HIV-AIDS. SARS. Ebola. Bird Flu. Swine Flu. Rabies. These are emerging infectious diseases where the viruses have jumped from one animal species into another and now infect humans. This is a phenomenon known as cross-species transmission (CST) and scientists are working to determine what drives it.
Gary McCracken, a professor at the University of Tennessee, Knoxville, and department head in Ecology and Evolutionary Biology, is one of those scientists and has made a groundbreaking discovery into how viruses jump from host to host.
His article, "Host Phylogeny Constrains Cross-Species Emergence and Establishments of Rabies Virus in Bats," will appear in the Aug. 6 edition of Science and will be featured on the issue's cover.
It has been a long-held belief that rapid mutation is the main factor that allows viruses to overcome host-specific barriers in cellular, molecular or immunological defenses. Therefore, it has been argued that viruses emerge primarily between species with high contact rates.
McCracken and his colleagues now report that CST may have less to do with virus mutation and contact rates and more to do with host similarity.
"That innate similarity in the defenses of closely related species may favor virus exchange by making it easier for natural selection to favor a virus' ability to infect new hosts," McCracken explained.
McCracken performed his research with former UT Knoxville Ph.D. student Amy Turmelle who now works with the Centers for Disease Control (CDC) and Maarten J. Vonhof, a former post-doctoral scholar at UT Knoxville, who is now with Western Michigan University. Other colleagues include CDC Rabies Team Members Ivan Kuzmin, Charles Rupprecht and Daniel Streicker, who is also with the University of Georgia.
The team made their discovery by analyzing hundreds of rabies viruses in 23 species of bats. In the United States, there are at least 45 different species of bats
|Contact: Whitney Holmes|
University of Tennessee at Knoxville