Pathology of acute fatal babesiosis in hamsters experimentally infected with the WA-1 strain of Babesia
Dao, A.H.; Eberhard, M.L.
Laboratory Investigation; A Journal of Technical Methods and Pathology 74(5): 853-859
1996
ISSN/ISBN: 0023-6837 PMID: 8642781 Document Number: 460395
A strain of Babesia sp. (strain WA-1), recently isolated from a human in Washington State, USA, was found to be unusually virulent for hamsters; it caused acute infection and death in a large proportion of animals by 5 to 7 days pi. To assess the pathology associated with this infection, 30 male Syrian hamsters (Mesocricetus auratus) were inoculated intraperitoneally with the WA-1 strain. Twelve animals (40%) died within 5 to 6 days. The other 18 animals, all infected and clinically ill, were killed on days 6 or 7 pi for biochemical study. All 12 animals that died from the infection showed high parasitaemia, heavy intravascular haemolysis and pronounced vascular stasis with red-cell sequestration in the spleen, liver, lungs, kidneys and brain. Serological study revealed severe anaemia (mean haematocrit, 29) with haemolysed serum and marked elevation of serum transaminases. The mechanism of death was thought to be diffuse anoxic tissue damage secondary to vascular stasis, which led to multiorgan failure.