The researchers were surprised to find that the monkeys harbored antibodies to some, but not all, of the proteins associated with the known poxviruses, Goldberg said. Whatever had infected the monkeys looked a little bit like monkeypox virus, a little bit like vaccinia virus, a little bit like cowpox virus, but not exactly like any of them, he said.
We were forced to conclude in the end based on a series of progressive laboratory tests that yes, these monkeys had been exposed to a poxvirus, but that it was different from any poxvirus that we were using as a reference, he said.
All the animals were healthy at the time of the study, and no recent cases of human orthopoxvirus infection have been reported in Uganda.
Traditionally, global health authorities look for disease in wildlife only after outbreaks occur in humans. Monkeypox, for example, has caused hundreds of cases of illness in Africa. A 2003 outbreak of monkeypox in humans in the U.S. traced to rodents imported as pets from sub-Saharan Africa increased interest in this disease.
Little is known about the global distribution of orthopoxviruses, Goldberg said, but their potential to cross from other animals into humans warrants more attention. (Some believe that smallpox, which killed 300 to 500 million people in the 20th century before it was eradicated in 1980, originated in African rodents thousands of years ago.)
The red colobus monkeys of Kibale are probably not the primary hosts of the virus that infected them, Goldberg said. None of the monkeys was sick when they were tested, an indication that their immune systems had successfully cleared the pathogen. Other mammals, such as rodents, may function as incubators of the virus, he said.
Under the right circumstances, orthopoxviruses can jump from a host species into a new species. This is worrisome in a region known to harbor a diversity of wildlife and where interactions between people and
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign