The effects of schistosomiasis on spontaneous play activity in black schoolchildren in the endemic areas. An ethological study.

An ethological study was undertaken in two primary schools in Natal to assess the effect of schistosome infections on the spontaneous activity of schoolchildren in endemic areas. Results indicate that there is selective exposure of more active children to the disease. In low-level infections with Schistosoma haematobium (less than 1000 eggs excreted in a 2-hour midday period) or S. mansoni (less than 1000 eggs/g dry weight of stool) there is little evidence of a decrease in energetic activity under normal conditions in subjects with higher egg counts or infections with both schistosomes activity levels generally fall, especially under hot, humid weather conditions, when the fall in activity is greater than that for control subjects.