Environmental Factors and their Influence on Seasonal Variations of Schistosomiasis Intermediate Snail Hosts Abundance in Weija Lake, Ghana

Schistosomiasis, which remains a key Neglected Tropical Disease, is facilitated by the population dynamics of the intermediate snail host that is reported to be influenced by environmental factors. In Ghana fewer studies on environmental factors have been carried out with the advent of climate change and it predicted influence on the ecology of vectors of diseases that tend to be focal. This study therefore sought to investigate the influence of environmental factors on seasonal variations on intermediate snail hosts abundance. Snails were sampled monthly at a demarcated zone on the Weija Lake near Tomefa, a schistosomiasis endemic community using the scoop net and hand picking techniques. A total of 2,612 snails including 739 dead/empty shells were collected throughout the sampling period. Of this number, 1, 367 (inclusive of 600 dead) Biomphalaria pfeifferi and 1, 245 (inclusive of 139 dead) Bulinus truncatus were collected. Total dissolved solids, temperature and turbidity significantly influenced snail abundance (p<0.05). Five aquatic plant species were found to support both snail species, with Ceratophyllum spp being the most common. Snail abundance varied seasonally with TDS, turbidity and temperature identified as important limiting environmental factors to intermediate snail hosts abundance. Aquatic plant species influenced snail abundance by providing shelter, food and sites for oviposition.