Article

Snail intermediate host/Schistosoma haematobium relationships from three transmission sites in Benin (West Africa)

Université de Perpignan Via Domitia, Perpignan, 66860, France, .
Parasitology Research (Impact Factor: 2.1). 10/2012; 112(1). DOI: 10.1007/s00436-012-3129-x
Source: PubMed

ABSTRACT

The relationships between three strains of Schistosoma haematobium (Doh, Sô-Tchanhoué and Toho-Todougba; from Benin, West Africa) and their snail hosts were assessed by measurement of several life-history traits, including the infection rate; pre-patent period; cercarial production of each parasite strain; and growth, fecundity and survival of the host snails. Adaptations to its local snail host was found for the Toho-Todougba strain and included a short pre-patent period, a long patent period and production of more cercariae in its local snail host. In contrast, the life-history traits of the Doh and Sô-Tchanhoué strains indicated non-local adaptations, as some sympatric host-parasite combinations were not compatible, the highest infection rates occurred in the allopatric snail Bulinus wrighti, and the duration of cercarial production was short because of the high level of mortality of the snails. Furthermore, snail reproduction ceased following infection by each of the three parasite strains, and the life-history traits were not influenced by the miracidial dose.

Download full-text

Full-text

Available from: Moudachirou Ibikounlé, Feb 27, 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objectif : Dans les zones intertropicales, les infestations par Schistosoma haematobium et autres espèces d’helminthes sont très répandues et le Bénin ne fait pas exception. Cette étude a pour objectif d’évaluer le statut épidémiologique de la Bilharziose urogénitale et des géohelminthiases chez les enfants d’âge scolaire 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 jeunes écoliers 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 partie de la commune de Sô-Ava. Six cent quatre échantillons d'urine ont été examinés par la technique de filtration et 363 échantillons de selles examinées par la technique de Kato-Katz. Les résultats d'analyse des urines révèlent les prévalences respectives à S. haematobium de 22,22% (N=153) ; 21,43% (N=182) et 46,47% (N=269) dans les trois villages pour une prévalence globale de 32,78% (N= 604) avec autant de garçons que de filles infestés et les enfants de 7 à 8 ans constituent la tranche d’âge la plus touchée. Les résultats 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 trichiura et Enterobius vermicularis. Aucun oeuf de S. mansoni n’a été observé dans les selles. Les résultats montrent enfin que les charges parasitaires de S. haematobium et des géohelminthes étaient plus importantes 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 mollusques impliqués dans la transmission des schistosomes. Trois espèces de mollusques connues comme hôtes intermédiaires 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 des géohelminthes au niveau des populations humaines de cette zone lacustre et permet d’envisager les moyens adéquats pour le contrôle de ces parasitoses.Mots clés : Schistosoma haematobium, Géohelminthes, Sô-Ava, Sud-Bénin, Epidémiologie.
    Full-text · Article · Dec 2013
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In Egypt, reclaiming portions of the desert using water from the Nile has resulted in large-scale invasion of Biomphalaria alexandrina in these regions. Studies exploring the local adaptation of Schistosoma mansoni to its snail host have been carried out to predict the extension of schistosomiasis to newly reclaimed areas. A meta-analysis of the relevant reports was conducted to compare the different biological characteristics of sympatric and allopatric Schistosoma mansoni and Biomphalaria alexandrina using different experimental designs. The results showed that there were no significant differences in the biological characteristics of sympatric and allopatric populations. The experimental design of some of the studies analyzed was found to affect the total cercarial production. The distance between the origin of the parasite and that of the snail did not affect any of the biological characteristics. The results showed that there is no evidence of local adaptation between Schistosoma mansoni and Biomphalaria alexandrina; however, the parasite is adapted to its intermediate host throughout the water bodies located in Egypt. The absence of local adaptation between Schistosoma mansoni and Biomphalaria alexandrina is likely of critical importance in predicting public health risks engendered by future reclaimed agriculture projects. Indeed, these results could assist in determining the appropriate balance between the development of water resource projects and schistosomiasis control in Egypt.
    Full-text · Article · Jan 2014 · Parasitology Research
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Schistosomiasis is a public health problem in Benin but prevalence estimates vary widely. Parasitological (from May to September 2010) and malacological surveys (from September 2010 to June 2012) were conducted to determine the current status of urinary schistosomiasis among 1 585 schoolchildren from 18 primary schools of Péhunco area, North-West Benin, using two parasitological tests. Pupils were enrolled with a mean age of 11 years (from 7 to 16 years-old age) and 51.48% of them were girls. Urines samples were examined using both urine reagent strips and filtration method. Structured questionnaires were used to identify environmental and socio-economic factors. Malacological surveys were conducted to ascertain general freshwater snail diversity and specific diversity of the schistosome host snails. The results showed a general prevalence of 29.40% with boys (36.67%) significantly more affected than girls (22.55%). Among the 844 collected snails, 5 species freshwater snails were identified: two species known as potential schistosome intermediate host snails, Bulinus forskalii and B. globosus, and three species known as non-schistosome transmitting snails Lymnaea natalensis, Physa marmorata and Melanoides tuberculata. B. forskalii was a most largely distributed snail and none of snails were found naturally infected by schistosome. No freshwater snails were found naturally infected by schistosome.
    Full-text · Article · Mar 2014 · Bulletin de la Société de pathologie exotique
Show more