Polyparasitism on the Kenya coast. 1. Prevalence, and association between parasitic infections.

A partially-stratified sample survey of people living in the catchment area of Kilifi General Hospital, Coast Province, Kenya, identified 19 species of parasites in blood and intestines. Age-prevalence curves of the common infections were of two distinct types, possibly reflecting the host's ability to mount a partially effective immune response. Although statistically-significant associations between pairs of infections were clearly demonstrable, these were almost wholly explained by environmental heterogeneity and epidemiological coincidence. There was no evidence of positive or negative influence of one infection on another.