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Apicomplexa phylum includes numerous obligate intracellular protozoan parasites that are life threatening for humans and animals. In this context, Plasmodium falciparum and Toxoplasma gondii are of particular interest, as they are responsible for malaria and toxoplasmosis, respectively, for which efficient vaccines are presently lacking and therapies need to be improved. Apicomplexan parasites have a highly polarized morphology, with their apical end containing specific secretory organelles named rhoptries and micronemes, which depend on the unique receptor and transporter sortilin TgSORT for their biogenesis. In the present study, we took advantage of the subcellular polarity of the parasite to engineer a clonal transgenic Toxoplasma line that expresses simultaneously the green fluorescent protein TgSORT-GFP in the post-Golgi-endosome-like compartment and the red fluorescent protein rhoptry ROP1-mCherry near the apical end. We utilized this fluorescent transgenic T. gondii to develop a miniaturized image-based phenotype assay coupled to an automated image analysis. By applying this methodology to 1,120 compounds, we identified 12 that are capable of disrupting the T. gondii morphology and inhibiting intracellular replication. Analysis of the selected compounds confirmed that all 12 are kinase inhibitors and intramembrane pumps, with some exhibiting potent activity against Plasmodium falciparum. Our findings highlight the advantage of comparative and targeted phenotypic analysis involving two related parasite species as a means of identifying molecules with a conserved mode of action.

Background The objective of this study was to estimate malaria transmission and insecticide resistance status in malaria vectors in Adjrako village from Zè District in Southern Benin. The present study was carried out prior to investigations on infectivity of blood from asymptomatic carriers of Plasmodium falciparum to malaria vector mosquitoes. Methods Human landing collections (HLCs) were performed in Adjrako village during the rainy season (September—November 2021). In this village, host-seeking mosquitoes were collected during three nights per survey from 22:00 to 06:00 in six randomly selected houses. Malaria vectors were dissected in orders to determinate their parity. Plasmodium falciparum infection in malaria vectors was determined by qPCR and the entomological inoculation rate (EIR) was calculated. The World Health Organization (WHO) insecticide susceptibility test-kits were used to evaluate the susceptibility of Anopheles gambiae sensu lato (s.l.) to deltamethrin at 0.05% and bendiocarb at 0.1%. Results A total of 3260 females of mosquitoes belonging to 4 genera (Anopheles, Culex, Aedes and Mansonia) were collected. Most of the mosquitoes collected were An. gambiae sensu lato (s.l.). The entomological inoculation rate (EIR) for the three collection months was 8.7 infective bites per person and the parity rate was 84%. Mortality rates of An. gambiae s.l. exposed to 0.05% deltamethrin and 0.1% bendiocarb were 18% and 96%, respectively, indicating that this vector population was resistant to deltamethrin and possibly resistant to bendiocarb in the study area. Conclusion This study showed that malaria transmission is effective in the study area and that An. gambiae s.l. is the main malaria vector. The entomological parameters indicate this study area is potentially favourable for investigations on P. falciparum asymptomatic carriers.

Background Immunoglobulin G (IgG) antibodies are thought to play important roles in the protection against Plasmodium falciparum (P. falciparum) malaria. A longitudinal cohort study performed in the Southern part of Benin, identified a group of infants who were able to control asymptomatic malaria infections (CAIG). Methods IgG antibodies against distinct merozoite antigens were quantified in plasma from Beninese infants. Functionality of these antibodies was assessed by the merozoite-phagocytosis assay using THP-1 cells and primary neutrophils as effector cells. Gm allotypes were determined by a serological method of haemagglutination inhibition. Results Purified IgG from infants in CAIG promoted higher levels of merozoite-phagocytosis than did IgG from children who were unable to control asymptomatic infections (Ologit multivariate regression model, Coef. = 0.06, 95% CI 0.02;0.10, P = 0.002). High level of merozoite-phagocytosis activity was significantly associated with high levels of IgG against AMA1 (Coef. = 1.76, 95% CI 0.39;3.14, P = 0.012) and GLURP-R2 (Coef. = 12.24, 95% CI 1.35;23.12, P = 0.028). Moreover, infants of the G3m5,6,10,11,13,14,24 phenotype showed higher merozoite-phagocytosis activity (Generalized linear model multivariate regression, Coef. = 7.46, 95% CI 0.31;14.61, P = 0.041) than those presenting other G3m phenotypes. Conclusion The results of the present study confirm the importance of antibodies to merozoite surface antigens in the control of asymptomatic malaria infection in Beninese infants. The study also demonstrated that G3m phenotypes impact the functional activity of IgG. This last point could have a considerable impact in the research of candidate vaccines against malaria parasites or other pathogens.

Objectives The aim of this study was to investigate the relationship between anthropometric characteristics and both geophagy and cognitive function of children. Study design The study prospectively followed singleton children whose mothers participated in the MiPPAD clinical trial in Allada, Benin, from birth to age 12 months. Anthropometric measurements were taken at birth and 9 and 12 months. Wasting, stunting and underweight were defined as weight-for-length, length-for-age and weight-for-age Z-scores less than −2, respectively. Cognitive and motor functions were assessed using the Mullen Scales of Early Learning. Parent-reported geophageous habits of children were collected when the children were 12 months. Multiple linear and logistic regressions were used to analyse the data. Results A total of 632 children (49.7% girls) were involved in the study. Stunting, wasting and underweight were observed in 14.1%, 13.6% and 17.7%, respectively, at 9 months and 17.3%, 12.7% and 17.2%, respectively, at 12 months. The prevalence of geophagy among the children was 48.2%. Impaired growth at 9 and 12 months was consistently associated with low cognitive and gross motor (GM) score. Children stunted at 9 months had lower GM scores at 12 months compared with their non-stunted peers (β = −3.48, 95% confidence interval −6.62 to −0.35). Conclusions Stunting, wasting and underweight are associated with cognitive and GM deficits in infants. In this setting, impaired growth was not associated with geophagy. Further research evaluating geophagy and growth prospectively and concurrently from birth to 36 months is needed.

Background Plasmodium falciparum-infected erythrocytes bind to specific endothelial cell receptors via members of the PfEMP1 family exported onto the erythrocyte surface. These interactions are mediated by different types of cysteine-rich interdomain region (CIDR) domains found in the N-terminal region of all PfEMP1. CIDRα1 domains bind endothelial protein C receptor (EPCR), CIDRα2–6 domains bind CD36, whereas the receptor specificity of CIDRβ/γ/δ domains is unknown. Methods In this study, we investigated the level of immunoglobulin (Ig)G targeting the different types of PfEMP1 CIDR during the first year of life. We used plasma collected longitudinally from children of pregnant women who had been followed closely through pregnancy. Results Antibodies to CIDRα1 domains were more frequent in cord blood compared with antibodies to CIDRα2–6 domains. Higher IgG levels to EPCR-binding CIDRα1 variants positively correlated with the timing of first infections. Antibodies to all PfEMP1 types declined at similar rates to the point of disappearance over the first 6 months of life. At 12 months, children had acquired antibody to all types of CIDR domains, mostly in children with documented P falciparum infections. Conclusions These observations agree with the notion that the timing and phenotype of first P falciparum infections in life are influenced by the immune status of the mother.

Background Malaria in early pregnancy occurs at a time when the placenta is developing, with possible consequences for placental function and fetal growth. We assessed the association between first trimester malaria and fetal growth documented through repeated ultrasound scans. Methods The RECIPAL preconceptional cohort included 411 Beninese pregnant women followed from 7 weeks’ gestation (wg) until delivery. Among them, 218 had 4 scans for fetal monitoring at 16, 22, 28, and 34 wg. Multivariate seemingly unrelated regression models were used to assess association of microscopic malaria in the first trimester ( Results Of 39% (86/218) of women with at least 1 microscopic malarial infection during pregnancy, 52.3% (45/86) were infected in the first trimester. Most women (88.5%) were multiparous. There was no association between adjusted z-scores for fetal growth parameters and first trimester malaria. Parity, newborn sex, socioeconomic level, and maternal body mass index significantly influenced fetal growth. Conclusions In a context where malaria infections in pregnancy are well detected and treated, their adverse effect on fetal growth may be limited. Our results argue in favor of preventing and treating infections as early as the first trimester.

Pregnant women constitute a promising sentinel group for continuous monitoring of malaria transmission. To identify antibody signatures of recent Plasmodium falciparum exposure during pregnancy, we dissected IgG responses against VAR2CSA, the parasite antigen that mediates placental sequestration. We used a multiplex peptide-based suspension array in 2,354 samples from pregnant women from Mozambique, Benin, Kenya, Gabon, Tanzania, and Spain. Two VAR2CSA peptides of limited polymorphism were immunogenic and targeted by IgG responses readily boosted during infection and with estimated half-lives of

Background In the context of global malaria elimination efforts, special attention is being paid to submicroscopic Plasmodium falciparum infections. In pregnant, sub-Saharan African women, such infections are more prevalent than microscopic infections, and are thought to have adverse effects on both mothers’ and newborns’ health. However, no study has studied the dynamics and determinants of these infections throughout pregnancy. Retard de Croissance Intra-uterin et Paludisme (RECIPAL), a preconception cohort study carried out in Benin between 2014 and 2017, represented a unique opportunity to assess this issue. Methods We used data from 273 pregnant Beninese women who were followed-up from preconception to delivery. We studied the dynamics of and factors influencing submicroscopic (and microscopic) P. falciparum infections during the 3 trimesters of pregnancy, using an ordinal logistic mixed model. Results The incidence rate of submicroscopic P. falciparum infections during pregnancy was 12.7 per 100 person-months (95% confidence interval [CI] 10.8–14.9), compared to 6.7 per 100 person-months (95% CI 5.5–8.1) for microscopic infections. The prevalences were highest in the first trimester for both submicroscopic and microscopic infections. After adjustment for potential confounding factors, we found that those of young age and those with a submicroscopic P. falciparum infection prior to pregnancy were at significantly higher risks of submicroscopic and microscopic infections throughout pregnancy, with a more pronounced effect in the first trimester of pregnancy. Conclusions The first trimester of pregnancy is a particularly high-risk period for P. falciparum infection during pregnancy, especially for the youngest women. Malaria prevention tools covering the preconception period and early pregnancy are urgently needed to better protect pregnant women and their newborns., In a preconception malaria cohort study, the prevalence of submicroscopic versus microscopic Plasmodium falciparum infections was higher throughout pregnancy, most markedly in the first trimester, and young women with submicroscopic infections before pregnancy had a higher subsequent risk of infection.

A national mapping of human schistosomiasis was conducted in Benin to provide the baseline epidemiological data required to implement the national strategy for schistosomiasis control and elimination to achieve the WHO's goal of reaching at least 75% of school-age children in endemic areas by 2020.Parasitological surveys were conducted from 2013 to 2015, among 19,250 children aged 8-14 years randomly sampled in 385 units (schools/villages) across all districts. Urine and stool samples were examined using parasite-egg filtration for urine samples and the Kato-Katz technique for stool specimens.Human schistosome eggs from two major species (S. haematobium and S. mansoni) were detected in the surveyed population with variable prevalence and parasite intensity. Urinary schistosomiasis due to S. haematobium was widely distributed and detected in 76/77 districts with a national average prevalence of 17.56% (95 °CI:16.80%- 18.32%), compared to S. mansoni detected in 28/77 districts with a national prevalence of 2.45% (95 °CI:2.14%-2.76%). The combined national prevalence of schistosomiasis, defined by infections with either or both schistosome species was 19.78% (95% CI:18.90% -20.49%), and was detected in 76/77 districts. Based on our findings, 31 districts were classified as low-risk (0% and10%); 37 as moderate-risk (≥10% and50%); and 8 as high-risk (≥50%) of schistosome infection. No infection was detected in Kpomassè district in this study. In several districts where the two species were endemic with prevalence ≥10%, S. haematobium was the most prevalent schistosome species. Boys were relatively more infected than girls (18.29% v 16.82%, p = 0.007). Of note, heavy infections with S. haematobium (50 eggs/10 mL) were detected in several districts of Atacora, Donga, Borgou, Collines, Ouémé and Atlantique departments.The schistosomiasis mapping reported here clearly present a nationwide view of the epidemiological pattern of Schistosoma infections and the baseline data for implementing an effective control strategy by preventive chemotherapy (PCT). Although PCT might not be required in 32/77 districts, a yearly and bi-annual deworming is needed in 2 and 43 districts, respectively. If no environmental change occurs, and no mass treatment is delivered, prevalence is likely to remain stable for many years owing to poor hygiene and sanitation.

Made available in DSpace on 2021-06-25T11:03:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-08-01 Institut de Recherche pour le Développement Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Background: Little attention has been devoted to the role of the immunoregulatory HLA-E/-F/−G genes in malaria. We evaluated the entire HLA-E/-F/−G variability in Beninese children highly exposed to Plasmodium falciparum (P.f.) malaria. Methods: 154 unrelated children were followed-up for six months and evaluated for the presence and number of malaria episodes. HLA-E/-F/−G genes were genotyped using massively parallel sequencing. Anti P.f. antibodies were evaluated using ELISA. Results: Children carrying the G allele at HLA-F (−1499,rs183540921) showed increased P.f. asymptomatic/symptomatic ratio, suggesting that these children experienced more asymptomatic P.f. episodes than symptomatic one. Children carrying HLA-G-UTR-03 haplotype exhibited increased risk for symptomatic P.f. episodes and showed lower IgG2 response against P.f. GLURP-R2 when compared to the non-carriers. No associations were observed for the HLA-E gene. Conclusion: HLA-F associations may be related to the differential expression profiles of the encoded immunomodulatory molecules, and the regulatory sites at the HLA-G 3'UTR may be associated to posttranscriptional regulation of HLA-G and to host humoral response against P.f. Post-graduate Program in Basic and Applied Immunology Ribeirão Preto Medical School University of São Paulo, Avenida Bandeirantes, 3900, Monte Alegre Immunogenetic Laboratory Immunology Department Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Av. Moraes rego, s/n, Campus da UFPE, Cidade Universitária Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance (CERPAGE) faculté des Sciences de la Santé Cotonou Université de Paris, UMR 261 MERIT, IRD Département de Zoologie faculté des Sciences et Techniques Université d'Abomey-Calavi Intertryp IRD Cirad University of Montpellier, Avenue Agropolis São Paulo State University (UNESP) School of Medicine Molecular Genetics and Bioinformatics Laboratory, Av. Prof. Dr. Walter Maurício Correa, s/n Centre Médical Saint Joseph Sô Ava CEA DRF-Institut François Jacob Service de Recherches en Hémato-Immunologie, Hopital Saint-Louis Université de Paris CEA U976 HIPI Unit (Human Immunology Physiopathology Immunotherapy) Institut de Recherche Saint-Louis Departamento de Química Faculdade de Filosofia Ciências e Letras de Ribeirão Preto Universidade de São Paulo, AV Bandeirantes, 3900 Laboratoire de Biologie et Physiologie Cellulaire Université d'Abomey-Calavi São Paulo State University (UNESP) Department of Pathology School of Medicine São Paulo State University (UNESP) School of Medicine Molecular Genetics and Bioinformatics Laboratory, Av. Prof. Dr. Walter Maurício Correa, s/n São Paulo State University (UNESP) Department of Pathology School of Medicine CAPES: #304931/2014-1 CAPES: #466036/2013-5 CAPES: 302060/2019-07 CAPES: 406594/2013-9 CNPq: PROCAD#88881-068436/2014-1

Background Harmful maternal and neonatal health outcomes result from malaria in pregnancy, the prevention of which primarily relies on intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP). The World Health Organization recommends IPTp-SP in sub-Saharan Africa, but implementation is highly heterogeneous and often suboptimal in terms of the number of doses and their timing. In this study, we assessed the impact of this heterogeneity on malaria in pregnancy, mainly with respect to submicroscopic Plasmodium falciparum infections. Methods We used data from 273 Beninese women followed throughout pregnancy. Screening for P. falciparum infections, using both microscopy-based and polymerase chain reaction (PCR)–based methods, was performed monthly, and information on IPTp-SP doses was collected. Gestational age was estimated by repeated ultrasound scans. Using a negative binomial model, we investigated the effect of IPTp-SP doses and timing after 17 weeks of gestation on the number of P. falciparum infections, focusing on submicroscopic infections detectable only by PCR. Results At least 2 IPTp-SP doses were taken by 77.3% of the women. The median gestational age at the first IPTp-SP dose was 22 weeks. A late first IPTp-SP dose (>21.2 weeks) was marginally associated with an increased number of P. falciparum infections (adjusted incidence rate ratio [aIRR] = 1.3; P = .098). The number of IPTp-SP doses was not associated with the number of submicroscopic infections (aIRR = 1.2, P = .543). Conclusions A late first IPTp-SP dose failed to provide optimal protection against P. falciparum, especially submicroscopic infections. This highlights the need for a new antimalarial drug for IPTp that could be taken early in pregnancy., In a cohort study, increased numbers of Plasmodium falciparum infections were found in pregnant women with suboptimal dose numbers and late first doses of intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP). The timing of IPTp-SP primarily affects submicroscopic infections.

Malaria during pregnancy is a major cause of maternal morbidity as well as fetal and neonatal mortality. Previous studies, including our own, suggested that placental and peripheral cytokine and chemokine levels measured at delivery can be used as biomarkers for pregnancy outcomes. However, the timing of malaria infection during pregnancy matters, and these studies do not address the effect of different cytokines in peripheral blood plasma samples taken at early and midpregnancy and at delivery. Here, we aimed to investigate whether peripheral plasma cytokine levels were associated with pregnancy outcomes in a cohort of 400 Beninese pregnant women. Using a high-sensitivity cytometry-based method, we quantified the levels of interleukin-4 (IL-4), IL-5, IL-10, IL-12p70, and gamma interferon (IFN-γ) in peripheral plasma samples taken at two time points during pregnancy and at delivery in various groups of pregnant women identified with Plasmodium falciparum infection, with anemia, with preterm births, or giving birth to babies who are small for their gestational age. We found that, consistently at all time points, elevated levels of IL-10 were strongly and significantly associated with P. falciparum infection, while the levels of IFN-γ at inclusion and delivery were weakly but also significantly associated. Low levels of IL-5 at delivery were associated with a greater risk of both preterm births and small-for-gestational-age babies. The immunosuppressive effects of IL-10 likely affect the overall cytokine equilibrium during pregnancy in women harboring P. falciparum infections. Our findings highlight the peripheral signature of pregnancy outcomes and strengthen the idea of using cytokines as diagnostic or prognostic markers.

An amendment to this paper has been published and can be accessed via the original article.

Snakebite is a critical public health issue in tropical countries, particularly in Africa, where 20% of snakebites globally occur. In 2017, the WHO added snakebite envenoming to the category A of neglected tropical diseases. In 2019, thanks to broad institutional and international NGO support, including strong mobilization of African experts and governments, WHO launched a strategy for prevention and control of snakebite envenoming with more ambitious goals. In sub-Saharan Africa, accessibility of antivenoms and symptomatic, adjuvant or replacement therapy is a priority. Several antivenoms are available but their evaluation has not been properly carried out and they remain expensive. To date, there are no manufacturers of antivenom in sub-Saharan Africa (except in South Africa), which requires their importation from other continents. The lack of experience in antivenom choice and its use by health authorities, health personnel and population largely explains the shortage in sub-Saharan Africa. The deficiency of epidemiological data does not allow the implementation of appropriate and efficient care. It is crucial to strengthen the health system which does not have the necessary means for emergency management in general and envenoming in particular. Providing peripheral health centers with antivenoms would decrease complications and deaths. The motivation of communities at risk, identified through the epidemiological data, would be to reduce the delay in consultation that is detrimental to the efficiency of treatment. Partnerships need to be coordinated to optimize resources from international institutions, particularly African ones, and share the burden of treatment costs among all stakeholders. We propose here a project of progressive implementation of antivenom manufacturing in sub-Saharan Africa. The various steps, from the supply of appropriate venoms to the production of purified specific antibodies and vial filling, would be financed by international, regional and local funding promoting technology transfer from current manufacturers compensated by interest on the sale of antivenoms.

Summary Background Scale-up of insecticide-based interventions has averted more than 500 million malaria cases since 2000. Increasing insecticide resistance could herald a rebound in disease and mortality. We aimed to investigate whether insecticide resistance was associated with loss of effectiveness of long-lasting insecticidal nets and increased malaria disease burden. Methods This WHO-coordinated, prospective, observational cohort study was done at 279 clusters (villages or groups of villages in which phenotypic resistance was measurable) in Benin, Cameroon, India, Kenya, and Sudan. Pyrethroid long-lasting insecticidal nets were the principal form of malaria vector control in all study areas; in Sudan this approach was supplemented by indoor residual spraying. Cohorts of children from randomly selected households in each cluster were recruited and followed up by community health workers to measure incidence of clinical malaria and prevalence of infection. Mosquitoes were assessed for susceptibility to pyrethroids using the standard WHO bioassay test. Country-specific results were combined using meta-analysis. Findings Between June 2, 2012, and Nov 4, 2016, 40 000 children were enrolled and assessed for clinical incidence during 1·4 million follow-up visits. 80 000 mosquitoes were assessed for insecticide resistance. Long-lasting insecticidal net users had lower infection prevalence (adjusted odds ratio [OR] 0·63, 95% CI 0·51–0·78) and disease incidence (adjusted rate ratio [RR] 0·62, 0·41–0·94) than did non-users across a range of resistance levels. We found no evidence of an association between insecticide resistance and infection prevalence (adjusted OR 0·86, 0·70–1·06) or incidence (adjusted RR 0·89, 0·72–1·10). Users of nets, although significantly better protected than non-users, were nevertheless subject to high malaria infection risk (ranging from an average incidence in net users of 0·023, [95% CI 0·016–0·033] per person-year in India, to 0·80 [0·65–0·97] per person year in Kenya; and an average infection prevalence in net users of 0·8% [0·5–1·3] in India to an average infection prevalence of 50·8% [43·4–58·2] in Benin). Interpretation Irrespective of resistance, populations in malaria endemic areas should continue to use long-lasting insecticidal nets to reduce their risk of infection. As nets provide only partial protection, the development of additional vector control tools should be prioritised to reduce the unacceptably high malaria burden. Funding Bill & Melinda Gates Foundation, UK Medical Research Council, and UK Department for International Development.

In pregnancy-associated malaria, infected erythrocytes accumulate in the placenta. It is unclear if in polyclonal infections this results in distinct peripheral and placental parasite populations. We used long amplicon deep sequencing of Plasmodium falciparum var2csa ID1-DBL2X from 15 matched peripheral and placental samples collected at delivery from a high transmission area to determine genetic homology. Despite substantial sequence variation and detecting 23 haplotypes, the matched pairs mostly contained the same genetic variants, with 11 pairs sharing 100% of their variants, whereas others showed some heterogeneity. Thus, at delivery, peripheral and placental parasites appear to intermix and placental genotypes can be inferred through peripheral sampling.

Background Despite several years of school-based MDA implementation, STH infections remain an important public health problem in Benin, with a country-wide prevalence of 20% in 2015. The DeWorm3 study is designed to assess the feasibility of using community-based MDA with albendazole to interrupt the transmission of STH, through a series of cluster-randomized trials in Benin, India and Malawi. We used the pre-treatment baseline survey data to describe and analyze the factors associated with STH infection in Comé, the study site of the DeWorm3 project in Benin. These data will improve understanding of the challenges that need to be addressed in order to eliminate STH as a public health problem in Benin. Methods Between March and April 2018, the prevalence of STH (hookworm spp., Ascaris and Trichuris trichiura) was assessed by Kato-Katz in stool samples collected from 6,153 residents in the community of Comé, Benin using a stratified random sampling procedure. A standardized survey questionnaire was used to collect information from individual households concerning factors potentially associated with the presence and intensity of STH infections in pre-school (PSAC, aged 1–4), school-aged children (SAC, aged 5–14) and adults (aged 15 and above). Multilevel mixed-effects models were used to assess associations between these factors and STH infection. Results The overall prevalence of STH infection was 5.3%; 3.2% hookworm spp., 2.1% Ascaris lumbricoides and 0.1% Trichuris. Hookworm spp. were more prevalent in adults than in SAC (4.4% versus 2.0%, respectively; p = 0.0001) and PSAC (4.4% versus 1.0%, respectively; p, Author summary Despite several years of deworming campaigns targeting school-aged children, soil-transmitted helminths (STH) remains a public health problem in most developing countries, including Benin. The burden is mostly on children and pregnant women, but also on the whole society. Soil-transmitted helminths are responsible for malnutrition, anemia, low birth weight, cognitive impairment, decrease of school performance, and subsequently economic loss. The current strategy of the Benin National Neglected Tropical Diseases (NTD) Program is to achieve STH control through mass drug administration campaigns targeting school-aged children (SAC). The baseline data of Deworm3 study, implemented in Comé, southern Benin, as part of a multicountry (Benin, Malawi and India) STH elimination trial, shows that previous school deworming campaigns decreased STH prevalence; however there is a persistent reservoir of STH infection in adults and pre-school aged children that should be targeted for a better impact. In order to eliminate STH as a public health problem, Benin National NTD Program would need to increase its target population, from the SAC to the whole community. The future results of Deworm3 trial would demonstrate whether the STH elimination goal STH using community wide mass drug administration would be achievable.

Background Innovative approaches are needed to limit antimalarial resistance evolution. Understanding the role of intermittent preventive treatment in pregnancy (IPTp) on the selection for resistance and the impact such selection has on pregnancy outcomes can guide future interventions. Methods Plasmodium falciparum isolates (n = 914) from 2 randomized clinical trials were screened for pfmdr1 copy number variation and pfcrt, pfmdr1, pfdhfr, and pfdhps resistance markers. The trials were conducted between 2010 and 2013 in Benin, Gabon, Kenya, and Mozambique to establish the efficacy of IPTp-mefloquine (MQ) compared with IPTp-sulphadoxine-pyrimethamine (SP) in human immunodeficiency virus (HIV)-uninfected and to IPTp-placebo in HIV-infected women. Results In HIV-uninfected women, the prevalence of pfcrt mutants, pfdhfr/pfdhps quintuple mutants, and pfmdr1 copy number was similar between women receiving IPT-SP and IPTp-MQ. However, prevalence of pfmdr1 polymorphism 86Y was lower in the IPTp-MQ group than in the IPTp-SP group, and within the IPTp-MQ group it was lower at delivery compared with recruitment. No effect of IPTp-MQ on resistance markers was observed among HIV-infected women. The carriage of resistance markers was not associated with pregnancy outcomes. Conclusions Selection of wild-type pfmdr1 polymorphism N86 by IPTp-MQ highlights the strong selective pressure IPTp can exert and the opportunity for using negative cross-resistance in drug choice for clinical treatment and IPTp.

Introduction: HLA-G plays a key role on immune tolerance. Pathogens can induce soluble HLA-G (sHLA-G) production to down-regulate the host immune response, creating a tolerogenic environment favorable for their dissemination. To our knowledge, no study has yet been conducted to assess the relationship between sHLA-G and geohelminth infections. Methods: The study was conducted in Allada, Southeastern Benin, from 2011 - 2014. The study population encompassed 400 pregnant women, included before the end of the 28th week of gestation and followed-up until delivery. At two antenatal care visits and at delivery, stool and blood samples were collected. Helminths were diagnosed by means of the Kato-Katz concentration technique. We used quantile regression to analyze the association between helminth infections and sHLA-G levels during pregnancy. Results: sHLA-G levels gradually increased during pregnancy and reached maximal levels at delivery. Prevalence of helminth infections was low, with a majority of hookworm infections. We found significantly more hookworm-infected women above the 80th quantile (Q80) of the distribution of the mean sHLA-G level (p < 0.03, multivariate quantile regression). Considering only women above the Q80 percentile, the mean sHLA-G level was significantly higher in hookworm-infected compared to uninfected women (p = 0.04). Conclusion: High levels of sHLA-G were associated with hookworm infection in pregnant women. This result is consistent with the potential involvement of sHLA-G in immune tolerance induced by helminths during pregnancy.

IntroductionIn 2016, an estimated 216 million cases and 445 000 deaths of malaria occurred worldwide, in 91 countries. In Benin, malaria causes 26.8% of consultation and hospitalisation motif in the general population and 20.9% in children under 5 years old.The goal of the NeuroCM project is to identify the causative factors of neuroinflammation in the context of cerebral malaria. There are currently very few systematic data from West Africa on the aetiologies and management of non-malarial non-traumatic coma in small children, and NeuroCM will help to fill this gap. We postulate that an accurate understanding of molecular and cellular mechanisms involved in neuroinflammation may help to define efficient strategies to prevent and manage cerebral malaria.Methods and analysisThis is a prospective, case-control study comparing cerebral malaria to uncomplicated malaria and non-malarial non-traumatic coma. This study takes place in Benin, precisely in Cotonou for children with coma and in Sô-Ava district for children with uncomplicated malaria. We aim to include 300 children aged between 24 and 71 months and divided in three different clinical groups during 12 months (from December 2017 to November 2018) with a 21 to 28 days follow-up for coma. Study data, including clinical, biological and research results will be collected and managed using CSOnline-Ennov Clinical.Ethics and disseminationEthics approval for the NeuroCM study has been obtained fromComité National d’Ethique pour la Recherche en santéof Benin (n°67/MS/DC/SGM/DRFMT/CNERS/SA; 10/17/2017). NeuroCM study has also been approved byComité consultatif de déontologie et d’éthiqueof Institut de Recherche pour le Développement (IRD; 10/24/2017). The study results will be disseminated through the direct consultations with the WHO’s Multilateral Initiative on Malaria (TDR-MIM) and Roll Back Malaria programme, through scientific meetings and peer-reviewed publications in scientific or medical journals, and through guidelines and booklets.

BACKGROUND: Substantial evidence indicates that cytophilic IgG responses to Plasmodium falciparum merozoite antigens play a role in protection from malaria. The specific targets mediating immunity remain unclear. Evaluating antibody responses in infants naturally-exposed to malaria will allow to better understand the establishment of anti-malarial immunity and to contribute to a vaccine development by identifying the most appropriate merozoite candidate antigens.METHODS: The study was based on parasitological and clinical active follow-up of infants from birth to 18 months of age conducted in the Tori Bossito area of southern Benin. For 399 infants, plasma levels of cytophilic IgG antibodies with specificity for five asexual stage malaria vaccine candidate antigens were determined by ELISA in infants' peripheral blood at 6, 9, 12 and 15 months of age. Multivariate mixed logistic model was used to investigate the association between antibody levels and anti-malarial protection in the trimester following the IgG quantification. Moreover, the concentrations of merozoite antigen-specific IgG were compared between a group of infants apparently able to control asymptomatic malaria infection (CAIG) and a group of infants with no control of malaria infection (Control group (NCIG)). Protective effect of antibodies was also assessed after 15 months of malaria exposure with a Cox regression model adjusted on environmental risk.RESULTS: Cytophilic IgG responses to AMA1, MSP1, MSP2-3D7, MSP2-FC27, MSP3 and GLURP R2 were associated with increasing malarial infection risk in univariate analysis. The multivariate mixed model showed that IgG1 and IgG3 to AMA1 were associated with an increased risk of malarial infection. However infants from CAIG (n = 53) had significantly higher AMA1-, MSP2-FC27-, MSP3-specific IgG1 and AMA1-, MSP1-, MSP2-FC27-, MSP3 and GLURP-R2-specific IgG3 than those from NCIG (n = 183). The latter IgG responses were not associated with protection against clinical malaria in the whole cohort when protective effect is assessed after 15 months of malaria exposition.CONCLUSION: In this cohort, merozoite antigen-specific cytophilic IgG levels represent a marker of malaria exposure in infants from 6 to 18 months of age. However, infants with resolution of asymptomatic infection (CAIG) seem to have acquired naturally immunity against P. falciparum. This observation is encouraging in the context of the development of multitarget P. falciparum vaccines.

BACKGROUND Few studies have evaluated the effect of malaria on intrauterine growth restriction on the basis of the fetal growth rate, rather than just the small-for-gestational age z score. Here, we assessed the impact of malaria on IUGR, using data from a longitudinal, ultrasonography-based follow-up study of Beninese women. METHODS A total of 1016 women were followed up from gestational week 17 to delivery. Malaria was detected every month. Women underwent ultrasonography 4 times for gestational age determination and fetal biometry. We assessed the effect of malaria on birth weight-for-gestational age z score (n = 735 women) and fetal growth velocity (n = 664), defined as a change in fetal weight z score over time. RESULTS Malaria was detected in 43% of women. Fetal growth velocity was negative overall, decreasing further at the end of the third trimester. Women with ≥2 malarial parasite infections tended to have lower z scores than uninfected women. Malaria both in early and late pregnancy was associated with a reduction in fetal growth velocity, which occurred either immediately or with a delay after infection. DISCUSSIONS We confirmed the deleterious effect of malaria during both early and late pregnancy on fetal growth. This stresses the importance of starting preventive measures against malaria as early as possible during pregnancy.

Background In sub-Saharan Africa, malaria in the first half of pregnancy is harmful for both the mother and her fetus. However, malaria in the first trimester of pregnancy, when women are usually not protected against malaria, has been little investigated. For the first time, we assessed the effects of malaria in the first trimester on maternal and birth outcomes using a preconceptional study design. Methods From June 2014 to March 2017, 1214 women of reproductive age were recruited and followed monthly until 411 became pregnant. The pregnant women were then followed from 5–6 weeks of gestation until delivery. Path analysis was used to assess the direct effect (ie, not mediated by malaria in the second or third trimester) of malaria in the first trimester on maternal anemia and poor birth outcomes. The cumulative effect of infections during pregnancy on the same outcomes was also evaluated. Results The prevalence of malaria infections in the first trimester was 21.8%. Malaria in the first trimester was significantly associated with maternal anemia in the third trimester (adjusted odds ratio 2.25, 95% confidence interval 1.11–4.55). While we did not find evidence of any direct effect of first trimester malaria infections on birth outcomes, their association with infections later in pregnancy tended to increase the risk of low birth weights. Conclusions Malaria infections in the first trimester were highly prevalent and have deleterious effects on maternal anemia. They highlight the need for additional preventive measures, starting in early pregnancy or even before conception.

Background. According to the Developmental Origins of Health and Diseases paradigm, the fetal period is highly vulnerable and may have profound effects on later health. Few studies assessed the effect of small-for-gestational age (SGA), a proxy for fetal growth impairment, on risk of malaria during infancy in Africa. Methods. We used data from a cohort of 398 mother-child pairs, followed from early pregnancy to age 1 year in Benin. Malaria was actively and passively screened using thick blood smear. We assessed the effect of SGA on risk of malaria infection and clinical malaria from birth to 12 months, after stratifying on the infant's age using a logistic mixed regression model. Results. After adjustment for potential confounding factors and infant's exposure to mosquitoes, SGA was associated with a 2-times higher risk of malaria infection (adjusted odds ratio [aOR] = 2.16; 95% confidence interval [CI], 1.04-4.51; P = .039) and clinical malaria (aOR = 2.33; 95% CI, 1.09-4.98; P = .030) after age 6 months. Conclusion. Results suggest higher risk of malaria during the second semester of life in SGA infants, and argue for better follow-up of these infants after birth, as currently for preterm babies.

Objective To investigate the relationship between prenatal geophagy, maternal prenatal haematological indices, malaria, helminth infections and cognitive and motor development among offspring. Methods: At least a year after delivery, 552 of 863 HIV-negative mothers with singleton births who completed a clinical trial comparing the efficacy of sulfadoxine-pyrimethamine and mefloquine during pregnancy in Allada, Benin, responded to a nutrition questionnaire including their geophagous habits during pregnancy. During the clinical trial, helminth infection, malaria, haemoglobin and ferritin 3 concentrations were assessed at 1st and 2nd antenatal care visits (ANV) and at delivery. After the first ANV, women were administered daily iron and folic acid supplements until three months postdelivery. Singleton children were assessed for cognitive function at age 1 year using the Mullen Scales of Early Learning. Results: The prevalence of geophagy during pregnancy was 31.9%. Pregnant women reporting geophagy were more likely to be anaemic (AOR = 1.9, 95% CI [1.1, 3.4]) at their first ANV if they reported geophagy at the first trimester. Overall, prenatal geophagy was not associated with maternal haematological indices, malaria or helminth infections, but geophagy during the third trimester and throughout pregnancy was associated with poor motor function (AOR = -3.8, 95% CI [-6.9, -0.6]) and increased odds of geophagous behaviour in early childhood, respectively. Conclusions: Prenatal geophagy is not associated with haematological indices in the presence of micronutrient supplementation. However, it may be associated with poor child motor function and infant geophagy. Geophagy should be screened early in pregnancy.

Background The whole blood clotting test (WBCT) is a simple test of coagulation that is often used in the assessment, diagnosis, and therapeutic monitoring of snakebite patients in sub-Saharan Africa. WBCT requires only a clean glass tube and several milliliters of venous blood and is ideal for use in poorly equipped health centers throughout the rural areas where 95% of snakebites occur. However, questions surrounding the accuracy and reliability of the test remain unanswered due to variations in testing conditions and a lack of comparative research with which to validate them. This is the first study to evaluate WBCT results at both 20-min (WBCT20) and 30-min (WBCT30) reading times in the same group of snakebite patients. Methods In order to define the best reading time, the authors compared the results of serial WBCT evaluation at both 20 and 30 min after collection in 23 patients treated for snake envenomation in Bembèrèkè, northern Benin. Results WBCT results were identical at both reading times in patients without coagulopathy or when coagulation was restored permanently following a single dose of antivenom. Out of 17 patients with coagulopathy, 14 showed discrepancies between WBCT20 and WBCT30 results in at least one pair of serial evaluations. These could be completely contradictory results (e.g. normal clot at WBCT20 and no clot at WBCT30) or a marked difference in the quality of the clot (e.g. no clotting activity at WBCT20 and an unstable partial clot at WBCT30). WBCT discrepancies were encountered most frequently in three situations: initial normalization of hemostasis following antivenom therapy, detection of a secondary resumption of coagulopathy, or final restoration of hemostasis after a secondary resumption had occurred. Conclusions This study suggests that the WBCT is robust and that a sequential reading should improve the diagnosis and monitoring of venom-induced coagulopathies. It also indicates the possibility of discrepancies in the sensitivity of WBCT20 and WBCT30 for detecting the resolution or reoccurrence of coagulopathy and identifies how these findings, if confirmed, may be used to increase the efficacy and efficiency of antivenom treatment in the field.

Background Pregnant women are more susceptible to Plasmodium falciparum than before pregnancy, and infection has consequences for both mother and offspring. The World Health Organization recommends that pregnant woman in areas of transmission receive intermittent preventive treatment (IPTp) starting in the second trimester. Consequently, women are not protected during the first trimester, although P. falciparum infections are both frequent and harmful. Methods A cohort of nulligravid women was followed up during subsequent pregnancy. Malaria was diagnosed by means of microscopy and polymerase chain reaction. Parasites were genotyped at polymorphic loci. Results Among 275 nulligravidae enrolled, 68 women became pregnant and were followed up during pregnancy. Before pregnancy, P. falciparum prevalence rates were 15% by microscopy and 66% by polymerase chain reaction. Microscopic infection rates increased to 29% until IPTp administration, and their density increased by 20-fold. Conversely, submicroscopic infection rates decreased. After IPTp administration, all types of infections decreased, but they increased again late in pregnancy. The risk of infection during pregnancy was higher in women with a microscopic (odds ratio, 6.5; P = .047) or submicroscopic (3.06; P = .05) infection before pregnancy and was not related to the season of occurrence. Most infections during pregnancy were persistent infections acquired before pregnancy. Conclusions Microscopic and submicroscopic malaria infections were frequent in nulligravid women from south Benin. During the first trimester of pregnancy, microscopic infections were more frequent, with a higher parasite density, and mainly derived from parasites infecting the woman before conception. Preventive strategies targeting nonpregnant women with a desire for conception need to be designed.

Immunity requires a vaccine that inhibits binding of infected erythrocytes to chondroitin sulfate., Placental malaria is caused by Plasmodium falciparum–infected erythrocytes that bind to placental tissue. Binding is mediated by VAR2CSA, a parasite antigen coded by the var gene, which interacts with chondroitin sulfate A (CSA). Consequences include maternal anemia and fetal growth retardation. Antibody-mediated immunity to placental malaria is acquired during successive pregnancies, but the target of VAR2CSA-specific protective antibodies is unclear. We assessed VAR2CSA-specific antibodies in pregnant women and analyzed their relationships with protection against placental infection, preterm birth, and low birthweight. Antibody responses to the N-terminal region of VAR2CSA during early pregnancy were associated with reduced risks for infections and low birthweight. Among women infected during pregnancy, an increase in CSA binding inhibition was associated with reduced risks for placental infection, preterm birth, and low birthweight. These data suggest that antibodies against VAR2CSA N-terminal region mediate immunity to placental malaria and associated outcomes. Our results validate current vaccine development efforts with VAR2CSA N-terminal constructs.

Background. There is a lack of data on the burden of malaria in the first trimester of pregnancy in Africa, mainly because pregnant women generally attend the maternity clinic late. Bed nets are rarely provided to women before the second trimester of pregnancy and intermittent preventive treatment with sulfadoxine-pyrimethamine is not recommended before the second trimester, leaving women insufficiently or not protected in early pregnancy.& para;& para;Methods. To assess the burden of first trimester malaria, 387 women were followed up monthly from preconception to delivery. They were screened for malaria monthly from early pregnancy until delivery. A logistic multilevel model was used to assess maternal factors associated with malaria during the first trimester.& para;& para;Results. The proportion of women with at least 1 microscopic malaria infection during the first trimester of pregnancy was 20.8%. Women infected with malaria preconception were more likely to be infected during the first trimester (adjusted odds ratio: 2.68; 95% confidence interval, 1.24-5.78). Early gestational age was also positively correlated with malaria infection.& para;& para;Conclusions. Using a preconceptional study design, we showed that malaria was highly prevalent in early pregnancy. This calls for the assessment of new strategies that could protect women as soon as the first trimester.

Background Malaria control is heavily reliant on insecticides, especially pyrethroids. Resistance of mosquitoes to insecticides may threaten the effectiveness of insecticide-based vector control and lead to a resurgence of malaria in Africa. Methods In 21 villages in Southern Benin with high levels of insecticide resistance, the resistance status of local vectors was measured at the same time as the prevalence of malaria infection in resident children. Results Children who used LLINs had lower levels of malaria infection [odds ratio = 0.76 (95% CI 0.59, 0.98, p = 0.033)]. There was no evidence that the effectiveness of nets was different in high and low resistance locations (p = 0.513). There was no association between village level resistance and village level malaria prevalence (p = 0.999). Conclusions LLINs continue to offer individual protection against malaria infection in an area of high resistance. Insecticide resistance is not a reason to stop efforts to increase coverage of LLINs in Africa.

Background The antigen VAR2CSA plays a pivotal role in the pathophysiology of pregnancy-associated malaria (PAM) caused by Plasmodium falciparum . A VAR2CSA-based vaccine candidate, PAMVAC, is under development by an EU-funded multi-country consortium (PlacMalVac project). As part of PAMVAC's clinical development, we quantified naturally acquired vaccine antigen-specific memory B and T cell responses in Beninese primigravidae recruited at the beginning of pregnancy and followed up to delivery and beyond. Methods Clinical and parasitological histories were compiled from monthly clinic visits. On 4 occasions (first and fifth month of pregnancy, delivery, 6 months post-delivery) peripheral blood mononuclear cells were isolated for in vitro assays. PAMVAC-specific memory B cells as well as those specific for a PAM unrelated P. falciparum antigen (PfEMP1-CIDR1a) and for tetanus toxoid were quantified by ELISpot. Memory T cell responses were assessed by quantifying cytokines (IL-5, IL-6, IL-10, IL-13, IFN-γ, TNF-α) in supernatants of cells stimulated in vitro either with PAMVAC, or mitogen (PHA). Results Both tetanus toxoid- and PAMVAC-specific memory B cell frequencies increased to reach peak levels in the 5th month and at delivery, respectively and persisted post-delivery. The frequency of CIDR1a-specific memory B cells was stable during pregnancy, but declined post-delivery. The cumulated prevalence of infection with P. falciparum during pregnancy was 61% by microscopy. In women with a history of such infections, a significantly higher frequency of PAMVAC-specific memory B cells was observed at delivery. PAMVAC-specific pro-inflammatory (IFN-γ, TNF) responses tended to be higher at delivery in those with a history of infection. Mitogen-induced IL-5/IL-13 responses were significantly enhanced in the same women. Conclusions PAMVAC-specific memory B cells are induced during first pregnancies and are maintained post-delivery. Women with a T helper cell profile biased towards production of Th2-type cytokines have a greater risk of infection with P. falciparum.

Resume Objectif Determiner la place des candidoses vulvo-vaginales (CVV) au cours des infections genitales basses et rechercher les facteurs de risque associes chez les femmes au Benin. Patientes et methodes L’etude s’est deroulee au laboratoire de mycologie de l’hopital de la Mere et de l’Enfant Lagune de Cotonou du 1er mars au 31 juillet 2013. Elle a concerne toutes les femmes envoyees par le gynecologue ou la sage-femme de l’hopital pour infection genitale basse et a qui il a ete demande un prelevement vaginal. Ces femmes doivent avoir donne leur consentement sous forme ecrit. Apres l’administration d’un questionnaire en vue de recueillir les donnees epidemiologiques (dont la prise recente d’antibiotique) et cliniques (leucorrhee, prurit vulvaire, dyspareunie), le prelevement vaginal est realise pour la mesure du PH, le test a la potasse, l’examen a l’etat frais, la coloration de Gram, la culture sur milieu Sabouraud-chloramphenicol, sur gelose ordinaire et sur gelose au sang frais. Une serologie VIH a ete realisee pour toutes les femmes ne pouvant pas prouver leur etat serologique. Resultats Cent trente et un femmes ont ete incluses au cours de la periode d’etude. Les signes cliniques sont domines par la leucorrhee (74,8 %), le prurit vulvaire (51,9 %) et la dyspareunie (36,6 %). La culture sur milieu Sabouraud-chloramphenicol est positive dans 51 cas soit une prevalence de 38,9 %. Candida albicans est isole dans 96,1 % des cas contre 3,9 % de Candida glabrata. Les facteurs de risque impliques sont : la grossesse, la prise d’antibiotique, le port frequent de pantalons serres et l’utilisation des sous-vetements synthetiques. Outre les Candida, Gardnerella vaginalis est retrouvee dans 36,6 % des prelevements avec une association avec C. albicans dans 28,2 % des cas. Conclusion Cette etude montre que les CVV constituent la premiere cause des infections genitales basses de la femme au Benin avec implication de plusieurs facteurs de risque.

The study aimed at assessing performance and cost of phenotypic tests for detecting methicillin resistance in Staphylococcus spp. isolates in Cotonou, Benin. Isolates consecutively collected from various specimens from four medical laboratories in Cotonou from December 2012 to April 2013 were included in the study. The isolates were subjected to five phenotypic tests: disk diffusion tests with cefoxitin (Cefox) and moxalactam (Moxa) on Mueller Hinton agar incubated at 37°C, oxacillin on Mueller Hinton agar incubated at 30°C (Oxa30), oxacillin on salt Mueller Hinton agar incubated at 37°C (Oxa37) and agglutination test for PBP2a detection (TPBP 2a). Results were compared with polymerase chain reaction (PCR) of mecA gene which was used as the gold standard. In addition, cost per reagent of each phenotypic test was assessed. Considering the general agreement with PCR, Cefox and Moxa were the best tests in S. aureus while in non-aureus Staphylococcus isolates, TPBP 2a was the best test but its cost was 20 times higher than that of disk diffusion tests. Key words: Staphylococcus spp., methicillin resistance, diffusion disk tests, PBP 2a, mecA.

Artemisinin-based combination therapies (ACTs) are the main option to treat malaria, and their efficacy and susceptibility must be closely monitored to avoid resistance. We assessed the association of Plasmodium falciparum polymorphisms and ex vivo drug susceptibility with clinical effectiveness. Patients enrolled in an effectiveness trial comparing artemether-lumefantrine ( n = 96), fixed-dose artesunate-amodiaquine ( n = 96), and sulfadoxine-pyrimethamine ( n = 48) for the treatment of uncomplicated malaria 2007 in Benin were assessed. pfcrt , pfmdr1 , pfmrp1 , pfdhfr , and pfdhps polymorphisms were analyzed pretreatment and in recurrent infections. Drug susceptibility was determined in fresh baseline isolates by Plasmodium lactate dehydrogenase enzyme-linked immunosorbent assay (ELISA). A majority had 50% inhibitory concentration (IC 50 ) estimates (the concentration required for 50% growth inhibition) lower than those of the 3D7 reference clone for desethylamodiaquine, lumefantrine, mefloquine, and quinine and was considered to be susceptible, while dihydroartemisinin and pyrimethamine IC 50 s were higher. No association was found between susceptibility to the ACT compounds and treatment outcome. Selection was observed for the pfmdr1 N86 allele in artemether-lumefantrine recrudescences (recurring infections) (4/7 [57.1%] versus 36/195 [18.5%]), and of the opposite allele, 86Y, in artesunate-amodiaquine reinfections (new infections) (20/22 [90.9%] versus 137/195 [70.3%]) compared to baseline infections. The importance of pfmdr1 N86 in lumefantrine tolerance was emphasized by its association with elevated lumefantrine IC 50 s. Genetic linkage between N86 and Y184 was observed, which together with the low frequency of 1246Y may explain regional differences in selection of pfmdr1 loci. Selection of opposite alleles in artemether-lumefantrine and artesunate-amodiaquine recurrent infections supports the strategy of multiple first-line treatment. Surveillance based on clinical, ex vivo , molecular, and pharmacological data is warranted.

BACKGROUND The aim of this study was to describe the contribution of prematurity and small for gestational age (SGA) to low birth weight (LBW) as well as to identify risk factors associated with preterm birth and SGA and to explore their impact on birth weight. METHODS A cross-sectional study was carried out in southern Benin between June 2007 and July 2008. At delivery, women's characteristics and newborn's anthropometric measurements were collected. Gestational age was estimated using the Ballard method; SGA was defined using the William's reference curve. Analyses were performed by multiple logistic and linear regressions. RESULTS In total, 526 mother-infant pairs were enrolled. LBW (

Background In Africa, snakebite envenomations are frequently complicated by life-threatening hemorrhagic syndromes. The authors of the present study conducted a prospective analysis at the University Hospital of Parakou (north of Benin) for seven months (January 1 to July 31, 2014) to assess the contribution of ultrasonography to the diagnosis of internal bleedings and management of envenomation. Methods An ultrasound examination was performed in all patients with clinical envenomation regardless of its severity. The study involved 32 patients admitted to the ICU of the University Hospital of Parakou. Results The average age was 27 ± 13.9 years. The main signs of severity were: prolongation of clotting time (88 %), severe anemia (41 %), clinical hemorrhage (47 %), and shock (19 %). The ultrasound imaging showed internal hemorrhage in 18 patients (56 %). There were hematomas (22 %), hemoperitoneum (13 %) or a combination of both (22 %). The occurrence of internal bleeding and hemoperitoneum were mainly related to the delay of hospital presentation (p = 0.007) and the existence of external bleeding (p = 0.04). Thirty patients (94 %) received antivenom. Case fatality rate was 3.1 %. Conclusion Ultrasonography may help in diagnosing internal bleeding, even in patients that did not show external hemorrhages, and evaluating its importance. As a consequence, the management of snakebite victims may be significantly improved.

Les piqures de scorpion en Afrique du Nord et les morsures de serpent en Afrique subsaharienne sont respectivement responsables de 750 000 envenimations, avec 1 700 deces [1], et de 320 000 envenimations, dont une dizaine de milliers de morts et autant de sequelles handicapantes [2]. Les envenimations concernent les populations rurales, le plus souvent de jeunes agriculteurs dont le revenu est faible. De nombreuses enquetes communautaires ont etabli que la quasi-totalite des victimes de [...]

International audience; Background: HLA‑G, a non‑classical HLA class I antigen, is of crucial interest during pregnancy by inhibiting mater‑ nal immune response. Its role during infections is discussed, and it has been described that high levels of soluble HLA‑G during childhood increase the risk of malaria. To explore more precisely interactions between soluble HLA‑G and malaria, latent class analysis was used to test whether distinct sub‑populations of children, each with distinctive soluble HLA‑G evolutions may suggest the existence of groups presenting variable malaria susceptibility. Method: A study was conducted in Benin from 2010 to 2013 and 165 children were followed from birth to 12 months. Evolution of soluble HLA‑G was studied by the latent class method. Results: Three groups of children were identified: one with consistently low levels of soluble HLA‑G during follow‑up, a second with very high levels and a last intermediate group. In all groups, low birth weight, high number of malaria infections and high exposure to malaria transmission were associated with high level of soluble HLA‑G. Placental malaria was not. Presence of soluble HLA‑G in cord blood increased the probability of belonging to the highest trajectory. Conclusion: These results, together with previous ones, confirm the important role of HLA‑G in the individual sus‑ ceptibility to malaria. Assaying soluble HLA‑G at birth could be a good indicator of newborns more fragile and at risk of infections during childhood.

The risk factors for maternal anemia (hemoglobin level less than 110 g/L) were studied in human immunodeficiency virus–negative pregnant women in Benin at the time of first antenatal visit and prior to any prevention. Data for the first 1,005 pregnant women included in a multicentre randomized controlled trial were analyzed. Anemia was common (68.3%), and malaria and helminth infestations were prevalent in 15.2% and 11.1% of the women. A total of 33.3%, 31.3% and 3.6% of the women were iron, folic acid and vitamin B12 deficient, respectively. These parasitic infections and nutrient deficiencies were associated with a high risk of anemia. Twenty-one percent, 15%, 12%, 11% and 7% of anemia were attributable to malnutrition, malaria, iron, folic acid deficiencies, and helminth infestations, respectively. Most anemia was caused by factors that could be prevented by available tools, stressing the need to reinforce their implementation and to evaluate their effectiveness throughout the course of the pregnancy.

et de Recherche sur le Paludisme Associe a la Grossesse et a l’Enfant (CERPAGE), Cotonou, Benin Background. Several studies have shown that the risk of malaria infection increases for children born to a mother with placental malaria infection. An immune tolerance phenomenon has been hypothesized. We addressed whether Plasmodium falciparum placental infection could additionally be associated with the risk of nonmalaria fevers in infants. Methods. From 2007 to 2009, 553 infants were followed up from birth to 18 months in Benin. The occurrence of fever was actively screened by trained community workers. Malaria fevers (temperature >37.5°C with positive results of rapid diagnostic test or thick blood smear) were excluded from analysis. The association between placental malaria infection and the number of total, gastrointestinal, and respiratory febrile episodes was explored using binomial negative regression, with adjustment for maternal age, parity, parents’ schooling, socioeconomic level, sex, village of birth, season of birth, prematurity, Apgar score and nutritional status. Results. The prevalence of placental malaria infection was 11.2%. During a median follow-up of 17.8 months, 624 nonmalaria fevers were registered. Placental malaria infection was associated with a higher risk of nonmalaria fever episodes (adjusted incidence rate ratio, 1.4; 95% confidence interval, 1.1–1.8) as well as gastrointestinal (1.6; 1.1–2.5) and respiratory (1.5; 1.1–2.1) febrile syndromes. The same pattern was obtained when considering consultations after the age of 6 months. Conclusions. These results suggest an association between placental malaria infection and nonmalaria infections in the first 18 months of life. Immune tolerance could lead to impaired immune development not specifi ct o malaria infections in infants born to mothers with placental malaria infection, but further studies are needed.

International audience; Background: The estimates of risk of malaria in early childhood are imprecise given the current entomologic and parasitological tools. Thus, the utility of anti-Anopheles salivary gSG6-P1 peptide antibody responses in measuring exposure to Anopheles bites during early infancy has been assessed.Methods: Anti-gSG6-P1 IgG and IgM levels were evaluated in 133 infants (in Benin) at three (M3), six (M6), nine (M9) and 12 (M12) months of age. Specific IgG levels were also assessed in their respective umbilical cord blood (IUCB) and maternal blood (MPB).Results: At M3, 93.98 and 41.35% of infants had anti-gSG6-P1 IgG and IgM Ab, respectively. Specific median IgG and IgM levels gradually increased between M3 and M6 (p < 0.0001 and p < 0.001), M6–M9 (p < 0.0001 and p = 0.085) and M9–M12 (p = 0.002 and p = 0.03). These levels were positively associated with the Plasmodium falciparum infection intensity (p = 0.006 and 0.003), and inversely with the use of insecticide-treated bed nets (p = 0.003 and 0.3). Levels of specific IgG in the MPB were positively correlated to those in the IUCB (R = 0.73; p < 0.0001) and those at M3 (R = 0.34; p < 0.0001).Conclusion: The exposure level to Anopheles bites, and then the risk of malaria infection, can be evaluated in young infants by assessing anti-gSG6-P1 IgM and IgG responses before and after 6-months of age, respectively. This tool can be useful in epidemiological evaluation and surveillance of malaria risk during the first year of life.

In areas where Plasmodium falciparum is endemic, pregnancy is associated with accumulation of infected red blood cells (RBCs) in the placenta, a condition referred to as placental malaria (PM). Infants born to PM-positive mothers are at an increased risk of malaria, which is putatively related to the transplacental passage of parasite-derived antigens, with consequent tolerization of the fetal immune system. Here we addressed the impact of PM on the regulation of neonatal T cell responses. We found that the frequency of regulatory CD25 + CD127 −/low Foxp3 + CD4 + T cells was significantly decreased in neonates born to mothers with high levels of P. falciparum -induced placental inflammation, consisting mainly of primigravid mothers. However, at the individual level, the ratio between regulatory and effector (CD25 + CD127 + Foxp3 − ) CD4 + T cells was unaffected by PM. In addition, parasite-induced CD4 + T cell activation and production of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and IL-10 were strongly reduced in neonates born to PM-positive mothers. Thus, our results show that active PM at delivery is associated with a marked suppression of P. falciparum -specific cellular neonatal immune responses, affecting secretion of both pro- and anti-inflammatory cytokines. Additionally, our results suggest that, as in adults, effector and regulatory CD4 + T cell populations are tightly coregulated in all neonates, irrespective of the maternal infection status.

The efficiency of malaria prevention during pregnancy was compared between three studies in Benin for malaria infection of the placenta (MIP) and low birth weight (LBW). The first was carried out when chloroquine prophylaxis was still recommended, the second was an intermittent preventive treatment in pregnancy (IPTp) clinical trial comparing sulfadoxine pyrimetamine (SP) versus mefloquine, and the third was an observational study after SP-IPTp national implementation. We showed an association between the use of IPTp and the reduction of LBW (10% with national IPTp and 8.7% in IPTp trial versus 15.7% in pre-trial study). The effect on MIP was better in the trial (2.9% versus 11.2% and 16.7% for national IPTp and pre-trial studies, respectively). In spite of a good overall compliance with the national IPTp (with 84% of women taking at least one dose of SP), there are still failures in adherence to the directly observed therapy (DOT) scheme and needs for better training of health staff.

Although consequences of malaria in pregnancy are well known, the period of pregnancy in which infection has the highest impact is still unclear. In Benin, we followed up a cohort of 1,037 women through pregnancy until delivery. The objective was to evaluate the relationship between the timing of infection and birth weight, and maternal anemia at delivery. At the beginning of pregnancy, peripheral infections were associated with a decrease in mean birth weight (-98.5 g; P = 0.03) and an increase in the risk of anemia at delivery (adjusted odds ratio [aOR] = 1.6; P = 0.03). Infections in late pregnancy were related to a higher risk of maternal anemia at delivery (aOR = 1.7; P = 0.001). To fully protect the women during the whole pregnancy, already implemented measures (insecticide-treated nets and intermittent preventive treatment) should be reinforced. In the future, a vaccine against pregnancy-associated malaria parasites could protect the women in early pregnancy, which seems to be a high-risk period.

Background. We compared sulfadoxine-pyrimethamine (SP) with unsupervised artemether-lumefantrine (AL) and unsupervised amodiaquine-artesunate (ASAQ) fixed-dose formulation for the treatment of uncomplicated malaria in children in Benin. Methods. This open-label, noninferiority comparative trial included children aged 6―60 months. The follow-up period was 6 weeks, and the primary objective was a comparison of polymerase chain reaction (PCR)―adjusted effectiveness rates at day 28. Results. The study included 240 children (48 received SP, and 96 each received AL and ASAQ). The intention-to-treat analysis showed effectiveness rates on day 28 of 20.8%, 78.1 %, and 70.5% for SP, AL, and ASAQ, respectively. After adjustment for PCR results, these rates were 27.1%, 83.3%, and 87.4%, respectively. The per-protocol analysis (217 patients) showed effectiveness rates on day 28 of 21.7%, 88.0%, and 76.1% for SP, AL, and ASAQ, respectively. After adjustment for PCR results, these rates were 28.3%, 94.0%, and 93.2%, respectively. SP was less effective than the other drugs in the PCR-adjusted analysis, whereas AL and ASAQ were equally effective. The rate of new infection was higher among children treated with ASAQ than among those treated with AL. Conclusions. This was the first trial, to our knowledge, to compare unsupervised AL with unsupervised ASAQ fixed-dose formulation; both treatments provided high PCR-adjusted day 28 effectiveness rates. Efficacy rates for SP were surprisingly low. Clinical trials registration. NCT00460369.

Summary Objective To evaluate the in vivo therapeutic efficacy of chloroquine (CQ), sulfadoxine-pyrimethamine (SP) and mefloquine (MQ) in children presenting with uncomplicated malaria in Benin. Methods Drug efficacy was tested according to the WHO in vivo 28-day protocol. For failures that occurred after 7 days of follow-up, paired pre- and post-treatment blood samples were genotyped at msp1 and msp2 loci to distinguish new infections and recrudescent strains. Children enrolled were randomly assigned to a therapeutic group (CQ, n = 14; SP, n = 42; MQ, n = 44). The number of CQ treatment was intentionally restricted after 1 month, as its use was considered to constitute a danger for children. Results Chloroquine and SP showed very high failure rates (85.7% and 50%, respectively), whereas MQ treatment was successful in 97.5%. The molecular tool allowed to re-evaluate two new infections previously considered as failures. Conclusions Chloroquine should no longer be used to treat children presenting with Plasmodium falciparum malaria in Benin. Objectif Evaluer l'efficacite therapeutique in vivo de la chloroquine (CQ), de la sulfadoxine-pyrimethamine (SP) et de la mefloquine (MQ) chez les enfants presentant un paludisme simple au Benin. Methodes L'efficacite des medicaments a eteetudiee in vivo pendant 28 jours selon le protocole de l'OMS. Pour les echecs survenus apres 7 jours de suivi, des echantillons de sang apparies preleves avant et apres traitement ont ete genotypes au niveau des loci msp1 et msp2 afin de distinguer les nouvelles infections des souches recrudescentes. Les enfants enroles ont ete aleatoirement affectes a un groupe therapeutique (CQ, n = 14; SP, n = 42; MQ, n = 44). Le nombre de traitements a la CQ a ete intentionnellement limite apres un mois car son utilisation a ete consideree comme dangereuse pour les enfants. Resultats CQ et la SP ont demontre des taux d’echec tres eleves (85,7 et 50% respectivement), tandis que le traitement a la MQ etait efficace dans 97,5% des cas. L'outil moleculaire a permis de reevaluer deux nouvelles infections precedemment considerees comme des echecs. Conclusions La chloroquine ne devrait plus etre utilisee pour traiter les enfants presentant un paludisme simple aP. falciparum au Benin. Objetivo Evaluar la eficacia terapeutica in vivo de la cloroquina (CQ), la sulfadoxina-pirimetamina (SP) y la mefloquina (MQ), en ninos con malaria no complicada en Benin. Metodos Se evaluo la eficacia de los medicamentos siguiendo el protocolo in vivo de 28-dias de la OMS. Para fallos que ocurrieron despues de 7 dias de seguimiento, se genotiparon los genes msp1 y msp2 en muestras de sangre pareadas antes y despues del tratamiento, para distinguir nuevas infecciones de cepas recrudescentes. Los ninos incluidos fueron asignados de forma aleatoria a un grupo terapeutico (CQ, n = 14; SP, n = 42; MQ, n = 44). El numero de tratamientos con CQ fue intencionalmente limitado despues de 1 mes, puesto que se consideraba que su uso entranaba un riesgo para los ninos. Resultados CQ y SP presentaron unas tasas de fallo muy altas (85.7 y 50% respectivamente), mientras que el tratamiento con MQ fue exitoso en un 97.5%. La herramienta molecular permitio reevaluar dos infecciones nuevas, previamente consideradas fallos. Conclusiones No se deberia continuar utilizando la cloroquina para tratar ninos con malaria por P. falciparum en Benin.

Antibodies that impede the invasion of Plasmodium falciparum (P. falciparum) merozoites into erythrocytes play a critical role in anti-malarial immunity. The Growth Inhibition Assay (GIA) is an in vitro measure of the functional capacity of such antibodies to limit erythrocyte invasion and/or parasite growth. Up to now, it is unclear whether growth-inhibitory activity correlates with protection from clinical disease and there are inconsistent results from studies performed with GIA. Studies that have focused on the relationship between IgGs and their in vitro parasite Growth Inhibition Activity (GIAc) in infants aged less than two years old are rare. Here, we used clinical and parasitological data to precisely define symptomatic or asymptomatic infection with P. falciparum in groups of infants followed-up actively for 18 months post-natally. We quantified the levels of IgG1 and IgG3 directed to a panel of candidate P. falciparum vaccine antigens (AMA-1, MSP1, 2, 3 and GLURP) using ELISA and the functional activity of IgG was quantified using GIA. Data were then correlated with individuals' infection status. At 18 months of age, infants harbouring infections at the time of blood sampling had an average 19% less GIAc than those not infected (p=0.004, multivariate linear regression). GIAc decreased from 12 to 18 months of age (p=0.003, Wilcoxon matched pairs test). Antibody levels quantified at 18 months in infants were strongly correlated with their exposure to malarial infection, however GIAc was not correlated with malaria infectious status (asymptomatic and symptomatic groups). In conclusion, both infection status at blood draw and age influence parasite growth inhibition mediated by IgG in the GIA. Both factors must be taken into account when correlations between GIAc and anti-malarial protection or vaccine efficacy have to be made.