Prevalence and Intensity of Schistosomiasis in School Children in a Large Sugar Irrigation Estates of Zimbabwe

A schistosomiasis prevalence and intensity survey was carried out among school children in three schools of Hippo Valley one of the largest irrigated sugar estates in Zimbabwe from April-June 2004 and December 2004-February 2005. The estates have a long history of schistosomiasis that had been successfully reduced to less than 10% prevalence in 2001. In the current study the mean prevalence of schistosomiasis per school was 22.74 and 24.36% in the wet and dry seasons, respectively. There was a positive correlation between school and schistosome species. Nyawagi had the highest S. haematobium prevalence (24.43%) and Chikomo had the highest S. mansoni prevalence (26.08%). S. haematobium infections were light with a mean infection intensity of 13.07 eggs 10 mL-1 urine whereas S. mansoni infections were moderate to heavy with a mean infection intensity of 123.58 eggs g-1 of stool. Mean prevalence of schistosomiasis was significantly different in the 5-8 years and 13-15 years age groups and in the 9-12 years and 13-15 years age group (p<0.05). Chikomo had the highest number of infected B. pfeifferi while Nyawagi had the highest infection rate for B. globosus. The increase in the prevalence of Schistosoma at Hippo Valley Estates schools is attributed to poor sanitation and a breakdown in the snail control program. Schistosomiasis that had been brought under control 4 years ago is currently a major health problem in the irrigated Hippo Valley estates.