Impacts des Hydrocarbures Aromatiques Polycycliques sur les poissons: Cas des Tilapias du lac Nokoué au Sud du Bénin (Afrique de l’Ouest)

Les résultats issus des analyses physico-chimiques et toxicologiques des eaux et des poissons du lac Nokoué nous ont permis de constater que les Hydrocarbures Aromatiques Polycycliques retrouvés dans le lac influencent sensiblement la qualité des poissons et que les valeurs limites sont dépassées pour certains paramètres. Les valeurs de conductivité moyenne (2752 μS/cm) et de concentration moyenne des nitrites (7,78 mg/L) ont montré que les échantillons d’eau prélevés sur le lac Nokoué sont pollués. Le dosage des polluants a permis de constater que les individus de Tilapia guineensis, Hemichromis fasciatus et de Sarotherodon melanotheron prélevés dans les eaux du lac sont respectivement contaminés à 10%, 18% et 10% au niveau de la rivière Sô à Dogodo, à 26%, 25% et 23% à Kétonou, 32%, 29% et 40% à 6 km de Domèguédji et 32%, 28%, 27% à l’embarcadère d’Abomey-Calavi. The results from physico-chemical and toxicological analyzes of the waters and fish of lake Nokoué have shown that the Polycyclic Aromatic Hydrocarbons found in the lake have a significant influence on the quality of the fish and that the limit values are exceeded for certain parameters. The mean conductivity and mean concentration values of the nitrites, estimated at 2752 μS / cm at 7.78 mg / L respectively, show that the water samples taken from lake Nokoué are polluted. The bioaccumulation factor revealed that individuals of Tilapia guineensis, Hemichromis fasciatus and Sarotherodon melanotheron taken from lake waters are respectively 10%, 18% and 10% contaminated at the Sô River level in Dogodo, at 26%, 25% and 23% at Kétonou, 32%, 29% and 40% at 6 km from Domèguédji and 32%, 28%, 27% at the Abomey-Calavi jetty

Evaluating the sustainability, scalability, and replicability of an STH transmission interruption intervention: The DeWorm3 implementation science protocol.

Hybrid trials that include both clinical and implementation science outcomes are increasingly relevant for public health researchers that aim to rapidly translate study findings into evidence-based practice. The DeWorm3 Project is a series of hybrid trials testing the feasibility of interrupting the transmission of soil transmitted helminths (STH), while conducting implementation science research that contextualizes clinical research findings and provides guidance on opportunities to optimize delivery of STH interventions. The purpose of DeWorm3 implementation science studies is to ensure rapid and efficient translation of evidence into practice. DeWorm3 will use stakeholder mapping to identify individuals who influence or are influenced by school-based or community-wide mass drug administration (MDA) for STH and to evaluate network dynamics that may affect study outcomes and future policy development. Individual interviews and focus groups will generate the qualitative data needed to identify factors that shape, contextualize, and explain DeWorm3 trial outputs and outcomes. Structural readiness surveys will be used to evaluate the factors that drive health system readiness to implement novel interventions, such as community-wide MDA for STH, in order to target change management activities and identify opportunities for sustaining or scaling the intervention. Process mapping will be used to understand what aspects of the intervention are adaptable across heterogeneous implementation settings and to identify contextually-relevant modifiable bottlenecks that may be addressed to improve the intervention delivery process and to achieve intervention outputs. Lastly, intervention costs and incremental cost-effectiveness will be evaluated to compare the efficiency of community-wide MDA to standard-of-care targeted MDA both over the duration of the trial and over a longer elimination time horizon

Assessing the feasibility of interrupting the transmission of soil-transmitted helminths through mass drug administration: The DeWorm3 cluster randomized trial protocol

DeWorm3 collectionThe file attached is the Published/publisher’s pdf version of the article.© 2018 Ásbjörnsdóttir et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Les schistosomoses au Bénin : épidémiologie et écologie des interactions hôte-parasite

This work presents an epidemiological and an ecological study of schistosomiasis in Benin.At the epidemiological level, a bibliographical summary of the state of work carried out on schistosomiasis in the area of ​​the Economic Community of West African States (ECOWAS) was reported. In Benin, our epidemiological analyzes confirmed the existence of two species of human schistosomes: S. haematobium and S. mansoni out of the five reported in the ECOWAS region in which Benin is located (S. haematobium, S. mansoni , S. guineensis, S. bovis and S. curassoni). The general prevalence obtained for S. haematobium is 85% and that of S; mansoni is 30% with the existence of foci of mixed transmission. Malacological surveys revealed the presence in Benin of at least five species of mollus that five vectors B. forskalii, B. globosus and B. truncatus, vectors of S. haematobium, B. pfeifferi, vector of S. mansoni and I. exustus , an exotic mollusk in Benin, known as a vector of S. indicum, S. spindale and S. nasale in Southeast Asia. We report the presence of I. exustus for the first time in Benin where this mollusk seems to be, for the moment, passive in the transmission of schistosomiasis.In terms of the ecology of mollusc-parasite interactions, our study has shown that the different populations of S. haematobium are differently compatible with three of the four groups of Bulinus molluscs: the africanus group, the forskalii group and the reticulatus group while the different populations of S. mansoni are all also compatible with B. pfeifferi. The analysis of six life history traits, prepatent period, prevalence, cercarial production in the parasite and growth, reproduction and survival of molluscs was approached with five local populations of schistosomes including three populations of S. haematobium (Doh, Sô -Tchanhoué and Toho-Todougba) and two populations of S. mansoni (Kpinnou and Toho-Todougba) and revealed that while the populations of S. haematobium appear to be adapted to a local vector, this is not the case in the S. mansoni species.In terms of the ecology of vertebrate-parasite interactions, our study revealed the existence of a particular hourly cercarial emission rate, of the infradian type, both in S. haematobium and in S. mansoni. The anthropic study carried out at one of the transmission foci (Toho-Todougba) where the two species are present has made it possible to observe a perfect synergy between the cercarial chronobiology and the dynamics of activities in humans: it could be act of a strategy developed by the parasite to maintain its appointments with its natural vertebrate host.Ce travail présente une étude épidémiologique et une étude des interactions hôte-parasite sur les schistosomoses au Bénin. Au plan épidémiologique, une synthèse bibliographique de l'état des travaux réalisés sur les schistosomoses dans l'espace de la Communauté Economique des Etats de l'Afrique de l'Ouest (CEDEAO) a été menée. Au Bénin, nos analyses épidémiologiques ont permis de confirmer l'existence de deux espèces de schistosomes humains : S. haematobium et S. mansoni sur les cinq signalées dans l'espace CEDEAO dans lequel le Bénin se situe (S. haematobium, S. mansoni, S. guineensis, S. bovis et S. curassoni). La prévalence générale obtenue pour S. haematobium est de 85% et celle de S; mansoni est de 30% avec l'existence de foyers de transmission mixtes. Les prospections malacologiques ont révélé la présence au Bénin d'au moins cinq espèces de mollusques potentiellement vectrices : B. forskalii, B. globosus et B. truncatus, vectrices de S. haematobium, B. pfeifferi, vectrice de S. mansoni et I. exustus, mollusque exotique au Bénin, connu comme vecteur de S. indicum, S. spindale et S. nasale en Asie du sud-est. Nous signalons la présence de I. exustus pour la première fois au Bénin où ce mollusque semble être, pour le moment, passif dans la transmission des schistosomoses. Au plan de l'écologie des interactions mollusque-parasite, notre étude a montré que les différentes populations de S. haematobium sont différemment compatibles avec trois des quatre groupes de mollusques Bulinus : le groupe africanus, le groupe forskalii et le groupe reticulatus alors que les différentes populations de S. mansoni sont toutes également compatibles avec B. pfeifferi. L'analyse de six traits d'histoire de vie, période prépatente, prévalence, production cercarienne chez le parasite et croissance, reproduction et survie des mollusques a été abordée avec cinq populations locales de schistosomes dont trois populations de S. haematobium (Doh, Sô-Tchanhoué et Toho-Todougba) et deux populations de S. mansoni (Kpinnou et Toho-Todougba) et a révélé que si les populations de S. haematobium semblent être adaptées à un vecteur local, ce n'est pas le cas chez l'espèce S. mansoni. Au plan de l'écologie des interactions vertébré-parasite, notre étude a révélé l'existence d'un rythme d'émission cercarienne horaire particulier, de type infradien, à la fois chez S. haematobium et chez S. mansoni. L'étude anthropique réalisée au niveau d'un des foyers de transmission (Toho-Todougba) où les deux espèces sont présentes a permis de constater une parfaite synergie entre la chronobiologie cercarienne et la dynamique des activités chez l'Homme : il pourrait s'agir d'une stratégie développée par le parasite pour maintenir ses rendez-vous avec son hôte naturel vertébré

Les Schistosomoses au Bénin (épidémiologie et écologie des interactions hôte-parasite)

Ce travail présente une étude épidémiologique et une étude des interactions hôte-parasite sur les schistosomoses au Bénin. Au plan épidémiologique, une synthèse bibliographique de l'état des travaux réalisés sur les schistosomoses dans l'espace de la Communauté Economique des Etats de l'Afrique de l'Ouest (CEDEAO) a été menée. Au Bénin, nos analyses épidémiologiques ont permis de confirmer l'existence de deux espèces de schistosomes humains : S. haematobium et S. mansoni sur les cinq signalées dans l'espace CEDEAO dans lequel le Bénin se situe (S. haematobium, S. mansoni, S. guineensis, S. bovis et S. curassoni). La prévalence générale obtenue pour S. haematobium est de 85% et celle de S. mansoni est de 30%, avec l'existence de foyers de transmission mixtes. Les prospections malacologiques ont révélé la présence au Bénin d'au moins cinq espèces de mollusques potentiellement vectrices : B. forskalii, B. globosus et B. truncatus, vectrices de S. haematobium, B. pfeifferi, vectrice de S. mansoni et I. exustus, mollusque exotique au Bénin, connu comme vecteur de S. indicum, S. spindale et S. nasale en Asie du sud-est. Nous signalons la présence de I. exustus pour la première fois au Bénin où ce mollusque semble être, pour le moment, passif dans la transmission des schistosomoses. Au plan de l'écologie des interactions mollusque-parasite, notre étude a montré que les différentes populations de S. haematobium sont différemment compatibles avec trois des quatre groupes de mollusques Bulinus : le groupe africanus, le groupe forskalii et le groupe reticulatus alors que les différentes populations de S. mansoni sont toutes également compatibles avec B. pfeifferi. L'analyse de six traits d'histoire de vie, période prépatente, prévalence, production cercarienne chez le parasite et croissance, reproduction et survie des mollusques a été abordée avec cinq populations locales de schistosomes dont trois populations de S. haematobium (Doh, Sô-Tchanhoué et Toho-Todougba) et deux populations de S. mansoni (Kpinnou et Toho-Todougba) et a révélé que si les populations de S. haematobium semblent être adaptées à un vecteur local, ce n'est pas le cas chez l'espèce S. mansoni. Au plan de l'écologie des interactions vertébré-parasite, notre étude a révélé l'existence d'un rythme d'émission cercarienne horaire particulier, de type infradien, à la fois chez S. haematobium et chez S. mansoni. L'étude anthropique réalisée au niveau d'un des foyers de transmission (Toho-Todougba) où les deux espèces sont présentes a permis de constater une parfaite synergie entre la chronobiologie cercarienne et la dynamique des activités chez l'Homme : il pourrait s'agir d'une stratégie développée par le parasite pour maintenir ses rendez-vous avec son hôte naturel vertébré.This work presents an epidemiological and an ecological study of schistosomiasis in Benin. A synthesis of the epidemiological knowledge of schistosomiasis in the space of the Economic Community of West Africa States (ECOWAS) was carried out. Furthermore, in Benin, we confirmed the existence of the two human schistosomes : S. haematobium and S. mansoni on the five existing in the ECOWAS space in which Benin is located (S. haematobium, S. mansoni, S. guineensis, S. bovis and S. curassoni). The prevalence obtained for S. haematobium was 85% and that for S. mansoni was 30%, and there was evidence for mixed human infections. We could find in Benin at least five potentially snail vector species : B. forskalii, B. globosus and B. truncatus for S. haematobium, B. pfeifferi for S. mansoni and I. exustus, an exotic snail known to be the snail vector for S. indicum, S. spindale and S. nasale in South-East Asia. I. exustus is recorded for the first time in Benin in this work and no evidence of active transmission was made. The study of the snail-schistosome interactions showed that the different S. haematobium populations were differently compatible with three of the four groups of Bulinus : the africanus group, the forskalii group and the reticulatus group and that the different S. mansoni populations were equally compatible with B. pfeifferi. The six life-history traits, parasite prepatent period, prevalence and cercarial production and snail growth, reproduction and survival were analyzed using five schistosome populations from Benin including three populations of S. haematobium (Doh, Sô-Tchanhoué and Toho-Todougba) and two populations of S. mansoni (Kpinnou and Toho-Todougba) and revealed that if the S. haematobium populations seemed to be adapted to a local vector, this was not the case for the S. mansoni populations. The study of the vertebrate-schistosome interactions revealed the existence of an infradian rhythm in the cercarial emissions of both S. haematobium and S. mansoni. The human behaviour, followed in one of the transmission sites (Toho-Todougba) where both schistosome species are present, was perfectly correlated with the schistosome chronobiology. This was interpreted in terms of adaptative strategy favouring the transmission of the parasite to its human host.PERPIGNAN-BU Sciences (661362101) / SudocSudocFranceF

Partial replacement of fish meal with Azola meal in diets for Nile tilapia (Oreochromis niloticus L.) affects growth and whole body fatty acid composition

The replacement of fishmeal (FM) with Azolla meal (AM) in diets on growth and fatty acid in Nile tilapia, Oreochromis niloticus (initial mean weight: 16.4 g) was studied. Fish were fed with six isonitrogenous (29.2% CP) and isoenergetic (16.9 kJ.g-1) diets containing 0%, 10%, 20%, 30%, 40% and 50% AM respectively, as partial FM substitute. Diet A0 acted as a control. The final weight (51.0-88.3 g), the weight gain (210.8-438.3%) and the SGR (1.3-1.9%day-1) decreased when AM level higher than 10% in diets (P < 0.05). The FCR (1.44 to 2.35) significantly increased when AM level exceeded 20% (P < 0.05). The protein efficiency ratio and the apparent net protein utilization decreased consequently. The fatty acids in the whole fish were significantly influenced by the diets. The replacement of FM by AM produced fish with lower (n-3) highly unsaturated fatty acids mainly docosahexaenoic acid, and higher arachidonic acid (P < 0.05). The n-3/n- 6 fatty acid ratio ranged from 0.08 to 0.17, and was lower in fish fed A40 and A50 (P < 0.05). The findings suggest that high AM in diets affects Nile tilapia growth and the fern could be incorporated in diets up to 30% without any adverse effect on fish fatty acid composition. However, alternative additional source of lipid must be used to improve the quality of fish fed AM-diets

Soil-transmitted helminth infection in pregnancy and long-term child neurocognitive and behavioral development: A prospective mother-child cohort in Benin

International audienceBackground: An estimated 30% of women in Sub-Saharan Africa suffer from soil-transmitted helminth infection during pregnancy (SHIP), which has been shown to increase risk of pre-term birth, low birth weight, and maternal anemia. A previous study in Benin found that SHIP was associated with impaired cognitive and gross motor development scores in 635 one-year-old children. The objective of the present study was to follow children prospectively to investigate whether the association between SHIP and child neurocognitive and behavioral development persisted at age six.Principal findings: Our prospective child cohort included 487 live-born singletons of pregnant women enrolled in the Malaria in Pregnancy Preventive Alternative Drugs clinical trial in Allada, Benin. SHIP was assessed at three antenatal visits (ANVs) through collection and testing of stool samples. Neurocognitive and behavioral development was assessed in six-year-old children by trained investigators using the Kaufman Assessment Battery for Children 2 nd edition and the parent-reported Strengths and Difficulties Questionnaire (SDQ). Multiple linear regression models generated coefficients and 95% confidence intervals and potential mediating factors were tested. Prevalence of SHIP was 13% at the 1 st ANV, 9% at the 2 nd ANV, and 1% at delivery. SHIP was not associated with low neurocognitive scores in children at six years. Higher SDQ internalizing scores, indicating increased emotional impairments in children, were associated with helminth infection at the 2 nd ANV/delivery 1.07 (95% CI 0.15, 2.00) and at least once during pregnancy 0.79 (95% CI 0.12, 1.46) in adjusted models. Mediation analysis did not reveal significant indirect effects of several mediators on this association.Conclusions: Our study shows that while SHIP is not associated with impaired long-term neurocognitive development, infections may have significant negative impacts on emotional development in six-year-old children. SHIP remains a critical public health issue, and adequate prevention and treatment protocols should be enforced in low- and middle-income countries

Schistosomiasis and Soil Transmitted Helminths Distribution in Benin: A Baseline Prevalence Survey in 30 Districts

<div><p>In 2013, Benin developed strategies to control neglected tropical diseases and one of the first step was the disease mapping of the entire country in order to identify endemic districts of schistosomiasis and soil transmitted helminths (STH). This study was carried out in 30 of the 77 districts of Benin. Of these 30 districts 22 were previously treated for Lymphatic Filariasis (LF) using the Ivermectin and Albendazole combination. In each district, five schools were selected and 50 children aged 8 to 14 years were sampled in each school, making a total of 250 children sampled in the district. The schools were selected mainly according to their proximity to lakes or any bodies of water that were likely to have been used by the children. Samples of faeces and urine were collected from each pupil. Urinary schistosomiasis was identified using the urine filtration technique while STH and intestinal schistosomiasis were identified through the Kato Katz method. Overall a total of 7500 pupils were surveyed across 150 schools with a gender ratio of 1:1. Hookworm was identified in all 30 districts with a prevalence ranging from 1.2% (95%CI: 0.0–2.5) to 60% (95%CI: 53.9–66.1). <i>Ascaris lumbricoides</i> was detected in 19 districts with a prevalence rate between 1% (95%CI: 0.0–2.2) and 39% (95%CI: 32.9–45.0). In addition to these common STH, <i>Trichuris trichiura</i>, <i>Enterobius vermicularis</i> and <i>Strongyloides stercoralis</i> were found at low prevalence. Only 16 districts were endemic to <i>Schistosoma mansoni</i>, while 29 districts were endemic to <i>S</i>. <i>haematobium</i>. The <i>S</i>. <i>haematobium</i> prevalence ranged from 0.8% (95% CI: 0.0–1.9) to 56% (95% CI: 50.2–62.5) while the prevalence of <i>S</i>. <i>mansoni</i> varied from 0.4% (95%CI: 0.0–1.2) to 46% (95% CI: 39.8–52.2). The 22 districts, where LF was successfully eliminated, still require mass drug administration (MDA) of albendazole indicating that school-based MDA would be needed even after LF elimination in districts co-endemic to LF and STH in Benin.</p></div