Piped water supply and intestinal parasitism in Zimbabwean schoolchildren.

The prevalence of intestinal parasitism in primary schoolchildren in three areas, communal (peasant farm) lands, commercial farms and urban townships, was assessed by examination of concentrated and stained stool specimens to determine the effect of water supply on intestinal parasitism. Piped water in communal lands was associated with decreased frequency of schistosomiasis and hymenolepiasis, but not with decreased frequency of protozoa. Schistosomiasis was very common in commercial farm labour communities, particularly on farms adjoining the local river, despite the availability of stored borehole water supplied through communal taps. The prevalence of intestinal parasitism in children from urban areas with municipal water supplied to taps in each household was similar to that of children in communal areas who obtained water from surface streams. The frequency of Giardia lamblia infection was higher in urban than in rural schoolchildren, and within communal areas was higher in children with access to protected borehole water. The provision of piped water was, therefore, not found to be associated with reduced prevalence of intestinal parasitism, though additional factors such as frequency of contact with infected water, the provision of ancillary improvements and the actual usage of available water supplies would need to be more closely assessed.