >80% mortality in tunnel tests. Polyethylene
matched the performance of polyester in all bioassays in contrast to cotton and
nylon which produced low mortality and knock-down in cone and cylinder bioassays.
After 20 washes 16.5% of the loading dose of deltamethrin remained on the
polyester nets compared with 28.7% on polyethylene, 38.9% on cotton and 2.2% on
nylon. Cotton nets retained a high concentration of insecticide but the
relatively poor performance in terms of knock-down and mortality suggest most
insecticide is bound within the cotton fibres rather than on the surface. K-O Tab
1-2-3 renders insecticide wash fast on polyethylene nets, less so on cotton and
nylon. Nets made from polyethylene can be treated in the home to render the
insecticide long-lasting.

5: Acta Trop. 2009 Jun 16. [Epub ahead of print]

Use of Intermittent Preventive Treatment for malaria by pregnant women in Buea,
Cameroon.

Takem DE, Achidi DE, Ndumbe PP.

Ministry of Health, BP 281, Buea, Cameroon.

We identified individual factors associated with IPT use, by comparing
characteristics of pregnant women who use IPT to those who do not. A
cross-sectional study was conducted in antenatal clinics in Buea, Cameroon from
December 2006 to December 2007. Information on factors: age, parity, gravidity,
gestational age, level ofeducation, use of insecticide treated nets (ITN),
socioeconomic status and IPT use were collected through interview and filled in a
questionnaire. Data was entered using EPIDATA version 3 and analysis done using
STATA version 8.2. A total of 527 pregnant women were interviewed with a mean
(+/-SD) age of 26.45 +/- 5.37 years. 69.71% of the pregnant women used at least
two doses of IPT. Logistic regression revealed women with higher educational
status were more likely to use IPT compared to those with lower educational
status (OR= 3.14, 95% CI=1.20-8.25, p=0.02). Meanwhile, multigravid women tend to
use IPT less than their primigravid counterparts (OR = 0.47, 95% CI=0.26-0.84,
p=0.01). There was no evidence that maternal age, parity, marital status,
gestational age, use of ITN and socioeconomic status were each associated to IPT
use.In antenatal clinics in Buea, South Western Cameroon, educational status and
gravidity are the key determinants of IPT use.

6: Acta Trop. 2009 Jun 16. [Epub ahead of print]

varDB: a database of antigenic variant sequences- current status and future
prospects.

Diez D, Hayes N, Joannin N, Normark J, Kanehisa M, Wahlgren M, Wheelock CE, Goto
S.

Bioinformatics Center, Institute for Chemical Research, Kyoto University, Uji,
Kyoto 611-0011 Japan.

Antigenic variation is a common mechanism employed by many pathogenic organisms
to avoid recognition of surface proteins by the host immune system. The malaria
parasite, Plasmodium falciparum, among many others, exploits this mechanism and
manages to survive in an otherwise hostile environment. Although similarities in
the mechanisms used among different species to generate antigenic variation are
broadly recognized, there is a lack of studies using cross-species data. The
varDB project (http://www.vardb.org) was created to study antigenic variation at
a range of different levels, both within and among species. The project aims to
serve as a resource to increase our understanding of antigenic variation by
providing a framework for comparative studies. In this review we describe the
varDB project, its construction, and the overall organization of information with
the intent of increasing the utility of varDB to the research community. The
current version of varDB supports 27 species involved in 19 different diseases
affecting humans as well as other species. These data include 42 gene families
that are represented by over 67,000 sequences. The varDB project is still in its
infancy but is expected to continue to grow with the addition of new organisms
and gene families as well as input from the general research community.

7: Am J Public Health. 2009 Jun 18. [Epub ahead of print]

Indoor Residual Spraying of DDT for Malaria Control.

Chen HH, Chen AL.

8: Am J Trop Med Hyg. 2009 Jul;81(1):146-51.

Etiology of acute undifferentiated febrile illness in the Amazon basin of
Ecuador.

Manock SR, Jacobsen KH, de Bravo NB, Russell KL, Negrete M, Olson JG, Sanchez JL,
Blair PJ, Smalligan RD, Quist BK, Espín JF, Espinoza WR, MacCormick F, Fleming
LC, Kochel T.

Rural Medical Services, Parrottsville, Tennessee 37843, USA.
stevemanock@yahoo.com

We conducted a longitudinal observational study of 533 patients presenting to two
hospitals in the Ecuadorean Amazon basin with acute undifferentiated febrile
illness (AUFI) from 2001 through 2004. Viral isolation, reverse
transcription-polymerase chain reaction (RT-PCR), IgM seroconversion, and malaria
smears identified pathogens responsible for fever in 122 (40.1%) of 304 patients
who provided both acute and convalescent blood samples. Leptospirosis was found
in 40 (13.2%), malaria in 38 (12.5%), rickettsioses in 18 (5.9%), dengue fever in
16 (5.3%), Q fever in 15 (4.9%), brucellosis in 4 (1.3%), Ilhéus infection in 3
(1.0%), and Venezuelan equine encephalitis (VEE), Oropouche, and St. Louis
encephalitis virus infections in less than 1% of these patients. Viral isolation
and RT-PCR on another 229 participants who provided only acute samples identified
3 cases of dengue fever, 2 of VEE, and 1 of Ilhéus. None of these pathogens,
except for malaria, had previously been detected in the study area.

9: Am J Trop Med Hyg. 2009 Jul;81(1):34-9.

Risk factors for visceral leishmaniasis in a new epidemic site in Amhara Region,
Ethiopia.

Bashaye S, Nombela N, Argaw D, Mulugeta A, Herrero M, Nieto J, Chicharro C,
Cañavate C, Aparicio P, Vélez ID, Alvar J, Bern C.

Malaria & Other Vector Borne Diseases, Prevention and Control Program, Ministry
of Health, Addis Ababa, Ethiopia.

We conducted a case-control study to evaluate risk factors for visceral
leishmaniasis during an epidemic in a previously unaffected district of Ethiopia.
We also collected blood and bone marrow specimens from dogs in the outbreak
villages. In multivariable analyses of 171 matched case-control pairs, dog
ownership, sleeping under an acacia tree during the day, and habitually sleeping
outside at night were associated with significantly increased risk. Specimens
from 7 (3.8%) dogs were positive by immunofluorescent antibody test (IFAT) and
both enzyme-linked immunosorbent assays (ELISAs), whereas Leishmania DNA was
detected in 5 (2.8%) bone marrow aspirates (from 3 seropositive and 2
seronegative dogs). Insecticide-treated nets may only protect a portion of those
at risk. Further research on the vectors, the role of the dog in the transmission
cycle, and the effect of candidate interventions are needed to design the best
strategy for control.

10: Am J Trop Med Hyg. 2009 Jul;81(1):27-33.

Comparative study of serologic tests for the diagnosis of asymptomatic visceral
leishmaniasis in an endemic area.

Romero HD, Silva Lde A, Silva-Vergara ML, Rodrigues V, Costa RT, Guimarães SF,
Alecrim W, Moraes-Souza H, Prata A.

Department of Tropical Medicine and Infectology, Federal University of Triângulo
Mineiro, Uberaba, MG, Brazil.

Serologic tests have been widely used for the diagnosis of asymptomatic visceral
leishmaniasis. This study evaluated five serologic tests used for the diagnosis
of asymptomatic infection: enzyme-linked immunosorbent assay (ELISA) using
promastigote antigen (ELISAp), ELISA using recombinant K39 (ELISA rK39), and K26
(ELISA rK26) antigens, an indirect immunofluorescence test using Leishmania
(Leishmania) amazonensis promastigote antigen (IIFT), and an
immunochromatographic test using rK39 antigen (TRALd). As a reference regarding
the performance of the tests, patients with classic visceral leishmaniasis
originating from Minas Gerais, Brazil (N = 36), were defined as the positive
group and samples of healthy individuals from nonendemic areas (Argentina) (N =
127) were used as negative controls. Patients with other diseases such as
cutaneous leishmaniasis (N = 53) and malaria (N = 56) were also studied to
evaluate the chance of cross-reactivity in these tests. Finally, subjects from an
area endemic for visceral leishmaniasis in Brazil (Porteirinha, northern Minas
Gerais) (N = 1241) were screened for asymptomatic infection with Leishmania and
Chagas disease. The sensitivity of the serologic tests was 50% (18/36), 66.7%
(24/36), 69.4% (25/36), 83.3% (30/36), and 88.9% (32/36) for ELISAp, ELISA rK26,
ELISA rK39, IIFT, and TRALd, respectively. Specificity, calculated using the
truly negative group, was 96% (122/127) for TRALd, 97.6% (124/127) for ELISAp and
IIFT, and 100% (127/127) for ELISA rK39 and rK26. Positivity in at least one test
employing recombinant antigen was observed in 24 (45%) patients with cutaneous
leishmaniasis and 47 (82.4%) with malaria. In the visceral leishmaniasis-endemic
area, the positivity of the serologic tests ranged from 3.9% to 37.5%. The
enzyme-linked immunosorbent assay (ELISA) tests using recombinant antigens were
more frequently positive in subjects with a history of exposure to human or
canine visceral leishmaniasis (ELISArK39: 14.6% [149/1017] versus 37.5% [84/224];
ELISA rK26: 12.7% [129/1017] versus 21.4% [48/224], P 90%
for the 58R, 117N, 382C, and 383G. A new mutation (116G) in pvdhfr was found at a
frequency of 3.3%. Six different pvdhfr/dhps multilocus genotypes were observed
with the predominance of the quintuple mutant-type 58R/117N/173L-382C/383G
(59.3%). No significant differences were observed between the prevalence of
haplotypes and the year of collection. Our results indicate that, in this area,
the fixation of SP drug-resistant parasites in the P. vivax population is stable.

12: Am J Trop Med Hyg. 2009 Jul;81(1):13-8.

Molecular epidemiology of malaria in Cameroon. XXVIII. In vitro activity of
dihydroartemisinin against clinical isolates of Plasmodium falciparum and
sequence analysis of the P. falciparum ATPase 6 gene.

Tahar R, Ringwald P, Basco LK.

Institut de Recherche pour le Développement and Laboratoire de Recherche sur le
Paludisme, Organisation de Coordination pour la Lutte Contre les Endémies en
Afrique Centrale, Yaoundé, Cameroon. rachida.tahar@ird.fr

The Plasmodium falciparum ATPase 6 (Pfatp6), homolog of sarco-endoplasmic
reticulum, calcium-dependent ATPase in malaria parasites, has been proposed to be
the main target of artemisinins. Four distinct point mutations (L263E, E431K,
A623E, and S769N) have been reported to be associated with artemisinin
resistance. The Pfatp6 sequence polymorphism was determined to evaluate the
prevalence of these mutations in fresh clinical isolates in Yaounde, Cameroon,
and compare sequence data with in vitro response to dihydroartemisinin. Two major
haplotypes were observed: the wild-type LEAS (n = 60, 62%) and a single mutant
LKAS (n = 35, 36%). These amino acid substitutions did not influence the level of
in vitro response to dihydroartemisinin (P > 0.05). Plasmodium falciparum
isolates from Cameroon are highly sensitive in vitro to artemisinins. However,
the relatively high prevalence of E431K may be a warning signal that warrants a
regular monitoring of these molecular markers and/or in vitro activity of
artemisinin derivatives.

13: Am J Trop Med Hyg. 2009 Jul;81(1):5-12.

Linking deforestation to malaria in the Amazon: characterization of the breeding
habitat of the principal malaria vector, Anopheles darlingi.

Vittor AY, Pan W, Gilman RH, Tielsch J, Glass G, Shields T, Sánchez-Lozano W,
Pinedo VV, Salas-Cobos E, Flores S, Patz JA.

Department of Internal Medicine, University of Pennsylvania, Philadelphia,
Pennsylvania, USA.

This study examined the larval breeding habitat of a major South American malaria
vector, Anopheles darlingi, in areas with varying degrees of ecologic alteration
in the Peruvian Amazon. Water bodies were repeatedly sampled across 112 km of
transects along the Iquitos-Nauta road in ecologically varied areas. Field data
and satellite imagery were used to determine the landscape composition
surrounding each site. Seventeen species of Anopheles larvae were collected.
Anopheles darlingi larvae were present in 87 of 844 sites (10.3%). Sites with A.
darlingi larvae had an average of 24.1% forest cover, compared with 41.0% for
sites without A. darlingi (P 60 days met the
WHO criteria for a syndrome of ‘pneumonia’ on admission, only 215 of the 693
(31%) such children had a final diagnosis of lower respiratory tract infection
(LRTI). The most predictive signs for hypoxaemia included shock, a heart rate 60 breaths per
minute and impaired consciousness. However, 5-15% of the children who had
hypoxaemia on admission were missed, and 18% of the children were incorrectly
identified as hypoxaemic. CONCLUSION: The syndromes of pneumonia make it possible
to identify most hypoxaemic children, including those without LRTI. Shock,
bradycardia and irregular breathing are important predictive signs, and severe
malaria with respiratory distress is a common cause of hypoxaemia. Overall,
however, clinical signs are poor predictors of hypoxaemia, and using pulse
oximetry in resource-poor health facilities to target oxygen therapy is likely to
save costs.

15: Clin Infect Dis. 2009 Jun 23. [Epub ahead of print]

HIV Infection, Malnutrition, and Invasive Bacterial Infection among Children with
Severe Malaria.

Berkley JA, Bejon P, Mwangi T, Gwer S, Maitland K, Williams TN, Mohammed S, Osier
F, Kinyanjui S, Fegan G, Lowe BS, English M, Peshu N, Marsh K, Newton CR.

Centre for Geographic Medicine Research, Kilifi, and 2Nairobi Kenya Medical
Research Institute (KEMRI)-Wellcome Trust Collaborative Research Programme,
Kenyatta National Hospital, Nairobi, Kenya; 3Centre for Clinical Vaccinology and
Tropical Medicine and 4Department of Paediatrics, University of Oxford, Oxford,
and 5Department of Paediatrics and Wellcome Trust Centre for Clinical Tropical
Medicine, Imperial College, 6Infectious Disease Epidemiology Unit, Department of
Epidemiology and Population Health, London School of Hygiene and Tropical
Medicine, and 7Institute of Child Health, University College London, London,
United Kingdom.

Background. Human immunodeficiency virus (HIV) infection, malnutrition, and
invasive bacterial infection (IBI) are reported among children with severe
malaria. However, it is unclear whether their cooccurrence with falciparum
parasitization and severe disease happens by chance or by association among
children in areas where malaria is endemic. Methods. We examined 3068 consecutive
children admitted to a Kenyan district hospital with clinical features of severe
malaria and 592 control subjects from the community. We performed multivariable
regression analysis, with each case weighted for its probability of being due to
falciparum malaria, using estimates of the fraction of severe disease
attributable to malaria at different parasite densities derived from
cross-sectional parasitological surveys of healthy children from the same
community. Results. HIV infection was present in 133 (12%) of 1071 consecutive
parasitemic admitted children (95% confidence interval [CI], 11%-15%). Parasite
densities were higher in HIV-infected children. The odds ratio for admission
associated with HIV infection for admission with true severe falciparum malaria
was 9.6 (95% CI, 4.9-19); however, this effect was restricted to children aged 1
year. Malnutrition was present in 507 (25%) of 2048 consecutive parasitemic
admitted children (95% CI, 23%-27%). The odd ratio associated with malnutrition
for admission with true severe falciparum malaria was 4.0 (95% CI, 2.9-5.5). IBI
was detected in 127 (6%) of 2048 consecutive parasitemic admitted children (95%
CI, 5.2%-7.3%). All 3 comorbidities were associated with increased case fatality.
Conclusions. HIV, malnutrition and IBI are biologically associated with severe
disease due to falciparum malaria rather than being simply alternative diagnoses
in co-incidentally parasitized children in an endemic area.

16: Clin Infect Dis. 2009 Jun 23. [Epub ahead of print]

No Man Is an Island: Multiple Pathologies in Patients with Malaria.

Breman JG. Fogarty International Center, US National Institutes of Health, Bethesda,
Maryland.

17: J Infect Dis. 2009 Jun 1. [Epub ahead of print]

Analysis of Plasmodium falciparum var Genes Expressed in Children from Papua New
Guinea.

Falk N, Kaestli M, Qi W, Ott M, Baea K, Cortés A, Beck HP.

Swiss Tropical Institute and 2F. Hoffmann-La Roche AG, Basel, Switzerland; 3Papua
New Guinea Institute of Medical Research, Madang, Papua New Guinea.

Background. The variable antigen P. falciparum erythrocyte membrane protein-1
(PfEMP1) is a major virulence factor in malaria. A large number of var genes
encode PfEMP1, and we hypothesized that a restricted PfEMP1 repertoire determines
clinical disease presentation. We conducted a case-control study in Papua New
Guinea and analyzed transcribed var genes in naturally infected children.
Methods. var messenger RNA was isolated from 78 children with asymptomatic, mild,
or severe malaria. We prepared complementary DNA from the upstream region into
the DBL1alpha domain and picked, on average, 20 clones for sequencing. Results.
Twenty-five percent of centrally located var genes were shared between children,
whereas only 5% of subtelomeric genes were shared, indicating lower diversity in
the former group. Linkage between group B or C var upstream sequences and
DBL1alpha groups was not observed, which impeded prediction by DBL1alpha
analysis. A higher proportion of var group A sequences was detected in
symptomatic malaria, and a subgroup of frequently encountered var genes with
complex head structure seems to be associated with severe malaria. A subset of
var group C genes was frequently expressed in older children with asymptomatic
high levels of parasitemia. Conclusion. Despite this vast diversity, restricted
disease-associated var genes were identified and might be used for innovative
interventions based on PfEMP1.

18: J Toxicol Environ Health A. 2009;72(13):842-51.

Comparing water, bovine milk, and indoor residual spraying as possible sources of
DDT and pyrethroid residues in breast milk.

Sereda B, Bouwman H, Kylin H.

Agricultural Research Council, Plant Protection Research Institute, Pretoria,
South Africa.

The presence of pollutants in human breast milk is of major concern, especially
in malaria control areas where 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane
(DDT) is currently used as indoor residual spray (IRS). The levels of DDT and
pyrethroids (PYR) were determined in breast milk, bovine milk, and drinking water
from northern KwaZulu-Natal, South Africa. Both reference and exposed mothers
used the same market food, but the DDT levels in the exposed mothers (mean
SigmaDDT 10 microg/g milk fat [mf]) were much higher than for the reference
mothers (mean SigmaDDT 1.3 microg/g milk fat). This difference in residue levels
indicates uptake from IRS-applied DDT, most likely via air and skin contact, and
excludes food as the main source of pollutants. DDT levels in bovine milk (mean
SigmaDDT 0.15 microg/g mf) from the exposed area were less than levels in breast
milk from the reference area, and lower than the 20 microg/L maximum residue
limit (MRL) set by the Food and Agriculture Organization (FAO). Mean SigmaDDT in
water was 0.0065 microg/L, much lower then the WHO limit of the sum of all
metabolites in drinking water of 1 microg/L, and therefore highly unlikely to
have contributed to any extent toward levels in breast milk. Permethrin in breast
milk (mean 1.1-1.6 microg/g milk fat) was probably derived from home garden and
indoor use, while the other PYR (cypermethrin and cyfluthrin) at lower
concentrations were probably derived from food and agricultural exposure. It is
postulated that a better understanding of the indoor dynamics of DDT and other
insecticides, through a concept of Total Homestead Environment Approach (THEA),
is crucial for investigating options of reducing human exposure and uptake under
malaria control conditions.

19: Malar J. 2009 Jun 27;8(1):142. [Epub ahead of print]

The spatial and temporal patterns of falciparum and vivax malaria in Peru:
1994-2006.

Chowell G, Munayco CV, Escalante AA, McKenzie FE.

ABSTRACT: BACKGROUND: Malaria is the direct cause of approximately one million
deaths worldwide each year, though it is both preventable and curable. Increasing
the understanding of the transmission dynamics of falciparum and vivax malaria
and their relationship could suggest improvements for malaria control efforts.
Here the weekly number of malaria cases due to Plasmodium falciparum (1994-2006)
and Plasmodium vivax (1999-2006) in Peru at different spatial scales in
conjunction with associated demographic, geographic and climatological data are
analysed. METHODS: Malaria periodicity patterns were analysed through wavelet
spectral analysis, studied patterns of persistence as a function of community
size and assessed spatial heterogeneity via the Lorenz curve and the summary Gini
index. RESULTS: Wavelet time series analyses identified annual cycles in the
incidence of both malaria species as the dominant pattern. However, significant
spatial heterogeneity was observed across jungle, mountain and coastal regions
with slightly higher levels of spatial heterogeneity for P. vivax than P.
falciparum. While the incidence of P. falciparum has been declining in recent
years across geographic regions, P. vivax incidence has remained relatively
steady in jungle and mountain regions with a slight decline in coastal regions.
Factors that may be contributing to this decline are discussed. The time series
of both malaria species were significantly synchronized in coastal (rho=0.9,
P<0.0001) and jungle regions (rho=0.76, P95%
efficacy for policy implementation. Trial registration NCT00203736 and
NCT00203814.

21: Malar J. 2009 Jun 26;8(1):140. [Epub ahead of print]

Characterization of the repertoire diversity of the Plasmodium falciparum stevor
multigene family in laboratory and field isolates.

Blythe JE, Niang M, Marsh K, Holder AA, Langhorne J, Preiser PR.

ABSTRACT: BACKGROUND: The evasion of host immune response by the human malaria
parasite Plasmodium falciparum has been linked to expression of a range of
variable antigens on the infected erythrocyte surface. Several genes are
potentially involved in this process with the var, rif and stevor multigene
families being the most likely candidates and coding for rapidly evolving
proteins. The high sequence diversity of proteins encoded by these gene families
may have evolved as an immune evasion strategy that enables the parasite to
establish long lasting chronic infections. Previous findings have shown that the
hypervariable region (HVR) of STEVOR has significant sequence diversity both
within as well as across different P. falciparum lines. However, these studies
did not address whether or not there are ancestral stevor that can be found in
different parasites. METHODS: DNA and RNA sequences analysis as well as
phylogenetic approaches were used to analyse the stevor sequence repertoire and
diversity in laboratory lines and Kilifi (Kenya) fresh isolates. RESULTS:
Conserved stevor genes were identified in different P. falciparum isolates from
different global locations. Consistent with previous studies, the HVR of the
stevor gene family was found to be highly divergent both within and between
isolates. Importantly phylogenetic analysis shows some clustering of stevor
sequences both within a single parasite clone as well as across different
parasite isolates. CONCLUSION: This indicates that the ancestral P. falciparum
parasite genome already contained multiple stevor genes that have subsequently
diversified further within the different P. falciparum populations. It also
confirms that STEVOR is under strong selection pressure.

22: Malar J. 2009 Jun 24;8(1):138. [Epub ahead of print]

Highly focused anopheline breeding sites and malaria transmission in Dakar.

Machault V, Gadiaga L, Vignolles C, Jarjaval F, Bouzid S, Sokhna C, Lacaux JP,
Trape JF, Rogier C, Pages F.

ABSTRACT: BBackground Urbanization has a great impact on the composition of the
vector system and malaria transmission dynamics. In Dakar, some malaria cases are
autochthonous but parasite rates and incidences of clinical malaria attacks have
been recorded at low levels. Ecological heterogeneity of malaria transmission was
investigated in Dakar, in order to characterize the Anopheles breeding sites in
the city and to study the dynamics of larval density and adult aggressiveness in
ten characteristically different urban areas. METHODS: Ten study areas were
sampled in Dakar and Pikine. Mosquitoes were collected by human landing
collection during four nights in each area (120 person-nights). The Plasmodium
falciparum circumsporozoite (CSP) index was measured by ELISA and the
entomological inoculation rates (EIR) were calculated. Open water collections in
the study areas were monitored weekly for physico-chemical characterization and
the presence of anopheline larvae. Adult mosquitoes and hatched larvae were
identified morphologically and by molecular methods. RESULTS: In
September-October 2007, 19,451 adult mosquitoes were caught among which, 1,101
were Anopheles gambiae s.l. The Human Biting Rate ranged from 0.1 bites per
person per night in Yoff Village to 43.7 in Almadies. Seven out of 1,101 An.
gambiae s.l. were found to be positive for P. falciparum (CSP index = 0.64%). EIR
ranged from 0 infected bites per person per year in Yoff Village to 16.8 in
Almadies. The An. gambiae complex population was composed of Anopheles arabiensis
(94.8%) and Anopheles melas (5.2%). None of the An. melas were infected with P.
falciparum. Of the 54 water collection sites monitored, 33 (61.1%) served as
anopheline breeding sites on at least one observation. No An. melas was
identified among the larval samples. Some physico-chemical characteristics of
water bodies were associated with the presence/absence of anopheline larvae and
with larval density. A very close parallel between larval and adult densities was
found in six of the ten study areas. CONCLUSIONS: The results provide evidence of
malaria transmission in downtown Dakar and its surrounding suburbs. Spatial
heterogeneity of human biting rates was very marked and malaria transmission was
highly focal. In Dakar, mean figures for transmission would not provide a
comprehensive picture of the entomological situation; risk evaluation should
therefore be undertaken on a small scale.

23: Malar J. 2009 Jun 23;8(1):137. [Epub ahead of print]

Analysis of von Willebrand factor A domain-related protein (WARP) polymorphism in
temperate and tropical Plasmodium vivax field isolates.

Gholizadeh S, Djadid ND, Basseri HR, Zakeri S, Ladoni H.

ABSTRACT: BACKGROUND: The identification of key molecules is crucial for
designing transmission-blocking vaccines (TBVs), among those ookinete micronemal
proteins are candidate as a general class of malaria transmission-blocking
targets. Here, the sequence analysis of an extra-cellular malaria protein
expressed in ookinetes, named von Willebrand factor A domain-related protein
(WARP), is reported in 91 Plasmodium vivax isolates circulating in different
regions of Iran. METHODS: Clinical isolates were collected from north temperate
and southern tropical regions in Iran. Primers have been designed based on P.
vivax sequence (ctg_6991) which amplified a fragment of about 1044bp with no size
variation. Direct sequencing of PCR products was used to determine polymorphism
and further bioinformatics analysis in P. vivax sexual stage antigen, pvwarp.
RESULTS: Amplified pvwarp gene showed 886 bp in size, with no intron. BLAST
analysis showed a similarity of 98-100% to P. vivax Sal-I strain; however,
Iranian isolates had 2 bp mismatches in 247 and 531 positions that were
non-synonymous substitution [T (ACT) to A (GCT) and R (AGA) to S (AGT)] in
comparison with the Sal-I sequence. CONCLUSIONS: This study presents the first
large-scale survey on pvwarp polymorphism in the world, which provides baseline
data for developing WARP-based TBV against both temperate and tropical P. vivax
isolates.

24: Malar J. 2009 Jun 22;8(1):136. [Epub ahead of print]

Marked differences in CRP genotype frequencies between the Fulani and sympatric
ethnic groups in Africa.

Israelsson E, Ekstrom M, Nasr A, Dolo A, Kearsley S, Arambepola G, Vafa Homann M,
Maiga B, Doumbo OK, Elghazali G, Giha HA, Troye-Blomberg M, Berzins K, Tornvall
P.

ABSTRACT: BACKGROUND: C-reactive protein (CRP) is an acute phase protein that can
activate various immune cells and bind to certain Fcgamma receptors. The latter
may compete with the binding of IgG antibodies to these receptors and could
thereby interfere with the antigen-specific immune response. Polymorphisms in the
promoter region of the CRP gene have been strongly associated with the plasma
concentration of CRP. The known lower susceptibility to malaria in the Fulani
ethnic group, as compared to their sympatric neighbours in Africa, has been
linked to different genetic backgrounds. The present study was performed to
investigate if polymorphisms in the CRP gene could contribute to the lower
susceptibility to malaria seen in the Fulani ethnic group. METHODS: The CRP -717
T>C, -286 C>T>A, and +1444 C>T polymorphisms were analysed in asymptomatic Fulani
and non-Fulani individuals from Mali and Sudan using Pyrosequencing (TM) and
TaqMan (R) MGB probes. RESULTS: The rare -286 A allele, previously shown to be
associated with increased CRP expression and plasma levels, was shown to be more
frequent in the non-Fulani ethnic groups as compared to the sympatric Fulani
ethnic group both in Mali and Sudan. The common -717 T allele was more prevalent
in the non-Fulani ethnic group compared to the sympatric Fulani ethnic group, but
only in Mali. The parasite prevalence was increased for the -286 A allele, but
not for the -717 T allele. No differences regarding genotype frequency or
parasite prevalence were seen for +1444 C>T. CONCLUSIONS: This study indicate
that CRP may play an important role in the immune responses to malaria, and that
the -286 C/T/A CRP polymorphism may be a contributing factor to the lower
susceptibility to malaria seen in the Fulani.

25: Malar J. 2009 Jun 20;8(1):135. [Epub ahead of print]

Plasmodium falciparum genotypes diversity in symptomatic malaria of children
living in an urban and a rural setting in Burkina Faso.

Soulama I, Nebie I, Ouedraogo A, Gansane A, Diarra A, Tiono AB, Bougouma EC,
Konate AT, Kabre GB, Taylor WR, Sirima SB.

ABSTRACT: BACKGROUND: The clinical presentation of malaria, considered as the
result of a complex interaction between parasite and human genetics, is described
to be different between rural and urban areas. The analysis of the Plasmodium
falciparum genetic diversity in children with uncomplicated malaria, living in
these two different areas, may help to understand the effect of urbanization on
the distribution of P. falciparum genotypes. METHODS: Isolates collected from 75
and 89 children with uncomplicated malaria infection living in a rural and an
urban area of Burkina Faso, respectively, were analysed by a nested PCR
amplification of msp1 and msp2 genes to compare P. falciparum diversity. RESULTS:
The K1 allelic family was widespread in children living in the two sites,
compared to other msp1 allelic families (frequency >90 %). The MAD 20 allelic
family of msp1 was more prevalent (p= 0.0001) in the urban (85.3%) than the rural
area (63.2%). In the urban area, the 3D7 alleles of msp2 were more prevalent
compared to FC27 alleles, with a high frequency for the 3D7300bp allele (>30%).
The multiplicity of infection was in the range of one to six in the urban area
and of one to seven in the rural area. There was no difference in the frequency
of multiple infections (p= 0.6): 96.0% (95% C.I: 91.6-100) in urban versus 93.1 %
(95%C.I: 87.6-98.6) in rural areas. The complexity of infection increased with
age [p= 0.04 (rural area), p=0.06 (urban area)]. CONCLUSION: Urban-rural area
differences were observed in some allelic families (MAD20, FC27, 3D7), suggesting
a probable impact of urbanization on genetic variability of P. falciparum. This
should be taken into account in the implementation of malaria control measures.

26: Malar J. 2009 Jun 17;8:134.

Malaria and vitamin A deficiency in African children: a vicious circle?

Sanjoaquin MA, Molyneux ME.

Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine,
Po Box 30096, Chichiri, Blantyre 3, Malawi. msanjoaquin@mlw.medcol.mw.

ABSTRACT: Vitamin A deficiency and malaria are both highly prevalent health
problems in Africa. Vitamin A deficiency affects over 30 million children, most
of whom are in the age-group (under five years) most affected by malaria. Vitamin
A deficiency increases all-cause mortality in this part of the population, and
malaria is an important cause of death in children at this age. A low serum
retinol concentration (a marker of vitamin A deficiency) is commonly found in
children suffering from malaria, but it is not certain whether this represents
pre-existing vitamin A deficiency, a contribution of malaria to vitamin A
deficiency, or merely an acute effect of malaria on retinol metabolism or
binding. In this paper, available evidence in support of a causal relationship in
each direction between vitamin A deficiency and malaria is reviewed. If such a
relationship exists, and especially if this is bidirectional, interventions
against either disease may convey an amplified benefit for health.

27: Malar J. 2009 Jun 16;8(1):133. [Epub ahead of print]

Risk factors for malaria deaths in Jalpaiguri district, West Bengal, India:
evidence for further action.

Sarkar J, Murhekar MV, Shah NK, Hutin Y.

ABSTRACT: BACKGROUND: In 2006, a cluster of malaria deaths in the highly endemic
Jalpaiguri district, West Bengal, India, led to assignment of additional
resources. Malaria deaths decreased, but continued to occur. A study was
conducted to identify the risk factors for residual malaria deaths. METHODS:
Malaria death was defined as a death from fever with microscopically confirmed
Plasmodium falciparum among residents of Jalpaiguri during 2007-2008. For each
case, three age-, sex- and locality-matched controls were recruited among
microscopically confirmed falciparum malaria patients cured during the same
period. Clinical and treatment information was abstracted from records.
Information about knowledge about malaria, presence of bed nets and DDT spraying
was collected through interviews of the close relatives of study subjects. Odds
ratio (OR) were calculated using multivariate methods. RESULTS: 51 malaria deaths
were matched with 153 controls, which did not differ by age (median: 35 versus 36
years) and proportion of males (63% versus 63%). On multiple logistic regression
analysis, compared with survivors, malaria deaths were more likely to have been
admitted with already existing complications [OR = 4.1, 95% confidence interval
(CI)=1.6-10)], treated at a private facility (OR= 3.7, 95% CI= 1.2-12), received
treatment after 48 hours of fever onset (OR= 14, 95% CI= 2.9- 64), received
chloroquine (OR=13.3, 95% CI= 3.7- 47). Households of the deceased were also more
likely to miss bed nets (OR= 6.3, 95% CI= 1.9-24) and DDT spraying (OR=9.2, 95%
CI= 2.8-31). CONCLUSIONS: Elimination of malaria deaths will require education of
providers for prompt referral before complications, engagement of the private
sector, community awareness for early treatment as well as scaled-up use of bed
nets use and DDT. Use of newer generation anti-malarials must to be generalized.

28: Malar J. 2009 Jun 12;8:130.

Spatial and temporal distribution of falciparum malaria in China.

Lin H, Lu L, Tian L, Zhou S, Wu H, Bi Y, Ho SC, Liu Q.

National Institute for Communicable Disease Control and Prevention, China CDC,
State Key Laboratory for Infectious Disease Prevention and Control, Beijing, PR
China. linhualiang@cuhk.edu.hk

BACKGROUND: Falciparum malaria is the most deadly among the four main types of
human malaria. Although great success has been achieved since the launch of the
National Malaria Control Programme in 1955, malaria remains a serious public
health problem in China. This paper aimed to analyse the geographic distribution,
demographic patterns and time trends of falciparum malaria in China. METHODS: The
annual numbers of falciparum malaria cases during 1992-2003 and the individual
case reports of each clinical falciparum malaria during 2004-2005 were extracted
from communicable disease information systems in China Center for Diseases
Control and Prevention. The annual number of cases and the annual incidence were
mapped by matching them to corresponding province- and county-level
administrative units in a geographic information system. The distribution of
falciparum malaria by age, gender and origin of infection was analysed.
Time-series analysis was conducted to investigate the relationship between the
falciparum malaria in the endemic provinces and the imported falciparum malaria
in non-endemic provinces. RESULTS: Falciparum malaria was endemic in two
provinces of China during 2004-05. Imported malaria was reported in 26
non-endemic provinces. Annual incidence of falciparum malaria was mapped at
county level in the two endemic provinces of China: Yunnan and Hainan. The sex
ratio (male vs. female) for the number of cases in Yunnan was 1.6 in the children
of 0-15 years and it reached 5.7 in the adults over 15 years of age. The number
of malaria cases in Yunnan was positively correlated with the imported malaria of
concurrent months in the non-endemic provinces. CONCLUSION: The endemic area of
falciparum malaria in China has remained restricted to two provinces, Yunnan and
Hainan. Stable transmission occurs in the bordering region of Yunnan and the
hilly-forested south of Hainan. The age and gender distribution in the endemic
area is characterized by the predominance of adult men cases. Imported falciparum
malaria in the non-endemic area of China, affected mainly by the malaria
transmission in Yunnan, has increased both spatially and temporally. Specific
intervention measures targeted at the mobile population groups are warranted.

29: Med Trop (Mars). 2009 Apr;69(2):160-4.

[Vector control methods against malaria and vector resistance to insecticides in
Africa] [Article in French]

Djogbénou L.

Institut Régional de Santé Publique, Ouidah, Bénin. luc.djogbenou@ird.fr

Vector control methods against malaria must be adapted to the targeted vectors.
Control methods against malaria currently depend on deploying insecticide-treated
nets, indoor spraying of remanent insecticides and, to a lesser extent,
eliminating larval breeding sites. The remanence of the insecticidal effect and
efficacy of the vector control must be evaluated. Vector resistance to
insecticides is one of the main limitations for use.

30: Med Trop (Mars). 2009 Apr;69(2):151-9.

[Contribution of remote sensing to malaria control] [Article in French]

Machault V, Pages F, Rogier C.

Unité de recherche en biologie et épidémiologie parasitaires, URMITE, UMR6236,
Institut de recherche biomédicale des armées, Allée du Médecin colonel Jamot,
Parc du Pharo, Marseille cedex 07, France. vanessamachault@yahoo.com.br

Despite national and international efforts, malaria remains a major public health
problem and the fight to control the disease is confronted by numerous hurdles.
Study of space and time dynamics of malaria is necessary as a basis for making
appropriate decision and prioritizing intervention including in areas where field
data are rare and sanitary information systems are inadequate. Evaluation of
malarial risk should also help anticipate the risk of epidemics as a basis for
early warning systems. Since 1960-70 civilian satellites launched for earth
observation have been providing information for the measuring or evaluating
geo-climatic and anthropogenic factors related to malaria transmission and
burden. Remotely sensed data gathered for several civilian or military studies
have allowed setup of entomological, parasitological, and epidemiological risk
models and maps for rural and urban areas. Mapping of human populations at risk
has also benefited from remotely sensing. The results of the published studies
show that remote sensing is a suitable tool for optimizing planning, efficacy and
efficiency of malaria control.

31: Nat Immunol. 2009 Jul;10(7):673-8.

NIAID workshop on immunity to malaria: addressing immunological challenges.

Augustine AD, Hall BF, Leitner WW, Mo AX, Wali TM, Fauci AS.

National Institute of Allergy and Infectious Diseases, National Institutes of
Health, Bethesda, Maryland, USA.

The US National Institute of Allergy and Infectious Diseases convened a workshop
of malaria investigators and immunologists to foster collaborations and attract
more immunologists into malaria research. Discussions highlighted research gaps
and underscored the incomplete understanding of basic immune mechanisms that
contribute to the pathogenesis of or protection against malaria.

32: Nature. 2009 Jun 18;459(7249):918-9.

Comment on:
Nature. 2009 Jun 18;459(7249):945-9.

Malaria: The gatekeeper revealed.

Reiff SB, Striepen B.

Publication Types:
Comment
News

33: Parasitol Int. 2009 Jun 13. [Epub ahead of print]

Cross-reactivity in rapid diagnostic tests between human malaria and zoonotic
simian malaria parasite Plasmodium knowlesi infections.

Kawai S, Hirai M, Haruki K, Tanabe K, Chigusa Y.

Center for Tropical Medicine and Parasitology, Dokkyo Medical University,
Tochigi, 321-0293, Japan.

Plasmodium knowlesi has a relatively broad host range extending to humans, in
whom it causes zoonotic malaria. Recent studies have shown that human infection
with P. knowlesi is widely distributed in forested areas of Southeast Asia. In
the present study, we evaluated commercial rapid diagnostic tests (RDTs) for
human malaria to assess their reactivity and sensitivity in detecting P. knowlesi
parasites using blood samples obtained from infected monkeys. The blood samples
were assayed using two commercial RDTs based on immunochromatographic assays: (i)
the OptiMAL-IT, designed to detect parasite lactate dehydrogenase (pLDH) of both
P. falciparum and other plasmodia, and (ii) the Entebe Malaria Cassette (MC),
designed to detect P. falciparum-specific histidine-rich protein 2 (PfHRP2) and
P. vivax-specific pLDH. Interestingly, when the P. knowlesi-infected blood
samples were examined with the RDTs, OptiMAL test results were interpreted as
falciparum malaria-positive, while Entebe MC test results were interpreted as
vivax malaria-positive. The sensitivities of both tests in detecting P. knowlesi
parasite were similar to those for P. falciparum and higher than P. vivax. Thus,
commercial RDTs based on detection of pLDH should be used with great caution, and
should not replace conventional microscopy in the diagnosis of suspected cases of
P. knowlesi malaria.

34: Parasitol Res. 2009 Jun 26. [Epub ahead of print]

Spatial distribution, blood feeding pattern, and role of Anopheles funestus
complex in malaria transmission in central Kenya.

Muturi EJ, Kamau L, Jacob BG, Muriu S, Mbogo CM, Shililu J, Githure J, Novak RJ.

Department of Medicine, William C. Gorgas Center for Geographic Medicine,
University of Alabama at Birmingham, 206-C BBRB, 845 19th Street South
Birmingham, Birmingham, 35294, AL, USA, emuturi@uab.edu.

Studies were conducted to determine the role of sibling species of Anopheles
funestus complex in malaria transmission in three agro-ecosystems in central
Kenya. Mosquitoes were sampled indoors and outdoors, and rDNA PCR was
successfully used to identify 340 specimens. Anopheles parensis (91.8%), A.
funestus (6.8%), and Anopheles leesoni (1.5%) were the three sibling species
identified. A. parensis was the dominant species at all study sites, while 22 of
23 A. funestus were collected in the non-irrigated study site. None of the 362
specimens tested was positive for Plasmodium falciparum circumsporozoite proteins
by enzyme-linked immunosorbent assay. The most common blood-meal sources (mixed
blood meals included) for A. parensis were goat (54.0%), human (47.6%), and
bovine (39.7%), while the few A. funestus s.s. samples had fed mostly on humans.
The human blood index (HBI) for A. parensis (mixed blood meals included) in the
non-irrigated agro-ecosystem was 0.93 and significantly higher than 0.33 in
planned rice agro-ecosystem. The few samples of A. funestus s.s. and A. funestus
s.l. also showed a trend of higher HBI in the non-irrigated agro-ecosystem. We
conclude that agricultural practices have significant influence on distribution
and blood feeding behavior of A. funestus complex. Although none of the species
was implicated with malaria transmission, these results may partly explain why
non-irrigated agro-ecosystems are associated with higher risk of malaria
transmission by this species compared to irrigated agro-ecosystems.

35: Parasitol Res. 2009 Jun 20. [Epub ahead of print]

Plasmodium falciparum and Plasmodium vivax: so similar, yet very different.

Das A, Sharma M, Gupta B, Dash AP.

Evolutionary Genomics and Bioinformatics Laboratory, National Institute of
Malaria Research, Sector 8, Dwarka, New Delhi, 110 077, India,
aparup@mrcindia.org.

The recently published whole genome sequence information of one of the human
malaria parasites, Plasmodium vivax, have provided opportunities to compare
similar features with Plasmodium falciparum that causes the most deadly form of
human malaria. We herewith present comparative genomic insights into the whole
genome of the two parasites and also to several other characteristics in terms of
disease pathogenecity, evolution, etc. We show that while high similarities exist
at the functional gene level, several contrasting features for other
characteristics are hallmarks of these two human malaria parasites.

36: Pediatr Infect Dis J. 2009 Jul;28(7):644-646.

PEDIATRIC AND ADOLESCENT IMPORTED MALARIA IN CAPE TOWN.

Gray TC, Cooke ML, Rabie H, Kidd M, Cotton MF.

From the *Department of Pediatrics and Child Health, Faculty of Health Sciences,
Stellenbosch University, Cape Town, South Africa; and daggerDepartment of
Statistics and Actuarial Sciences Centre for Statistical Consultation,
Stellenbosch University, Cape Town, South Africa.

We reviewed 42 cases of pediatric and adolescent imported malaria in Cape Town.
Patients were predominantly new and returned immigrants from other African
countries. Rapid diagnosis occurred in most cases. Eleven of 42 (26%) had severe
malaria. Management issues included delay to and inappropriate treatment,
inadequate monitoring for hypoglycemia, and under notification to health
authorities.

37: Pediatr Infect Dis J. 2009 Jun 22. [Epub ahead of print]

Protocol for Management of Imported Pediatric Malaria Decreases Time to
Medication Administration.

Goldfarb DM, Gaboury I, Dayneka N, Le Saux N.

From the *Division of infectious Disease, Children’s Hospital of Eastern Ontario,
Ottawa, Ontario; daggerFaculty of Medicine, University of Ottawa, Ottawa,
Ontario; and double daggerDepartment of Community Health Sciences, University of
Calgary, Calgary, Alberta.

BACKGROUND:: A malaria management protocol was developed and implemented at a
tertiary care children’s hospital in September 1999. We retrospectively evaluated
children admitted with malaria 10-years preimplementation and 7-years
postimplementation to determine the impact the protocol had on management and
time delay to appropriate antimalarial therapy. METHODS:: This before and after
study compared all admissions with the discharge diagnosis of malaria in the
study period. Retrospective chart review was used to determine the time from
emergency department (ED) registration to administration of antimalarial
treatment. Other outcomes measured included mortality, length of hospital stay,
and intensive care unit admission. RESULTS:: Fifty-eight admissions were
identified during the defined period, most of which were due to Plasmodium
falciparum[r] malaria. Thirty-one (53.4%) cases were before implementation of the
protocol. Children were more likely to receive appropriate investigations to
assess for possible severe malaria before transfer from the ED to the ward after
protocol implementation (18% vs. 63%, P = 0.005). Analysis of index cases of
malaria, excluding patients diagnosed after the diagnosis of a sibling, showed
there was a significant reduction in time to medication administration (8 vs. 5.5
hours, P = 0.036). CONCLUSION:: After broad-based implementation of a malaria
treatment protocol in a pediatric hospital, children received more thorough
investigations, were more likely to receive therapy before leaving the ED and had
a shorter delay before receiving appropriate antimalarial therapy.

38: Planta Med. 2009 Jun 23. [Epub ahead of print]

Overexpression of the HMG-CoA Reductase Gene Leads to Enhanced Artemisinin
Biosynthesis in Transgenic Artemisia annua Plants.

Aquil S, Husaini AM, Abdin MZ, Rather GM.

Centre for Transgenic Plant Development, Department of Biotechnology, Jamia
Hamdard, New Delhi, India.

An effective and affordable treatment against malaria is still a challenge for
medicine. Most contemporary drugs either are too expensive to produce or are not
effective against resistant strains of the malaria parasite PLASMODIUM
FALCIPARUM. The plant ARTEMISIA ANNUA L. is the source of artemisinin, an
effective drug against malaria for which no resistant strains of the bacterium
have been reported. However, the artemisinin content of A. ANNUA is very low,
which makes its production expensive. Here we report the use of transgenic
technology to increase the artemisinin content of A. ANNUA. We report the
production of transgenic plants of A. ANNUA into which we transferred
3-hydroxy-3-methylglutaryl CoA reductase ( HMGR) gene from CATHARANTHUS ROSEUS
(L.) G. Don using AGROBACTERIUM-mediated gene transfer technology. Transgene
integration and copy number were assessed by PCR and Southern hybridization,
which confirmed the stable integration of multiple copies of the transgene in 7
different transgenic lines of A. ANNUA. The leaf tissue of three of the A. ANNUA
transgenic lines possessed significantly higher HMGR activity compared with
wild-type controls, and this activity was associated exclusively with microsomal
membranes. The artemisinin content of the shoots of one of the transgenic lines
depicted an increase of 22.5 % artemisinin content compared with wild-type
control A. ANNUA plants.

39: Planta Med. 2009 Jun 23. [Epub ahead of print]

Isolation and Identification of Novel Genes Involved in Artemisinin Production
from Flowers of Artemisia annua Using Suppression Subtractive Hybridization and
Metabolite Analysis.

Liu S, Tian N, Li J, Huang J, Liu Z.

Natural Products Research Center, Hunan Agricultural University, Changsha, P. R.
China.

Malaria is a global health problem that threatens 300-500 million people and
kills more than one million people annually. Artemisinin is highly effective
against multidrug-resistant PLASMODIUM FALCIPARUM and it has been widely used as
part of the artemisinin-based combination therapies against malaria. To elucidate
the biosynthetic pathway of artemisinin and to clone related genes in ARTEMISIA
ANNUA, differentially expressed genes between blooming flowers and flower buds
were isolated and characterized by a combined approach of suppression subtractive
hybridization (SSH) and metabolite analysis. A total of 350 cDNA clones from a
subtractive cDNA library were randomly picked, sequenced and analyzed and 253
high-quality sequences were obtained. BLASTX comparisons indicated that about 9.9
% of the clones encoded enzymes involved in isoprenoid (including artemisinin)
biosynthesis. The expression of 4 gene transcripts involved in artemisinin
biosynthesis was examined by RT-PCR and the results confirmed the higher
expression of these transcripts in blooming flowers than in flower buds. In
addition, 2 putative transcript factors transparenta testa glabra 1 (TTG1) and
ENHANCER OF GLABRA3 (GL3), which promote trichome initiation, were presented in
the library. Finally, this study demonstrated that the increase of expression
level of the putative TTG1 gene correlated with the improvement of glandular
trichome density and artemisinin production in A. ANNUA leaves. The subtractive
cDNA library described in the present study provides important candidate genes
for future research in order to increase the artemisinin content in A. ANNUA.

40: Planta Med. 2009 Jun 22. [Epub ahead of print]

Secondary Metabolic Profiling and Artemisinin Biosynthesis of Two Genotypes of
Artemisia annua.

Wang H, Ma C, Ma L, Du Z, Wang H, Ye H, Li G, Liu B, Xu G.

Key Laboratory of Photosynthesis and Environmental Molecular Physiology,
Institute of Botany, the Chinese Academy of Sciences, Beijing, P. R. China.

Artemisinin has been proven to be an effective antimalarial compound, especially
for chloroquine-resistant and cerebral malaria. However, its biosynthesis pathway
is still not completely clear. In order to get new clues about artemisinin
biosynthesis, metabolic profiling by gas chromatography (GC) and gas
chromatography-mass spectrometry (GC-MS) was applied to compare the secondary
metabolites of two ARTEMISIA ANNUA L., genotype SP18 and 001, for some phenotypic
and agricultural trait differences, including artemisinin content, existed
between the two genotypes. Samples at 7 time points of three growth stages were
studied. The data of profiles were subjected to multivariate analysis with
partial least squares discriminant analysis (PLS-DA). The results indicated that
there were clear differences in terpenoids and artemisinin metabolism between
different growth stages and genotypes. Twenty-one compounds, including
artemisinin and its related precursors, were selected as the marker compounds of
the PLS-DA between the two genotypes. Among them, artemisinic acid, arteannuin B,
borneol, beta-farnesene and an unidentified sesquiterpenoid (peak 48) were
abundant in 001, while camphor, methyl artemisinic acid and lanceol accumulated
mainly in SP18. The relationship between these differences and artemisinin
biosynthesis in the two genotypes of A. ANNUA were discussed.

41: PLoS Negl Trop Dis. 2009 Jun 16;3(6):e459.

A Combined CXCL10, CXCL8 and H-FABP Panel for the Staging of Human African
Trypanosomiasis Patients.

Hainard A, Tiberti N, Robin X, Lejon V, Ngoyi DM, Matovu E, Enyaru JC, Fouda C,
Ndung’u JM, Lisacek F, Müller M, Turck N, Sanchez JC.

Biomedical Proteomics Research Group, Medical University Centre, Geneva,
Switzerland.

BACKGROUND: Human African trypanosomiasis (HAT), also known as sleeping sickness,
is a parasitic tropical disease. It progresses from the first, haemolymphatic
stage to a neurological second stage due to invasion of parasites into the
central nervous system (CNS). As treatment depends on the stage of disease, there
is a critical need for tools that efficiently discriminate the two stages of HAT.
We hypothesized that markers of brain damage discovered by proteomic strategies
and inflammation-related proteins could individually or in combination indicate
the CNS invasion by the parasite. METHODS: Cerebrospinal fluid (CSF) originated
from parasitologically confirmed Trypanosoma brucei gambiense patients. Patients
were staged on the basis of CSF white blood cell (WBC) count and presence of
parasites in CSF. One hundred samples were analysed: 21 from stage 1 (no
trypanosomes in CSF and 5 WBC/microL) patients. The concentration of H-FABP, GSTP-1 and S100beta
in CSF was measured by ELISA. The levels of thirteen inflammation-related
proteins (IL-1ra, IL-1beta, IL-6, IL-9, IL-10, G-CSF, VEGF, IFN-gamma, TNF-alpha,
CCL2, CCL4, CXCL8 and CXCL10) were determined by bead suspension arrays. RESULTS:
CXCL10 most accurately distinguished stage 1 and stage 2 patients, with a
sensitivity of 84% and specificity of 100%. Rule Induction Like (RIL) analysis
defined a panel characterized by CXCL10, CXCL8 and H-FABP that improved the
detection of stage 2 patients to 97% sensitivity and 100% specificity.
CONCLUSION: This study highlights the value of CXCL10 as a single biomarker for
staging T. b. gambiense-infected HAT patients. Further combination of CXCL10 with
H-FABP and CXCL8 results in a panel that efficiently rules in stage 2 HAT
patients. As these molecules could potentially be markers of other CNS infections
and disorders, these results should be validated in a larger multi-centric cohort
including other inflammatory diseases such as cerebral malaria and active
tuberculosis.

42: PLoS One. 2009 Jun 29;4(6):e6083.

Rapid assessment of malaria transmission using age-specific sero-conversion
rates.

Stewart L, Gosling R, Griffin J, Gesase S, Campo J, Hashim R, Masika P, Mosha J,
Bousema T, Shekalaghe S, Cook J, Corran P, Ghani A, Riley EM, Drakeley C.

Department of Infectious and Tropical Diseases, London School of Hygiene and
Tropical Medicine, London, UK.

BACKGROUND: Malaria transmission intensity is a crucial determinant of malarial
disease burden and its measurement can help to define health priorities. Rapid,
local estimates of transmission are required to focus resources better but
current entomological and parasitological methods for estimating transmission
intensity are limited in this respect. An alternative is determination of
antimalarial antibody age-specific sero-prevalence to estimate sero-conversion
rates (SCR), which have been shown to correlate with transmission intensity. This
study evaluated SCR generated from samples collected from health facility
attendees as a tool for a rapid assessment of malaria transmission intensity.
METHODOLOGY AND PRINCIPAL FINDINGS: The study was conducted in north east
Tanzania. Antibodies to Plasmodium falciparum merozoite antigens MSP-1(19) and
AMA-1 were measured by indirect ELISA. Age-specific antibody prevalence was
analysed using a catalytic conversion model based on maximum likelihood to
generate SCR. A pilot study, conducted near Moshi, found SCRs for AMA-1 were
highly comparable between samples collected from individuals in a conventional
cross-sectional survey and those collected from attendees at a local health
facility. For the main study, 3885 individuals attending village health
facilities in Korogwe and Same districts were recruited. Both malaria parasite
prevalence and sero-positivity were higher in Korogwe than in Same. MSP-1(19) and
AMA-1 SCR rates for Korogwe villages ranged from 0.03 to 0.06 and 0.07 to 0.21
respectively. In Same district there was evidence of a recent reduction in
transmission, with SCR among those born since 1998 [MSP-1(19) 0.002 to 0.008 and
AMA-1 0.005 to 0.014 ] being 5 to 10 fold lower than among individuals born prior
to 1998 [MSP-1(19) 0.02 to 0.04 and AMA-1 0.04 to 0.13]. Current health facility
specific estimates of SCR showed good correlations with malaria incidence rates
in infants in a contemporaneous clinical trial (MSP-1(19) r(2) = 0.78, p<0.01 &
AMA-1 r(2) = 0.91, p<0.001). CONCLUSIONS: SCRs generated from age-specific
anti-malarial antibody prevalence data collected via health facility surveys were
robust and credible. Analysis of SCR allowed detection of a recent drop in
malaria transmission in line with recent data from other areas in the region.
This health facility-based approach represents a potential tool for rapid
assessment of recent trends in malaria transmission intensity, generating
valuable data for local and national malaria control programs to target, monitor
and evaluate their control strategies.

43: PLoS One. 2009 Jun 23;4(6):e6004.

Histamine H(3) receptor-mediated signaling protects mice from cerebral malaria.

Beghdadi W, Porcherie A, Schneider BS, Morisset S, Dubayle D, Peronet R, Dy M,
Louis J, Arrang JM, Mécheri S.

Unité des Réponses Précoces aux Parasites et Immunopathologie, Institut Pasteur,
Paris, France.

BACKGROUND: Histamine is a biogenic amine that has been shown to contribute to
several pathological conditions, such as allergic conditions, experimental
encephalomyelitis, and malaria. In humans, as well as in murine models of
malaria, increased plasma levels of histamine are associated with severity of
infection. We reported recently that histamine plays a critical role in the
pathogenesis of experimental cerebral malaria (CM) in mice infected with
Plasmodium berghei ANKA. Histamine exerts its biological effects through four
different receptors designated H1R, H2R, H3R, and H4R. PRINCIPAL FINDINGS: In the
present work, we explored the role of histamine signaling via the histamine H3
receptor (H3R) in the pathogenesis of murine CM. We observed that the lack of H3R
expression (H3R(-/-) mice) accelerates the onset of CM and this was correlated
with enhanced brain pathology and earlier and more pronounced loss of blood brain
barrier integrity than in wild type mice. Additionally tele-methylhistamine, the
major histamine metabolite in the brain, that was initially present at a higher
level in the brain of H3R(-/-) mice was depleted more quickly post-infection in
H3R(-/-) mice as compared to wild-type counterparts. CONCLUSIONS: Our data
suggest that histamine regulation through the H3R in the brain suppresses the
development of CM. Thus modulating histamine signaling in the central nervous
system, in combination with standard therapies, may represent a novel strategy to
reduce the risk of progression to cerebral malaria.

44: Trop Med Int Health. 2009 Jun 22. [Epub ahead of print]

Intermittent preventive treatment of malaria in infants: how does it work and
where will it work?

Gosling RD, Carneiro I, Chandramohan D.

London School of Hygiene & Tropical Medicine, UK.

Summary We discuss the potential public health impact of IPTi by estimating the
cases of malaria, anaemia and hospital admissions likely to be averted in
different transmission settings; and we review the mechanism of action, choice of
drugs regimens, and the effect on immunity of IPTi. IPTi using an efficacious
drug is likely to substantially reduce cases of clinical malaria in moderate to
high transmission settings. However, geographical heterogeneity in malaria
transmission could hamper rolling out IPTi as a national policy.

45: Trop Med Int Health. 2009 Jun 22. [Epub ahead of print]

Severe malaria and concomitant bacteraemia in children admitted to a rural
Mozambican hospital.

Bassat Q, Guinovart C, Sigaúque B, Mandomando I, Aide P, Sacarlal J, Nhampossa T,
Bardají A, Morais L, Machevo S, Letang E, Macete E, Aponte JJ, Roca A, Menéndez
C, Alonso PL.

Barcelona Center for International Health Research, University of Barcelona,
Spain.

Objectives To describe the prevalence, aetiology and prognostic implications of
coexisting invasive bacterial disease in children admitted with severe malaria in
a rural Mozambican Hospital. Methods Retrospective study of data systematically
collected from June 2003 to May 2007 in a rural Mozambican hospital, from all
children younger than 5 years admitted with severe malaria. Results Seven
thousand and forty-three children were admitted with a diagnosis of malaria.
25.2% fulfilled the criteria for severe malaria. 5.4% of the children with severe
malaria and valid blood culture results had a concomitant bacteraemia. Case
fatality rates of severe malaria cases rose steeply when bacteraemia was also
present (from 4.0% to 22.0%, P < 0.0001), and bacteraemia was an independent risk
factor for death among severe malaria patients (adjusted OR 6.2, 95% CI 2.8-13.7,
P = 0.0001). Streptococcus pneumoniae, Gram-negative bacteria, Staphilococcus
aureus and non-typhoid Salmonella (NTS) were the most frequently isolated
microorganisms among severe malaria cases. Their frequency and associated case
fatality rates (CFR) varied according to age and to syndromic presentation.
Streptococcus pneumoniae had a relatively low CFR, but was consistently
associated with severe malaria syndromes, or anaemia severity groups. No
clear-cut relationship between malarial anaemia and NTS bacteraemia was found.
Conclusions The coexistence of malaria and invasive bacterial infections is a
frequent and life-threatening condition in many endemic African settings. In
Mozambique, S. pneumoniae is the leading pathogen in this interaction, possibly
as a consequence of the high HIV prevalence in the area. Measures directed at
reducing the burden of both those infections are urgently needed to reduce child
mortality in Africa.

46: Trop Med Int Health. 2009 Jun 22. [Epub ahead of print]

Adherence to artesunate-amodiaquine combination therapy for uncomplicated malaria
in children in Zanzibar, Tanzania.

Beer N, Ali AS, Rotllant G, Abass AK, Omari RS, Al-Mafazy AW, Björkman A,
Källander K.

Division of International Health (IHCAR), Department of Public Health Sciences,
Karolinska Institutet, Stockholm, Sweden.

Summary Objectives To estimate caretaker adherence to co-blistered, but not
co-formulated, artesunate-amodiaquine (AsAq) for uncomplicated malaria and
identify factors associated with caretaker adherence. Methods Cross sectional
household survey of caretakers of 210 children under 5 years of age who had been
prescribed and dispensed AsAq at 21 public health facilities (HFs). The
caretakers were interviewed in their homes on the 4th day of receiving the 3 day
treatment. Adherence of caretakers was assessed by self report and pill count.
Results Caretaker adherence to AsAq was 77% (95% CI: 67%-87%). Non-adherence
resulted in under-dosing (3/4) of the time and was most often in the form of
wrong daily doses due to misunderstanding or forgetting the correct dose
regimens. Predictors of adherence were education exceeding 7 years (OR = 5.08, P
= 0.008) and receiving the exact number of pills to complete the treatment
regimen (OR = 4.09, P = 0.006). All caretakers of children who were administered
the first dose at the HF had adhered to the treatment. Conclusion We found
moderate levels of caretaker adherence to AsAq. Further improvement could be
achieved by producing dose-specific packaging for infants, providing clear
instructions and giving the first dose under observation at the HF.

47: Vaccine. 2009 Jun 19. [Epub ahead of print]

Age-dependent systemic antibody responses and immunisation-associated changes in
mice orally and nasally immunised with Lactococcus lactis expressing a malaria
parasite protein.

Moorthy SA, Yasawardena SG, Ramasamy R.

National Science Foundation, Sri Lanka.

Gram positive food-grade bacteria such as lactococci have significant advantages
over attenuated pathogens as vaccine delivery vehicles because of their
inherently greater safety. Plasmodium falciparum merozoite surface antigen 2
(MSA2) was expressed in recombinant Lactococcus lactis both intracellularly and
covalently anchored to the peptidoglycan of the cell wall (MSA2cP). Balb/c mice
of different ages were immunised with the MSA2cP expressing L. lactis in a
combined oral and nasal immunisation procedure. Serum IgG antibody responses to
MSA2 were higher in young adult Balb/c mice compared to old mice and neonates.
The elicited serum IgG antibodies reacted with native MSA2 on the surface of P.
falciparum merozoites in an immunofluorescence assay. The serum IgG antibody
isotypes in young adult mice were mainly IgG1, IgG2a and IgG2b, while IgG3 tended
to be higher in old mice. IgA antibodies to MSA2 were also produced in young
mice. Enlarged mesenteric lymph nodes, and more prominent lymphoid tissue in the
lamina propria of the ileum and lymphoid follicles in the spleen, were observed
in mice fed L. lactis. These findings are relevant for developing L. lactis as a
vector to deliver vaccines in human populations.

1: Acta Trop. 2009 Jun 1.

In vitro antimalarial interactions between mefloquine and cytochrome P450
inhibitors.

Wisedpanichkij R, Chaijaroenkul W, Sangsuwan P, Tantisawat J, Boonprasert K,
Na-Bangchang K.

Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences,
Thammasat University.

The treatment and control of malaria is becoming increasingly difficult due to
resistance of Plasmodium falciparum strains resistance to commonly used
antimalarials. Combination therapy is currently the strategy for combating
multi-drug resistant falciparum malaria, through exploiting phamacodynamic
synergistic effect and delaying the emergence of drug resistance. The objective
of the present study was to investigate antimalarial activity of inhibitors of
cytochrome P450 (CYP) enzyme including their interactions with the antimalarial
mefloquine against chloroquine resistant (K1) and chloroquine sensitive (3D7) P.
falciparum clones in vitro. Results showed IC(50) (drug concentration which
produces 50% schizont maturation inhibition) values [mean (range)] of mefloquine
against K1 and 3D7 clones to be 8.6 (8.0-9.3) and 12.1 (10.5-13.8) nM,
respectively. The corresponding values for the IC(50) of quinidine were 32.2
(31.9-32.5) and 28.7 (28.4-29.0) nM, and for ketoconazole were 3.9 (3.7-4.1) and
4.8 (4.6-5.1) muM, respectively. Analysis of isobologram revealed a trend of
decreasing of fraction IC(50) (FIC), which indicates synergistics of the either
quinidine or ketoconazole with mefloquine for both chloroquine resistant and
chloroquine sensitive clones.

2: Acta Trop. 2009 Jun 1. [Epub ahead of print]

Malaria severity status in patients with soil-transmitted helminth infections.

Degarege A, Animut A, Legesse M, Erko B.

Bahir Dar University, P. O. Box 79, Bahir Dar, Ethiopia.

OBJECTIVE: To investigate the possible impact of soil-transmitted helminth (STH)
infection on malaria severity, level of parasitaemia and clearance/reduction of
Plasmodium parasites following treatment with antimalarial drugs METHODS: 458
voluntary malaria patients who visited the Alaba Kulito Health Center, southern
Ethiopia, for medical treatment in November and December 2007 were included in
this study. Giemsa-stained thick and thin blood films were used for determination
of parasitaemia and identification of Plasmodium species, respectively. Stool
sample was collected from these patients and diagnosed for intestinal helminths
using Kato-Katz technique. Haemoglobin concentration was measured using a
portable spectrophotometer (HemoCue HB 201). Malaria parasite clearance was
checked on day 3 post-treatment. FINDINGS: The prevalence of co-infection of
malaria with the major soil-transmitted helminths (STHs), i.e., with hookworm
species, Ascaris lumbricoides and Trichuris trichiura was 9.6%, 6.3% and 2.1%,
respectively. About 8.1% of the study subjects had severe malaria. Intensity of
hookworm infection showed positive association with malaria parasite densities
(F=3.510, P=0.033). STHs infection in general was negatively correlated with the
symptoms of severe malaria (OR=0.317, 95% CI=0.315-0.86, P=0.01), but a small
proportion (4.5%) of malaria patients who were concurrently harboring one or more
intestinal helminths had severe malaria. Only few malaria patients (2.3%)
co-infected with STHs were found positive for Plasmodium parasites on day 3 post
treatment. CONCLUSION: The present findings indicate that soil-transmitted
helminths have very little contribution to malaria severity in co-infected
individuals. The findings also indicate that STHs do not have significant impact
on clearance rate of Plasmodium falciparum and P. vivax when treated with
antimalarial drugs.

3: Acta Trop. 2009 May 29.

Evaluation of the performance of CareStart Malaria Pf/Pv Combo and Paracheck
Pf((R)) tests for the diagnosis of malaria in Wondo Genet, southern Ethiopia.

Bekele Sharew, Mengistu Legesse, Abebe Animut, Daddi Jima, Girmay Medhin, Berhanu
Erko.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176,
Addis Ababa, Ethiopia.

OBJECTIVE: To evaluate the diagnostic performance of CareStart Malaria Pf/Pv
Combo test relative to microscopy for the diagnosis of falciparum and vivax
malaria in Ethiopia. METHODS: 668 febrile patients visiting two health centers in
Wondo Genet, southern Ethiopia, involved in this study in 2008. Giemsa-stained
thin and thick blood smears were prepared and microscopically examined under a
100x oil immersion microscope objective for Plasmodium species identification and
determination of parasitaemia, respectively. CareStart Malaria Pf/Pv Combo test
and Paracheck Pf((R)) test were performed as per the manufacturers’ instruction.
FINDINGS: The diagnostic validity of CareStart Malaria Pf/Pv Combo test for the
diagnosis of Plasmodium falciparum were very good with sensitivity of 99.4%,
specificity of 98%, positive predictive value of 94.4% and negative predictive
value of 99.8%. Sensitivity, specificity, positive predictive value and negative
predictive value of the test for the diagnosis of P. vivax were 99.4%, 98.2%,
94.5% and 99.8%, respectively. The diagnostic performance of CareStart Malaria
Pf/Pv Combo test is comparable to that of Paracheck Pf((R)) test for the
diagnosis of P. falciparum (sensitivity 99.4%, specificity 98.2%). CONCLUSION:
Although CareStart Malaria Pf/Pv Combo test and Paracheck Pf((R)) test have
comparable diagnostic performance for the diagnosis of P. falciparum, CareStart
Malaria Pf/Pv Combo test has the added advantage of diagnosing P. vivax. Hence,
it is preferable to use CareStart Malaria Pf/Pv Combo test for the diagnosis of
malaria in areas where microscopy is not accessible and where malaria due to P.
falciparum and P. vivax are co-endemic as in Ethiopia.

4: Acta Trop. 2009 May 29. [Epub ahead of print]

IgG subclasses pattern and high-avidity antibody to the C-terminal region of
merozoite surface protein 1 of Plasmodium vivax in an unstable hypoendemic region
in Iran.

Mehrizi AA, Zakeri S, Salmanian AH, Sanati MH, Djadid ND.

Malaria and Vector Research Group (MVRG), Biotechnology Research Center, Pasteur
Institute of Iran, Pasteur Avenue, P.O. Box 1316943551, Tehran, Iran; National
Research Center for Genetic Engineering and Biotechnology, Tehran, Iran.

The C-terminal region of Plasmodium vivax merozoite surface protein 1
(PvMSP-1(19)) is a leading vaccine candidate for inclusion in a polyvalent
malaria vaccine. In the present study, the IgG subclasses profile and the avidity
of IgG to PvMSP-1(19) were evaluated in individuals (n=94) naturally exposed to
P. vivax parasite in malaria endemic areas in Chabahar districts, Iran. In
individuals with patent P. vivax malaria, 86.1% was sero-positive to PvMSP-1(19)
and IgG1 (81.9%) was the predominant subclass. In addition, to determine the
persistence of specific IgG, IgG1 and IgG3 antibodies to PvMSP-1(19), the
frequency of antibodies was determined in the infected subjects (n=74) after
treatment with standard chloroquine and it was detected that the frequency of
responders was significantly reduced to 51.3%, 51% and 16.2%, respectively. The
antigen-binding avidity of IgG antibodies to PvMSP-1(19) was measured in
sero-positive sera and the high-avidity of IgG, IgG1 and IgG3 was found in 66.6%,
61% and 47% of the infected subjects with P. vivax, respectively. The present
result shows that individuals who exposed to vivax malaria in the endemic region
in Iran develop antibodies with high-avidity to PvMSP-1(19). These results could
help to understand the interactions between the host and P. vivax parasite in
development of MSP-1(19)-based vaccine.

5: Acta Trop. 2009 May 28. [Epub ahead of print]

Erythrocyte invasion and functionally inhibitory antibodies in Plasmodium
falciparum malaria.

Persson KE.

Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobels
väg 16, SE-17177 Stockholm, Sweden.

Malaria is a disease that kills several million people every year. P. falciparum
merozoites invade new erythrocytes every 48hours, causing fever, anemia and
cerebral malaria. Effective immunity against malaria develops slowly and only
after repeated exposure. Antibodies are an important part of this immunity.
However, the antigens that mediate immunity by inducing functionally imperative
antibodies have not yet been identified. This review gives an overview of the
erythrocyte invasion process, which has been described to include several
different antigens. Invasion inhibitory antibodies can inhibit merozoite
penetration of new erythrocytes, and different methods for measurement of the
presence of functionally important antibodies have been employed. ELISA, Invasion
inhibition assays and ADCI are some of the methods discussed.

6: Antimicrob Agents Chemother. 2009 Jun 8. [Epub ahead of print]

Evaluation of Artemisone Combinations in Aotus Monkeys infected with Plasmodium
falciparum.

Obaldia N 3rd, Kotecka BM, Edstein MD, Haynes RK, Fugmann B, Kyle DE, Rieckmann
KH.

Tropical Medicine Research, Malaria Drug and Vaccine Evaluation Center/Gorgas
Memorial Institute of Health Studies, Panama, Panama; Australian Army Malaria
Institute, Brisbane, Australia; The Hong Kong University of Science and
Technology, Kowloon, Hong Kong; and Bayer Innovation, Düsseldorf, Germany.

Artemisone (single oral dose, 10 mg/kg) cured non-immune Aotus monkeys of their
Plasmodium falciparum infections when combined with mefloquine (single oral dose,
5 and 10 mg/kg, but not 2.5 mg/kg). In combination with amodiaquine (20
mg/kg/day), artemisone (10 mg/kg/day) given orally for 3 days cured all infected
monkeys. 3-days treatment with artemisone (30 mg/kg/day) and clindamycin (100
mg/kg/day) was also curative.

7: Antimicrob Agents Chemother. 2009 Jun 1. [Epub ahead of print]

Stability of peroxide antimalarials in the presence of human hemoglobin.

Creek DJ, Ryan E, Charman WN, Chiu FC, Prankerd RJ, Vennerstrom JL, Charman SA.

Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical
Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville,
Victoria 3052, AUSTRALIA; College of Pharmacy, University of Nebraska Medical
Centre, Omaha, NE 68198, USA.

Peroxide antimalarials, including artemisinin, are important for the treatment of
multi-drug resistant malaria. These peroxides are known to react with iron or
heme to produce reactive intermediates that are thought to be responsible for
their antimalarial activity. This study investigated the potential interaction of
selected peroxide antimalarials with oxyhemoglobin, the most abundant form of
iron in the human body. The observed stability of artemisinin derivatives and
1,2,4-trioxolanes in the presence of oxyhemoglobin was in contrast to previous
reports in the literature. Spectroscopic analysis of hemoglobin found it to be
unstable under the conditions used for previous studies, and it appears likely
that artemisinin reactivity reported in these studies may be attributed to free
heme released by protein denaturation. The stability of peroxide antimalarials
with intact oxyhemoglobin, and reactivity with free heme, may explain the
selective toxicity of these antimalarials towards infected, but not healthy,
erythrocytes.

8: Curr Opin Immunol. 2009 Jun 1. [Epub ahead of print]

Immune evasion by malaria parasites: a challenge for vaccine development.

Casares S, Richie TL.

US Military Malaria Vaccine Program, Infectious Diseases Directorate, Naval
Medical Research Center/Walter Reed Army Institute of Research. 503 Robert Grant
Avenue, Silver Spring, MD, United States.

Malaria is a deadly infectious disease that affects one to two billion people and
kills up to one million children yearly. Despite decades of intensive research,
we are still lacking an effective vaccine against malaria. Our efforts are being
challenged by the complexity of Plasmodium’s life cycle, its ability to
parasitize and hide within the host cells, and its masterful ability to avoid
clearance by the innate and adaptive host immune responses. In this article we
will review the main mechanisms of immune evasion used by malaria parasites and
discuss the implications for malaria vaccine development.

9: Int J Parasitol. 2009 Jun 5. [Epub ahead of print]

Plant-like phosphofructokinase from Plasmodium falciparum belongs to a novel
class of ATP-dependent enzymes.

Mony BM, Mehta M, Jarori GK, Sharma S.

Department of Biological Sciences, Tata Institute of Fundamental Research, Homi
Bhabha Road, Mumbai – 400 005, India.

Malaria parasite-infected erythrocytes exhibit enhanced glucose utilization and
6-phospho-1-fructokinase (PFK) is a key enzyme in glycolysis. Here we present the
characterization of PFK from the human malaria parasite Plasmodium falciparum. Of
the two putative PFK-genes on chromosome 9 (PfPFK9) and 11 (PfPFK11), only the
PfPFK9 gene appeared to possess all the catalytic features appropriate for PFK
activity. The deduced PfPFK proteins contain domains homologous to the plant-like
pyrophosphate (PPi)-dependent PFK beta and alpha subunits, which are quite
different from the human erythrocyte PFK protein. The PfPFK9 gene beta and alpha
regions were cloned and expressed as His(6)- and GST-tagged proteins in
Escherichia coli. Complementation of PFK-deficient E. coli and activity analysis
of purified recombinant proteins confirmed that PfPFK9beta possessed catalytic
activity. Monoclonal antibodies against the recombinant beta protein confirmed
that the PfPFK9 protein has beta and alpha domains fused into a 200 kDa protein,
as opposed to the independent subunits found in plants. Despite an overall
structural similarity to plant PPi-PFKs, the recombinant protein and the parasite
extract exhibited only ATP-dependent enzyme activity, and none with PPi. Unlike
host PFK, the Plasmodium PFK was insensitive to fructose-2,6-bisphosphate
(F-2,6-bP), phosphoenolpyruvate (PEP) and citrate. A comparison of the deduced
PFK proteins from several protozoan PFK genome databases implicates a unique
class of ATP-dependent PFK present amongst the apicomplexan protozoans.

10: Int J Parasitol. 2009 Jun 5. [Epub ahead of print]

Malaria vectors of Papua New Guinea.

Cooper RD, Waterson DG, Frances SP, Beebe NW, Pluess B, Sweeney AW.

Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, Queensland,
4052, Australia.

Understanding malaria transmission in Papua New Guinea (PNG) requires exact
knowledge of which Anopheles species are transmitting malaria and is complicated
by the cryptic species status of many of these mosquitoes. To identify the
malaria vectors in PNG we studied Anopheles specimens from 232 collection
localities around human habitation throughout PNG (using CO(2)baited light traps
and human bait collections). A total of 22,970 mosquitoes were individually
assessed using a Plasmodium sporozoite enzyme-linked immunosorbent assay to
identify Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae
circumsporozoite proteins. All mosquitoes were identified to species by
morphology and/or PCR. Based on distribution, abundance and their ability to
develop sporozoites, we identified five species as major vectors of malaria in
PNG. These included: Anopheles farauti, Anopheles hinesorum (incriminated here,
to our knowledge, for the first time), Anopheles farauti 4, Anopheles koliensis
and Anopheles punctulatus. Anopheles longirostris and Anopheles bancroftii were
also incriminated in this study. Surprisingly, An. longirostris showed a high
incidence of infections in some areas. A newly identified taxon within the
Punctulatus Group, tentatively called An. farauti 8, was also found positive for
circumsporozoite protein. These latter three species, together with Anopheles
karwari and Anopheles subpictus, incriminated in other studies, appear to be only
minor vectors, while Anopheles farauti 6 appears to be the major vector in the
highland river valleys (>1500 m above sea level). The nine remaining Anopheles
species found in PNG have been little studied and their bionomics are unknown;
most appear to be uncommon with limited distribution and their possible role in
malaria transmission has yet to be determined.

11: J Clin Virol. 2009 Jun 3. [Epub ahead of print]

Sensitivity of human herpesvirus 6 and other human herpesviruses to the
broad-spectrum antiinfective drug artesunate.

Milbradt J, Auerochs S, Korn K, Marschall M.

Institute for Clinical and Molecular Virology, Medical Center Erlangen,
University of Erlangen-Nuremberg, Germany.

BACKGROUND: Antiviral therapy for HHV-6 infection with conventional
anti-herpesviral drugs is problematic so novel drugs are required. Artesunate is
a well-tolerated drug approved for malaria therapy which possesses antiviral
activity. OBJECTIVE: The artesunate sensitivity of HHV-6 was analyzed and
compared to that of several other human herpesviruses. STUDY DESIGN: Cultured
human cells were productively infected with strains of HHV-6 or other human
herpesviruses to measure artesunate inhibition of viral protein synthesis
(Western blot analysis) or viral genome replication (qPCR), and to determine
IC(50) values by immunofluorescence or plaque reduction assays. RESULTS:
Sensitivity of HHV-6 to artesunate was demonstrated with an IC(50) of
3.80+/-1.06muM. This is in a range similar to IC(50) values for HCMV and EBV.
Artesunate treatment of HHV-6-infected cells significantly reduced viral early
and late protein synthesis that occurred in the absence of drug-induced apoptosis
or necrotic cytotoxicity. HHV-6A genome replication was markedly reduced by
artesunate. CONCLUSIONS: Artesunate possesses anti-HHV-6 activity in vitro and
may be useful for treatment of HHV-6 infections.

12: J Ethnopharmacol. 2009 Jun 25;123(3):413-22.

Medicinal plants from the Yanesha (Peru): evaluation of the leishmanicidal and
antimalarial activity of selected extracts.

Valadeau C, Pabon A, Deharo E, Albán-Castillo J, Estevez Y, Lores FA, Rojas R,
Gamboa D, Sauvain M, Castillo D, Bourdy G.

IFEA UMIFRE 17 CNRS/MAEE, Casilla 18-1217, Lima, Peru.

AIM OF THE STUDY: Ninety-four ethanolic extracts of plants used medicinally by
the Yanesha, an Amazonian Peruvian ethnic group, for affections related to
leishmaniasis and malaria were screened in vitro against Leishmania amazonensis
amastigotes and against a Plasmodium falciparum chloroquine resistant strain.
MATERIALS AND METHODS: The viability of Leishmania amazonensis amastigote stages
was assessed by the reduction of tetrazolium salt (MTT) while the impact on
Plasmodium falciparum was determined by measuring the incorporation of
radio-labelled hypoxanthine. RESULTS AND CONCLUSIONS: Six plant species displayed
good activity against Plasmodium falciparum chloroquine resistant strain (IC(50)
< 10 microg/ml): a Monimiaceae, Siparuna aspera (Ruiz & Pavon), A. DC., two
Zingiberaceae, Renealmia thyrsoidea (Ruiz & Pavon) Poepp. & Endl. and Renealmia
alpinia (Rottb.), two Piperaceae (Piper aduncum L. and Piper sp.) and the leaves
of Jacaranda copaia (Aubl.) D. Don (Bignoniaceae). Eight species displayed
interesting leishmanicidal activities (IC50 < 10 microg/ml): Carica papaya L.
(Caricaceae), Piper dennisii Trel (Piperaceae), Hedychium coronarium J. König
(Zingiberaceae), Cestrum racemosum Ruiz & Pav. (Solanaceae), Renealmia alpinia
(Rottb.) Zingiberaceae, Lantana sp. (Verbenaceae), Hyptis lacustris A. St.-Hil.
ex Benth. (Lamiaceae) and Calea montana Klat. (Asteraceae). Most of them are used
against skin affections by Yanesha people. Results are discussed herein,
according to the traditional use of the plants and compared with data obtained
from the literature.

13: J Ethnopharmacol. 2009 Jun 25;123(3):504-9. Epub 2009 Feb 14.

Anti-parasitic activity and cytotoxicity of selected medicinal plants from Kenya.

Kigondu EV, Rukunga GM, Keriko JM, Tonui WK, Gathirwa JW, Kirira PG, Irungu B,
Ingonga JM, Ndiege IO.

Institute of Tropical Medicine and Infectious Diseases (ITROMID), P.O. Box 54840,
Nairobi 00200, Kenya.

Indigenous rural communities in the tropics manage parasitic diseases, like
malaria and leishmaniasis, using herbal drugs. The efficacy, dosage, safety and
active principles of most of the herbal preparations are not known. Extracts from
6 selected plant species, used as medicinal plants by indigenous local
communities in Kenya, were screened for in vitro anti-plasmodial and
anti-leishmanial activity, against 2 laboratory-adapted Plasmodium falciparum
isolates (D6, CQ-sensitive and W2, CQ-resistant) and Leishmania major
(IDU/KE/83=NLB-144 strain), respectively. The methanol extract of Suregada
zanzibariensis leaves exhibited good anti-plasmodial activity (IC(50) 4.66+/-0.22
and 1.82+/-0.07 microg/ml for D6 and W2, respectively). Similarly, the methanol
extracts of Albizia coriaria (IC(50) 37.83+/-2.11 microg/ml for D6) and
Aspergillus racemosus (32.63+/-2.68 and 33.95+/-2.05 microg/ml for D6 and W2,
respectively) had moderate anti-plasmodial activity. Acacia tortilis (IC(50)
85.73+/-3.36 microg/ml for W2) and Albizia coriaria (IC(50) 71.17+/-3.58
microg/ml for W2) methanol extracts and Aloe nyeriensis var kedongensis (IC(50)
87.70+/-2.98 and 67.84+/-2.12 microg/ml for D6 and W2, respectively) water
extract exhibited mild anti-plasmodial activity. The rest of the extracts did not
exhibit any anti-plasmodial activity. Although the leishmanicidal activity of
extracts were lower than for pentosam (80%), reasonable activity was observed for
Aloe nyeriensis methanol (68.4+/-6.3%), Albizia coriara water (66.7+/-5.0%),
Maytenus putterlickoides methanol (60.0+/-6.23%), Asparagus racemosus methanol
and water (58.3+/-8.22 and 56.8+/-6.58%, respectively), Aloe nyeriensis water
(53.3+/-5.1%) and Acacia tortilis water (52.9+/-6.55%) extracts at 1000
microg/ml. Leishmania major infected macrophages treated with methanol extracts
of Suregada zanzibariensis and Aloe nyeriensis var kedongensis and pentostam had
infection rates of 28+/-2.11, 30+/-1.22 and 40+/-3.69%, respectively at 1000
microg/ml, indicating better anti-leishmanial activity for the extracts. The
methanol extract of Albizia coriara (44.0+/-3.69%) and aqueous extracts of
Asparagus racemosus (42+/-3.84%) and Acacia tortilis (44+/-5.59%) had similar
activity to pentosam. Multiplication indices for Leishmania major amastigotes
treated with methanol extracts of Albizia coriaria, Suregada zanzibariensis and
Aloe nyeriensis var kedongensis, aqueous extract of Acacia tortilis and pentosam
were 28.5+/-1.43, 29.4+/-2.15, 31.1+/-2.22, 35.9+/-3.49 and 44.0+/-3.27%,
respectively, at 1000 microg/ml, confirming better anti-leishmanial activity for
the extracts. Aqueous extracts of Aloe nyeriensis (46.7+/-3.28%) and Albizia
coriaria (47.5+/-3.21%) had similar activity level to pentosam. The plant
extracts have better inhibitory activity while pentosam has better leishmanicidal
activity. All extracts exhibited very low cytotoxicity (CC(50) > 500 microg/ml)
against human embryonic lung fibroblast (HELF) cells. The investigations
demonstrated the efficacy and safety of some extracts of plants that are used by
rural indigenous communities for the treatment of parasitic diseases.

14: J Infect Dis. 2009 Jun 5. [Epub ahead of print]

Antibodies to Variant Surface Antigens of Plasmodium falciparum-Infected
Erythrocytes Are Associated with Protection from Treatment Failure and the
Development of Anemia in Pregnancy.

Feng G, Aitken E, Yosaatmadja F, Kalilani L, Meshnick SR, Jaworowski A, Simpson
JA, Rogerson SJ.

Department of Medicine (Royal Melbourne Hospital/Western Hospital) and 2Centre
for Molecular, Environmental, Genetic, and Analytic Epidemiology, School of
Population Health, University of Melbourne, Parkville, 3Centre for Virology,
Burnet Institute, Melbourne, and 4Department of Medicine, Monash University,
Clayton, Victoria, Australia; 5College of Medicine, University of Malawi,
Blantyre, Malawi; 6Department of Epidemiology and Department of Microbiology and
Immunology, University of North Carolina, Chapel Hill.

Background. In pregnancy-associated malaria (PAM), Plasmodium falciparum-infected
erythrocytes (IEs) express variant surface antigens (VSA-PAM) that evade existing
immunity and mediate placental sequestration. Antibodies to VSA-PAM develop with
gravidity and block placental adhesion or opsonize IEs for phagocytic clearance,
helping to prevent maternal anemia and low birth weight in infants. Methods.
Using serum samples from 141 pregnant Malawian women with parasitemia enrolled in
a randomized trial of antimalarials and VSA-PAM-expressing CS2 IEs, we quantified
levels of immunoglobulin (Ig) G to VSA-PAM by flow cytometry and levels of
opsonizing antibodies by measuring uptake of IEs by THP1 promonocytes. Results.
After controlling for gravidity and antimalarial treatment, higher levels of IgG
to VSA-PAM were associated with decreased anemia at delivery (odds ratio [OR],
0.66 [95% confidence interval {CI}, 0.46-0.93]; [Formula: see text]) and were
weakly associated with decreased parasitological failure (OR, 0.78 [95% CI,
0.60-1.03]; [Formula: see text]), especially reinfection (OR, 0.73 [95% CI,
0.53-1.01]; [Formula: see text]). Higher levels of opsonizing antibodies to CS2
IEs were associated with less maternal anemia (OR, 0.31 [95% CI, 0.13-0.74];
[Formula: see text]) and treatment failure (OR, 0.48 [95% CI, 0.25-0.90];
[Formula: see text]), primarily because of recrudescent infection (OR, 0.49 [95%
CI, 0.21-1.12]; [Formula: see text]). Conclusion. Higher levels of both IgG
antibodies to VSA-PAM and opsonizing antibodies, a functional measure of
immunity, correlate with parasite clearance and less anemia in pregnancy malaria.

15: J Med Entomol. 2009 May;46(3):680-92.

Geographic distribution and ecology of potential malaria vectors in the Republic
of Korea.

Foley DH, Klein TA, Kim HC, Sames WJ, Wilkerson RC, Rueda LM.

Division of Entomology, Walter Reed Army Institute of Research, 503 Robert Grant
Ave., Silver Spring, MD 20910, USA. foleydes@si.edu

Environmental geospatial data and adult and larval mosquito collection data for
up to 106 sites throughout the Republic of Korea (ROK) were used to develop
ecological niche models (ENMs) of the potential geographic distribution for eight
anopheline species known to occur there. The areas predicted suitable for the
Hyrcanus Group species were the most extensive for Anopheles sinensis Wiedemann,
An. kleini Rueda, An. belenrae Rueda, and An. pullus Yamada, intermediate for An.
sineroides Yamada, and the most restricted for An. lesteri Baisas and Hu and the
non-Hyrcanus Group species An. koreicus Yamada and Watanabe and An. lindesayi
Yamada. The relative vectorial importance of these species is unknown, and all,
except An. koreicus and An. lindesayi, are predicted to occur widely in the
northwest of the ROK where malaria transmission has been sporadic since its
resurgence in 1993. Our ENMs suggest that it is unlikely that An. koreicus and
An. lindesayi are vectors, but we do not document consistent geographic
differentiation that might incriminate any of the other species as vectors.
Because all species are predicted to occur in North Korea, we also cannot reject
the hypothesis that malaria infected mosquitoes from North Korea may have been
the cause of the resurgence of malaria in the ROK. Ecological differentiation of
the eight species is inferred from collection locations and 34 environmental
layers based on remote sensing and global climatic averages. Interspecific
differences were noted, and characterizing mosquito habitats by ground-based and
remote sensing methods is proposed.

16: J Med Entomol. 2009 May;46(3):516-22.

Pyrethrum: a mixture of natural pyrethrins has potential for malaria vector
control.

Duchon S, Bonnet J, Marcombe S, Zaim M, Corbel V.

Institut de Recherche pour le Développement, Society and Health Department, 213
rue La Fayette, F-75480 Paris cedex 10, France.

Pyrethrum is a natural mixture of six insecticidal esters, recognized for low
mammalian toxicity and limited persistence in the environment. In this study,
World Health Organization standard bioassays were used to evaluate the
performance of pyrethrum against both susceptible and pyrethroid-resistant
Anopheles gambiae s.s. The results showed that the intrinsic activity of
pyrethrum was similar to that of permethrin but lower than that of deltamethrin
against susceptible mosquitoes. However, pyrethrum was less affected by the
presence of the kdr mutation than synthetic pyrethroids (with lower resistance
ratios) and showed good knock-down effect, repellency, and blood-feeding
inhibition against the pyrethroid-resistant strain. In laboratory condition,
mosquito nets treated with 500-1,000 mg/m2 (pyrethrum) remained effective, i.e.,
> 80% mortality and/or > 95% KD effect, for 9 mo. Conversely, the efficacy and
residual activity of pyrethrum (Pynet 5% EC) on substrates was not conclusive,
especially concerning mud, which is a porous substrate (mortality < 80% after 3
mo at 2 g/m2). These findings suggested that pyrethrum may be a potential
alternative candidate for the impregnation of mosquito nets and textiles in areas
where resistance to pyrethroids has become problematic.

17: J Med Entomol. 2009 May;46(3):505-10.

Importance of eaves to house entry by anopheline, but not culicine, mosquitoes.

Njie M, Dilger E, Lindsay SW, Kirby MJ.

School of Biological and Biomedical Sciences, Durham University, Science
Laboratories, South Rd., Durham DH1 3LE, United Kingdom.

Screening homes is an effective way of reducing house entry by mosquitoes. Here,
we assess how important blocking the eaves is for reducing house entry by
anopheline and culicine mosquitoes for houses that have screened doors and no
windows. Twelve houses, with two screened doors and no windows, in which a single
adult male slept, were included in a simple crossover design. In the first
period, six houses were randomly selected and had the eaves blocked using a
mixture of rubble and mortar; the other six were left with open eaves. Mosquitoes
were sampled using CDC light traps from each house twice a week for 4 wk.
Mosquito control activities and the number and type of domestic animals within
the compound was recorded on each sampling occasion. Before beginning the second
sampling period, homes with blocked eaves had them opened, and those with open
eaves had them closed. Mosquitoes were then sampled from each house for a further
4 wk. When houses had their eaves closed, a three-fold reduction in Anopheles
gambiae s.l. Giles caught indoors was observed. However, there was no reduction
in total culicine numbers observed. This study demonstrates that the eaves are
the major route by which An. gambiae enters houses. By contrast, culicine
mosquitoes enter largely through doors and windows. Sealing the eave gap is an
important method for reducing malaria transmission in homes where doors and
windows are screened.

18: J Med Entomol. 2009 May;46(3):460-4.

Diversity cascades and malaria vectors.

Carlson JC, Dyer LA, Omlin FX, Beier JC.

Department of Pediatrics, Tulane University, New Orleans, LA 70112, USA.
jcarlso@tulane.edu

The interactions between predator diversity and primary consumer abundance can
include direct effects and indirect, cascading effects. Understanding these
effects on immature Anopheles mosquitoes is important in sub-Saharan Africa,
where most cases of malaria occur. Aquatic predators and immature mosquitoes were
collected from shallow pools of varying age previously excavated by brickmakers
in the western highlands of Kenya. Path analysis showed an indirect negative
effect of habitat age on An. gambiae (Giles, 1902) mediated by effects on
predator diversity. Disturbance resets habitats to an earlier successional stage,
diminishing predator diversity and increasing An. gambiae populations. The
increase in vector abundance as a result of reduced predator diversity highlights
the public health value in conserving native insect diversity.

19: Malar J. 2009 Jun 11;8(1):129. [Epub ahead of print]

Evaluation of the SD FK70 Malaria Ag Plasmodium vivax rapid diagnostic test in a
non-endemic setting.

Gillet P, Bosselaers K, Cnops L, Bottieau E, Van Esbroeck M, Jacobs J.

ABSTRACT: BACKGROUND: For clinical and epidemiological reasons, it is interesting
to diagnose non-falciparum malaria to the species level. This retrospective study
assessed the performance of the SD BIOLINE Malaria Antigen Pv test (FK70), a
two-band immunochromatographic test detecting Plasmodium vivax-specific lactate
dehydrogenase, on samples of international travellers in a non-endemic setting.
METHODS: Stored blood samples from international travellers suspected of malaria
were used, with microscopy corrected by PCR as the reference method. Samples
infected by Plasmodium vivax (n = 100), Plasmodium falciparum (n = 75),
Plasmodium ovale (n = 75) and Plasmodium malariae (n = 25) were included, as well
as 100 malaria-negative samples. End points were sensitivity, specificity,
inter-reader reliability and reproducibility. RESULTS: The overall sensitivity of
the FK70 for the diagnosis of P. vivax was 88.0% (95% confidence interval (CI):
83.6% – 90.3%). For parasite densities >500/ul, a sensitivity of 97.2% (CI: 92.6%
- 99.1%) was obtained. Specificity was 98.5%, with 4 out of 75 P. falciparum
samples testing positive. None of the P. ovale samples tested positive. Nearly
two-thirds (57/88, 64.7%) of positive P. vivax samples showed faint or weak line
intensities, with stronger line intensities at higher parasite densities. The
test showed excellent reproducibility and reliability for test results and line
intensities (kappa values exceeding 0.98 and 0.87 respectively). CONCLUSIONS: The
FK70 test performed well in diagnosing P. vivax infections in a non-endemic
reference setting. It can be of added value to microscopy in species
differentiation of malaria infections, especially at parasite densities >500/ul.

20: Malar J. 2009 Jun 9;8(1):128. [Epub ahead of print]

An early burst of IFN-gamma induced by the pre-erythrocytic stage favours
Plasmodium yoelii parasitaemia in B6 mice.

Soulard V, Roland J, Gorgette O, Barbier E, Cazenave PA, Pied S.

ABSTRACT: BACKGROUND: In murine models of malaria, an early proinflammatory
response has been associated with the resolution of blood-stage infection. To
dissect the protective immune mechanims that allow the control of parasitaemia,
the early immune response of C57BL/6 mice induced during a non-lethal plasmodial
infection was analysed. METHODS: Mice were infected with Plasmodium yoelii 265BY
sporozoites, the natural invasive form of the parasite, in order to complete its
full life cycle. The concentrations of three proinflammatory cytokines in the
sera of mice were determined by ELISA at different time points of infection. The
contribution of the liver and the spleen to this cytokinic response was evaluated
and the cytokine-producing lymphocytes were identified by flow cytometry. The
physiological relevance of these results was tested by monitoring parasitaemia in
genetically deficient C57BL/6 mice or wild-type mice treated with anti-cytokine
neutralizing antibody. Finally, the cytokinic response in sera of mice infected
with parasitized-RBCs was analysed. RESULTS: The early immune response of C57BL/6
mice to sporozoite-induced malaria is characterized by a peak of IFN-gamma in the
serum at day 5 of infection and splenic CD4 T lymphocytes are the major producer
of this cytokine at this time point. Somewhat unexpected, the parasitaemia is
significantly lower in P. yoelii-infected mice in the absence of IFN-gamma. More
precisely, at early time points of infection, IFN-gamma favours parasitaemia,
whereas helping to clear efficiently the blood-stage parasites at later time
points. Interestingly, the early IFN-gamma burst is induced by the
pre-erythrocytic stage. CONCLUSION: These results challenge the current view
regarding the role of IFN-gamma on the control of parasite growth since they show
that IFN-gamma is not an essential mediator of protection in P. yoelii-infected
C57BL/6 mice. Moreover, the mice parasitaemia is more efficiently controlled in
the absence of an early IFN-gamma production, suggesting that this cytokine
promotes parasite’s growth. Finally, this early burst of IFN-gamma is induced by
the pre-erythrocytic stage, showing the impact of this stage on the immune
response taking place during the subsequent erythrocytic stage.

21: Malar J. 2009 Jun 8;8(1):127. [Epub ahead of print]

Simulation of the cost-effectiveness of malaria vaccines.

Tediosi F, Maire N, Penny M, Studer A, Smith TA.

ABSTRACT: BACKGROUND: A wide range of possible malaria vaccines is being
considered and there is a need to identify which vaccines should be prioritized
for clinical development. An important element of the information needed for this
prioritization is a prediction of the cost-effectiveness of potential vaccines in
the transmission settings in which they are likely to be deployed. This analysis
needs to consider a range of delivery modalities to ensure that clinical
development plans can be aligned with the most appropriate deployment strategies.
METHODS: The simulations are based on a previously published individual-based
stochastic model for the natural history and epidemiology of Plasmodium
falciparum malaria. Three different vaccine types: pre-erythrocytic vaccines
(PEV), blood stage vaccines (BSV), mosquito-stage transmission-blocking vaccines
(MSTBV), and combinations of these, are considered each delivered via a range of
delivery modalities (Expanded Programme of Immunization – EPI-, EPI with booster,
and mass vaccination combined with EPI). The cost-effectiveness ratios presented
are calculated for four health outcomes, for assumed vaccine prices of US$ 2 or
US$ 10 per dose, projected over a 10-year period. RESULTS: The simulations
suggest that PEV will be more cost-effective in low transmission settings, while
BSV at higher transmission settings. Combinations of BSV and PEV are more
efficient than PEV, especially in moderate to high transmission settings, while
compared to BSV they are more cost-effective in moderate to low transmission
settings. Combinations of MSTBV and PEV or PEV and BSV improve the effectiveness
and the cost-effectiveness compared to PEV and BSV alone only when applied with
EPI and mass vaccinations. Adding booster doses to the EPI is unlikely to be a
cost-effective alternative to delivering vaccines via the EPI for any vaccine,
while mass vaccination improves effectiveness, especially in low transmission
settings, and is often a more efficient alternative to the EPI. However, the
costs of increasing the coverage of mass vaccination over 50% often exceed the
benefits. CONCLUSIONS: The simulations indicate malaria vaccines might be
efficient malaria control interventions, and that both transmission setting and
vaccine delivery modality are important to their cost-effectiveness. Alternative
vaccine delivery modalities to the EPI may be more efficient than the EPI. Mass
vaccination is predicted to provide substantial health benefits at low additional
costs, although achieving high coverage rates can lead to substantial incremental
costs.

22: Malar J. 2009 Jun 8;8(1):126. [Epub ahead of print]

Diagnostic comparison of malaria infection in peripheral blood, placental blood
and placental biopsies in Cameroonian parturient women.

Anchang-Kimbi JK, Achidi EA, Nkegoum B, Sverremark-Ekstrom E, Troye-Blomberg M.

ABSTRACT: BACKGROUND: In sub-Saharan Africa, Plasmodium falciparum malaria in
pregnancy presents an enormous diagnostic challenge. The epidemiological and
clinical relevance of the different types of malaria diagnosis as well as risk
factors associated with malaria infection at delivery were investigated. METHOD:
In a cross-sectional survey, 306 women reporting for delivery in the Mutengene
maternity clinic, Fako division, South West province, Cameroon were screened for
P. falciparum in peripheral blood, placental blood and placental tissue sections
by microscopy. Information relating to the use of intermittent preventive
treatment in pregnancy with sulphadoxine/pyrimethamine, history of fever attack,
infant birth weights and maternal anaemia were recorded. RESULTS: Among these
women, P. falciparum infection was detected in 5.6%, 25.5% and 60.5% of the cases
in peripheral blood, placental blood and placental histological sections
respectively. Placental histology was more sensitive ( 97.4 %) than placental
blood film (41.5%) and peripheral blood (8.0%) microscopy. In multivariate
analysis, age ([less than or equal to] 20 years old) (OR = 4.61, 95% CI = 1.47 -
14.70), history of fever attack (OR = 2.98, 95% CI = 1.58 – 5.73) were
significant risk factors associated with microscopically detected parasitaemia.
The use of [greater than or equal to] 2 SP doses (OR= 0.18, 95% CI = 0.06 – 0.52)
was associated with a significant reduction in the prevalence of microscopic
parasitaemia at delivery. Age (>20years) (OR = 0.34, 95% CI = 0.15 – 0 .75) was
the only significant risk factor associated with parasitaemia diagnosed by
histology only in univariate analysis. Microscopic parasitaemia (OR = 2.74, 95%
CI = 1.33- 5.62) was a significant risk factor for maternal anaemia at delivery,
but neither infection detected by histology only, nor past infection were
associated with increased risk of anaemia. CONCLUSIONS: Placenta histological
examination was the most sensitive indicator of malaria infection at delivery.
Microscopically detected parasitaemia was associated with increased risk of
maternal anaemia at delivery, but not low-grade parasitaemia detected by
placental histology only.

23: Malar J. 2009 Jun 8;8(1):124. [Epub ahead of print]

Larvicidal activity of neem oil (Azadirachta indica) formulation against
mosquitoes.

Dua VK, Pandey AC, Raghavendra K, Gupta A, Sharma T, Dash AP.

ABSTRACT: BACKGROUND: Mosquitoes transmit serious human diseases, causing
millions of deaths every year. Use of synthetic insecticides to control vector
mosquitoes has caused physiological resistance and adverse environmental effects
in addition to high operational cost. Insecticides of botanical origin have been
reported as useful for control of mosquitoes. Azadirachta indica (Meliaceae) and
its derived products have shown a variety of insecticidal properties. The present
paper discusses the larvicidal activity of neem-based biopesticide for the
control of mosquitoes. METHODS: Larvicidal efficacy of an emulsified concentrate
of neem oil formulation ( neem oil with polyoxyethylene ether, sorbitan dioleate
and epichlorohydrin ) developed by BMR & Company, Pune, India, was evaluated
against late 3rd and early 4th instar larvae of different genera of mosquitoes.
The larvae were exposed to different concentrations (0.5- 5.0 ppm) of the
formulation along with untreated control. Larvicidal activity of the formulation
was also evaluated in field against Anopheles, Culex, and Aedes mosquitoes. The
formulation was diluted with equal volumes of water and applied @ 140 mg a.i. /
m2 to different mosquito breeding sites with the help of pre calibrated knapsack
sprayer. Larval density was determined at pre and post application of the
formulation using a standard dipper. RESULTS: Median lethal concentration (LC50)
of the formulation against Anopheles stephensi, Culex quinquefasciatus and Aedes
aegypti was found to be 1.6, 1.8 and 1.7 ppm respectively. LC50 values of the
formulation stored at 260C, 400C and 450C for 48 hours against Ae. aegypti were
1.7, 1.7, 1.8 ppm while LC90 values were 3.7, 3.7 and 3.8 ppm respectively.
Further no significant difference in LC50 and LC90 values of the formulation was
observed against Ae. aegypti during 18 months storage period at room temperature.
An application of the formulation at the rate of 140 mg a.i./m2 in different
breeding sites under natural field conditions provided 98.1% reduction of
Anopheles larvae on day 1; thereafter 100% reduction was recorded up to week 1
and more than 80% reduction up to week 3, while percent reduction against Culex
larvae was 95.5% on day 1, and thereafter 80% reduction was achieved up to week
3. The formulation also showed 95.1% and, 99.7% reduction of Aedes larvae on day
1 and day 2 respectively; thereafter 100% larval control was observed up to day
7. CONCLUSION: The neem oil formulation was found effective in controlling
mosquito larvae in different breeding sites under natural field conditions. As
neem trees are widely distributed in India, their formulations may prove to be an
effective and eco-friendly larvicide, which could be used as an additional tool
for malaria control.

24: Malar J. 2009 Jun 7;8(1):123. [Epub ahead of print]

Spatial and temporal distribution of the malaria mosquito Anopheles arabiensis in
northern Sudan: influence of environmental factors and implications for vector
control.

Ageep TB, Cox J, Hassan MM, Knols BG, Benedict MQ, Malcolm CA, Babiker A, El
Sayed BB.

ABSTRACT: BACKGROUND: Malaria is an important public health problem in northern
Sudan, but little is known about the dynamics of its transmission. Given the
characteristic low densities of Anopheles arabiensis and the difficult terrain in
this area, future vector control strategies are likely to be based on area-wide
integrated pest management (AW-IPM) that may include the sterile insect technique
(SIT). To support the planning and implementation of future AW-IPM activities,
larval surveys were carried out to provide key data on spatial and seasonal
dynamics of local vector populations. METHODS: Monthly cross-sectional larval
surveys were carried out between March 2005 and May 2007 in two localities
(Dongola and Merowe) adjacent to the river Nile. A stratified random sampling
strategy based on the use of Remote Sensing (RS), Geographical Information
Systems (GIS) and the Global Positioning System (GPS) was used to select survey
locations. Breeding sites were mapped using GPS and data on larval density and
breeding site characteristics were recorded using handheld computers. Bivariate
and multivariate logistic regression models were used to identify breeding site
characteristics associated with increased risk of presence of larvae. Seasonal
patterns in the proportion of breeding sites positive for larvae were compared
visually to contemporaneous data on climate and river height. RESULTS: Of a total
of 3,349 aquatic habitats sampled, 321 (9.6%) contained An. arabiensis larvae.
The frequency with which larvae were found varied markedly by habitat type.
Although most positive sites were associated with temporary standing water around
the margins of the main Nile channel, larvae were also found at brickworks and in
areas of leaking pipes and canals – often far from the river. Close to the Nile
channel, a distinct seasonal pattern in larval populations was evident and
appeared to be linked to the rise and fall of the river level. These patterns
were not evident in vector populations breeding in artificial water sources away
from the river. CONCLUSIONS: The GIS-based survey strategy developed in this
study provides key data on the population dynamics of An. arabiensis in Northern
State. Quantitative estimates of the contributions of various habitat types and
their proximity to settlements provide a basis for planning a strategy for
reducing malaria risk by elimination of the vector population.

25: Malar J. 2009 Jun 7;8(1):122. [Epub ahead of print]

Human T cell recognition of the blood stage antigen Plasmodium hypoxanthine
guanine xanthine phosphoribosyl transferase (HGXPRT) in acute malaria.

Woodberry T, Pinzon-Charry A, Piera KA, Panpisutchai Y, Engwerda CR, Doolan DL,
Salwati E, Kenangalem E, Tjitra E, Price RN, Good MF, Anstey NM.

ABSTRACT: BACKGROUND: The Plasmodium purine salvage enzyme, hypoxanthine guanine
xanthine phosphoribosyl transferase (HGXPRT) can protect mice against Plasmodium
yoelii pRBC challenge in a T cell-dependent manner and has, therefore, been
proposed as a novel vaccine candidate. It is not known whether natural exposure
to Plasmodium falciparum stimulates HGXPRT T cell reactivity in humans. METHODS:
PBMC and plasma collected from malaria-exposed Indonesians during infection and
7-28 days after anti-malarial therapy, were assessed for HGXPRT recognition using
CFSE proliferation, IFNg ELISPOT assay and ELISA. RESULTS: HGXPRT-specific T cell
proliferation was found in 44% of patients during acute infection; in 80% of
responders both CD4+ and CD8+ T cell subsets proliferated. Antigen-specific T
cell proliferation was largely lost within 28 days of parasite clearance.
HGXPRT-specific IFN-g production was more frequent 28 days after treatment than
during acute infection. HGXPRT-specific plasma IgG was undetectable even in
individuals exposed to malaria for at least two years. CONCLUSIONS: The
prevalence of acute proliferative and convalescent IFNg responses to HGXPRT
demonstrates cellular immunogenicity in humans. Further studies to determine
minimal HGXPRT epitopes, the specificity of responses for Plasmodia and
associations with protection are required. Frequent and robust T cell
proliferation, high sequence conservation among Plasmodium species and absent IgG
responses distinguish HGXPRT from other malaria antigens.

26: Malar J. 2009 Jun 5;8(1):121. [Epub ahead of print]

Anti-Anopheles darlingi saliva antibodies as marker of Plasmodium vivax infection
and clinical immunity in the Brazilian Amazon.

Andrade BB, Rocha BC, Reis-Filho A, Camargo LM, Tadei WP, Moreira LA, Barral A,
Barral-Netto M.

ABSTRACT: BACKGROUND: Despite governmental and private efforts on providing
malaria control, this disease continues to be a major health threat. Thus,
innovative strategies are needed to reduce disease burden. The malaria vectors,
through the injection of saliva into the host skin, play important role on
disease transmission and may influence malaria morbidity. This study describes
the humoral immune response against Anopheles darlingi saliva in volunteers from
the Brazilian Amazon and addresses the association between levels of specific
antibodies and clinical presentation of Plasmodium vivax infection. METHODS:
Adult volunteers from communities in the Rondonia state, Brazil, were screened in
order to assess the presence of P. vivax infection by light microscopy and nested
PCR. Non-infected volunteers and individuals with symptomatic or symptomless
infection were randomly selected and plasma collected. An. darlingi salivary
gland sonicates (SGS) were prepared and used to measure anti-saliva antibody
levels. Plasma interleukin (IL)-10 and interferon (IFN)-gamma levels were also
estimated and correlated to anti-SGS levels. RESULTS: Individuals infected with
P. vivax presented higher levels of anti-SGS than non-infected individuals and
antibody levels could discriminate infection. Furthermore, anti-saliva antibody
measurement was also useful to distinguish asymptomatic infection from
non-infection, with a high likelihood ratio. Interestingly, individuals with
asymptomatic parasitaemia presented higher titers of anti-SGS and lower
IFN-gamma/IL-10 ratio than symptomatic ones. In P. vivax-infected asymptomatic
individuals, the IFN-gamma/IL-10 ratio was inversely correlated to anti-SGS
titers, although not for while in symptomatic volunteers. CONCLUSIONS: The
estimation of anti-An. darlingi antibody levels can indicate the probable P.
vivax infection status and also could serve as a marker of disease severity in
this region of Brazilian Amazon.

27: Malar J. 2009 Jun 5;8(1):120. [Epub ahead of print]

T-cell epitope polymorphisms of the Plasmodium falciparum circumsporozoite
protein among field isolates from Sierra Leone: age-dependent haplotype
distribution?

Jalloh A, Jalloh M, Matsuoka H.

ABSTRACT: BACKGROUND: In the context of the development of a successful malaria
vaccine, understanding the polymorphisms exhibited by malaria antigens in natural
parasite populations is crucial for proper vaccine design. Recent observations
have indicated that sequence polymorphisms in the C-terminal T-cell epitopes of
the Plasmodium falciparum circumsporozoite protein (Pfcsp) are rather low and
apparently stable in low endemic areas. This study sought to assess the pattern
in a malaria endemic setting in Africa, using samples from Freetown, Sierra
Leone. METHODS: Filter-paper blood samples were collected from subjects at a
teaching hospital in Freetown during September-October 2006 and in April-May
2007. The C-terminal portion of the Pfcsp gene spanning the Th2R and Th3R
epitopes was amplified and directly sequenced; sequences were analysed with
subject parameters and polymorphism patterns in Freetown were compared to that in
other malaria endemic areas. Results and Discussion Overall, the genetic
diversity in Freetown was high. From a total of 99 sequences, 42 haplotypes were
identified with at least three accounting for 44.4% (44/99): the 3D7-type
(19.2%), a novel type, P-01 (17.2%), and E12 (8.1%). Interestingly, all were
unique to the African sub-region and there appeared to be predilection for
certain haplotypes to distribute in certain age-groups: the 3D7 type was detected
mainly in hospitalized children under 15 years of age, while the P-01 type was
common in adult antenatal females (Pearson Chi-square = 48.750, degrees of
freedom = 34, P = 0.049). In contrast, the single-haplotype predominance
(proportion > 50%) pattern previously identified in Asia was not detected in
Freetown. CONCLUSION: Haplotype distribution of the T-cell epitopes of Pfcsp in
Freetown appeared to vary with age in the study population, and the polymorphism
patterns were similar to that observed in neighbouring Gambia, but differed
significantly at the sequence level from that observed in Asia. The findings
further emphasize the role of local factors in generating polymorphisms in the
T-cell epitopes of the P. falciparum circumsporozoite protein.

28: Malar J. 2009 Jun 4;8(1):119. [Epub ahead of print]

A qualitative study on the acceptability and preference of three types of
long-lasting insecticide-treated bed nets in Solomon Islands: implications for
malaria elimination.

Atkinson JA, Bobogare A, Fitzgerald L, Boaz L, Appleyard B, Toaliu H, Vallely A.

ABSTRACT: BACKGROUND: In March 2008, the Solomon Islands and Vanuatu governments
raised the goal of their National Malaria Programmes from control to elimination.
Vector control measures, such as indoor residual spraying (IRS) and long-lasting
insecticidal bed nets (LLINs) are key integral components of this programme.
Compliance with these interventions is dependent on their acceptability and on
the socio-cultural context of the local population. These factors need to be
investigated locally prior to programme implementation. METHOD: Twelve focus
group discussions (FGDs) were carried out in Malaita and Temotu Provinces,
Solomon Islands in 2008. These discussions explored user perceptions of
acceptability and preference for three brands of long-lasting insecticide-treated
bed nets (LLINs) and identified a number of barriers to their proper and
consistent use. RESULTS: Mosquito nuisance and perceived threat of malaria were
the main determinants of bed net use. Knowledge of malaria and the means to
prevent it were not sufficient to guarantee compliance with LLIN use. Factors
such as climate, work and evening social activities impact on the use of bed
nets, particularly in men. LLIN acceptability plays a varying role in compliance
with their use in villages involved in this study. Participants in areas of
reported high and year round mosquito nuisance and perceived threat of malaria
reported LLIN use regardless of any reported unfavourable characteristics. Those
in areas of low or seasonal mosquito nuisance were more likely to describe the
unfavourable characteristics of LLINs as reasons for their intermittent or
non-compliance. The main criterion for LLIN brand acceptability was effectiveness
in preventing mosquito bites and malaria. Discussions highlighted considerable
confusion around LLIN care and washing which may be impacting on their
effectiveness and reducing their acceptability in Solomon Islands. CONCLUSION:
Providing LLINs that are acceptable will be more important for improving
compliance in areas of low or seasonal mosquito nuisance and malaria
transmission. The implications of these findings on malaria elimination in
Solomon Islands are discussed.

29: Malar J. 2009 Jun 4;8:118.

Factors related to compliance to anti-malarial drug combination: example of
amodiaquine/sulphadoxine-pyrimethamine among children in rural Senegal.

Souares A, Lalou R, Sene I, Sow D, Le Hesran JY.

Faculté de Pharmacie, Institut de Recherche pour le Développement, UR10, Paris,
France. souares@uni-heidelberg.de

BACKGROUND: The introduction of new anti-malarial treatment that is effective,
but more expensive, raises questions about whether the high level of
effectiveness observed in clinical trials can be found in a context of family
use. The objective of this study was to determine the factors related to
adherence, when using the amodiaquine/sulphadoxine-pyrimethamine (AQ/SP)
association, a transitory strategy before ACT implementation in Senegal. METHODS:
The study was conducted in five rural dispensaries. Children, between two and 10
years of age, who presented mild malaria were recruited at the time of the
consultation and were prescribed AQ/SP. The child’s primary caretaker was
questioned at home on D3 about treatment compliance and factors that could have
influenced his or her adherence to treatment. A logistic regression model was
used for the analyses. RESULTS: The study sample included 289 children. The
adherence rate was 64.7%. Two risks factors for non-adherence were identified:
the children’s age (8-10 years) (ORa = 3.07 [1.49-6.29]; p = 0.004); and the
profession of the head of household (retailer/employee versus farmer) (ORa = 2.71
[1.34-5.48]; p = 0.006). Previously seeking care (ORa = 0.28 [0.105-0.736],
p=0.001] satisfaction with received information (ORa = 0.45 [0.24-0.84]; p =
0.013), and the quality of history taking (ORa = 0.38 [0.21-0.69]; p = 0.001)
were significantly associated with good compliance. CONCLUSION: The results of
the study show the importance of information and communication between caregivers
and health center staff. The experience gained from this therapeutic transition
emphasizes the importance of information given to the patients at the time of the
consultation and drug delivery in order to improve drug use and thus prevent the
emergence of rapid drug resistance.

30: Malar J. 2009 Jun 4;8(1):117. [Epub ahead of print]

Inferring selection in the Anopheles gambiae species complex: an example from
immune-related serine protease inhibitors.

Obbard DJ, Welch JJ, Little TJ.

ABSTRACT: BACKGROUND: Mosquitoes of the Anopheles gambiae species complex are the
primary vectors of human malaria in sub-Saharan Africa. Many host genes have been
shown to affect Plasmodium development in the mosquito, and so are expected to
engage in an evolutionary arms race with the pathogen. However, there is little
conclusive evidence that any of these mosquito genes evolve rapidly, or show
other signatures of adaptive evolution. METHODS: Three serine protease inhibitors
have previously been identified as candidate immune system genes mediating
mosquito-Plasmodium interaction, and serine protease inhibitors have been
identified as hot-spots of adaptive evolution in other taxa. Population-genetic
tests for selection, including a recent multi-gene extension of the
McDonald-Kreitman test, were applied to 16 serine protease inhibitors and 16
other genes sampled from the An. gambiae species complex in both East and West
Africa. RESULTS: Serine protease inhibitors were found to show a marginally
significant trend towards higher levels of amino acid diversity than other genes,
and display extensive genetic structuring associated with the 2La chromosomal
inversion. However, although serpins are candidate targets for strong
parasite-mediated selection, no evidence was found for rapid adaptive evolution
in these genes. CONCLUSION: It is well known that phylogenetic and population
history in the An. gambiae complex can present special problems for the
application of standard population-genetic tests for selection, and this may
explain the failure of this study to detect selection acting on serine protease
inhibitors. The pitfalls of uncritically applying these tests in this species
complex are highlighted, and the future prospects for detecting selection acting
on the An. gambiae genome are discussed.

31: Malar J. 2009 May 30;8:114.

Utilization, retention and bio-efficacy studies of PermaNet in selected villages
in Buie and Fentalie districts of Ethiopia.

Fettene M, Balkew M, Gimblet C.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, PO Box 1176,
Addis Ababa, Ethiopia. messayg@yahoo.com

BACKGROUND: Malaria remains a major public health problem in Ethiopia.
Pyrethroid-treated mosquito nets are one of the major tools available for the
prevention and control of malaria transmission. PermaNet is a long-lasting
insecticide-treated net (LLIN) recommended by WHO for malaria control. OBJECTIVE:
The objective of the study was to assess utilization and retention of PermaNet
nets distributed for malaria control in Buie and Fentalie districts and monitor
the bio-efficacy of the nets using the WHO cone bioassay test procedures.
METHODS: A cross sectional study was carried out by interviewing household heads
or their representative in Buie and Fentalie districts. The two districts were
selected based on a priori knowledge of variations on ethnic background and
housing construction. Clusters of houses were chosen within each of the study
villages for selection of households. 20 households that had received one or more
PermaNet nets were chosen randomly from the clusters in each village. A total of
eight used PermaNet nets were collected for the bio-efficacy test. The
bio-efficacy of PermaNet nets was monitored according to the standard WHO
procedures using a susceptible colony of Anopheles arabiensis to deltamethrin.
RESULTS: A total of 119 household heads were interviewed during the study. The
retention rate of nets that were distributed in 2005 and 2006 season was 72%. A
total of 62.2% of the interviewees claimed children under five years of age slept
under LLIN, while only 50.7% of the nets were observed to be hanged inside houses
when used as a proxy indicator of usage of LLIN. For the bio-efficacy test the
mean knock-down was 94% and 100%, while the mean mortality rate observed after 24
hr holding period was 72.2% and 67% for Buie and Fentalie districts respectively.
CONCLUSION: The study revealed a moderately high retention of PermaNet in the
study villages and effectiveness of the nets when tested according to the
standard WHO procedure.

32: Malar J. 2009 May 29;8(1):113. [Epub ahead of print]

Co-ordinated stage-dependent enhancement of Plasmodium falciparum antioxidant
enzymes and heat shock protein expression in parasites growing in oxidatively
stressed or G6PD-deficient red blood cells.

Akide-Ndunge OB, Tambini E, Giribaldi G, McMillan PJ, Muller S, Arese P, Turrini
F.

ABSTRACT: BACKGROUND: Plasmodium falciparum-parasitized red blood cells (RBCs)
are equipped with protective antioxidant enzymes and heat shock proteins (HSPs).
The latter are only considered to protect against thermal stress. Important
issues are poorly explored: first, it is insufficiently known how both systems
are expressed in relation to the parasite developmental stage; secondly, it is
unknown whether P. falciparum HSPs are redox-responsive, in view of redox
sensitivity of HSP in eukaryotic cells; thirdly, it is poorly known how the
antioxidant defense machinery would respond to increased oxidative stress or
inhibited antioxidant defense. Those issues are interesting as several
antimalarials increase the oxidative stress or block antioxidant defense in the
parasitized RBC. In addition, numerous inhibitors of HSPs are currently developed
for cancer therapy and might be tested as anti-malarials. Thus, the joint
disruption of the parasite antioxidant enzymes/HSP system would interfere with
parasite growth and open new perspectives for anti-malaria therapy. METHODS:
Stage-dependent mRNA expression of ten representative P. falciparum antioxidant
enzymes and hsp60/70-2/70-3/75/90 was studied by quantitative real-time RT-PCR in
parasites growing in normal RBCs, in RBCs oxidatively-stressed by moderate H2O2
generation and in G6PD-deficient RBCs. Protein expression of antioxidant enzymes
was assayed by Western blotting. The pentosephosphate-pathway flux was measured
in isolated parasites after Sendai-virus lysis of RBC membrane. RESULTS: In
parasites growing in normal RBCs, mRNA expression of antioxidant enzymes and HSPs
displayed co-ordinated stage-dependent modulation, being low at ring, highest at
early trophozoite and again very low at schizont stage. Additional exogenous
oxidative stress or growth in antioxidant blunted G6PD-deficient RBCs indicated
remarkable flexibility of both systems, manifested by enhanced, co-ordinated mRNA
expression of antioxidant enzymes and HSPs. Protein expression of antioxidant
enzymes was also increased in oxidatively-stressed trophozoites. CONCLUSIONS:
Results indicated that mRNA expression of parasite antioxidant enzymes and HSPs
was co-ordinated and stage-dependent. Secondly, both systems were
redox-responsive and showed remarkably increased and co-ordinated expression in
oxidatively-stressed parasites and in parasites growing in antioxidant blunted
G6PD-deficient RBCs. Lastly, as important anti-malarials either increase oxidant
stress or impair antioxidant defense, results may encourage the inclusion of
anti-HSP molecules in anti-malarial combined drugs.

33: Neotrop Entomol. 2009 Mar-Apr;38(2):272-80.

Entomological characterization and natural infection of anophelines in an area of
the Atlantic Forest with autochthonous malaria cases in mountainous region of
Espírito Santo State, Brazil.

Rezende HR, Soares RM, Cerutti C Jr, Alves IC, Natal D, Urbinatti PR, Yamasaki T,
Falqueto A, Malafronte Rdos S.

Unidade de Medicina Tropical, Univ. Federal do Espírito Santo.

Autochthonous malaria cases in the state of Espírito Santo, Brazil, are
distributed in mountainous regions surrounded by the Atlantic Forest. While some
aspects of this disease are unclear, detection of possible vector species can
help to elucidate epidemiological uncertainties. Entomological and natural
infection studies were carried out using anophelines (Diptera: Culicidae)
captured in the municipality of Santa Tereza, ES. Monthly captures were made from
March 2004 to February 2006. CDC-CO2 traps were used from dusk (6:00 P.M.) to
dawn (6:00 A.M.) to capture anophelines in the following habitats: near the
houses, in open areas (at ground level) and inside, and at the margins of the
forest (canopy and ground level). Shannon light traps were also used at the same
locations of the CDC-CO2 traps. A total of 2,290 anophelines within 10 species
were captured. The relative frequency of Anopheles (Kerteszia) cruzii Dyar & Knab
/ A.(K.) homunculus Komp was the highest, with the majority captured in CDC-CO2
traps installed in the forest canopy. The main species captured in Shannon traps
was A.(Nyssorhynchus) strodei Root. The largest number of anophelines was
captured from July to September and from 6:00 P.M. to 10:00 P.M. Anopheles (K.)
cruzii is the probable vector for malaria transmission inside or near the
Atlantic Forest fragments, but the role of other species cannot be ignored, as
53% of the sampled anophelines belonged to the subgenus Nyssorhynchus. The
natural infection of A. cruzii, A. parvus (Chagas) and A. galvaoi Causey, Deane &
Deane by Plasmodium vivax detected by PCR from DNA extracted from their thoraxes
supports this view.

34: Prescrire Int. 2008 Aug;17(96):168-70.

Intravenous artesunate for severe malaria.

(1) Plasmodium falciparum malaria can be fatal in non-immune individuals.
Artemisinin derivatives are effective in the treatment of simple malaria attacks,
but what is their role in treating severe malaria? (2) It has been estimated that
intravenous quinine halves the mortality rate due to malaria. However, it has
frequent dose-dependent adverse effects (tinnitus, hearing disorders, dizziness),
and carries a risk of rare life-threatening reactions. Intravenous quinine has
been a standard treatment for many years; (3) A very large trial has been
conducted among adults and children in Southeast Asia. The mortality rate was
lower with intravenous artesunate: 15% versus 22% with intravenous quinine.
Other, smaller trials have provided similar results. The two treatments have
similar adverse effects; (4) In practice, in Southeast Asia, intravenous
artesunate has the best risk-benefit balance of the treatments available for
severe malaria. Elsewhere, in the absence of parasite resistance, quinine remains
the standard treatment. Comparisons with artesunate are awaited.

35: Prescrire Int. 2008 Aug;17(96):162-8.

Artemisinin derivatives and malaria: useful, in combination with other
antimalarials.

(1) Plasmodium falciparum malaria can be fatal, especially in young children and
non-immune persons. Several drugs are effective but emergence of parasite
resistance limits the choice in various parts of the world. Resistance to
mefloquine and even to quinine has been reported in Southeast Asia; (2) What is
the role of artemisinin derivatives (mainly artesunate and artemether) in the
treatment of uncomplicated P. falciparum malaria? To answer this question we
conducted a review of the literature, based on Prescrire’s standard methodology;
(3) Trials of single-agent therapy with artemisinin derivatives showed rapid
clinical and parasitological effects, but relapses were frequent during the weeks
following treatment. Artemisinin derivatives are therefore used in combination
with other antimalarials; (4) In 2006, no parasite resistance to artemisinin
derivatives has been detected in Southeast Asia after about 10 years of use; (5)
In Southeast Asia, parasitological failure at 28 days was less frequent after
treatment with artesunate (for 3 days) plus mefloquine than with mefloquine
alone. The artemether + lumefantrine combination has similar efficacy to the
artesunate + mefloquine combination. In Africa, several trials have shown that
combinations based on artemisinin derivatives are more consistently effective
than combinations not including artemisinin derivatives. In regions with
high-level resistance to amodiaquine, one trial showed that artemether +
lumefantrine was more effective than artesunate + amodiaquine; (6) The main
adverse effects of artemisinin derivatives are gastrointestinal and neurological
disorders, but less are rarely severe. Combinations based on artemisinin
derivatives have different adverse effects, depending on the drugs used; (7)
Artesunate is the artemisinin derivative most widely studied in pregnant women:
in a series of more than 400 pregnancies, abnormalities were no more frequent
than in the general population; (8) In practice, in regions where P. falciparum
malaria is endemic, early combination therapy based on artemisinin derivatives is
often recommended. For uncomplicated malaria in travellers, combination therapy
based on artemisinin derivatives is one option, along with atovaquone +
proguanil, quinine (less convenient) and mefloquine (frequent neuropsychological
effects).

36: Trans R Soc Trop Med Hyg. 2009 Jun 6. [Epub ahead of print]

A new global malaria eradication strategy: implications for malaria research from
an Indian perspective.

Singh N.

Regional Medical Research Centre for Tribals (ICMR), Nagpur Road, Garha,
Jabalpur, Madhya Pradesh 482003, India.

The Roll Back Malaria Partnership has developed the Global Malaria Action Plan
for a substantial reduction in the burden of malaria and its eradication in the
long term. The challenges faced by countries in their malaria control efforts are
varied. In India there are many efficient vectors causing epidemics of both
Plasmodium vivax and P. falciparum. The interruption of P. vivax transmission is
difficult to achieve due to liver-stage infection. We need new drugs,
insecticides and other intervention tools with sufficient coverage to achieve the
goal of malaria control or elimination. The issues important for malaria
eradication are discussed from an Indian perspective.

37: Trop Med Int Health. 2009 May 26. [Epub ahead of print]

From malaria control to eradication: The WHO perspective.

Mendis K, Rietveld A, Warsame M, Bosman A, Greenwood B, Wernsdorfer WH.

Global Malaria Programme, World Health Organization, Geneva, Switzerland.

Summary Efforts to control malaria have been boosted in the past few years with
increased international funding and greater political commitment. Consequently,
the reported malaria burden is being reduced in a number of countries throughout
the world, including in some countries in tropical Africa where the burden of
malaria is greatest. These achievements have raised new hopes of eradicating
malaria. This paper summarizes the outcomes of a World Health Organization’s
expert meeting on the feasibility of such a goal. Given the hindsight and
experience of the Global Malaria Eradication Programme of the 1950s and 1960s,
and current knowledge of the effectiveness of antimalarial tools and
interventions, it would be feasible to effectively control malaria in all parts
of the world and greatly reduce the enormous morbidity and mortality of malaria.
It would also be entirely feasible to eliminate malaria from countries and
regions where the intensity of transmission is low to moderate, and where health
systems are strong. Elimination of malaria requires a re-orientation of control
activity, moving away from a population-based coverage of interventions, to one
based on a programme of effective surveillance and response. Sustained efforts
will be required to prevent the resurgence of malaria from where it is
eliminated. Eliminating malaria from countries where the intensity of
transmission is high and stable such as in tropical Africa will require more
potent tools and stronger health systems than are available today. When such
countries have effectively reduced the burden of malaria, the achievements will
need to be consolidated before a programme re-orientation towards malaria
elimination is contemplated. Malaria control and elimination are under the
constant threat of the parasite and vector mosquito developing resistance to
medicines and insecticides, which are the cornerstones of current antimalarial
interventions. The prospects of malaria eradication, therefore, rest heavily on
the outcomes of research and development for new and improved tools. Malaria
control and elimination are complementary objectives in the global fight against
malaria.

38: Trop Med Int Health. 2009 May 26. [Epub ahead of print]

Intermittent preventive treatment using artemisinin-based combination therapy
reduces malaria morbidity among school-aged children in Mali.

Barger B, Maiga H, Traore OB, Tekete M, Tembine I, Dara A, Traore ZI, Gantt S,
Doumbo OK, Djimde AA.

School of Medicine, University of Washington, Seattle, WA, USA.

Summary Objective To assess the efficacy of intermittent preventive treatment
(IPT) against malaria in school-aged children. Methods This was an open
randomized controlled trial of seasonal IPT among school children (IPTsc) aged
6-13 years in Kollé, Mali. The study began in September 2007 and completed
follow-up in May 2008. Students were randomized to one of three study arms:
Sulfadoxine-pyrimethamine plus artesunate (SP/AS), amodiaquine plus artesunate
(AQ/AS) or vitamin C. All students received two full treatment doses, given 2
months apart during the season of high transmission from September to December.
Groups were compared with respect to incidence of clinical malaria, asymptomatic
parasitemia and haemoglobin concentration. Results A total of 296 students were
randomized, and retention in the study was 99.3%. Clinical malaria incidence in
the SP/AS and AQ/AS arms was reduced by 66.6% and 46.5%, respectively, vs.
vitamin C (P < 0.001). There were fewer clinic visits for any cause among the
children receiving SP/AS or AQ/AS (P = 0.024). The prevalence of asymptomatic
parasitemia was fivefold higher in the vitamin C arm than either SP/AS or AQ/AS
at each post-treatment evaluation (P < 0.001). At the end of the transmission
period, children treated with IPT had lower rates of anaemia (SP/AS, 17.7%;
AQ/AS, 16.0%; vitamin C, 29.6%; P = 0.039). Conclusion IPT among school children
reduced the rates of clinical malaria, all-cause acute clinic visits,
asymptomatic parasitemia and anaemia among school-aged children.