Bulinus truncatus

About: Bulinus truncatus is a research topic. Over the lifetime, 414 publications have been published within this topic receiving 5640 citations.

Plagiorchis elegans (Trematoda) and Incompatible Snail Hosts: Implications for Snail Life History Traits and Biocontrol of Human Schistosomiasis

Abstract: We examined the effect of Plagiorchis elegans on egg production and survival on Bulinus truncatus and Helisoma trivolvis trivolvis. Both species are incompatible hosts for P. elegans. Helisoma t. trivolvis occurs sympatrically with P. elegans; B. truncatus does not. Overall, P. elegans had no effect on survivorship or egg production in H. t. trivolvis or on the survivorship of B. truncatus. Its effect on egg production in B. truncatus was transitory; egg production was reduced by 50% for 5 wk following exposure but returned to normal thereafter. Neither egg production nor survivorship was affected in adult H. t. trivolvis. Egg production ceased at 14 wk post-exposure (PE), but resumed when the snails were paired. Young H. t. trivolvis also produced eggs after exposure, but later than the adults and only after they had been paired with another snail. This suggests that a need for periodic cross-fertilization in H. t. trivolvis rather than the effect of the parasite is responsible for the cessation of egg production in this species. Survivorship in young H. t. trivolvis was significantly higher in exposed snails between wk 7 to 10 PE than in controls.

Effect of some algal species on the snail intermediate hosts of schistosomiasis in egypt ii. growth, infection and mortality rates

Abstract: This investigation was carried out using isolates of four algal species. Three cyanobacteria (Lyngbya perelegans, Oscillatoria accuminata and Phormidium valderianum) and one green alga (Spirogyra sp.) collected from Kafr Hakem (+ snails) and Sadek canals (- snails) in Giza Governorate, in addition to Nostoc muscorum obtained from Theodor Bilharz Research Institute (TBRI). Snails were fed separately on fresh algal species, on a combination of two species and on a mixture of the five algal species, during twenty weeks (5 months) and lettuce was used as control. Growth rate of snails (shell diameter and height), infection rate and mortality percentage were recorded weekly during the experimental time. Biomphalaria alexandrina and Bulinus truncatus snails fed on separate algal species, sublethal concentration of Phormidium valderianum (LC0) and lettuce demonstrated the highest growth rates, while the lowest rate was recorded in Spirogyra sp. Using mixed food of two algal species, the maximum rate of snail growth was observed in snails fed on the LC0 of Phormidium valderianum + Spirogyra sp, followed by those fed on Oscillatoria accuminata + Spirogyra sp. Snails fed on a mixture of all algal species exhibited the maximum growth rate. The highest rate of infection and lowest percentage of mortality were recorded in both snail species fed on lettuce (59% & 19% for B. alexandrina and 77.3% & 10.7% for B. truncatus, respectively). The minimum rate of infection and maximum percentage of mortality were observed in snails fed on Spirogyra sp. The nutritional value of the algal species and lettuce, using Carbon to Nitrogen ratio (C/N ratio), were analyzed and discussed on the light of the obtained results.

Epidemiologic study of S. haematobium bilharziasis in the rice fields of Yagoua (North Cameroon) II. Distribution and ecology of intermediate hosts

Abstract: While inventoring the local malacological fauna and evaluating the density of species acting as intermediate hosts of human schistosomes it has been shown that Bulinus truncatus is predominant in the study area. Bulinus globosus is scarcely encountered. Biomphalaria pfeifferi is only found in the Mayo Guerleo, in irrigation canals and draining ditches. But B. globosus and B. pfeifferi have not yet invaded the recent aquatic network and are not found in the lake nor in the newly created irrigation systems. Snails shedding cercariae of S. haematobium and S. mansoni have been collected in the area. Bulinus forskalii is found in all types of permanent of temporary waterbodies but S. intercalatum has not yet been reported from North-Cameroon. Lymnaea natalensis, the intermediate host of Fasciola gigantica, is found in the lake and in the canals, in the Mayo Guerleo and in the Toupasko pool. The rice field does not form by itself a favorable environment for snails to develop in it. Spots where transmission occurare more often in the area the secondary of tertiary irrigation canals and the brains. The ditches obstructed by plants are the places where the snails are developing best. Bulinus spp. are found in large numbers in the lowest parts of the aquatic network and they accumulate there to survive drought conditions in the mud. The recently built irrigation systems are not massively invaded by the snails yet and the prevalence of bilharziasis in the area correspond to the distribution of the intermediate hosts of schistosomes and to the density of the snails populations.

Cleaning and molluscicide treatment for schistosomiasis control

Abstract: We evaluated the effect of niclosamide treatment and the additional cleaning of basins and pools on the density and infection rate of Bulinus truncatus within the irrigation network of Oudaya. The period prior to molluscicide treatment (January-May) revealed a mean density of 151 snails/m2 in 1995-96 and 127 snails/m2 in 1997-98. After cleaning had started, the mean density prior to molluscicide treatment fell to 84 snails/m2 in 1999-2000. After molluscicide treatment, densities dropped to very low levels only rising again from October. In November 1999-96 mean density reached 150 snails/m2 but after cleaning started in 1997-98 this only reached 80 snails/m2; in 1999-2000, when cleaning was undertaken 3 months before and after molluscicide treatment, it reached only 18 snails/m2. From 1995 to 1996, the infection rate rose slightly (4.54% to 5.44%), but, from 1997, there was a significant drop (3.13% to 2.16%).