Fairfax County officials identified four positive pools of West Nile Virus in late May and early June, but said the infection rate is extremely low.

“For the last several years we have detected the presence of WVN in mosquitoes in Fairfax County. It is not unexpected,” Glen Barbour, Public Safety Information Officer for the Fairfax County Health Department, wrote in an email to Patch.

To date this season, Fairfax County officials have tested 578 pools. “The positive pools were taken between May 28 and June 10.  I’m told that our infection rate is less than 1/1,000 – which is considered very low,” Barbour said.

West Nile Virus was found in Culex mosquitoes.

Fairfax County has not had a wide-spread mosquito spraying program in more than 10 years, but county officials do treat known mosquito breeding areas throughout the summer with larvacides. They also encourage residents to eliminate standing water and take over preventative measures. 

"The purpose of our mosquito surveillance it to monitor public health risk levels and enable the Health Department to act quickly when these risk levels are elevated," Barbour said. 

Woodbridge officials reported yesterday they have found West Nile Virus-positive mosquitoes in that region, as well.  Unlike Fairfax, Prince William County officials do conduct a spraying program. 

Understanding and Preventing West Nile Virus

West Nile Virus symptoms may be flu-like, including fever, headache, tiredness, and body aches, occasionally with a skin rash (on the trunk of the body) and swollen lymph glands, according to the Centers for Disease Control and Prevention.

About 80 percent of people who contract West Nile Virus have no symptoms. However, about 1 in every 150 people may wind up with much more severe symptoms, up to and including West Nile encephalitis.

This week is Mosquito Awareness Week in Fairfax County. (See Fairfax County’s mosquito tips slideshow on Flickr here.

Fairfax County Health Department officials have these recommendations for residents:

•  When spending time outdoors, use insect repellent.  Always use mosquito repellents according to label instructions.
• Wear long, loose-fitting, light-colored clothing.
• Turn over or remove containers in your yard where water collects, such as old tires, potted plant trays, buckets and toys.
• Eliminate standing water on tarps, such as those that may be used to cover wood piles.
• Clean out bird baths and wading pools once a week.
• Clean roof gutters and make sure black corrugated drain pipes drain properly.