Functional significance of periovular granuloma in schistosomiasis.

1. Mice infected with 30 Schistosoma mansoni cercariae for 8 weeks presented viable eggs in the tissues up to the 17th day following curative chemotherapy, as demonstrated by the miracidium eclosion test. 2. These results were similar for eggs entrapped within different morphological types of granulomas such as those formed during early or late infection or located in different organs. 3. The present findings indicate that the periovular granuloma occurring in schistosomiasis probably serves to protect the host tissues from the miracidial secretions rather than to attack and kill the miracidium as suggested by previous studies.