THE IMPACT OF CONTROL MEASURES ON URINARY SCHISTOSOMIASIS IN PRIMARY-SCHOOL CHILDREN IN NORTHERN CAMEROON - A UNIQUE OPPORTUNITY FOR CONTROLLED OBSERVATIONS

As part of a program to integrate schistosomiasis control into the pri mary health care system in northern Cameroon, an unexpected opportunit y to undertake a controlled evaluation of the impact of interventions was recognized. Inadvertently, a large part of Mindjil, one of four as sessment villages, had been essentially excluded from the program, cre ating a unique natural control. The prevalence of infection with Schis tosoma hematobium in school-aged children was 7% in the areas where th e control program was implemented, and 71% in the excluded areas (P < 0.0002). High intensity infection was 1% and 26% in the two areas, res pectively (P < 0.0002). Children in the school where the control inter ventions were implimented had a significantly lower prevalence of infe ction with Schistosoma hematobium (P < 0.005). Subjects in interventio n areas demonstrated greater knowledge about the transmission of schis tosomiasis than those in the control area. This study documented and q uantified program impact in a controlled manner not usually possible i n field studies and also illustrated how unrecognized intracultural di versity (within culture differences) in target populations may effect disease control programs in communities.