Encephalomyocarditis virus (EMCV) was isolated from eight nonhuman primates, one Thomson's gazelle (Gazella thomsoni), and one dromedary camel (Camelus dromedarius) that died peracutely between January 1985 and October 1987 at Audubon Park Zoo, New Orleans, Louisiana. Gross pathology consisted of excessive pericardial fluid, epicardial hemorrhages, and pale foci within the myocardium. Microscopic changes included myofiber necrosis, edema, and mononuclear cell infiltration within the myocardium. Anti-EMCV antibody was found in a variety of species including a capybara (Hydrochoerus hydrochaeris), which subsequently died of a necrotizing myocarditis but from which virus was not isolated. Although one hospital staff member had a high anti-EMCV antibody titer, all primate keepers were seronegative. Encephalomyocarditis virus was recovered from 38 wild rodents, one opposum (Didelphis virginiana), and one rabbit (Sylvilagus sp.) collected on the zoo grounds. Fifty-five percent of the positive samples were found in areas where confirmed deaths had occurred or antibody-positive animals were housed. A killed vaccine was developed and administered to six domestic cats, 12 primates, and one camel. Antibody response to vaccination was variable.
Journal of Zoo and Wildlife Medicine 20, 291-296