Investigation into the prevalence of urinary schistosomiasis in the Agulu Lake area of Anambra State, Nigeria.

In epidemiological surveys for urinary schistosomiasis caused by Schistosoma haematobium in communities around Agulu Lake, Anambra State, Nigeria, between 1990 and 1992, the infection was found to be endemic in the area, especially in three towns: Nri, Agulu, and Adazi Nnukwu. The prevalence rates varied between these communities and with the year. Inter-town prevalence rates ranged from 5.96% to 54.00%. Intravillage prevalence rates ranged between 5.50% to 96.43%. Prevalence rates were highest in villages very close to Agulu lake. There was no significant difference in prevalence between the schools. Host age, but not sex, was found to play a significant role in prevalence and intensity of infection. There was also a strong correlation between visible haematuria and egg count per 10 ml urine, but eggs could be isolated in urine samples of different shades of coloration. Analysis of incidence of infection in these communities shows that Schistosoma haematobium incidence is high in Nri (55.17%) and low at Adazi Nnukwu (5.26%). Both Bulinus globosus and B. truncatus were found in the lake and both shed mammalian bifid schistosome cercariae.