Comparative histopathology of two strains of Bolivian hemorrhagic fever virus infections in suckling hamsters

The histopathology of Machupo virus infection in intracerebrally inoculated suckling hamsters was studied and compared to the histopathology of a virus isolated from a case of hemorrhagic fever from Cochabamba, Bolivia. Both virus isolates were pathogenic for suckling hamsters; however, Machupo virus killed the hamsters earlier than Cochabamba virus. Lesions were most commonly observed in liver and lymphoid and central nervous systems. The lesions varied in incidence, time of occurrence and severity. A nonsuppurative encephalitis which developed in the Cochabamba-virus-infected hamsters was not a consistent finding in the animals inoculated with Machupo virus.