Released May 11, 2005

HATTIESBURG – A study underway at The University of Southern Mississippi could shed new light on how birds help to spread the West Nile virus.

With funding from the National Science Foundation, biologists at Southern Miss are teaming with Oberlin College in Ohio to test whether the stress of migration can reactivate West Nile virus that has gone dormant in birds.

Previous groundbreaking research at Southern Miss demonstrated that birds infected with West Nile virus will continue to migrate, sometimes as much as 500-600 miles in a single day.

“This research will provide the model for understanding how West Nile virus and other related pathogens spread,” said Dr. Jennifer Owen, lead researcher on the three-year $450,000 grant project.

By artificially simulating migratory conditions in the laboratory, scientists can observe whether infected birds become active carriers more than once. After being bitten by a mosquito that carries the deadly disease, a bird will stay infectious for three to five days. If bitten again during this infectious period, birds can transmit the virus back to other mosquitoes, which can then transmit it to humans, birds or livestock.

“We’re also testing to see if high testosterone levels in birds can act as a catalyst to reactivate the virus,” Owen said.

Owen and graduate assistant Amanda Jo Williams will conduct their experiment with 60 gray catbirds captured in Ohio and inoculated with the virus at Southern Miss. Using photo stimulation to manipulate day-length in the laboratory, the scientists will induce a spring migration in January. The birds will also receive testosterone implants as part of the experiment.

Owen said, “Any knowledge we can gain will help us in understanding and predicting how fast the virus will spread.”

West Nile virus has blanketed the country in a relatively short span, said Dr. Frank Moore, chair of the Department of Biological Sciences.

“It’s important to realize that the virus first appeared in the New York area in 1999. By 2002, it had stretched almost across the continental United States, and by 2004, it was being reported in the lower 48 States,” said Moore.

Humans are not the only ones being adversely affected by West Nile virus, Moore said. Wild bird populations, along with other livestock like horses, are getting sick and dying.

“There is serious concern about the impact of West Nile virus on the avian population,” said Moore, adding that all bird species are susceptible to the disease. “We have even gotten calls from Hawaii, where people who’ve heard about our research are concerned what West Nile could do to their endangered bird species should the virus ever spread to the islands.”

Moore said that West Nile virus has had the most impact on the group of birds known as corvids, to which crows and blue jays belong.

“West Nile virus is particularly devastating to those social birds that travel in groups and facilitate the spread of the virus,” he said.

Owen stated that the spread of West Nile virus is more than just a public health concern; it’s a wildlife health concern.

“West Nile virus can affect horses, alligators, dogs, cats, raccoons, and lots of other animals. It’s a threat to us from a domestic standpoint, but it’s also an agricultural and ecological threat as well,” she said.

For more information about the study, contact Owen at (601) 266-4394 or Moore at (601) 266-4748.

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