Preliminary studies on the prevalence and distribution of urinary schistosomiasis in Ondo State, Nigeria.

The prevalence of S. haematobium infection in 18 Local Government Area (LGA) in Ondo state was determined by examining pupils from randomly selected schools in the state. A total of 4266 urine samples were examined and 1303 (30.5%) were infected with the parasite. The infection was recorded in both rural and urban communities in each LGA. The overall prevalence was significantly higher in males (33.7%) than in females (26.0%) (P = -0.001). The LGA exhibiting the highest overall prevalence of infection was Akure north (86.2%; Cl, 0.82-0.9). The infection was most common in subjects between the ages of 11 and 15 years. Seven species of aquatic snails were encountered and B. (P). globosus was the most abundant and widespread species. The Owena river/dam in Idanre LGA was richest in molluscan fauna. B. (P). globosus and Biomphalaria pfeifferi shedding cercariae were recovered from Owena river and dam. The study shows that there were spatial heterogeneities in the prevalence of infections in both human population and the snail intermediate hosts. The implications of the clustering nature of the disease, for a successful control program in the state, were discussed.