Predicting the geo-spatial distribution of Bulinus snail vector of urinary schistosomiasis in Abeokuta, South Western Nigeria

Abstract

Bulinus spp, are freshwater snails that serve as intermediate hosts of Schistosoma heamatobium which cause urinary schistosomiasis in human beings. The knowledge of their spatial distributions can be used to map the extent and risk of the disease in endemic areas. This paper therefore, presents the geo-spatial distribution of Bulinus sp. in Abeokuta in Ogun State. Bulinus snails collected from 31 water bodies consisting of 19 rivers, 9 streams, 2 dams and 1 canal were examined for infection. A total of 58 Bulinus snails made up of Bulinus forskalii 2 (3.4%), and Bulinus truncatus 56 (96.4%) were collected respectively. The B. truncatus was collected from 15 sites out of which infected B. truncatus was collected from 12 sites. The regression analysis of Bulinus distribution using remotely-sensed environmental data showed that rainfall was the only significant predictor of the distribution of B. truncatus (B= 26.690, Sig= 0.040). (B= -3.182, Sig= 0.050). A predictive risk map constructed for B. truncatus indicated the probability presence of 1.0 for Abeokuta area. These results suggest a likelihood and potential spread of urinary schistosomiasis into other areas of Abeokuta in the absence of snail control measures or mass chemotherapy.

Keywords: geo-spatial distribution, Bulinus truncatus, Schistosoma heamatobium, Abeokuta, Nigeria

The Zoologist, 10:53-60 (2012)