Acute fulminating babesiosis in hamsters infected with Babesia microti.

In this study, Babesia microti (ATCC30222) from mice was adapted to golden hamsters. The parasite was passaged to immunosuppressed and then adapted to normal hamsters. When 30 normal hamsters were inoculated with this strain, parasitaemia increased to 74% of erythrocytes by day 7 and 70% of the hamsters died. By day 12, parasitaemia extended to 90%, with 97% mortality. Hearts and kidneys from infected animals were enlarged. Histopathology revealed acute myocarditis, hepatitis, pneumonitis, glomerulonephritis and splenomegaly. Giemsa, Acridine Orange and Rhodamine staining of the parasite were compared. Scanning electron microscopy of blood from infected hamsters revealed from 1 to 5 intra-erythrocytic parasites.