School-based schistosomiasis control programmes: a comparative study on the prevalence and intensity of urinary schistosomiasis among Nigerian school-age children in and out of school.

A cross-sectional study was conducted in February 1998 on the prevalence and intensity of urinary schistosomiasis among school-age children in and out of school at Adim village in Nigeria to test the objective of delivering a control programme through the school system. School enrollment figures and non-attendance rate were collated from questionnaires that were self-administered by heads of families. Prevalence and intensity of infection were determined following filtration of urine and counting of carbol fuchsin-stained eggs of Schistosoma haematobium. The rates of regular school attendance, irregular attendance and non-attendance were 69.1%, 5.1%, and 25.8%, respectively. These indices were not significantly associated with the age of the schoolchildren (P > 0.05). Boys (76.6%) were more associated with regular attendance than girls (61.4%) (P < 0.0001) while girls had a higher rate of non-attendance (32.7%) than males (19.1%) (P < 0.0001). Although more out-of-school children were infected (90.7%) than those in school (86.8%), the difference was not statistically significant (P > 0.05). The same association was established in the variation of mean egg count between the 2 study populations though intensity was higher among out-of-school children. The principal reasons proffered for the high rate of non-attendance listed in their order of importance were: economic, sickness, poor performance, refusal, farming and fishing. A dual method of control that would in incorporate the integration of recognized local authorities is suggested in areas with moderate school attendance rate like Adim, as lack of treatment of infected out-of-school children ensures continuous contamination and re-infection.