Predisposition of humans to infection with Schistosoma mansoni: evidence from the reinfection of individuals following chemotherapy.

In a study of faecal egg counts of Schistosoma mansoni from 359 people of all ages from a rural Kenyan community, a positive association was demonstrated between infection intensity in individuals before treatment and reinfection intensity in the same individuals 9 months after treatment in certain age groups of the sampled population. Consequences and possible causes of these observations are discussed in terms of the epidemiology and control of schistosomiasis.