Épidémiologie de la bilharziose urinaire et des géohelminthiases chez les jeunes scolaires des zones lacustres de la commune de So-Ava, sud-Bénin

International audienceObjective: In the tropics, infections by Schistosoma haematobium and soil-transmitted helminths speciesare widespread and Republic of Benin is no exception. This study aims to assess the epidemiologicalstatus of urogenital schistosomiasis and soil-transmitted helminths in schoolchildren of Sô-Ava town in theDepartment of Atlantic in Southern Benin.Methodology and Results: The biological material was composed of urine and stool collected from fromPublic Primary Schools in Sôchanhoué, Sôtchanhoué Quarter and Sô-Zounko between April to August2012 . Six hundred and four urine samples were examined by filtration technique and 363 stool sampleswere examined by Kato-Katz test. Malacological surveys were conducted to assess the diversity offreshwater snails and determine the snail species involved in the transmission of schistosomiasis. Theresults showed infection rates of S. haematobium of 22.22% (N = 153), 21.43% (N = 182) and 46.47% (N =269) in the three prospected sites, respectively, with an overall infection rate of 32.78% (N = 604) with asmany boys as girls infected and children 7 to 8 years of age the most affected. Three species of soiltransmittedhelminths were found with an overall prevalence of 12.12% (N = 44) of people infected with atleast one of the three parasites Ascaris lumbricoides, Trichuris trichiura or Enterobius vermicularis. Theresults showed that the parasite densities of S. haematobium and soil-transmitted helminths were thegreatest in children aged 7 to 8 years, especially boys. Three species of freshwater snails known asintermediate hosts for schistosomes were collected: Bulinus forskalii, B. globosus and B. truncatus.Conclusion: This study was used to assess the level of endemicity of urinary schistosomiasis and soiltransmittedhelminths in human populations of the Nokoue Lake area and allows considering theappropriate means of controlling these parasites.Objectif : Dans les zones intertropicales, les infestations par Schistosoma haematobium et autres espècesd’helminthes sont très répandues et le Bénin ne fait pas exception. Cette étude a pour objectif d’évaluer lestatut épidémiologique de la Bilharziose urogénitale et des géohelminthiases chez les enfants d’âgescolaire de la commune de Sô-Ava, Département de l’Atlantique dans le Sud-Bénin.Méthodologie et Résultats : Le matériel biologique est composé d'urines et de selles provenant de jeunesécoliers âgés de 4 à 8 ans et scolarisés dans les Ecoles Primaires Publiques de Sô-Tchanhoué village, Sô-Tchanhoué Quartier et de Sô-Zounko de la commune de Sô-Ava. Les trois sites de prospection font partiede la commune de Sô-Ava. Six cent quatre échantillons d'urine ont été examinés par la technique defiltration et 363 échantillons de selles examinées par la technique de Kato-Katz. Les résultats d'analyse desurines révèlent les prévalences respectives à S. haematobium de 22,22% (N=153) ; 21,43% (N=182) et46,47% (N=269) dans les trois villages pour une prévalence globale de 32,78% (N= 604) avec autant degarçons que de filles infestés et les enfants de 7 à 8 ans constituent la tranche d’âge la plus touchée. Lesrésultats d'analyse des selles révèlent trois espèces d'helminthes avec une prévalence globale de 12,12%(N=44) de personnes infestées par au moins un des trois parasites Ascaris lumbricoides, Trichuris trichiuraet Enterobius vermicularis. Aucun oeuf de S. mansoni n’a été observé dans les selles. Les résultatsmontrent enfin que les charges parasitaires de S. haematobium et des géohelminthes étaient plusimportantes chez les enfants de 7 à 8 ans, en particulier chez les garçons. Les prospections malacologiques ont été réalisées afin d’évaluer la diversité malacologique et déterminer les mollusquesimpliqués dans la transmission des schistosomes. Trois espèces de mollusques connues comme hôtesintermédiaires de schistosomes ont été collectées Bulinus forskalii, B. globosus et B. truncatus.Conclusion : Cette étude a permis d’évaluer le niveau d’endémicité de la bilharziose urogénitale et desgéohelminthes au niveau des populations humaines de cette zone lacustre et permet d’envisager lesmoyens adéquats pour le contrôle de ces parasitose

HLA-G expression during hookworm infection in pregnant women

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