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Further assessment of Monkeypox Virus infection in Gambian pouched rats (Cricetomys gambianus) using in vivo bioluminescent imaging

October 30, 2015

Monkeypox is a zoonosis clinically similar to smallpox in humans. Recent evidence has shown a potential risk of increased incidence in central Africa. Despite attempts to isolate the virus from wild rodents and other small mammals, no reservoir host has been identified. In 2003,Monkeypox virus (MPXV) was accidentally introduced into the U.S. via the pet trade and was associated with the Gambian pouched rat (Cricetomys gambianus). Therefore, we investigated the potential reservoir competence of the Gambian pouched rat for MPXV by utilizing a combination of in vivo and in vitro methods. We inoculated three animals by the intradermal route and three animals by the intranasal route, with one mock-infected control for each route. Bioluminescent imaging (BLI) was used to track replicating virus in infected animals and virological assays (e.g. real time PCR, cell culture) were used to determine viral load in blood, urine, ocular, nasal, oral, and rectal swabs. Intradermal inoculation resulted in clinical signs of monkeypox infection in two of three animals. One severely ill animal was euthanized and the other affected animal recovered. In contrast, intranasal inoculation resulted in subclinical infection in all three animals. All animals, regardless of apparent or inapparent infection, shed virus in oral and nasal secretions. Additionally, BLI identified viral replication in the skin without grossly visible lesions. These results suggest that Gambian pouched rats may play an important role in transmission of the virus to humans, as they are hunted for consumption and it is possible for MPXV-infected pouched rats to shed infectious virus without displaying overt clinical signs.

Citation Information

Publication Year 2015
Title Further assessment of Monkeypox Virus infection in Gambian pouched rats (<i>Cricetomys gambianus</i>) using in vivo bioluminescent imaging
DOI 10.1371/journal.pntd.0004130
Authors Elizabeth Falendysz, Juan G. Lopera, Faye Lorenzsonn, Johanna S. Salzer, Christina L. Hutson, Jeffrey Doty, Nadia Gallardo-Romero, Darin S. Carroll, Jorge E. Osorio, Tonie E. Rocke
Publication Type Article
Publication Subtype Journal Article
Series Title PLoS Neglected Tropical Diseases
Index ID 70159857
Record Source USGS Publications Warehouse
USGS Organization National Wildlife Health Center