Long-Lasting Insecticide-Treated Nets Combined or Not with Indoor Residual Spraying May Not Be Sufficient to Eliminate Malaria: A Case-Control Study, Benin, West Africa.

In sub-Saharan Africa, despite the implementation of multiple control interventions, the prevalence of malaria infection and clinical cases remains high. The primary tool for vector control against malaria in this region is the use of long-lasting insecticide-treated nets (LLINs) combined or not with indoor residual spraying (IRS) to achieve a synergistic effect in protection. The objective of this study was to assess the effectiveness of LLINs, with or without IRS, protected against infection and uncomplicated clinical cases (UCC) of malaria in Benin.

Bayesian spatial modelling of malaria burden in two contrasted eco-epidemiological facies in Benin (West Africa): call for localized interventions.

Background: Despite a global decrease in malaria burden worldwide, malaria remains a major public health concern, especially in Benin children, the most vulnerable group. A better understanding of malaria's spatial and age-dependent characteristics can help provide durable disease control and elimination. This study aimed to analyze the spatial distribution of Plasmodium falciparum malaria infection and disease among children under five years of age in Benin, West Africa.

Single low-dose primaquine for blocking transmission of Plasmodium falciparum malaria - a proposed model-derived age-based regimen for sub-Saharan Africa.

Background: In 2012, the World Health Organization recommended blocking the transmission of Plasmodium falciparum with single low-dose primaquine (SLDPQ, target dose 0.25 mg base/kg body weight), without testing for glucose-6-phosphate dehydrogenase deficiency (G6PDd), when treating patients with uncomplicated falciparum malaria. We sought to develop an age-based SLDPQ regimen that would be suitable for sub-Saharan Africa.

Effectiveness of insecticidal nets on uncomplicated clinical malaria: a case-control study for operational evaluation.

Background: In a context of large-scale implementation of malaria vector control tools, such as the distribution of long-lasting insecticide nets (LLIN), it is necessary to regularly assess whether strategies are progressing as expected and then evaluate their effectiveness. The present study used the case-control approach to evaluate the effectiveness of LLIN 42 months after national wide distribution. This study design offers an alternative to cohort study and randomized control trial as it permits to avoid many ethical issues inherent to them.

Inland valley rice production systems and malaria infection and disease in the forest region of western Côte d'Ivoire.

Background: This study aimed to determine the epidemiological impact of rice cultivation in inland valleys on malaria in the forest region of western Côte d'Ivoire. The importance of malaria was compared in terms of prevalence and parasite density of infections and also in terms of clinical malaria incidence between three agro-ecosystems: (i) uncultivated inland valleys, (R0), (ii) inland valleys with one annual rice cultivation in the rainy season, (R1) and (iii) developed inland valleys with two annual rice cultivation cycles, (R2).

Methods: Between May 1998 and March 1999, seven villages of each agro-ecosystem (R0, R1 and R2) were randomly selected among villages pooled by farming system.

First attempt to validate human IgG antibody response to Nterm-34kDa salivary peptide as biomarker for evaluating exposure to Aedes aegypti bites.

Background: Much effort is being devoted for developing new indicators to evaluate the human exposure to Aedes mosquito bites and the risk of arbovirus transmission. Human antibody (Ab) responses to mosquito salivary components could represent a promising tool for evaluating the human-vector contact.

Methodology/principal Findings: To develop a specific biomarker of human exposure to Aedes aegypti bites, we measured IgG Ab response to Ae.

Combination of malaria vector control interventions in pyrethroid resistance area in Benin: a cluster randomised controlled trial.

Background: Malaria control efforts and elimination in Africa are being challenged by the development of resistance of parasites to antimalarial drugs and vectors to insecticides. We investigated whether the combination of long-lasting insecticidal mosquito nets (LLINs) with indoor residual spraying (IRS) or carbamate-treated plastic sheeting (CTPS) conferred enhanced protection against malaria and better management of pyrethroid-resistance in vectors than did LLINs alone.

Methods: We did a cluster randomised controlled trial in 28 villages in southern Benin, west Africa.

Impact of prenatal multiple micronutrients on survival and growth during infancy: a randomized controlled trial.

Background: Although prenatal multiple micronutrients can improve fetal growth, their benefit on postnatal health remains uncertain.

Objective: We assessed the effect of the UNICEF/WHO/United Nations University multiple micronutrient supplement for pregnant and lactating women (UNIMMAP) compared with the usual iron and folic acid supplement (IFA) on survival, growth, and morbidity during infancy.

Design: In a double-blind, randomized trial, we followed 1294 singleton newborns whose mothers had prenatally received either the UNIMMAP or IFA.

Dry season determinants of malaria disease and net use in Benin, West Africa.

Background: To achieve malaria eradication, control efforts have to be sustained even when the incidence of malaria cases becomes low during the dry season. In this work, malaria incidence and its determinants including bed net use were investigated in children of under 5 years of age in 28 villages in southern Benin during the dry season.

Methods And Findings: Mean malaria clinical incidence was measured in children aged 0-5 years by active case detection in 28 villages of the Ouidah-Kpomasse-Tori Bossito sanitary district between November 2007 and March 2008.

Prevention and control of malaria and sleeping sickness in Africa: where are we and where are we going?

The International Symposium on Malaria and Human African Trypanosomiasis: New Strategies for their Prevention & Control was held 7-8 October, 2010 in Cotonou, Benin with about 250 participants from 20 countries. This scientific event aimed at identifying the gaps and research priorities in the prevention and control of malaria and sleeping sickness in Africa and to promote exchange between North and South in the fields of medical entomology, epidemiology, immunology and parasitology. A broad range of influential partners from academia (scientists), stakeholders, public health workers and industry attempted the meeting and about 40 oral communications and 20 posters were presented by phD students and internationally-recognized scientists from the North and the South.

Randomized controlled trial of 2 prenatal iron supplements: is there a dose-response relation with maternal hemoglobin?

Background: The most appropriate dose of iron to prevent maternal anemia is still unclear.

Objective: We assessed the dose-response relation between maternal hemoglobin and 2 prenatal iron supplements.

Design: An intention-to-treat, double-blind, randomized controlled trial compared 30 mg Fe + folic acid and 13 other micronutrients (UNIMMAP; UNICEF/WHO/UNU multiple micronutrient supplement for pregnant and lactating women) with 60 mg Fe + folic acid (IFA) only in rural Burkina Faso.

Malaria infection and disease in an area with pyrethroid-resistant vectors in southern Benin.

Background: This study aimed to investigate baseline data on malaria before the evaluation of new vector control strategies in an area of pyrethroid-resistance of vectors. The burden of malaria was estimated in terms of infection (prevalence and parasite density) and of clinical episodes.

Methods: Between December 2007 and December 2008 in the health district of Ouidah-Kpomassè-Tori Bossito (southern Benin), a descriptive epidemiological survey of malaria was conducted.

Culicidae diversity, malaria transmission and insecticide resistance alleles in malaria vectors in Ouidah-Kpomasse-Tori district from Benin (West Africa): A pre-intervention study.

Background: To implement an Insecticide Resistance Management (IRM) strategy through a randomized controlled trial (phase III), 28 villages were selected in southern Benin. No recent entomological data being available in these villages, entomological surveys were performed between October 2007 and May 2008, before vector control strategies implementation, to establish baseline data.

Methods: Mosquitoes were sampled by human landing collection (16 person-nights per village per survey per village) during 5 surveys.

Effect of maternal multiple micronutrient supplements on cord blood hormones: a randomized controlled trial.

Background: Fetal growth improves in pregnant women who take daily maternal multiple micronutrients [United Nations International Multiple Micronutrient Preparation (UNIMMAP)] rather than iron and folic acid (IFA) alone.

Objective: Our objective was to test whether such an effect was mediated by changes in concentrations of cord hormones.

Design: In a double-blind, controlled trial carried out in Burkina Faso, we randomly assigned 1426 pregnant women to receive UNIMMAP or IFA supplements.

Intermittent preventive treatment of malaria with sulphadoxine-pyrimethamine during pregnancy in Burkina Faso: effect of adding a third dose to the standard two-dose regimen on low birth weight, anaemia and pregnancy outcomes.

Background: Intermittent preventive treatment with sulphadoxine-pyrimethamine (IPTp-SP) is being implemented in most malaria endemic countries as a standard two-doses regimen as it reduces the risk of low birth weight (LBW) and the prevalence of maternal anaemia. Nevertheless, where the risk of infection close to delivery is high because of intense transmission, a third IPTp-SP dose may further reduce the negative effects of malaria on pregnancy outcome.

Methods: Pregnant women in the 2nd or 3rd trimester were randomized to receive either 2 (SP2) or 3 doses (SP3) of SP.

Social and environmental malaria risk factors in urban areas of Ouagadougou, Burkina Faso.

Background: Despite low endemicity, malaria remains a major health problem in urban areas where a high proportion of fevers are presumptively treated using anti-malarial drugs. Low acquired malaria immunity, behaviour of city-dwellers, access to health care and preventive interventions, and heterogenic suitability of urban ecosystems for malaria transmission contribute to the complexity of the malaria epidemiology in urban areas.

Methods: The study was designed to identify the determinants of malaria transmission estimated by the prevalence of anti-circumsporozoite (CSP) antibodies, the prevalence and density of Plasmodium falciparum infection, and the prevalence of malarial disease in areas of Ouagadougou, Burkina-Faso.

Effects of maternal multiple micronutrient supplementation on fetal growth: a double-blind randomized controlled trial in rural Burkina Faso.

Background: Intrauterine growth retardation is a major predictor of child health in developing countries.

Objective: We tested whether providing pregnant women with the UNICEF/WHO/UNU international multiple micronutrient preparation (UNIMMAP), rather than iron and folic acid alone, improved fetal growth and its correlates.

Design: An intention-to-treat, double-blind, randomized controlled trial including 1426 pregnancies was carried out in rural Burkina Faso.

Antimalarial drug use in general populations of tropical Africa.

Background: The burden of Plasmodium falciparum malaria has worsened because of the emergence of chloroquine resistance. Antimalarial drug use and drug pressure are critical factors contributing to the selection and spread of resistance. The present study explores the geographical, socio-economic and behavioural factors associated with the use of antimalarial drugs in Africa.

Sequence analysis of Plasmodium falciparum cytochrome b in multiple geographic sites.

Background: The antimalarial drug atovaquone specifically targets Plasmodium falciparum cytochrome b (Pfcytb), a mitochondrial gene with uniparental inheritance. Cases of resistance to atovaquone associated with mutant Pfcytb have been reported, justifying efforts to better document the natural polymorphism of this gene. To this end, a large molecular survey was conducted in several malaria endemic areas where atovaquone was not yet in regular use.

Genetic diversity and structure of African Plasmodium falciparum populations in urban and rural areas.

The genetic variability and population structure of Plasmodium falciparum are key factors in malaria control strategies. Studies have suggested no P. falciparum population structure although linkage disequilibrium was observed in some African areas.

Protective efficacy of lambda-cyhalothrin treated nets in Anopheles gambiae pyrethroid resistance areas of Côte d'Ivoire.

The efficacy of nets treated with lambda-cyhalothrin, a pyrethroid insecticide, on malaria infection and disease was assessed for the first time at the community level in Anopheles gambiae pyrethroid resistance areas. The study was carried out in northern Côte d'Ivoire, which is an area of kdr resistance. Four pairs of villages were selected and matched according to demographic, sociological, and ecological criteria.

Social and health determinants of the efficiency of cotton farmers in Northern Côte d'Ivoire.

This article assesses the role of malaria and some social determinants on the agricultural development and more precisely on efficiency in the context of cotton crop in the Korhogo region in the North of Côte d'Ivoire. Data envelopment analyses (DEA) was first applied for the purpose of calculating relative efficiencies in production. A Tobit regression model was then used to explain the variation in the DEA scores and check the hypotheses that the efficiency deviations between farmers can be explained by the disparity of malaria morbidity rate among the farmers and their family, by social cohesiveness and cultural behaviour.