Effects of treatment for intestinal parasites and malaria on the cognitive abilities of schoolchildren in Zaire, Africa.

Ninety-seven Zairian schoolchildren were evaluated for cognitive ability, health status, and quality of home environment. Children successfully treated for serious types of chronic intestinal parasites demonstrated significant improvements in K-ABC Spatial Memory, supporting this task as one of the more sensitive measures to changes in general health and neurological integrity. These findings were not obtained for successful treatment of low-grade malaria infection. Children initially negative for intestinal parasites tended to come from more economically and socially favorable home environments. They also demonstrated more dramatic improvements in visual-spatial analysis tasks. The implication is that the home environment factors conducive to chronic infestation with intestinal parasites are markers for favorability of the developmental milieu affecting long-term intellectual development.