Showing papers on "Bulinus truncatus published in 2004"

Environmental control of schistosomiasis through community participation in a Moroccan oasis.

Abstract: Summary Akka oasis, in the province of Tata, southern Morocco, is one of the oldest foci of urinary schistosomiasis in Morocco where transmission is still taking place. We report the results of two studies: a cross-sectional snail survey investigated the distribution of Bulinus truncatus in relation to habitat factors in the Akka traditional irrigation system. The presence of aquatic vegetation, especially Potamogeton sp. was identified as a key factor determining snail occurrence and abundance in canals, impoundments and isolated small puddles and streamlets in the Akka riverbed. In a participatory rapid appraisal, the community identified snail control as a way to reduce transmission of schistosomiasis. Without any further outside incentives, the local irrigation committee implemented repeated cleaning and vegetation removal in canals. A longitudinal study evaluated the effect of these measures on populations of B. truncatus. Snail and egg mass densities showed significant reductions after repeated vegetation clearing in the study sites. The participatory approach led to low-cost, environment-friendly schistosomiasis control measures that were effective and sustainable.

Schistosomiasis endemic in Burkina Faso

Abstract: Burkina Faso, through the works of many teams of the OCCGE based in Bobo-Dioulasso, has signi-ficant data on several tropical endemics of which schistosomiasis. With the complementary works, it appears to be possible to establish a distribution of the schistosomiasis which reveals its importance. It will be the first stage of the planned national control program. The parasitologic data-gathering which covers the period of 1951 to 2000, used all the standard techniques. It is about Kato-Kartz and MIF for the intestinal schistosomiasis, centrifugation, filtration, serology reagent strips, macroscopy of urines and echography of the urinary system for the urinary schistosomiasis. All the eleven medical areas of the country have many sites submitted to parasitologic investigation. As regard the distribution of the two parasites involved with man (Schistosoma haematobium and S. mansoni), the data of prevalence (1% to 100%) and their distribution confirm their endemicity and the focal transmission. S. mansoni is located in eight medical areas particularly in the South and the West. S. haematobium is present in all the eleven medical areas of the country. In hydraulic planning as Sourou where the prevalences went from 23% to 70% for S. haematobium and from 0% to 69% for S. mansoni between 1987 and 1998. The situation requires a continuous monitoring. The spatial distribution of the six species of intermediate hosts shows that Bulinus truncatus and B. senegalensis Soudano-Sahelian species are present in all the ecological zones. B. globosus and Biomphalaria pfeifferi meet preferentially in the southern half of the country which reinforces the observation according to which the 14th northern parallel is often considered as the limit of septentrional extension of these two species. The other species Bulinus forskalii and B umbilicatus could have preference areas. All the species show a certain affinity with a type of biotope. The rarity and temporary aquatic systems lead to a concentration of the domestic and especially entertaining children activities around these biotopes very often contaminated. The phenomenon is amplified by the increase of contacts man-water, whose frequency and intensity are themselves dependent on activities related to hydro-agricultural planning. The analysis of the data shows, that in terms of colonization of the biotopes by molluscs and the relations between parasites and intermediate and final hosts, hydraulic planning turns out to be an amplifying factor of the species proliferation and parasitic flux host-parasite.

[Bulinus truncatus, intermediate host of Schistosoma haematobium in the Senegal River Basin (SRB)].

Abstract: Une etude des relations entre Bulinus truncatus et Schistosoma haematobium a ete effectuee dans le bassin du fleuve Senegal (BFS) pour evaluer le role de B. truncatus dans la transmission de la schistosomose urinaire au Senegal. Les tests de compatibilite montrent une susceptibilite de B. truncatus a l'infestation par S. haematobium dans la Haute vallee du BFS. Le suivi malacologique revele la presence de B. truncatus naturellement infestes dans la Moyenne vallee. En outre, l'identification de l'espece S. haematobium chez ces bulins par la technique du Single Strand Conformational Polymorphism (SSCP) confirme la participation de B. truncatus dans la dynamique de transmission.

Experimental study of the compatibility between Schistosoma haematobium and two species of Bulinus in Cameroon

Abstract: Pour estimer les risques de l'extension de la bilharziose urinaire au Cameroun, une etude de la compatibilite a confronte Schistosoma haematobium de trois localites relativement eloignees (Mourtourvva, Gounougou et Kekem) a 4 populations de Bulinus truncatus (Gounougou, Ngaoundere, Bertoua et Kekem) et 4 populations de B. globosus (Mourtourwa, Ouroudoukoudje, Bafia et Yaounde). Les descendants directs de mollusques sauvages ont ete exposes aux miracidiums liberes par des oeufs de S. haematobium des urines filtrees de bilharziens. Entre le 25 e et le 60e jour post-infestation, le nombre de mollusques survivants, celui des emetteurs de cercaires et la duree de la periode prepatente ont ete releves. Les differentes populations de B. truncatus ont ete sensibles a toutes les souches du parasite testees alors que seulement 2 des 4 populations de B. globosus ont ete sensibles a S. haematobium de Mourtourwa. Un taux de susceptibilite significativement plus eleve et une periode prepatente significativement plus courte ont ete trouves chez B. truncatus. prepdiente signi La compatibilite des couples homopatriques, meilleure que celle de couples allopatriques, a ete egalement caracterisee par un taux de susceptibilite plus eleve et une duree de la periode prepatente plus courte. B. truncatus jouerait un role potentiellement plus important que B. globosus dans l'extension de la bilharziose urinaire au Cameroun.

Epidemiology of Schistosoma mansoni infection and its relationship to snail distribution in a village at the Nile bank south to Cairo.

Abstract: The relationship between epidemiology of S. mansoni infection and snail distribution at a village, related to Guiza Governorate and lies south to Cairo, was investigated. A systematic random sample of houses was selected. All inhabitants of the houses were invited to share in the study. The Number examined was 704. Urine and stools were examined using Nucleopore filtration and standard Kato-Katz techniques, respectively. Snail collection was done from 35 sites along the water bodies related to the village. Snails collected were examined by cercariae shedding under light. Snail differentiation was done. The results showed that the prevalence of Schistosoma mansoni human infection was 25.1 % and GMEC was 2.4 +/- 5.5. Schistosoma haematobium infection was zero percent. Biomphlaria alexandrina snail infection rate was 3.7% with density equal 0.5 +/- 1.3. Bulinus truncatus snail infection rate was zero percent. The pattern of S. mansoni human infection was closely related to snail distribution and infection. Presence of a hybrid species of B. alexandrina and B. glabrata may explain the epidemiological pattern found in the studied village.

entre Schistosoma haematobium et deux espèces de bulins au Cameroun.

Abstract: Summary: Experimental study of the compatibility between Schistosoma haematobium and two species of Bulinus in Cameroon. A study on the compatibility between Schistosoma haematobium from three remote localities (Mourtourwa, Gounougou and Kekem) and four populations of Bulinus truncatus (Gounougou, Ngaoundere, Bertoua and Kekem) and four populations of B. globosus (Mourtourwa, Ouroudou koudje, Bafia and Yaounde) was undertaken in order to estimate the risk of extension of urinary schistosomiasis in Cameroon. First generation of offspring from wild Bulinus was exposed to miracidia liberated by schistosome eggs extracted from patient urine. Between the 25 th and the 60 th day post-infestation the number of snails still alive, the number emitting cercariae and the prepatent period duration were noted. Results showed that all B. truncatus samples were susceptible to the three strains of parasite whe reas only B. globosus of Mourtourwa and Ouroudoukoudje were susceptible to S. haematobium from Mourtourwa. The schistosome infection rate was then significantly higher in B. truncatus and the prepatent period significantly lower than in B. globosus. The compatibility characterised by a high infection rate and a low prepatent period was significantly better in homopatric couples than in allopatric combinations. The results suggested that B. truncatus might be potentially more implicated than B. globosus to the extension of the urinary bilharziasis in Cameroon.