SNAIL FAUNA AND Schistosoma haematobium TRANSMISSION PATTERNS IN FRESHWATER SYSTEMS OF ISHIELU LOCAL GOVERNMENT AREA, EBONYI STATE

SOURCE:

Faculty: Biosences
Department: Parasitology And Entomology

CONTRIBUTORS:

Ubaka, U.A;
Ekwunife, C.A;

ABSTRACT:

Freshwater snails are widespread in both 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. A study of freshwater snail fauna and patterns of Schistosoma haematobium transmission was carried out around freshwater bodies in Ishielu Local Government Area, Ebonyi State between June 2014 and May 2015. Using scoop and hand-picking techniques, snail collection was done within each 10m2 of site area sampled at 100m intervals against the water current in flowing waters habitats (FWH) and between 20m to 50m in stagnant water habitats (SWH). Bulinus species of snails collected were light-induced for cercarial shedding in the laboratory. A total of 923 snails were collected among which 625(67.7%) were Lymnaea natalensis, 213(23.1%) B. globosus and 85(9.2%) B. truncatus. The numbers of these snail species were significantly different (P<0.05). The number of Bulinus snails was a total of 82.4% in dry season months and 17.6% during rainy months in FWH whereas, in SWH, the number of Bulinus snails was a total of 5.6% in dry season and 94.4% in rainy season. The monthly collections of snails were significantly different (P<0.05) for FWH and SWH. Out of the 136 Bulinus snails collected from FWH, 43 (31.6%) were infected and out of 162 collected from SWH, 30 (18.5%) were infected. The monthly collection of Bulinus spp infected from either flowing waters or stagnant waters were not significantly different, FWH (P>0.05); SWH (P>0.05). In the FWH, the highest infection rates were observed to coincide with the dry season with a peak in February (45.8%). For SWH, the highest infection rates coincided with the rainy season with a peak in July (26.8%). The transmission potential (T.Ps) of the two types of habitats were shown to be very high during the dry season months (a total of 93.0%) with a peak in February (34.9%) in FWH and very low (a total of 0%) for SWH in the same season. During the rainy season months, the T.P was very high (a total of 100%) with a peak in July (50%) in SWH and very low (a total of 7.0%) for FWH in the same season. These findings indicate that season and habitat type influence the patterns of transmission of Schistosoma haematobium in Ishielu L.G.A. and demonstrate the periods of the year when the human populations are at the greatest risk of infections in the study habitats and can help in establishing programmes for proper health awareness and snail control.