ETIOLOGY OF OROYA FEVER

Abstract

Extraordinary variability in response to inoculation was observed in M. rhesus, from fatal, systemic disease resembling severe Oroya fever, to mild local reactions similar to benign verruga. Fever was usually moderate, with one or more periods of high temperature, but occasionally it was continuously high, and in 1 fatal instance it was present for a day only. Invasion of the blood by Bart. bacilliformis and anemia were in some instances so severe as to be comparable with human Oroya fever, but more often the parasite was not demonstrable in the blood by examination of stained films, though readily detected by the culture method. Invasion of the blood was as extensive in an animal inoculated locally as in one inoculated intravenously and intraperitoneally. Bart. bacilliformis was constantly demonstrated in the lymph glands of animals sacrificed late in the course of disease and usually also in spleen, bone marrow, and heart blood. It was obtained in culture from lymph glands, spleen, and heart blood taken at autopsy. Skin lesions always yielded cultures of the parasite.