Scientists Begin 2002 Monitoring for West Nile Virus

Auburn, April 18, 2002---Wildlife biologists and other scientists are poised to begin a third year of monitoring Alabama's 
bird population for West Nile virus (WNV).  In people, it can cause West Nile encephalitis, a potentially deadly 
inflammation of the brain.  Last year, the state had its first two human cases of WNV.  One person recovered, but a 
Jefferson County man died.
	
"The virus is spread by mosquitoes that get the disease from infected birds," says Ashley Rossi, who coordinates the 
West Nile surveillance team in Alabama. "Birds are the natural host for the virus, which can be fatal to birds, horses, 
humans and other mammals."
	
Rossi, who is a wildlife biologist with the U.S. Department of Agriculture's Wildlife Services program in Alabama, says 
testing of dead birds will be restricted to several species of birds including crows, blue jays and raptors.  Raptors found in 
Alabama include hawks, eagles, ospreys and owls.
	
Rossi says the surveillance team needs the public's assistance with the monitoring effort.
	
"The public can help by identifying and, if possible, collecting dead birds for us to examine," says Rossi.  "We will begin 
accepting dead birds for testing in May.  We are limiting the species we're looking at because to date WNV has been 
identified more frequently in these species."
	
Nationally, more crows have tested positive for WNV.  But in Alabama last year, 33 of the 59 WNV-positive birds were 
blue jays.  
	
"This may be related solely to how we receive our samples of dead birds," says Rossi.  "We received more samples from 
Jefferson and other urban counties.  Homeowners and others in these areas are more likely to see jays than crows."
	
Rossi says the public should take some basic precautions in collecting the dead bird.	

First, wear plastic gloves, or turn a large zipper-seal plastic bag inside out.  Place your hand in the bag, and pick up the 
bird with your covered hand.  Then, grasp the edges of the bag and pull so it encloses the bird.  Seal the bag.  Place the 
first bag in a second bag.  
	
If possible, put the sealed bag in a cooler with ice.  Then take the sample to your county Extension office.
	
"The county Extension offices know how to get in contact with us to arrange delivery of the sample," says Rossi.  "When 
we receive the sample, our scientists will conduct necropsies to determine if West Nile virus is present."
	
In 2001, more than 770 dead birds were tested for WNV as a result of the monitoring program.  That's almost three times 
the number tested in 2000.

In addition to monitoring the state's wild bird population for the disease, scientists are also collecting mosquito samples 
and examining them for the virus.  In 2001, nearly 125,000 mosquitoes collected in 22 Alabama counties were tested for 
WNV.  That's double the mosquito samples submitted for testing in 2000.  

But scientists are not restricting their examination of mosquitoes to WNV alone.  In addition, they are also testing 
mosquitoes for other forms of mosquito-borne diseases, including eastern equine encephalitis (EEE), St. Louis 
encephalitis and LaCrosse encephalitis.  

"The WNV surveillance effort is allowing us to look for other potentially serious diseases as well," says Rossi.  "For 
example, EEE is much more serious and deadly than WNV. " The mortality rate from EEE is more than 30 percent, while 
it is about 15 percent or less for WNV.

Rossi says the mosquito examination is the most time-consuming and labor-intensive part of the surveillance effort.  
Mosquitoes must be sorted, identified by species and counted by location.  With as many as 6,000 mosquitoes in one 
collection, the process takes a great deal of effort and man-hours.

"Extension as well as the Alabama Department of Public Health, among others, are all vital partners in the surveillance 
effort," says Rossi.  "The surveillance effort is far too broad to be accomplished without the work of people in a number of 
cooperating agencies."

Besides humans, horses are particularly vulnerable to both WNV and EEE.  More than 160 horses were screened for both 
diseases last year.  In 2001, there were four equine cases of WNV in Alabama.  Three of the animals fully recovered, but 
one had to be euthanized because of the disease.  In neighboring Florida, more than 450 horses were infected with WNV.
	
EEE was identified in 15 Alabama counties, primarily across the southern part of the state.  Thirty-six horses tested 
positive for EEE in 2001.  In addition, EEE was also identified in a dog as well as several emus. 
	
###

Source:  Ashley Rossi, USDA Animal and Plant Health Inspection Service