Endemicity of vesical schistosomiasis in the Ebonyi Benue River valley, South Eastern Nigeria

Abstract

The investigation on the prevalence of patent and clinically severe infections with Schistosoma haematobium was carried out amongst inhabitants of Ebonyi Benue river valley, South Eastern Nigeria between August 2000 and June 2001. The inhabitants are predominantly farmers. Of the 3296 subjects examined from 15 randomly selected villages in the valley, 776 (23.5%) were excreting the eggs of S. haematobium in their urine. Infection rates varied between 18.9% and 30.6%. The severity of infection calculated by arithmetic mean egg counts (AMEC) and geometric mean egg counts (GMEC) varied significantly between the age groups and the villages (P<0.05). The prevalence and severity of infection increased with age from 0 to 25 years and decreased thereafter. Symptoms associated with the disease include visible hematuria (63.1%), suprapubic pain (10.3%) and stranguary (9.9%). While 65 positive persons had more than one symptom, 64 of the positive persons had no noticeable symptoms. Visible hematuria showed moderate sensitivity and high specificity for the disease. Female genital schistosomiasis (FGS) of the lower reproductive tract was recorded in 19 females of child bearing age that complained of severe suprapubic pain. Eight snail species were recorded in the stagnant ponds and both Bulinus globosus and B. truncatus were infected with schistosome cercariae. The factors contributing to these observations and feasible control measures are discussed.