Absence of vaccinia virus detection in a remote region of the Northern Amazon forests, 2005-2015.

Vaccinia virus (VACV) circulates in Brazil and other South America countries and is responsible for a zoonotic disease that usually affects dairy cattle and humans, causing economic losses and impacting animal and human health. Furthermore, it has been detected in wild areas in the Brazilian Amazon. To better understand the natural history of VACV, we investigated its circulation in wildlife from French Guiana, a remote region in the Northern Amazon forest. ELISA and plaque reduction neutralization tests were performed to detect anti-orthopoxvirus antibodies. Real-time and standard PCR targeting C11R, A56R and A26L were applied to detect VACV DNA in serum, saliva and tissue samples. No evidence of VACV infection was found in any of the samples tested. These findings provide additional information on the VACV epidemiological puzzle. The virus could nevertheless be circulating at low levels that were not detected in areas where no humans or cattle are present.