UNIVERSITY PARK, Pa. -- When the penguin at the Seneca Park Zoo in Rochester, N.Y., contracted West Nile virus and died in August 2002, Adam Rohnke took note, but never dreamed it would mean much to him.

Today, the research assistant in Penn State's College of Agricultural Sciences is conducting songbird counts at two Centre County sites, checking some birds' blood for the virus and trapping mosquitoes to be tested to see whether they carry the disease-causing pathogen.

About all he can tell you about the presence of West Nile disease in central Pennsylvania now is that not much is known. "Talk to me in a year or so," he says. "There have been some crows and blue jays found dead that were infected with the disease, but we just don't know if West Nile is prevalent in birds across our region, or even if songbirds are carrying it."

The work being done by Rohnke, who is pursuing a master's degree in wildlife and fisheries science, is novel because he is focusing on songbirds, and their populations have been largely ignored by West Nile researchers. There have been many confirmed cases of larger birds succumbing to West Nile virus in Pennsylvania, but there is little information about whether their smaller cousins are widely infected.

"Big birds are easy to find when they die, but the songbirds migrate, so they could be spreading the virus," notes Rohnke, a Rochester native who graduated from SUNY College of Environmental Science and Forestry with a bachelor's degree in environmental forest biology. "Also, they have the closest interaction with humans, so they might pose the biggest threat."

He will get lots of help with his research. Rohnke -- who has been trained and certified by veterinarians in handling birds, extricating them from mist nets and drawing blood samples -- will be catching birds under the guidance of professor of wildlife resources Margaret Brittingham and his advisor, Rich Yahner, professor of wildlife conservation.

Mosquitoes will be collected in pheromone light and heat traps supplied by entomology professor K.C. Kim, who will be examining mosquitoes captured at both sites and cataloging species. The state Department of Environmental Protection will test mosquitoes for West Nile virus. Entomologist Liwang Cui will test the blood samples of birds taken by Rohnke.

The research sites have dramatically different characteristics. "One is near the wastewater treatment plant where water is sprayed every day," he explains. "The other is in the pine barrens near the Scotia Range, where the soil is dry and sandy. It will be interesting to see if infection rates of birds and mosquitoes differ between the two. We don't know what to expect. In a study done this year by the University of Southern Mississippi, 600 birds were tested and not a single case of West Nile was discovered."

West Nile encephalitis had never been documented in the Western Hemisphere before the late summer of 1999, when an outbreak occurred in the New York City metropolitan area. In 1999, the Centers for Disease Control and Prevention confirmed 62 human cases of encephalitis, including seven deaths, although the actual human infection rate was much higher. Most people who are infected with the West Nile virus have no symptoms or may experience mild illness such as fever, headache, body aches, mild skin rash or swollen lymph glands.

Infected mosquitoes transmit the West Nile virus. These mosquitoes usually bite and infect wild birds -- the primary host of the virus -- but also can infect horses and other mammals, in addition to humans. In September 2000, the first cases of West Nile virus were confirmed in birds, mosquitoes and a horse in Pennsylvania. By 2002, West Nile virus had spread throughout most of the United States and is now considered a threat everywhere.

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EDITORS: Contact Adam Rohnke at 814-865-1441 or by e-mail at atrl29@psu.edu.

Contact:

Jeff Mulhollem jjm29@psu.edu 814-863-2719 814-863-9877 fax #231