Vesical schistosomiasis at Odau village in Ahoada Local Government Area, Rivers State, Nigeria

Studies on Urinary schistosomiasis and its snail vector was undertaken between October 1991 and September 1992 in Odau. Of the 890 urine specimens examined 514 (57.8%) were infected. 235 (45.7%) were excreting under 100 eggs per 10ml urine, 167 (32.5%) were excreting between 100-500 eggs per 10ml urine while 112 (21.7%) were excreting more than 500 eggs in 10ml of urine. Of the 514 infected persons 336 (60.5%) were males and 178 (53.1%) were females. Overall peak infection (78.7%) occurred in 10-14 years group. Male infection peaked (83.7%) in the 15-19 age bracket while peak infection in the females (73.1%) was in 10-14 years age group. Two snail vectors, Bulinus globosus and Bulinus forskalii, were collected from the study area. Bulinus forskalii was not infected with cercarise of schistosome throughout the study period. B globosus was found infected with furcereus cercariae believed to be human schistosomes. Population trend of Bulinus globosus was closely studied and observed to be related to infection with schistosome cercaria. Two broad transmission foci were located. One was in the village ponds where more children were infected. The other was in the pits, ditches and swamps in the plantations where the adults were infected. Control of schistosome infection through chemotherapy will best be achieved by January because immediate reinfection of parasites is not possible owing to the drying out of the ponds in January and February. And control of the snail vectors will be best in March and April because a large proportion of snail population is young and highly vulnerable to molluscicide attacks.