In Wild Animals, Charting the Pathways of Disease

High in the Wallowa Mountains of northeastern Oregon, Raina K. Plowright and other researchers blindfolded and hobbled a herd of bighorn sheep in a corral so blood samples could be taken and their noses and throats swabbed. “There’s lots of places for pathogens to hide in the nasal cavity,” said Dr. Plowright, a wildlife scientist with the Center for Infectious Disease Dynamics at Penn State who is based in Bozeman. Peering into the nostrils of wild sheep is part of the nascent field of eco-immunology, which seeks both to understand the immune systems of wild animals and to use that knowledge to gain a better understanding of human immune systems. Until recently, this kind of knowledge has been gleaned almost exclusively by studying pampered, genetically similar lab animals, which don’t reflect a real-world scenario. Eco-immunology works to understand how disease spreads in wildlife populations — the bighorn sheep are in trouble because of pneumonia that spread from domestic sheep — and how it can be worsened by human and environmental factors like climate change. Another major goal is to understand the pathways that deadly diseases can follow from wildlife to humans. In the last 30 years, more than 300 infectious diseases in humans originated in animals, including AIDS, Ebola, SARS, Lyme, hantavirus, West Nile virus and new strains of flu. (Diseases do not travel in just one direction. Humans are believed to have passed metapneumovirus to mountain gorillas in Africa.)...more