Pneumonitis in Syrian golden hamsters (Mesocricetus auratus) infected with Rio Mamoré virus (family Bunyaviridae, genus Hantavirus)

•Rio Mamoré virus in Syrian golden hamsters is pathogenic but usually not lethal.•The pathology in hamsters during the acute phase of infection includes diffuse pneumonitis and pulmonary edema.•Rio Mamoré virus in hamsters may prove useful in the assessment of candidate therapies for hantavirus pulmonary syndrome.

Rio Mamoré virus is an etiological agent of hantavirus pulmonary syndrome in South America. The purpose of this study was to determine whether Rio Mamoré virus strain HTN-007 in Syrian golden hamsters is pathogenic. None of 37 adult hamsters infected by intramuscular injection of HTN-007, including 10 animals killed on Day 42 or 43 post-inoculation, exhibited any symptom of disease. Histological abnormalities included severe or moderately severe pneumonitis in 6 (46.2%) of the 13 animals killed on Day 7 or 10 post-inoculation. The primary target of infection in lung was the endothelium of the microvasculature. Collectively, these results indicate that Rio Mamoré virus strain HTN-007 in adult Syrian golden hamsters can cause a nonlethal disease that is pathologically similar to hantavirus pulmonary syndrome.