Tuesday, July 2, 2002
Andrea Gullickson recently heard that a West Nile virus-positive crow was found in Vienna. Later, after talking to some neighbors, she found out the crow died just a few houses from her house, along Corsica Street. She was concerned by the news, and said she will try to learn more about the virus.
"I’ll look on the Internet, and see what symptoms stand out, what to look for," Gullickson said. "You definitely want to educate yourself."
The West Nile virus is spread by mosquitoes and Gullickson said she would be sure to put bug spray on herself and her family before trips outdoors.
Roy Eiden, environmental health specialist with Fairfax County, advised that residents should take precautions, such as the use of insect repellent, to cut down on mosquito bites. But Eiden also said that deaths from the West Nile virus are extremely rare. Last year, throughout the United States, there were five deaths from the virus.
"And there were 20,000 deaths from the flu," Eiden noted. "[In the United States last year] there were 12,000 reported cases of Lyme disease, and only 56 cases of the West Nile virus."
Even so, West Nile virus is spreading quickly. In 2000 there was only one dead crow found with West Nile virus in Virginia. Last year 54 dead crows were found, with the first coming in late July. This year, in Virginia, six dead West Nile virus-positive crows have been found. Eiden expects more than 100 such crows to turn up before the year is out. He expects some mosquitoes will test positive for the disease, as well. No West Nile positive mosquitoes have ever been found in the state. But after mosquitoes start to turn up with the virus, Eiden expects that humans will be next.
"The birds bring it in, the mosquitoes bite them, and then they give it to us," Eiden said.
In the United States the virus has spread up and down the East Coast, from New York to Florida. Of the 30 different types of mosquitoes found in Virginia, Eiden said only six species bite both men and birds. The most prevalent of these is the common house mosquito, which breeds in pools of standing water. Such pools are most common in places like birdbaths, rain gutters and food bowls left out for pets. Most mosquitoes are poor flyers, and will not travel much farther than the yard in which they are hatched.
"I was noticing that my kids were getting eaten alive," Eiden said. "So I went and looked around the yard."
He found, and dumped out, several pools of standing water. He didn’t find the main source of the problem, though, until he climbed onto his roof and noticed the stopped-up water of his rain gutter, filled with mosquito eggs.
"Trapping mosquitoes, using mosquito magnets, is not that effective," Eiden said. "If you have those out, the mosquitoes will be attracted to the carbon dioxide. But when they get there, and you’re sitting outside, they would rather go to you than to the carbon dioxide."
He said mosquito traps have a psychological effect, when people see hundreds of insects dead in the traps. But while traps will kill 100s of mosquitoes at a time, tipping water pools will kill 10,000s of mosquitoes at a time, Eiden said.
"The traps give a false sense of security," he said.
Gullickson said she is concerned for three small children, after hearing the report of the dead crow in her neighborhood. But Eiden said children are not especially susceptible to the virus.
"Of those who die from the viruses, the average is 70," Eiden said. "This is not a disease of youth or children."
Of the people who are bitten by a West Nile virus positive mosquito, one out of 300 will have mild, flu-like symptoms, Eiden said. Of those who show mild symptoms, one in 150 will show severe symptoms. And of those with severe symptoms, between three and 15 percent will die from the virus.
Although all birds can carry West Nile virus, birds from the raptor family, such as crows, bluejays and hawks, are especially susceptible to the virus.
Anyone who finds one of these birds should contact Fairfax County, at 703-246-2300, so the bird can be analyzed. Eiden said such birds can’t have been dead for longer than 24 hours and can’t have died from obvious physical trauma, such as a car or a cat. And small blackbirds should not be reported. Crows are, typically, around a foot in length.
"We have a limited staff, so we’re not in the dead bird pick-up business," Eiden said.
For more information on the West Nile virus visit www.fairfaxcounty.gov/service/hd/ and click on "Mosquitoes" at the bottom of the page.