Prevalence and transmission dynamics of Schistosoma haematobium infection in a rural community of southwestern Ebonyi State, Nigeria

A twelve-month epidemio-ecological study on the prevalence, infection intensity, water contact and vector aspects of urinary schistosomiasis was conducted in a rural community of south-west Ebonyi State, Nigeria, using standard procedures, and involving 894 individuals (527, 58.9% males; and 367, 41.1% females). An overall community prevalence (15.3%) was established with more males (20.7%) than females (7.6%) being significantly positive for both micro-and macro-haematuria (chi(2)= 0.806; df = 1, p < 0.05). Intensity of infection was generally of the light category (< 100 eggs/10ml urine) with more infected males (n = 95, 87.2%) than infected females (n = 15, 53.6%). Correlation analysis showed no linear relationship between prevalence and intensity of infection. Individuals aged 16-20 years dominated interschool/intervillage infection profile (range 13.2 - 50%) while participants in 6-10 years age bracket recorded the lowest infection rates (range 2.8 - 5.0%). Age-related difference in prevalence was not significant (chi(2) = 1.80; df = 2, p > 0.05). A total of 2877 ova of Schistosoma haematobium were recovered providing an overall mean egg burden of 21 +/- 7 eggs/10 ml urine per infected person. Age-related infection intensity was similarly of the light category involving 80.3% of infected persons. Bulinus globosus (n = 308) was identified as the vector of the parasite with 20.1% snails found to be shedding cercariae. Monthly and seasonal infection rates in snails were season -dependent and peaking in May (35.5%). Participants aged 13-15 years accounted for 25.1% of total water contacts (n = 9938) whereas individuals aged 6-9 years accounted for only 9.6% contacts. The most performed water contact activity was bathing (33.3%), followed by washing of clothes (25.7%). Correlation analysis indicated that village of residence, age and cumulative water contacts were significant correlates of possible S. haematobium infection.