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Insect-borne diseases are responsible for important burdens on health worldwide particularly in Africa. Malaria alone causes close to half a million deaths every year, mostly in developing, tropical and subtropical countries, with 94% of the global deaths in 2019 occurring in the WHO African region. With several decades, vector control measures have been fundamental to fight against malaria. Considering the spread of resistance to insecticides in mosquitoes and to drugs in parasites, the need for novel strategies to inhibit the transmission of the disease is pressing. In recent years, several studies have focused on the interaction of malaria parasites, bacteria and their insect vectors. Their findings suggested that the microbiota of mosquitoes could be used to block Plasmodium transmission. A strategy, termed paratransgenesis, aims to interfere with the development of malaria parasites within their vectors through genetically-modified microbes, which produce antimalarial effectors inside the insect host. Here we review the progress of the paratransgenesis approach. We provide a historical perspective and then focus on the choice of microbial strains and on genetic engineering strategies. We finally describe the different steps from laboratory design to field implementation to fight against malaria.

International audience; Zika virus (ZIKV) and dengue virus (DENV) are two closely related members of the Flaviviridae family, both transmitted by mosquitoes of the genus Aedes, and are among the arboviruses most at risk to human health. Burkina Faso has been facing an upsurge in DENV outbreaks since 2013. Unlike DENV, there is no serological evidence of ZIKV circulation in humans in Burkina Faso. The main objective of our study was to determine the seroprevalence of ZIKV and DENV in blood donors in Burkina Faso. A total of 501 donor samples collected in the two major cities of the country in 2020 were first tested by a competitive enzyme-linked immunosorbent assay to detect flavivirus antibodies. Positive sera were then tested using Luminex to detect ZIKV and DENV antibodies and virus-specific microneutralization tests against ZIKV were performed. The ZIKV seroprevalence was 22.75% in the donor samples and we found seropositivity for all DENV-serotypes ranging from 19.56% for DENV-1 to 48.86% for DENV-2. Molecular analyses performed on samples from febrile patients and Aedes aegypti mosquitoes between 2019 and 2021 were negative. Our study showed the important circulation of ZIKV and DENV detected by serology although molecular evidence of the circulation of ZIKV could not be demonstrated. It is essential to strengthen existing arbovirus surveillance in Burkina Faso and more broadly in West Africa by focusing on fevers of unknown origin and integrating vector surveillance to assess the extent of ZIKV circulation and identify the circulating strain. Further studies are needed to better understand the epidemiology of this virus in order to define appropriate prevention and response methods.

Background: A severe outbreak of dengue occurred in Burkina Faso in 2016, with the most cases reported in Ouagadougou, that highlights the necessity to implement vector surveillance system. This study aims to estimate the risk of arboviruses transmission and the insecticide susceptibility status of potential vectors in four sites in Burkina Faso. Methods: From June to September 2016, house-to-house cross sectional entomological surveys were performed in four cities stretching along a southwest-to-northeast railway transect. The household surveys analyzed the presence of Aedes spp. larvae in containers holding water and the World Health Organization (WHO) larval abundance indices were estimated. WHO tube assays was used to evaluate the insecticide susceptibility within Aedes populations from these localities. Results: A total of 31,378 mosquitoes' larvae were collected from 1,330 containers holding water. Aedes spp. was the most abundant (95.19%) followed by Culex spp. (4.75%). Aedes aegypti a key vector of arboviruses (ARBOV) in West Africa was the major Aedes species found (98.60%). The relative larval indices, house index, container and Breteau indexes were high, up to 70, 35, and 10, respectively. Aedes aegypti tended to breed mainly in discarded tires and terracotta jars. Except in Banfora the western city, Ae. aegypti populations were resistant to deltamethrin 0.05% in the other localities with low mortality rate under 20% in Ouagadougou whereas they were fully susceptible to malathion 5% whatever the site. Intermediate resistance was observed in the four sites with mortality rates varying between 78 and 94% with bendiocarb 0.1%. Conclusions: This study provided basic information on entomological indices that can help to monitor the risks of ARBOV epidemics in the main cities along the railway in Burkina Faso. In these cities, all larval indices exceeded the risk level of ARBOV outbreak. Aedes aegypti the main species collected was resistant to deltamethrin 0.05% and bendiocarb 0.1% whereas they were fully susceptible to malathion 5%. The monitoring of insecticide resistance is also important to be integrated to the vector surveillance system in Burkina Faso.

There is a large genetic diversity of Plasmodium falciparum strains that infect people causing diverse malaria symptoms. This study was carried out to explore the effect of mixed-strain infections and the extent to which some specific P. falciparum variants are associated with particular malaria symptoms. P. falciparum isolates collected during pharmacovigilance study in Nanoro, Burkina Faso were used to determine allelic variation in two polymorphic antigens of the merozoite surface (msp1 and msp2). Overall, parasite density did not increase with additional strains, suggesting the existence of within-host competition. Parasite density was influenced by msp1 allelic families with highest parasitaemia observed in MAD20 allelic family. However, when in mixed infections with allelic family K1, MAD20 could not grow to the same levels as it would alone, suggesting competitive suppression in these mixed infections. Host age was associated with parasite density. Overall, older patients exhibited lower parasite densities than younger patients, but this effect varied with the genetic composition of the isolates for the msp1 gene. There was no effect of msp1 and msp2 allelic family variation on body temperature. Haemoglobin level was influenced by msp2 family with patients harboring the FC27 allele showing lower haemoglobin level than mono-infected individuals by the 3D7 allele. This study provides evidence that P. falciparum genetic diversity influenced the severity of particular malaria symptoms and supports the existence of within-host competition in genetically diverse P. falciparum.

In Burkina Faso, as in most Sahelian countries, the failure to follow good agricultural practices coupled with poor soil and climate conditions in the locust control context lead to high environmental contaminations with pesticide residues. Thus, consumers being orally exposed to a combination of multiple pesticide residues through food and water intake, the digestive tract is a tissue susceptible to be directly exposed to these food contaminants. The aim of our work was to compare in vitro the impact of five desert locust control pesticides (Deltamethrin DTM, Fenitrothion FNT, Fipronil FPN, Lambda-cyalothrine LCT, and Teflubenzuron TBZ) alone and in combination on the human intestinal Caco-2 cells viability and function. Cells were exposed to 0.1–100 μM pesticides for 10 days alone or in mixture (MIX). Our results showed a cytotoxic effect of DTM, FNT, FPN, LCT, and TBZ alone or in combination in human intestinal Caco-2 cells. The most efficient were shown to be FPN and FNT impacting the cell layer integrity and/or barrier function, ALP activity, antioxidant enzyme activity, lipid peroxidation, Akt activation, and apoptosis. The presence of antioxidant reduced lipid peroxidation level and attenuated the pesticides-induced cell toxicity, suggesting that key mechanism of pesticides cytotoxicity may be linked to their pro-oxidative potential. A comparative analysis with the predicted cytotoxic effect of pesticides mixture using mathematical modeling shown that the combination of these pesticides led to synergistic effects rather than to a simple independent or dose addition effect.

Background: The bacterial microbiota which colonize the mosquito midgut play an important role in vector-parasite interactions and consequently can modulate the level of malaria transmission. Their characterization may contribute to new control strategies of malaria transmission. However, these bacteria may also be eliminated in areas of high antibiotics usage. In this study, we identified paratransgenesis bacteria candidate in the gut of adults female Anopheles in Burkina Faso. Methods: The gut of 73 semi-field mosquitoes and 28 laboratory-reared mosquitoes from two villages in Burkina Faso were analyzed by conventional in vitro culture techniques to isolate and identify bacteria of the microbiota. The gene 16S sequencing was used to confirm the presence of bacteria of paratransgenesis interest. Due to the effect of antibiotics on bacteria, we evaluated in vitro their susceptibility to antibiotics generally used for infectious diseases treatment. Results: In total, eleven genera of bacteria were identified: Pantoea, Sphingomonas, Escherichia, Micrococcus, Staphylococcus, Klebsiella, Serratia, Acinetobacter, Pseudomonas, Citrobacter, Asaia. Among these bacteria isolated, Asaia. sp and Pantoea. sp have already been reported as candidates for paratransgenesis. In addition, we observed pathogenic bacteria such as Escherichia coli, Klebsiella pneumonia and Pseudomonas luteola. Investigation of the correlation between the bacterial microbiota and malaria infection status showed that mosquitoes engorged with blood containing Plasmodium falciparum contained a higher bacterial load than non-blood fed mosquitoes. The antibiotic susceptibility test showed that Asaia, Pantoea and Serratia, previously proposed as paratransgenesis candidates, were susceptible to different antibiotics tested in contrast to Escherichia coli, which were resistant. Discussion: Midgut analysis shows that the composition of the bacterial microbiota in wild field mosquitoes exhibits a large variability in contrast to laboratory-reared mosquitoes. The presence of genera already proposed as paratransgenesis candidates in previous studies among bacteria isolated in our study, suggested the possible implementation of this control strategy in Burkina Faso. Nevertheless, our data indicates that an in vivo verification of the stability of these bacteria is needed, as this strategy may be impaired by mass drug administration programs and antibiotic misuse.

International audience; Artemisinin-based Combination Therapy is recommended for the treatment of malaria in Burkina Faso but, most people in this country prefer to use herbal medicine because of its low cost and high availability. The aim of the study was to identify plants used by traditional healers from Sahel region of Burkina Faso in the prevention and the treatment of malaria. An ethno-botanical survey was carried out among traditional healers in the Sahel region of Burkina Faso. Questionnaires were administrated to people willing to participate in the survey and the plants used for prevention and treatment of malaria were recorded. A total of 80 traditional healers were interviewed. Forty two plants were identified as being commonly used in the treatment of malaria and 16 in repelling mosquitoes. The use of plants in the treatment and protection against malaria is widespread in the Sahel region of Burkina Faso.

International audience; Artemisinin-based Combination Therapy is recommended for the treatment of malaria in Burkina Faso but, most people in this country prefer to use herbal medicine because of its low cost and high availability. The aim of the study was to identify plants used by traditional healers from Sahel region of Burkina Faso in the prevention and the treatment of malaria. An ethno-botanical survey was carried out among traditional healers in the Sahel region of Burkina Faso. Questionnaires were administrated to people willing to participate in the survey and the plants used for prevention and treatment of malaria were recorded. A total of 80 traditional healers were interviewed. Forty two plants were identified as being commonly used in the treatment of malaria and 16 in repelling mosquitoes. The use of plants in the treatment and protection against malaria is widespread in the Sahel region of Burkina Faso.

Exposure to stress during an insect’s larval development can have carry-over effects on adult life history traits and susceptibility to pathogens. We investigated the effects of larval nutritional stress for the first time using field mosquito vectors and malaria parasites. In contrast to previous studies, we show that larval nutritional stress may affect human to mosquito transmission antagonistically: nutritionally deprived larvae showed lower parasite prevalence for only one gametocyte carrier; they also had lower fecundity. However, they had greater survival rates that were even higher when infected. When combining these opposing effects into epidemiological models, we show that larval nutritional stress induced a decrease in malaria transmission at low mosquito densities and an increase in transmission at high mosquito densities, whereas transmission by mosquitoes from well-fed larvae was stable. Our work underscores the importance of including environmental stressors towards understanding host–parasite dynamics to improve disease transmission models and control.

International audience; Introduction. Les médecins, premières personnes exposées et victimes des épidémies, sont au cœur des dispositifs de riposte à l’épidémie de Covid-19. Au printemps 2020, au cœur de la première vague épidémique, il est apparu essentiel de pouvoir documenter les connaissances, attitudes et pratiques (CAP) de ces maillons essentiels de la lutte contre la Covid-19 au Burkina Faso. Leur compréhension de la maladie, l’impact de la maladie sur leurs pratiques professionnelles, leur accès au matériel de protection, etc. sont autant d’aspects qui peuvent impacter directement la santé publique, nécessitant des prises de mesures par les autorités nationales. L’objectif principal de cette étude était de fournir aux acteurs nationaux impliqués dans la gestion de la crise des données probantes régulières et représentatives à l’échelle nationale sur les connaissances, attitudes et pratiques des médecins au Burkina Faso.Méthode. L’enquête CAP-CoV-BF a pu être financée dans le cadre du programme Aphro-CoV financé par l’Agence Française le Développement et mis en œuvre par le consortium REACTing. Le protocole de l’enquête a été développé en mai et juin 2020 et soumis au Comité d’Éthique pour la recherche en santé du Burkina Faso en juin 2020. L’enquête a été approuvée fin août. L’enquête CAP-CoV-BF est une série de trois vagues d’enquêtes quantitatives transversales (échantillons indépendants) par téléphone réalisée auprès d’un échantillon représentatif d’environ 200 médecins sur l’ensemble du territoire burkinabè. Les trois vagues ont été réalisées à différents stades de l’épidémie burkinabé : (i) alors que le nombre de cas était relativement peu important et plutôt stable en septembre 2020 ; (ii) début décembre 2020 alors que le pays faisait face au début d’un nouveau pic épidémique ; (iii) fin février 2021 à la fin de la vague épidémique ayant démarré en décembre 2020. La base d’échantillonnage était l’annuaire de l’ordre national des médecins du Burkina Faso (3548 médecins enregistrés). Résultats. Avant chaque vague d’enquête, 750 médecins étaient tirés au sort et recevaient un SMS de préannonce de l’enquête. Ils avaient la possibilité à cette étape de répondre au SMS pour refuser d’être appelé (vague 1 : 0 refus, vague 2 : 7, vague 3 : 9). L’envoi du SMS permettait également de vérifier si les numéros étaient toujours valides. Parmi les numéros valides et sans refus, un second échantillonnage était effectué. Chaque numéro de téléphone mis en production était rappelé au moins 5 fois (5 jours à des horaires différents) avant d’être considéré comme injoignable. Les refus de participer après décrochage sont restés relativement limités (respectivement 23, 5 et 10). Au final, 166 questionnaires ont été complété en 15 jours de collecte lors de la première enquête, 190 questionnaires en 13 jours pour la seconde et 203 questionnaires en 13 jours pour la troisième. Conclusion. Le dispositif d’enquête a permis de réaliser en des temps courts et avec un budget limité une enquête nationale et représentative des médecins au Burkina Faso. La passation par téléphone a permis à la fois de couvrir l’ensemble du territoire national tout en respectant les procédures de distanciations en vigueur.

Introduction A key component of achieving respectful maternal and newborn care is labor companionship. Despite important health benefits for the woman and baby, there are critical gaps in implementing labor companionship for all women globally. The paper aims to present the perceptions and experiences of pregnant women, postpartum women, and health care providers regarding companionship during labor and childbirth, and to identify barriers and facilitating factors to the implementation of labor companionship in Burkina Faso. Methods This is a formative study to inform the “Appropriate use of cesarean section through QUALIty DECision-making by women and providers” (QUALI-DEC) study, to design, adapt and implement a strategy to optimize the use of the cesarean section, including labor companionship. We use in-depth interviews (women, potential companions, and health workers) and health facility readiness assessments in eight hospitals across Burkina Faso. We use a thematic analysis approach for interviews, and narrative summaries to describe facility readiness assessment. Results In all, 77 qualitative interviews and eight readiness assessments are included in this analysis. The findings showed that all participants acknowledged an existing traditional companionship model, which allowed companions to support women only in the hospital waiting room and post-natal room. Despite recognizing clear benefits, participants were not familiar with companionship during labor and childbirth in the hospital as recommended by WHO. Key barriers to implementing companionship throughout labor and birth include limited space in labor and delivery wards, no private rooms for women, hospital rules preventing companionship, and social norms preventing the choice of a companion by the woman. Conclusion Labor companionship was considered highly acceptable in Burkina Faso, but more work is needed to adapt to the hospital environment. Revisions to hospital policies to allow companions during labor and childbirth are needed as well as changes to provide private space for women. Training potential companions about their roles and encouraging women’s rights to choose their companions may help to facilitate effective implementation.

Background Domesticated animals play a role in maintaining residual transmission of Plasmodium parasites of humans, by offering alternative blood meal sources for malaria vectors to survive on. However, the blood of animals treated with veterinary formulations of the anti-helminthic drug ivermectin can have an insecticidal effect on adult malaria vector mosquitoes. This study therefore assessed the effects of treating cattle with long-acting injectable formulations of ivermectin on the survival of an important malaria vector species, to determine whether it has potential as a complementary vector control measure. Methods Eight head of a local breed of cattle were randomly assigned to either one of two treatment arms (2 × 2 cattle injected with one of two long-acting formulations of ivermectin with the BEPO® technology at the therapeutic dose of 1.2 mg/kg), or one of two control arms (2 × 2 cattle injected with the vehicles of the formulations). The lethality of the formulations was evaluated on 3–5-day-old Anopheles coluzzii mosquitoes through direct skin-feeding assays, from 1 to 210 days after treatment. The efficacy of each formulation was evaluated and compared using Cox proportional hazards survival models, Kaplan–Meier survival estimates, and log-logistic regression on cumulative mortality. Results Both formulations released mosquitocidal concentrations of ivermectin until 210 days post-treatment (hazard ratio > 1). The treatments significantly reduced mosquito survival, with average median survival time of 4–5 days post-feeding. The lethal concentrations to kill 50% of the Anopheles (LC50) before they became infectious (10 days after an infectious blood meal) were maintained for 210 days post-injection for both formulations. Conclusions This long-lasting formulation of ivermectin injected in cattle could complement insecticide-treated nets by suppressing field populations of zoophagic mosquitoes that are responsible, at least in part, for residual malaria transmission. The impact of this approach will of course depend on the field epidemiological context. Complementary studies will be necessary to characterize ivermectin withdrawal times and potential environmental toxicity. Graphical Abstract

The transmission of malaria parasites from mosquito to human is largely determined by the dietary specialization ofAnophelesmosquitoes to feed on humans. Few studies have explored the impact of blood meal sources on the fitness of both the parasite and the mosquito. Our study investigated the effects of 3-4 consecutive blood meals from one of four vertebrate species (human, cattle, sheep, or chicken) on several fitness traits, including mosquito feeding rate, blood meal size, susceptibility to wild isolates ofPlasmodium falciparum, survival, fecundity, F1 offspring development time, and size. Our findings revealed no significant effect on parasite development. Similarly, parasite exposure had no overall effects on mosquito fitness. However, blood meal type did have a strong impact on mosquito feeding rate, survival, lifetime fecundity, and offspring size. Specifically, mosquitoes that were fed successive chicken blood meals produced fewer eggs and fewer and smaller F1 adults compared to those fed human blood. Combining our results in a theoretical model, we show a decrease in the vectorial capacity of mosquitoes fed chicken or cow blood and an increase in the capacity of those fed sheep blood compared to those fed human blood. These findings emphasize the importance of considering the diversity of blood meal sources in understanding mosquito ecology and their role in the transmission intensity of malaria parasites.

International audience; L’utilité des sciences sociales pour faire face à l’épidémie à virus Ebola ne fait plus débat aujourd’hui. Dans les pays en situation épidémique, des chercheurs en sciences sociales (anthropologues et sociologues) ont été précocement associés à la réponse pour adapter les messages d’information vers la population, favoriser l’acceptation des décisions de santé publique (surveillance communautaire des cas suspects, isolement des cas confirmés, enterrements sécurisés, etc.), pour « humaniser » les pratiques de soins et les pratiques funéraires ; mais aussi pour évaluer les impacts sociaux de l’épidémie. Une expérience de la contribution des sciences sociales a été acquise dans l’action sur le terrain.Dans les pays voisins d’un foyer épidémique, les systèmes de santé tentent de prévenir une flambée épidémique tout en s’y préparant. Ils anticipent l’organisation de la réponse médicale pour prendre en charge les malades et limiter les transmissions en disposant des équipements, en formant le personnel médical, en définissant des espaces de soins, etc. Les connaissances empiriques acquises dans les pays les plus touchés permettent aux autres pays de se préparer mieux et plus vite, en améliorant la stratégie et les procédures. Les sciences sociales doivent être associées à cette préparation des systèmes de santé car désormais les épidémies « se précèdent elles-mêmes », au sens où la diffusion des interprétations et leurs effets sociaux précèdent celle du virus.Une des conséquences de l’accélération et de la globalisation des échanges d’informations est qu’ avant même qu’un cas ne soit avéré dans une région ou un pays, des rumeurs, interprétations conspirationnistes (par exemple : c’est une maladie importée par les Occidentaux, c’est le vaccin qui inocule la maladie, etc.) ou des politiques (interférant avec les messages sanitaires destinés à la population), réactions xénophobes, revendications de fermeture des frontières ou refus des dispositifs de traitement sont déjà en place.De plus, la vulnérabilité des pays à l’épidémie dépend étroitement de déterminants sociaux préexistants qu’il faut comprendre, pour ajuster la réponse, tels que les flux migratoires entre pays et le statut des frontières par rapport aux découpages identitaires, l’acceptabilité du dispositif de prévention et dépistage de la maladie mis en place, les rapports de la population au système de santé, les tensions intercommunautaires, la mémoire d’autres épidémies qui conditionne les attitudes, l’intervention de l’Etat sur un mode répressif ou inclusif vis-à-vis des sociétés civiles, les parti-pris des médias, etc.La propagation de l’épidémie à virus Ebola en Afrique de l’Ouest a révélé la fragilité et les défaillances des systèmes de santé des pays touchés. Au-delà de la réponse immédiate à l’épidémie, la contribution des sciences sociales doit, à présent, se situer dans une perspective d’analyse des causes sociales et politiques, locales et globales, de cette épidémie. Il est également temps d’envisager dès à présent la situation post-Ebola, dans la perspective de la promotion de la santé, qui prenne en compte les aspects politiques (de gouvernance), sociaux (l’engagement de la société civile), économiques et culturels.Comme toute discipline scientifique, les sciences sociales nécessitent des ressources spécifiques et du temps de travail, pour étudier ces aspects sociaux, et pouvoir accompagner les réponses aux défaillances des systèmes sanitaires ou à la défiance des populations. Dans plusieurs pays à risque épidémique d’Afrique de l’Ouest, des équipes de sciences sociales ont engagé des recherches sur la maladie à virus Ebola et participent aux dispositifs nationaux de réponse. Elles se sont regroupées au sein d’un réseau pour favoriser leurs échanges et pour développer une approche régionale de l’épidémie.Or, à ce jour, la plupart de ces équipes peinent encore à trouver les financements qui leur permettraient de développer des études pourtant indispensables.L’urgence est de soutenir financièrement et institutionnellement les recherches en sciences sociales, à l’échelon régional, dans les pays à risque épidémique : les décideurs doivent en être conscients et leur accorder les moyens de leur action.

In dry savannahs of West-Africa, the malarial mosquitoes of the Anopheles gambiae sensu stricto complex annually survive the harsh desiccating conditions of the dry season. However, the physiological and biochemical mechanisms underlying how these mosquitoes survive such desiccating conditions are still undefined, and controversial. In this context, we provide the first work examining both proteomic and metabolomic changes in the two molecular forms of A. gambiae s.s (M and S forms) experimentally exposed to the rainy and dry season conditions as they experience in the field. Protein abundances of the mosquitoes were measured using a two-dimensional fluorescence difference gel electrophoresis (2D DIGE) coupled with a matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) and tandem mass spectrometry (MS) for protein identification. These assays were conducted by Applied Biomics (http://www.appliedbiomics.com, Applied Biomics, Inc. Hayward, CA, USA), and the mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository with the dataset identifier http://www.ebi.ac.uk/pride/archive/projects/PXD000294. The metabolomic analysis was conducted using both Acquity UPLC® system (for amino acid identification), and a gas-chromatography-mass spectrometry platform (for sugars identification). Metabolomic fingerprintings were assessed in the University of Rennes 1, UMR CNRS 6553 EcoBio (France). A detailed interpretation of the obtained data can be found in Hidalgo et al. (2014) [1] (Journal of Insect Physiology (2014)).

International audience; Characterizing the entomological profile of malaria transmission at fine spatiotemporal scales is essential for developing and implementing effective vector control strategies. Here, we present a fine-grained dataset of Anopheles mosquitoes (Diptera: Culicidae) collected in 55 villages of the rural districts of Korhogo (Northern Côte d’Ivoire) and Diébougou (South-West Burkina Faso) between 2016 and 2018. In the framework of a randomized controlled trial, Anopheles mosquitoes were periodically collected by Human Landing Catches experts inside and outside households, and analyzed individually to identify the genus and, for a subsample, species, insecticide resistance genetic mutations, Plasmodium falciparum infection, and parity status. More than 3,000 collection sessions were carried out, achieving about 45,000 h of sampling efforts. Over 60,000 Anopheles were collected (mainly A. gambiae s.s., A. coluzzii, and A. funestus). The dataset is published as a Darwin Core archive in the Global Biodiversity Information Facility, comprising four files: events, occurrences, mosquito characterizations, and environmental data.

K. R. Dabire1, A. Diabate1, M. Namountougou1, L. Djogbenou2, C. Wondji3, F. Chandre4, F. Simard5, J-B. Ouedraogo1, T. Martin6, M. Weill7 and T. Baldet8 1IRSS/Centre Muraz, BP 390 Bobo-Dioulasso, 2IRSP/ Ouidah, 3Liverpool School of Tropical Medicine, 4LIN/Montpellier UMR MIGEVEC 5IRD/IRSS, Bobo-Dioulasso UMR MIGEVEC, 6CIRAD, UR HORTSYS, Montpellier, 7ISEM, CNRS/Universite Montpellier 2, Montpellier, 8IRD/CIRAD/CREC, Cotonou, 1,5Burkina Faso 2,8Benin 3UK 4,6,7France

Despite its epidemiological importance, the time Plasmodium parasites take to achieve development in the vector mosquito (the extrinsic incubation period, EIP) remains poorly characterized. A novel non-destructive assay designed to estimate EIP in single mosquitoes, and more broadly to study Plasmodium–Anopheles vectors interactions, is presented. The assay uses small pieces of cotton wool soaked in sugar solution to collect malaria sporozoites from individual mosquitoes during sugar feeding to monitor infection status over time. This technique has been tested across four natural malaria mosquito species of Africa and Asia, infected with Plasmodium falciparum (six field isolates from gametocyte-infected patients in Burkina Faso and the NF54 strain) and across a range of temperatures relevant to malaria transmission in field conditions. Monitoring individual infectious mosquitoes was feasible. The estimated median EIP of P. falciparum at 27 °C was 11 to 14 days depending on mosquito species and parasite isolate. Long-term individual tracking revealed that sporozoites transfer onto cotton wool can occur at least until day 40 post-infection. Short individual EIP were associated with short mosquito lifespan. Correlations between mosquito/parasite traits often reveal trade-offs and constraints and have important implications for understanding the evolution of parasite transmission strategies.

Introduction In the general population, urinary sodium-to-potassium (uNa/K) ratio associates more strongly with high blood pressure (BP) than either urinary sodium or potassium alone. Whether this is also the case among patients with chronic kidney disease (CKD) is unknown. Methods We studied the associations of spot urine sodium-to-creatinine (uNa/Cr), potassium-to-creatinine (uK/Cr), and uNa/K ratios with a single office BP reading in 1660 patients with moderate to severe CKD at inclusion in the CKD-REIN cohort. Results Patients' median age was 68 (interquartile range [IQR], 59–76) years; most were men (65%), had moderate CKD (57%), and albuminuria (72%). Mean systolic and diastolic BP was 142/78 mm Hg. Spot uNa/Cr and uNa/K ratios were positively associated with systolic, mean arterial, and pulse pressures. The mean adjusted difference in systolic BP between the highest and the lowest quartile (Q4 vs. Q1) was 4.24 (95% confidence interval [CI], 1.53–6.96) mm Hg for uNa/Cr and 4.79 (95% CI, 2.18–7.39) mm Hg for uNa/K. Quartiles of spot uK/Cr were not associated with any BP index. The higher the quartile of uNa/K, the higher the prevalence ratio of uncontrolled (Q4 vs. Q1, 1.43; 95% CI, 1.19–1.72) or apparently treatment-resistant hypertension (Q4 vs. Q1, 1.35; 95% CI, 1.14–1.60). Findings were consistent in a subset of 803 individuals with 2 BP readings. Conclusion In patients with CKD, higher urinary sodium excretion is associated with higher BP, but unlike in general population, lower potassium excretion is not. Urinary Na/K does not add significant value in assessing high BP risk, except perhaps for hypertension control assessment., Graphical abstract

To evaluate the implementation of a screening strategy for the partners and children of pregnant women with hepatitis B virus (HBV) attending antenatal care.We identified pregnant women positive for HBV surface antigen (HBsAg) at antenatal consultation in Ouagadougou, Burkina Faso. At post-test counselling, women were advised to disclose their HBV status to partners and to encourage their partner and children to be screened for HBsAg. We used multivariable logistic regression to explore factors associated with uptake of screening and HBsAg positivity among family members.Of 1000 HBsAg-positive women, 436/1000 partners and 215/1281 children were screened. HBsAg was detected in 55 (12.6%) partners and 24 (11.2%) children. After adjusting for confounders, uptake of screening was higher in partners who were married, who attended the woman's first post-test consultation and to whom the woman had disclosed her HBV status. In children, HBsAg positivity was associated with being born before the introduction of infant hepatitis B vaccination in Burkina Faso (not significant in the multivariable analysis), having a mother positive for HBV e-antigen (adjusted OR: 8.57; 95% CI: 2.49-29.48) or having a mother with HBV DNA level ≥ 200 000 IU/mL (OR: 6.83; 95% CI: 1.61-29.00).In low-income countries, the antenatal consultation provides a cost-effective opportunity to identify HBV-infected household contacts and link them to care. Children born before the introduction of infant hepatitis B vaccination and whose mother has higher viral load or infectivity should be a priority for testing and linkage to care.Évaluer la mise en œuvre d'une stratégie de dépistage chez les partenaires et enfants de femmes enceintes porteuses du virus de l'hépatite B (VHB) faisant l'objet de soins prénatals.Nous avons identifié des femmes enceintes positives à l'antigène de surface du VHB (Ag HBs) dans le cadre de consultations prénatales à Ouagadougou, au Burkina Faso. Parallèlement aux conseils prodigués après le test, les femmes ont été incitées à informer leur partenaire de leur statut sérologique et à l'encourager, ainsi que leurs enfants, à se soumettre à un dépistage du Ag HBs. Nous avons employé un modèle de régression logistique multivariée pour examiner les facteurs associés à la participation au dépistage et à la positivité au Ag HBs parmi les membres d'une même famille.Pour 1000 femmes positives au Ag HBs, 436 partenaires sur 1000 et 215 enfants sur 1281 ont été dépistés. Le Ag HBs a été détecté chez 55 partenaires (12,6%) et 24 enfants (11,2%). Après ajustement en fonction des variables confusionnelles, la participation au dépistage s'est révélée plus élevée chez les partenaires mariés, ceux ayant assisté à la première consultation post-test de la femme et ceux à qui la femme avait dévoilé son statut sérologique. Chez les enfants, la positivité au Ag HBs était liée à une naissance avant l'instauration de la vaccination des nourrissons contre l'hépatite B au Burkina Faso (non significative dans l'analyse multivariée), au fait d'avoir une mère positive à l'antigène e du VHB (OR ajusté: 8,57; IC de 95%: 2,49–29,48) ou au fait d'avoir une mère dont le taux d'ADN du VHB ≥ 200 000 IU/mL (OR: 6,83; IC de 95%: 1,61–29,00).Dans les pays à revenu faible, la consultation prénatale offre une occasion peu coûteuse d'identifier les contacts infectés par le VHB au sein des foyers et de favoriser leur suivi médical. Les enfants nés avant l'instauration de la vaccination des nourrissons contre l'hépatite B ainsi que ceux dont la mère présentait une plus forte charge virale ou infectiosité doivent être prioritaires en matière de dépistage et de prise en charge.Evaluar la aplicación de una estrategia de cribado para las parejas y los hijos de las mujeres embarazadas con el virus de la hepatitisSe identificaron mujeres embarazadas positivas al antígeno de superficie del VHB (HBsAg) en la consulta prenatal en Ouagadougou, BurkinaDe 1000 mujeres positivas para el HBsAg, se analizaron 436/1000 parejas y 215/1281 hijos. Se detectó el HBsAg en 55 (12,6 %) parejas y 24 (11,2 %) hijos. Luego de ajustar por variables de confusión, la aceptación del cribado fue mayor en las parejas que estaban casadas, quienes asistieron a la primera consulta de la mujer posterior a la prueba y a quienes la mujer había revelado su estado de VHB. En los niños, la positividad del HBsAg se asoció con el hecho de haber nacido antes del inicio de la vacunación infantil contra la hepatitis B en Burkina Faso (no fue significativo en el análisis multivariable), tener una madre positiva al antígeno En los países de ingresos bajos, la consulta prenatal ofrece una oportunidad rentable para identificar a los contactos familiares infectados por el VHB y vincularlos a la atención. Los niños nacidos antes del inicio de la vacunación infantil contra la hepatitis B y cuyas madres tienen una carga viral o infectividad más elevada deberían ser objeto prioritario de pruebas de detección y vinculación a la atención sanitaria.الغرض تقييم تنفيذ استراتيجية فحص للشركاء وأطفال النساء الحوامل المصابات بفيروس الالتهاب الكبدي ب (HBV) الذين يحضرون الرعاية السابقة للولادة. الطريقة قمنا بتحديد النساء الحوامل المصابات بالمستضد السطحي للالتهاب الكبدي ب (HBsAg) في استشارة ما قبل الولادة في واغادوغو، بوركينا فاصو. في استشارة ما بعد الفحص، تم نصح النساء بالكشف عن حالة الإصابة بالالتهاب الكبدي ب لديهن لشركائهن، وتشجيع شركائهن وأطفالهن على الخضوع لفحص المستضد السطحي للالتهاب الكبدي ب. استخدمنا التحوف اللوجيستي متعدد المتغيرات لاستكشاف العوامل المرتبطة بالخضوع للفحص، والمستضد السطحي للالتهاب الكبدي ب بين أفراد الأسرة. النتائج من بين 1000 امرأة مصابة بالمستضد السطحي للالتهاب الكبدي ب، تم فحص 436/1000 شريك، و215/1281 طفلاً. تم اكتشاف المستضد السطحي للالتهاب الكبدي ب في 55 شريكًا (12.6%)، و24 طفلاً (11.2%). بعد التكيف مع المتغيرات المحيّرة، كان معدل الخضوع للفحص أعلى لدى الشركاء المتزوجين، والذين حضروا الاستشارة بعد أول فحص للمرأة، والذين كشفت لها المرأة عن حالة إصابتها بالتهاب الكبد ب. أما في الأطفال، فقد ارتبطت الإصابة بالمستضد السطحي للالتهاب الكبدي ب بالولادة قبل طرح لقاح التهاب الكبد ب للرضع في بوركينا فاصو (ليس مهمًا في التحليل متعدد المتغيرات)، مع وجود أم مصابة بمستضد التهاب الكبد ب الإلكتروني (نسبة الاحتمالات المعدلة: 8.57؛ ‏بفاصل ثقة 95%: 2.49 إلى 29.48)، أو وجود أم مصابة بالتهاب الكبد ب المستوى DNA ≥200000 وحدة دولية/مل (نسبة الاحتمالات: 6.83؛ ‏بفاصل ثقة 95%: 1.61 إلى 29.00). الاستنتاج في الدول ذات الدخل المنخفض، توفر استشارة ما قبل الولادة فرصة فعالة من حيث التكلفة لتحديد جهات الاتصال المنزلي المصابة بفيروس التهاب الكبد ب، وربطها بالرعاية. إن الأطفال المولودين قبل طرح لقاح التهاب الكبد ب للرضع، والذين كانت أمهاتهم تحملن حمولة فيروسية أعلى أو إصابة أقوى بالعدوى، يجب أن تكون لهم أولوية للاختبار والربط بالرعاية..评估对参加产前检查的孕妇的伴侣和子女进行乙肝病毒 (HBV) 筛查的实施情况。.我们在布基纳法索瓦加杜古的产前咨询中发现了 HBV 表面抗原 (HBsAg) 呈阳性的孕妇。在检测后的咨询中，我们建议这些妇女向其伴侣告知其 HBV 状况，并鼓励其伴侣和子女进行 HBsAg 筛查。我们使用多变量逻辑回归方法来探索家庭成员接受筛查且 HBsAg 呈阳性相关的因素。.在 1000 名 HBsAg 呈阳性的女性中，436/1000 名伴侣和 215/1281 名儿童接受了筛查。有 55 名（12.6%）伴侣和 24 名（11.2%）儿童检测为 HBsAg 呈阳性。在对混杂因素进行调整后，已婚妇女的伴侣、检测后参加首次询诊的妇女的伴侣以及向其伴侣告知 HBV 状况的妇女的伴侣进行筛查的比率更高。在儿童中，布基纳法索地区 HBsAg 呈阳性与婴儿在进行乙肝疫苗接种前出生（在多变量分析中不显著），母亲 HBV e 抗原呈阳性（调整后的 OR：8.57；95% 置信区间：2.49–29.48），或者母亲 HBV DNA 水平为³200,000 IU/毫升（OR：6.83；95% 置信区间：1.61–29.00）有关。.在低收入国家，产前咨询提供了经济有效的机会以确认感染 HBV 的家庭接触者并使其接受护理。对于母亲的病毒载量或传染性较高且在接受乙肝疫苗接种前出生的婴儿，应优先进行检测并使其接受护理。.Оценить осуществление стратегии скрининга для партнеров и детей беременных женщин, положительных по вирусу гепатита В (HBV), которые посещают учреждения дородовой помощи.Авторы выявляли беременных женщин, положительных по поверхностному антигену HBV (HBsAg), в женской консультации г. Уагадугу, Буркина-Фасо. На консультации после тестирования женщинам было рекомендовано сообщить о своем HBV-статусе партнеру и привести партнера и детей на скрининг по гепатиту В. Использовалась многопеременная логистическая регрессия для изучения факторов, ассоциируемых с тем, как члены семьи были охвачены скринингом и насколько часто выявлялась положительность по HBsAg.Для 1000 положительных по HBsAg женщин скрининг прошли 436/1000 партнеров и 215/1281 ребенок. HBsAg обнаружили у 55 партнеров (12,6%) и у 24 детей (11,2%). После внесения поправки на факторы, затрудняющие оценку причинно-следственной связи, оказалось, что охват скринингом был выше у женатых мужчин, которые пришли с супругами на первую консультацию после тестирования и которым жены рассказали о своем положительном статусе. У детей положительная реакция в тесте на HBsAg была связана с фактом рождения до начала кампании вакцинирования младенцев от гепатита В в Буркина-Фасо (незначимо для многопеременного анализа), с положительностью матери по е-антигену HBV (скорректированное ОШ: 8,57; 95%-й ДИ: 2,49–29,48) или с вирусной нагрузкой у матери по HBV ≥ 200 000 МЕ/мл (ОШ: 6,83; 95%-й ДИ: 1,61–29,00).В странах с низким уровнем дохода женская дородовая консультация позволяет экономичным образом выявить бытовые контакты инфицированных HBV лиц и дать им возможность получения медицинской помощи. Дети, родившиеся до начала кампании вакцинирования младенцев от гепатита В, и те, у кого матери имели более высокую вирусную нагрузку, должны проходить тестирование и приступать к лечению в первоочередном порядке.

Background Anthrax is a zoonotic disease that causes frequent outbreaks in livestock and fatal human cases in Burkina Faso. Effective surveillance of this disease calls for the establishment of an integrated surveillance system, in line with the One Health concept. However, despite a strong technical and financial support from international partners, surveillance is still poorly conducted within an integrated approach. Based on stakeholder perspectives, the study has for objective to deepen our understanding of the anthrax surveillance system and to identify the obstacles and levers towards a more integrated approach to anthrax surveillance in Burkina Faso. Methods The data was collected from a literature review and interviews with surveillance stakeholders. We first conducted a qualitative descriptive analysis of the data to characterize the surveillance system (programmes, actors, collaboration). In a second step, we conducted a thematic analysis of the informants' discourse in order to identify what represents an obstacle or, conversely, a lever for a more integrated approach to anthrax surveillance. Results The surveillance system of anthrax in Burkina Faso includes three programmes (in the livestock, wildlife and human sectors), which involves 30 actors. These sectoral programmes operate almost independently from one another, although some collaborations are existing for the governance and implementation of surveillance activities. Analysis of the discourse of key stakeholders led to the identification of four categories of factors that may influence the implementation of an integrated surveillance system in the country: knowledge; technical, organizational and social capacities; motivation; intersectoral governance. Conclusions This study highlights the difficulty of translating One Health governance to the national level and the need to better articulate the visions of all categories of stakeholders. This study also reveals the need to develop specific evaluation systems for integrated policies in order to provide credible evidence of their added value for a better management of zoonotic diseases. Finally, our study underlines the need to act upstream the emergence of zoonoses and allocate more resources to the prevention of zoonoses than to their control.

The spread of insecticide resistance in Anopheles mosquitoes and drug resistance in Plasmodium parasites is contributing to a global resurgence of malaria, making the generation of control tools that can overcome these roadblocks an urgent public health priority. We recently showed that the transmission of Plasmodium falciparum parasites can be efficiently blocked when exposing Anopheles gambiae females to antimalarials deposited on a treated surface, with no negative consequences on major components of mosquito fitness. Here, we demonstrate this approach can overcome the hurdles of insecticide resistance in mosquitoes and drug resistant in parasites. We show that the transmission-blocking efficacy of mosquito-targeted antimalarials is maintained when field-derived, insecticide resistant Anopheles are exposed to the potent cytochrome b inhibitor atovaquone, demonstrating that this drug escapes insecticide resistance mechanisms that could potentially interfere with its function. Moreover, this approach prevents transmission of field-derived, artemisinin resistant P. falciparum parasites (Kelch13 C580Y mutant), proving that this strategy could be used to prevent the spread of parasite mutations that induce resistance to front-line antimalarials. Atovaquone is also highly effective at limiting parasite development when ingested by mosquitoes in sugar solutions, including in ongoing infections. These data support the use of mosquito-targeted antimalarials as a promising tool to complement and extend the efficacy of current malaria control interventions.

Background Seasonal malaria chemoprevention (SMC) consists of administration of sulfadoxine-pyrimethamine (SP) + amodiaquine (AQ) at monthly intervals to children during the malaria transmission period. Whether the addition of azithromycin (AZ) to SMC could potentiate the benefit of the intervention was tested through a double-blind, randomized, placebo-controlled trial. The effect of SMC and the addition of AZ, on malaria transmission and on the life history traits of Anopheles gambiae mosquitoes have been investigated. Methods The study included 438 children randomly selected from among participants in the SMC + AZ trial and 198 children from the same area who did not receive chemoprevention. For each participant in the SMC + AZ trial, blood was collected 14 to 21 days post treatment, examined for the presence of malaria sexual and asexual stages and provided as a blood meal to An. gambiae females using a direct membrane-feeding assay. Results The SMC treatment, with or without AZ, significantly reduced the prevalence of asexual Plasmodium falciparum (LRT X22 = 69, P 22 = 54, P 22 = 61, P X22 = 22.8, P 21 = 5.2, P = 0.02), suggesting a significant effect of AZ on gametocyte infectivity. There was a slight negative effect of SPAQ and SPAQ + AZ on mosquito survival compared to mosquitoes fed with blood from control children (LRTX22 = 330, P Conclusion This study demonstrates that SMC may contribute to a reduction in human to mosquito transmission of P. falciparum, and the reduced mosquito longevity observed for females fed on treated blood may increase the benefit of this intervention in control of malaria. The addition of AZ to SPAQ in SMC appeared to enhance the infectivity of gametocytes providing further evidence that this combination is not an appropriate intervention.

International audience; BACKGROUND: Despite epidemiological importance, few studies have explored whether individual experience and learning could affect the vertebrate host choice of mosquito disease vectors. Here, we investigated whether a first successful blood meal can modulate mosquito preference during a second blood meal.METHODS: In no-choice situations, females of the mosquito Anopheles coluzzii, one of the primary African malaria vectors, were first allowed to feed on either human, rabbit or guinea pig. Four days later in dual-choice situations, the same mosquitoes were allowed to choose between the two uncommon hosts, rabbit and guinea pig, as a source of blood. ELISA assays were then used to determine which host mosquitoes fed on.RESULTS: Our results indicate that, overall, mosquitoes preferred to feed on rabbit over guinea pig and that the nature of the first blood meal had a significant impact on the mosquito host choice during the second blood meal. Compared to mosquitoes that previously fed on guinea pigs or humans, mosquitoes that fed on rabbits were less likely to choose this host species during a second exposition. The decreased preference for rabbit was observed four days after mosquitoes were first exposed to this host, suggesting that the effect lasts at least the duration of a gonotrophic cycle. Furthermore, this effect was observed after only one successful blood meal. Fitness measurements on mosquitoes fed on the three different vertebrate hosts showed that the origin of the blood meal affected mosquito longevity but not fecundity. In particular, human-fed mosquitoes lived longer than guinea pig-fed or rabbit-fed mosquitoes.CONCLUSIONS: Our study demonstrates that individual experience affects host choice in this mosquito species and might have strong repercussions on biting patterns in natural conditions and hence on malaria transmission.

Background Acacia senegal is a plant traditionally used for its various properties, including the treatment of infectious diseases. Recently, our team has demonstrated the ability of the hydroethanolic extract of the leaves to increase the activity of phenicol antibiotics against multi-resistant bacteria. The aim of this work is to determine the toxicological effects of the extract and its capacity to inhibit the bacterial mobility of Gram-negative bacteria, in order to evaluate the level of safety use of this plant. Methods The cytotoxicity test was performed using the neutral red absorption method. Acute and sub-acute oral toxicity were conducted on NMRI mice and Wistar rats. The behaviour and adverse effects were recorded during the 14 days of the acute study. For the subacute test, biochemical parameters, food and water consumption, and morphological parameters were determined. The anti-motility activities were evaluated on Pseudomonas aeruginosa PA01 and Escherichia coli AG100, using specific concentrations of Agar as required by the method. Results HEASG induced inhibition of keratinocytes cell growth with an IC50 of 1302 ± 60 μg/mL. For the acute toxicity study in mice, the single dose of extract of 2000 mg/kg body weight caused no deaths and no behavioural changes were observed; therefore, the median lethal dose (LD50) of HEASG was calculated to 5000 mg/kg body weight. In Wistar rats, no mortality was observed at 250, 500 and 1000 mg/kg/day during the 28-day subacute oral toxicity study. The weights of both females and males increased globally over time, regardless of the batch. No statistically significant differences were registered for organ weights and biochemical parameters, except for chloride for biochemical parameters. Water and food consumption did not change significantly. Furthermore, no macroscopic changes in organ appearance were observed. Regarding anti-motility activity, the extract has reduced the swarming motility of PA01 and AG100 significantly at the concentration of 32 μg/mL (P P Conclusions The results suggest that hydroethanolic extract of A. senegal leaves has significant activity against bacterial motility and relatively low toxicity.

BackgroundMalaria control and prevention programs are more efficient and cost-effective when they target hotspots or select the best periods of year to implement interventions. This study aimed to identify the spatial distribution of malaria hotspots at the village level in Diébougou health district, Burkina Faso, and to model the temporal dynamics of malaria cases as a function of meteorological conditions and of the distance between villages and health centers (HCs).MethodsCase data for 27 villages were collected in 13 HCs using continuous passive case detection. Meteorological data were obtained through remote sensing. Two synthetic meteorological indicators (SMIs) were created to summarize meteorological variables. Spatial hotspots were detected using the Kulldorf scanning method. A General Additive Model was used to determine the time lag between cases and SMIs and to evaluate the effect of SMIs and distance to HC on the temporal evolution of malaria cases. The multivariate model was fitted with data from the epidemic year to predict the number of cases in the following outbreak.ResultsOverall, the incidence rate in the area was 429.13 cases per 1,000 person-year with important spatial and temporal heterogeneities. Four spatial hotspots, involving 7 of the 27 villages, were detected, for an incidence rate of 854.02 cases per 1,000 person-year. The hotspot with the highest risk (relative risk = 4.06) consisted of a single village, with an incidence rate of 1,750.75 cases per 1,000 person-years. The multivariate analysis found greater variability in incidence between HCs than between villages linked to the same HC. The epidemic year was characterized by a major peak during the second part of the rainy season and a secondary peak during the dry-hot season. The time lag that generated the better predictions of cases was 9 weeks for SMI1 (positively correlated with precipitation variables and associated with the first peak of cases) and 16 weeks for SMI2 (positively correlated with temperature variables and associated with the secondary peak of cases). Euclidian distance to HC was not found to be a predictor of malaria cases recorded in HC. The prediction followed the overall pattern of the time series of reported cases and predicted the onset of the following outbreak with a precision of less than 3 weeks.ConclusionsOur spatio-temporal analysis of malaria cases in Diébougou health district, Burkina Faso, provides a powerful prospective method for identifying and predicting high-risk areas and high-transmission periods that could be targeted in future malaria control and prevention campaigns.

CAP-CoV-BF – Une enquête nationale sur les connaissances, attitudes et pratiques liées à la pandémie COVID-19 des médecins au Burkina FasoLes médecins, premières personnes exposées et victimes des épidémies, sont au cœur des dispositifs de riposte à l’épidémie de Covid-19. L’étude CAP-CoV-BF s’est concentrée exclusivement sur ces maillons essentiels de la lutte contre la Covid-19 au Burkina Faso. Leur compréhension de la maladie, l’impact de la maladie sur leurs pratiques professionnelles, leur accès au matériel de protection, les répercussions sur leur vie personnelle, etc. sont autant d’aspects différents qui peuvent impacter directement les mesures de santé publiques prises par les autorités nationales.Une enquête téléphonique en 3 vagues, entre septembre 2020 et février 2021Une enquête quantitative transversale par téléphone a été mise en place, menée auprès d’un échantillon représentatif d’environ 200 médecins sur l’ensemble du territoire burkinabè. Elle a été répétée 3 fois, à un intervalle régulier (environ tous les 2 mois). Cette temporalité a permis de confronter l’épidémie à différents stades : alors que le nombre de cas était relativement peu important et plutôt stable lors de 1re vague d’enquête en Septembre 2021, le pays a fait face à un pic épidémique en décembre 2020 et janvier 2021, qui a eu un impact important sur les médecins.L’objectif principal de cette étude était de fournir aux acteurs nationaux impliqués dans la gestion de la crise des données probantes régulières et représentatives à l’échelle nationale sur les connaissances, attitudes et pratiques des médecins au Burkina Faso.

Background Improving the knowledge and understanding of the environmental determinants of malaria vector abundance at fine spatiotemporal scales is essential to design locally tailored vector control intervention. This work is aimed at exploring the environmental tenets of human-biting activity in the main malaria vectors (Anopheles gambiae s.s., Anopheles coluzzii and Anopheles funestus) in the health district of Diébougou, rural Burkina Faso. Methods Anopheles human-biting activity was monitored in 27 villages during 15 months (in 2017–2018), and environmental variables (meteorological and landscape) were extracted from high-resolution satellite imagery. A two-step data-driven modeling study was then carried out. Correlation coefficients between the biting rates of each vector species and the environmental variables taken at various temporal lags and spatial distances from the biting events were first calculated. Then, multivariate machine-learning models were generated and interpreted to (i) pinpoint primary and secondary environmental drivers of variation in the biting rates of each species and (ii) identify complex associations between the environmental conditions and the biting rates. Results Meteorological and landscape variables were often significantly correlated with the vectors’ biting rates. Many nonlinear associations and thresholds were unveiled by the multivariate models, for both meteorological and landscape variables. From these results, several aspects of the bio-ecology of the main malaria vectors were identified or hypothesized for the Diébougou area, including breeding site typologies, development and survival rates in relation to weather, flight ranges from breeding sites and dispersal related to landscape openness. Conclusions Using high-resolution data in an interpretable machine-learning modeling framework proved to be an efficient way to enhance the knowledge of the complex links between the environment and the malaria vectors at a local scale. More broadly, the emerging field of interpretable machine learning has significant potential to help improve our understanding of the complex processes leading to malaria transmission, and to aid in developing operational tools to support the fight against the disease (e.g. vector control intervention plans, seasonal maps of predicted biting rates, early warning systems). Graphical abstract

CAP-CoV-BF : une enquête nationale réalisées auprès des médecins au Burkina FasoLe personnel de santé se trouve au cœur du dispositif élaboré dans le cadre de la réponse à l’épidémie de COVID-19, à la fois en tant qu’acteur essentiel du dispositif de réponse à l’épidémie, et en tant que premières personnes exposées et victimes. Il est ainsi essentiel de s’assurer de la compréhension de cette maladie (symptômes, modes de transmission, mesures de prévention, etc.) et de l’acceptabilité et de l’adaptation des médecins du Burkina Faso face aux mesures de santé publique préconisées. Cela permet d’identifier les difficultés et les barrières qu’ils rencontrent afin d’adopter les mesures de protection adéquates, proposer des interventions adaptées pour les surmonter et prioriser les messages qui leur sont destinés.L’objectif principal de cette étude est de fournir aux acteurs nationaux impliqués dans la gestion de la crise des données probantes régulières et représentatives à l’échelle nationale sur les connaissances, attitudes et pratiques des médecins au Burkina Faso.Une enquête quantitative transversale par téléphone a été mise en place auprès d’un échantillon représentatif de médecins sur l’ensemble du territoire. Une 1ère enquête a été menée en septembre 2020 (n=166) et une 2ème en décembre 2020 (n=190).

Background The World Health Organization recommends regularly assessing the efficacy of artemisinin-based combination therapy (ACT), which is a critical tool in the fight against malaria. This study evaluated the efficacy of two artemisinin-based combinations recommended to treat uncomplicated Plasmodium falciparum malaria in Burkina Faso in three sites: Niangoloko, Nanoro, and Gourcy. Methods This was a two-arm randomized control trial of the efficacy of artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP). Children aged 6–59 months old were monitored for 42 days. The primary outcomes of the study were uncorrected and PCR-corrected efficacies to day 28 for AL and 42 for DP. Molecular markers of resistance to artemisinin derivatives and partner drugs were also analysed. Results Of 720 children enrolled, 672 reached study endpoints at day 28, 333 in the AL arm and 339 in the DP arm. PCR-corrected 28-day per protocol efficacy in the AL arm was 74% (64–83%) in Nanoro, 76% (66–83%) in Gourcy, and 92% (84–96%) in Niangoloko. The PCR-corrected 42-day per protocol efficacy in the DP arm was 84% (75–89%) in Gourcy, 89% (81–94%) in Nanoro, and 97% (92–99%) in Niangoloko. No Pfk13 mutation previously associated with artemisinin-resistance was observed. No statistically significant association was found between treatment outcome and presence of the 86Y mutation in the Pfmdr1 gene. There was also no association observed between treatment outcome and Pfpm2 or Pfmdr1 copy number variation. Conclusion The results of this study indicate evidence of inadequate efficacy of AL at day 28 and DP at day 42 in the same two sites. A change of first-line ACT may be warranted in Burkina Faso. Trial Registry Pan African Clinical Trial Registry Identifier: PACTR201708002499311. Date of registration: 8/3/2017 https://pactr.samrc.ac.za/Search.aspx

Background Multi-genotype malaria infections are frequent in endemic area, and people commonly harbour several genetically distinct Plasmodium falciparum variants. The influence of genetic multiplicity and whether some specific genetic variants are more or less likely to invest into gametocyte production is not clearly understood. This study explored host and parasite-related risk factors for gametocyte carriage, and the extent to which some specific P. falciparum genetic variants are associated with gametocyte carriage. Methods Gametocytes and asexual forms were detected by light microscopy on thick smears collected between 2010 and 2012 in Nanoro, Burkina Faso. Merozoite surface protein 1 and 2 were genotyped by nested PCR on clinical samples. Associations between gametocyte carriage and factors, including multiplicity of infection, parasite density, patient age, gender, haemoglobin (Hb) level, and body temperature were assessed. The relationship between the presence of a particular msp1 and msp2 genetic variants and gametocyte carriage was also explored. Results Of the 724 samples positive to P. falciparum and successfully genotyped, gametocytes were found in 48 samples (6.63%). There was no effect of patient gender, age and body temperature on gametocyte carriage. However, the probability of gametocyte carriage significantly increased with increasing values of multiplicity of infection (MOI). Furthermore, there was a negative association between parasite density and gametocyte carriage. MOI decreased with parasite density in gametocyte-negative patients, but increased in gametocyte carriers. The probability of gametocyte carriage decreased with Hb level. Finally, the genetic composition of the infection influenced gametocyte carriage. In particular, the presence of RO33 increased the odds of developing gametocytes by 2 while the other allelic families K1, MAD20, FC27, and 3D7 had no significant impact on the occurrence of gametocytes in infected patients. Conclusion This study provides insight into potential factors influencing gametocyte production in symptomatic patients. The findings contribute to enhance understanding of risk factors associated with gametocyte carriage in humans. Trial registration NCT01232530.

International audience; Introduction: from a genetic point of view P. falciparum is extremely polymorphic. There is a variety of parasite strains infesting individuals living in malaria endemic areas. The purpose of this study is to investigate the relationship between polymorphisms in Plasmodium falciparum parasites and Pfcrt and Pfmdr1 gene mutations in Nanoro area, Burkina Faso.Methods: blood samples from plasmodium carriers residing in the Nanoro Health District were genotyped using nested PCR. Parasite gene mutations associated with resistance to antimalarial drugs were detected by PCR-RFLP.Results: samples of 672 patients were successfully genotyped. No msp1 and msp2 allelic families exhibited an increase in developing mutations in resistance genes. However, mutant strains of these genes were present at greater levels in monoclonal infections than in multi-clonal infections.Conclusion: this study provides an overview of the relationship between polymorphisms in Plasmodium falciparum parasites and mutations in resistance genes. These data will undoubtedly contribute to improving knowledge of the parasite´s biology and its mechanisms of resistance to antimalarial drugs.; Introduction: sur le plan génétique, Plasmodium falciparum (P. falciparum) est une espèce extrêmement polymorphe. Il existe une diversité de souches parasitaires qui infestent les individus vivant en zone d´endémie palustre. La présente étude vise à étudier la relation entre le polymorphisme de P. falciparum et les mutations au niveau des gènes Pfcrt et Pfmdr1 dans la zone de Nanoro au Burkina Faso.Méthodes: les échantillons sanguins de porteurs de plasmodiums résidant dans le district sanitaire de Nanoro ont fait l´objet d´un génotypage par PCR nichée. Les mutations au niveau des gènes de résistance du parasite aux antipaludiques ont été détectées par la technique PCR-RFLP.Résultats: les échantillons de 672 patients ont été génotypés avec succès. Aucune famille allélique des gènes msp1 et msp2 n´avaient une susceptibilité accrue à développer des mutations au niveau des gènes de résistance. Par contre, les souches mutantes de ces gènes étaient significativement plus importantes dans les infections monoclonales que dans les infections multi clonales.Conclusion: cette étude fournit un aperçu global de la relation entre le polymorphisme de P. falciparum et les mutations au niveau des gènes de résistance. Ces données contribueront sans doute à améliorer les connaissances sur la biologie du parasite et de ses mécanismes de résistance aux antipaludiques

Background Behavioural shifts in the canonical location and timing of biting have been reported in natural populations of anopheline malaria vectors following the implementation of insecticide-based indoor vector control interventions. These modifications increase the likelihood of human-vector contact and allow mosquitoes to avoid insecticides, both conditions being favourable to residual transmission of the malarial parasites. The biting behaviour of mosquitoes follows rhythms that are under the control of biological clocks and environmental conditions, modulated by physiological states. In this work we explore modifications of spontaneous locomotor activity expressed by mosquitoes in different physiological states to highlight phenotypic variability associated to circadian control that may contribute to explain residual transmission in the field. Methods The F10 generation progeny of field-collected Anopheles coluzzii from southwestern Burkina Faso was tested using an automated recording apparatus (Locomotor Activity Monitor, TriKinetics Inc.) under LD 12:12 or DD light regimens in laboratory-controlled conditions. Activity recordings of each test were carried out for a week with 6-day-old females belonging to four experimental treatments, representing factorial combinations of two physiological variables: insemination status (virgin vs inseminated) and gonotrophic status (glucose fed vs blood fed). Chronobiological features of rhythmicity in locomotor activity were explored using periodograms, diversity indices, and generalized linear mixed modelling. Results The average strength of activity, onset of activity, and acrophase were modulated by both nutritional and insemination status as well as by the light regimen. Inseminated females showed a significant excess of arrhythmic activity under DD. When rhythmicity was observed in DD, females displayed sustained activity also during the subjective day. Conclusions Insemination and gonotrophic status influence the underlying light and circadian control of chronobiological features of locomotor activity. Overrepresentation of arrhythmic chronotypes as well as the sustained activity of inseminated females during the subjective day under DD conditions suggests potential activity of natural populations of A. coluzzii during daytime under dim conditions, with implications for residual transmission of malarial parasites. Graphical abstract

Background This study reports an updated description on malaria vector diversity, behaviour, insecticide resistance and malaria transmission in the Diébougou and Dano peri-urban areas, Burkina Faso. Methods Mosquitoes were caught monthly using CDC light traps and pyrethrum spray catches. Mosquitoes were identified using morphological taxonomic keys. PCR techniques were used to identify the species of the Anopheles gambiae complex and insecticide resistance mechanisms in a subset of Anopheles vectors. The Plasmodium sporozoite infection status and origins of blood meals of female mosquitoes were determined by ELISA methods. Larvae were collected, breed in the insectary and tested for phenotypic resistance against four insecticides using WHO bioassays. Results This study contributed to update the entomological data in two peri-urban areas of Southwest Burkina Faso. Anopheles populations were mostly anthropophilic and endophilic in both areas and exhibit high susceptibility to an organophosphate insecticide. This offers an alternative for the control of these pyrethroid-resistant populations. These data might help the National Malaria Control Programme for decision-making about vector control planning and resistance management. Conclusions This study contributed to update the entomological data in two peri-urban areas of Southwest Burkina Faso. Anopheles populations were mostly anthropophilic and endophilic in both areas and exhibit high susceptibility to an organophosphate insecticide. This offers an alternative for the control of these pyrethroid-resistant populations. These data might help the National Malaria Control Programme for decision-making about vector control planning and resistance management.

Background The rapid spread of insecticide resistance in malaria vectors and the rebound in malaria cases observed recently in some endemic areas underscore the urgent need to evaluate and deploy new effective control interventions. A randomized control trial (RCT) was conducted with the aim to investigate the benefit of deploying complementary strategies, including indoor residual spraying (IRS) with pirimiphos-methyl in addition to long-lasting insecticidal nets (LLINs) in Diébougou, southwest Burkina Faso. Methods We measured the susceptibility of the Anopheles gambiae (s.l.) population from Diébougou to conventional insecticides. We further monitored the efficacy and residual activity of pirimiphos-methyl on both cement and mud walls using a laboratory susceptible strain (Kisumu) and the local An. gambiae (s.l.) population. Results An. gambiae (s.l.) from Diébougou was resistant to DDT, pyrethroids (deltamethrin, permethrin and alphacypermethrin) and bendiocarb but showed susceptibility to organophosphates (pirimiphos-methyl and chlorpyrimiphos-methyl). A mixed-effect generalized linear model predicted that pirimiphos-methyl applied on cement or mud walls was effective for 210 days against the laboratory susceptible strain and 247 days against the local population. The residual efficacy of pirimiphos-methyl against the local population on walls made of mud was similar to that of cement (OR = 0.792, [0.55–1.12], Tukey’s test p-value = 0.19). Conclusions If data on malaria transmission and malaria cases (as measured trough the RCT) are consistent with data on residual activity of pirimiphos-methyl regardless of the type of wall, one round of IRS with pirimiphos-methyl would have the potential to control malaria in a context of multi-resistant An. gambiae (s.l.) for at least 7 months. Graphical Abstract

International audience

CAP-CoV-BF : une enquête nationale réalisée auprès des médecins au Burkina FasoLe personnel de santé se trouve au cœur du dispositif élaboré dans le cadre de la réponse à l’épidémie de COVID-19, à la fois en tant qu’acteur essentiel du dispositif de réponse à l’épidémie, et en tant que premières personnes exposées et victimes. Il est ainsi essentiel de s’assurer de la compréhension de cette maladie (symptômes, modes de transmission, mesures de prévention, etc.) et de l’acceptabilité et de l’adaptation des médecins du Burkina Faso face aux mesures de santé publique préconisées. Cela permettra d’identifier les difficultés et les barrières qu’ils rencontrent afin d’adopter les mesures de protection adéquates, proposer des interventions adaptées pour les surmonter et prioriser les messages qui leur sont destinés.L’objectif principal de cette étude est de fournir aux acteurs nationaux impliqués dans la gestion de la crise des données probantes régulières et représentatives à l’échelle nationale sur les connaissances, attitudes et pratiques des médecins au Burkina Faso.Une enquête quantitative transversale par téléphone a été mise en place, menée auprès d’un échantillon représentatif de 166 médecins sur l’ensemble du territoire. Elle sera répétée trois fois à intervalles réguliers.

Objective We assess the existence of unfair inequalities in health and death using the normative framework of inequality of opportunities, from birth to middle age in Great Britain. Methods We use data from the 1958 National Child Development Study, which provides a unique opportunity to observe individual health from birth to the age of 54, including the occurrence of mortality. We measure health status combining self-assessed health and mortality. We compare and statistically test the differences between the cumulative distribution functions of health status at each age according to one childhood circumstance beyond people’s control: the father’s occupation. Results At all ages, individuals born to a ‘professional’, ‘senior manager or technician’ father report a better health status and have a lower mortality rate than individuals born to ‘skilled’, ‘partly skilled’ or ‘unskilled’ manual workers and individuals without a father at birth. The gap in the probability to report good health between individuals born into high social backgrounds compared with low, increases from 12 percentage points at age 23 to 26 at age 54. Health gaps are even more marked in health states at the bottom of the health distribution when mortality is combined with self-assessed health. Conclusions There is increasing inequality of opportunities in health over the lifespan in Great Britain. The tag of social background intensifies as individuals get older. Finally, there is added analytical value to combining mortality with self-assessed health when measuring health inequalities.

BackgroundPerinatal treatment with lopinavir boosted by ritonavir (LPV/r) is associated with steroidogenic abnormalities. Long-term effects in infants have not been studied.MethodsAdrenal-hormone profiles were compared at weeks 6 and 26 between human immunodeficiency virus (HIV)-1–exposed but uninfected infants randomly assigned at 7 days of life to prophylaxis with LPV/r or lamivudine (3TC) to prevent transmission during breastfeeding. LPV/r in vitro effect on steroidogenesis was assessed in H295R cells.ResultsAt week 6, 159 frozen plasma samples from Burkina Faso and South Africa were assessed (LPV/r group: n = 92; 3TC group: n = 67) and at week 26, 95 samples from Burkina Faso (LPV/r group: n = 47; 3TC group: n = 48). At week 6, LPV/r-treated infants had a higher median dehydroepiandrosterone (DHEA) level than infants from the 3TC arm: 3.91 versus 1.48 ng/mL (P < .001). Higher DHEA levels (>5 ng/mL) at week 6 were associated with higher 17-OH-pregnenolone (7.78 vs 3.71 ng/mL, P = .0004) and lower testosterone (0.05 vs 1.34 ng/mL, P = .009) levels in LPV/r-exposed children. There was a significant correlation between the DHEA and LPV/r AUC levels (ρ = 0.40, P = .019) and Ctrough (ρ = 0.40, P = .017). At week 26, DHEA levels remained higher in the LPV/r arm: 0.45 versus 0.13 ng/mL (P = .002). Lopinavir, but not ritonavir, inhibited CYP17A1 and CYP21A2 activity in H295R cells.ConclusionsLopinavir was associated with dose-dependent adrenal dysfunction in infants. The impact of long-term exposure and potential clinical consequences require evaluation.Clinical Trials RegistrationNCT00640263

This study reported the phytochemical composition of two hydroethanolic extracts of Acacia senegal and Acacia seyal trees from Burkina Faso and their activities, alone or in combination with selected antibiotics, against multidrug resistant bacteria. High performance thin layer chromatography (HPTLC) method was used for phytochemical screening. Total phenolic and total flavonoid ant tannins in leaves extracts contents were assessed by spectrophotometric method. The minimal inhibitory concentrations (MICs) of plant extracts and antibiotics were determined using the microdilution method and p-iodonitrotetrazolium chloride. Combinations of extracts and antibiotics were studied using checkerboard assays. Screening revealed the presence of phenolic compounds, flavonoids, and tannins in the hydroethanolic extract (HE) of the leaves. The HE of A. seyal showed the highest total phenolic (571.30 ± 6.97 mg GAE/g), total flavonoids (140.41 ± 4.01 mg RTE/g), and tannins (24.72 ± 0.14%, condensed; 35.77 ± 0.19%, hydrolysable tannins). However, the HE of A. senegal showed the lowest total phenolic (69.84 ± 3.54 mg GAE/g), total flavonoids (27.32 ± 0.57 mg RTE/g), and tannins (14.60 ± 0.01%, condensed; 3.09 ± 0.02%, hydrolysable). The MICs for HE and antibiotics were in the range of 2–512 and 0.008–1024 mg/L, respectively. All tested HE presented an MIC greater than 512 mg/L except HE of A. senegal. The lowest MIC value (128 mg/L) was obtained with HE of A. senegal against Klebsiella aerogenes EA298 and Escherichia coli AG100A. Interesting restoring effects on chloramphenicol and florphenicol activity were detected with alcoholic extracts of A. senegal against resistant E. coli and K. aerogenes strains that overproduce AcrAB or FloR pumps. The adjuvant effect of HE of A. senegal suggests that the crude extract of leaves could be a potential source of molecules for improving the susceptibility of bacteria to phenicols antibiotics.

International audience; Background: Several studies highlighted the impact of community-based interventions whose purpose was to reduce the vectors' breeding sites. These strategies are particularly interesting in low-and-middle-income countries which may find it difficult to sustainably assume the cost of insecticide-based interventions. In this case study we determine the spatial distribution of a community-based intervention for dengue vector control using different entomological indices. The objective was to evaluate locally where the intervention was most effective, using spatial analysis methods that are too often neglected in impact assessments.Methods: Two neighbourhoods, Tampouy and Juvenat in Ouagadougou, Burkina Faso, were chosen among five after a survey was conducted, as part of an assessment related to the burden of dengue. As part of the community-based intervention conducted in Tampouy between August and early October 2016, an entomological survey was implemented in two phases. The first phase consisted of a baseline entomological characterization of potential breeding sites in the neighbourhood of Tampouy as well as in Juvenat, the control area. This phase was conducted in October 2015 at the end of the rainy season. The mosquito breeding sites were screened in randomly selected houses: 206 in Tampouy and 203 in Juvenat. A second phase took place after the intervention, in October 2016. The mosquito breeding sites were investigated in the same yards as during the baseline phase. We performed several entomological analyses to measure site productivity as well as before and after analysis using multilevel linear regression. We used Local Indicators of Spatial Association (LISAs) to analyse spatial concentrations of larvae.Results: After the intervention, it is noted that LISAs at Tampouy reveal few aggregates of all types and the suppression of those existing before the intervention. The analysis therefore reveals that the intervention made it possible to reduce the number of concentration areas of high and low values of pupae.Conclusions: The contribution of spatial methods for assessing community-based intervention are relevant for monitoring at local levels as a complement to epidemiological analyses conducted within neighbourhoods. They are useful, therefore, not only for assessment but also for establishing interventions. This study shows that spatial analyses also have their place in population health intervention research.

Summary The microbiota of Anopheles mosquitoes influences malaria transmission. Antibiotics ingested during a blood meal impact the mosquito microbiome and malaria transmission, with substantial differences between drugs. Here, we assessed if amoxicillin affects the gut mosquito microbiota. We collected Anopheles larvae in Burkina Faso, kept them in semi-field conditions, and offered a blood meal to adult females. We tested the impact of blood supplementation with two alternative amoxicillin preparations on microbiota composition, determined by high-throughput sequencing in individual gut samples. Our analysis detected four major genera, Elizabethkingia, Wigglesworthia, Asaia, and Serratia. The antibiotic treatment significantly affected overall microbiota composition, with a specific decrease in the relative abundance of Elizabethkingia and Asaia during blood digestion. Besides its interest on the influence of amoxicillin on the mosquito microbiota, our study proposes a thorough approach to report negative-control data of high-throughput sequencing studies on samples with a reduced microbial load., Graphical abstract, Highlights • We sequenced bacterial 16S in mosquitoes collected as larvae in Burkina Faso • Elizabethkingia, Wigglesworthia, Asaia, and Serratia dominate the gut microbiota • Amoxicillin treatment and potentially gametocyte presence influence the microbiota • We set up methods to consider mock controls after sequencing low-biomass samples, Entomology; Microbiome

International audience; Several antimalarial drugs are known to prolong ventricular repolarization as evidenced by QT/QTc interval prolongation. This can lead to Torsades de Pointes, a potentially lethal ventricular arrhythmia. Whether this is the case with artemisinin-based combination therapies (ACTs) remains uncertain. Assessment of the extent of QTc prolongation with antimalarials is hampered by important variations of heart rate during malaria crises and previous studies have reported highly variable values of QTc prolongations with ACTs. We assessed QTc prolongation with four ACTs, using high quality ECG recording and measurement techniques, during the first episode of malaria in 2,091 African patients enrolled in the WANECAM study which also monitored clinical safety. Using an original and robust method of QTc assessment, independent from heart rate changes and from the method of QT correction, we were able to accurately assess the extent of mean maximum QTc prolongation with the four ACTs tested. There was no evidence of proarrhythmia with any treatment during the study although dihydroartemisinin-piperaquine, artesunate-amodiaquine and artemether-lumefantrine significantly prolonged QTc. The extent of prolongation of ventricular repolarization can be accurately assessed in studies where heart rate changes impede QTc assessment.

International audience; Within mosquito vector populations, infectious mosquitoes are the ones completing the transmission of pathogens to susceptible hosts and they are, consequently, of great epidemiological interest. Mosquito infection by malaria parasites has been shown to affect several traits of mosquito physiology and behavior, and could interplay with the efficacy of control tools. In this study, we evaluated, in pyrethroid resistant Anopheles gambiae, the effect of mosquito infection with the human malaria parasite Plasmodium falciparum on the efficacy of nets treated with either the insecticide deltamethrin or the repellent DEET, measuring (i) mosquito success to pass through the net, (ii) blood-feeding on a host and (iii) chemicals-induced mortality. Infection of mosquitoes at non-infectious stage did not affect their success to pass through the net, to blood-feed, nor chemicals-induced mortality. At infectious stage, depending on replicates, infected mosquitoes had higher mortality rates than uninfected mosquitoes, with stronger effect in presence of DEET. This data evidenced a cost of infection on mosquito survival at transmissible stages of infection, which could have significant consequences for both malaria epidemiology and vector control. This stresses the need for understanding the combined effects of insecticide resistance and infection on the efficacy on control tools. Mosquito-borne diseases are considerable public health issues, mostly affecting populations in developing countries 1,2. To reduce their incidence, controlling vector mosquitoes and limiting their contact with human hosts remains the most effective strategy 3. One promising approach for achieving this goal would be to selectively target, within mosquito populations, individuals that are the most dangerous for humans 4. Particularly, mosquitoes carrying transmissible forms of pathogens in their salivary glands (i.e. infectious mosquitoes), are of great epidemiological relevance. Yet, the implementation of control means that could specifically reach infectious mosquitoes is dependent upon an extensive knowledge of the effects of mosquito infection on its behavior and physiology. Infection by pathogens has been shown to affect mosquito phenotypic traits 5. Malaria-infected Anopheles mosquitoes generally display increase attraction, biting and feeding rate 6-10. Interestingly, these changes are often concomitant with the presence of transmissible stages of the pathogen and may contribute to increase the number of contacts between human hosts and infectious vectors 11. These effects may lead to substantial epidemiological consequences, with transmission rates of mosquito borne pathogens being potentially much higher than expected 12. On the other hand, infection by malaria parasites may induce fitness costs on mosquitoes, reducing their survival. This can be especially true when infection is associated with other biotic and abiotic stresses 13-15. Consequently, all the behavioral and physiological changes associated with infection could directly impact the efficacy of control means. To date, conventional control tools mostly rely on the use of insecticide-treated nets (ITNs), although their efficacy could be threatened by the increase of insecticide resistance mechanisms in mosquito populations 16. Besides, repellents such as DEET (N, N-diéthyl-3-méthylbenzamide) offer a great potential both in cutaneous

International audience