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