Vector snail fauna and Schistosoma haematobium transmission patterns in freshwater systems of Ishielu Local Government Area, Ebonyi State, Nigeria

Freshwater snails are widespread in tropical and temperate regions of the world where they serve as intermediate hosts for larval stages of parasitic trematodes which cause schistosomiasis that is endemic in Nigeria. Snail fauna and patterns of Schistosoma haematobium transmission were determined in flowing water habitats (FWH) and stagnant water habitats (SWH) in Ishielu, Local Government Area, Ebonyi State, Nigeria. Snail collection was done using scoop-net and hand-picking techniques. Bulinus species collected were exposed to sunlight/light-induced in laboratory for cercarial shedding. Cercariae were then observed under microscope. 923 snails were collected, 67.7% Lymnaea natalensis, 23.1% Bulinus globosus and 9.2% Bulinus truncatus. Their relative abundance was significantly different (P<0.05). 31.6% Bulinus snails from FWH were infected by S. haematobium whereas 18.5% from SWH were infected. Infectivity of Bulinus spp in each habitat group was not significantly different but was when compared the two groups of habitats (P<0.05). Highest infectivity (45.8%) occurred during dry season peaking in February (45.8%) for FWH and for SWH, highest infectivity occurred during rain peaking in July (26.8%). The transmission potential (T.P) was very high during dry season (93.0%) peaking in February (34.9%) in FWH and very low (0%) for SWH. During rain, the T.P was very high (100%) peaking in July (50%) in SWH and very low (7.0%) for FWH. Pools and rivers in Ishielu are suitable habitats for vector snails wherein season and habitat type influence snail abundance and transmission of Schistosomiasis, the findings of which can help in establishing programmes for proper health awareness and snail control.