WASHINGTON - The potentially deadly West Nile virus that continues to spread throughout the region has popped up in Fairfax County as well as in Prince William, reports The Washington Examiner.
The disease, which claimed the lives of two area residents in 2011, is generally carried by mosquitoes, which have descended upon the D.C. region in droves following a warm winter and early spring season. The Prince William County Health Department found mosquitoes that tested positive for West Nile.
Fairfax officials have found four groups of the insects that have also tested positive, the Examiner reports. Maryland officials have not yet started testing for West Nile in mosquitoes.
Health departments typically don't start seeing cases of West Nile until July, The Washington Post reports.
Four out of five people wouldn't know if they've been infected with the virus and wouldn't show any symptoms, according to the Centers for Disease Control and Prevention. One in 150 people will develop serious symptoms from the virus.
People over age 50 are at greater risk of developing meningitis or encephalitis - swelling caused by a virus - if infected, health officials say.
Symptoms resemble a fever or the flu and typically start between three to 14 days after being bitten. Antibiotics are not an effective remedy because the illness is not caused by bacteria.
The strongest form of prevention is to find and eliminate mosquito breeding grounds. Look for standing water in buckets, toys and potted plant trays. Use repellents like DEET and wear long-sleeved, light-colored clothing.
There were at least two incidents of West Nile in Virginia in 2011. There were five cases in 2010, one of which in Alexandria was deadly.
West Nile is mainly an infection of birds, but infected mosquitoes can transfer the virus to humans, according to D.C. health officials.
"When we have a lot of infected birds out there, and then we have high populations of mosquitoes that can transfer that virus from the bird population to the human population, that sets up the recipe for trouble," Michael J. Raupp, a professor of entomology at the University of Maryland, tells the Post.
Follow WTOP on Twitter.
(Copyright 2012 by WTOP. All Rights Reserved.)