Abstract

Fresh water snail vectors serve as intermediate hosts and play active role in the transmission of trematode parasites. Hence, the knowledge of their distribution becomes essential. This study assessed the distribution of snail intermediate hosts in selected areas of Rivers State. In the western part of Rivers State, freshwater snails were sampled and physico-chemical parameters of the water bodies were analysed using standard methods from April to September 2021. Snails sampled were identified morphologically and examined for infection. Out of 4672 freshwater snails recorded, Lymnaea natalensis was 3548 (75.94%), Bulinus truncatus 405 (8.67%), Bulinus globosus 400 (8.56%), Oncomelania spp. 204 (4.37%), Biomphalaria spp. 12 (0.26%) and Pila ovata 103 (2.20%). There was an observed statistical difference (P= 0.004; P<0.05) in the occurrence of the snail species. Snail abundance in relation to the location (P= 0.002) showed a significant difference. L. natalensis was the most abundant and widely distributed species; while Biomphalaria spp. was the least abundant. Only 0.13% of the snails were infected. The study revealed that the freshwater snail abundance varied monthly. Dissolved Oxygen and temperature significantly influenced snail abundance/distribution. A boom in snail reproductivity was observed by increased number of snails at the juvenile stage, suggesting a likelihood of disease resurgence in the near future if no control measure is enacted.