C-type viral particles in a urinary bladder neoplasm induced by Schistosoma haematobium

Abstract

NEOPLASMS may be induced in nonhuman primates after infection with Schistosoma haematobium (refs 1 and 2 and unpublished results of R. E. K., A. W. Cheever, B. J. Myers, S. W. Young and J. A. Moore). After various times, masses develop within the urinary bladders of the hosts, ranging from hyperplasia to papillary carcinoma as determined histopathologically. Although the basic mechanism of tumour induction in such cases is not known, the many factors involved could include stimulation of endogenous virus infections. It is therefore interesting that we have now found C-type viral particles in one out of four papillary carcinomas of capuchin (Cebus sp.) monkeys experimentally infected with S. haematobium. None were seen in two infected animals that developed only hyperplasia and squamous metaplasia. Previous examination of normal bladder tissue has failed to demonstrate similar C-type viruses. For electron microscopy and infection of the animals with S. haematobium we used published methods^1,3,4. The bladders were taken from monkeys previously infected with S. haematobium (Table 1). Histological evaluation based on examination of biopsy samples is also provided (Table 1).