Acute schistosomiasis mansoni in the baboon Papio anubis gives rise to goblet-cell hyperplasia and villus atrophy that are modulated by an irradiated cercarial vaccine.

A histopathology study of the intestines of four Kenyan baboons (Papio anubis) infected by 800 cercariae of Schistosoma mansoni and euthanized at 10 weeks postinfection was done. The pathology was compared with that of four baboons first vaccinated with 10,000 irradiated cercariae and then challenged 8-10 weeks later with the same number of cercariae. Two baboons that were neither vaccinated nor challenged were used as controls. On postmortem examination, multifocal to coalescing granulomatous inflammatory responses to the eggs in the submucosa of the terminal ileum and colon were seen in all baboons exposed to the parasite. The mean numbers of goblet cells detected per villus at 20 cm from the pylorus were 12.8 +/- 2.6, 30.4 +/- 6.6, and 20.2 +/- 3.7 in the two uninfected baboons, the infected unvaccinated baboons, and the vaccinated and challenged baboons, respectively. Mild to total villus atrophy was present in all eight baboons exposed to the parasite. These lesions, which were less marked in infected but vaccinated baboons, may contribute to the clinical signs seen in acute simian schistosomiasis mansoni.