With Maryland confirming its first case of West Nile virus (WNV) of the season, now seems a good time to remind the public of some easy steps to take to minimize your chance of contracting the virus. WNV is a mosquito-borne disease that affects the nervous system. It is one of a group of arboviruses (arthropod-borne viruses) belonging to the Flavivirus genus. 

The infected individual is an adult who lives in the National Capital Region. In addition, WNV has also been detected in a horse, also in the National Capital Region, and in mosquito pools collected in Harford, Montgomery, Prince George’s and Talbot Counties. A mosquito pool is a group of mosquitoes collected at one of several trap sites across the State. 

“This is the time of year we see West Nile virus cases in Maryland," said DHMH Secretary Dr. Joshua M. Sharfstein. "Our first confirmed cases of the season should serve as a reminder for all Maryland residents to take the basic steps that can reduce the risk of getting infected." 
Measures people can take to protect themselves include:

  • Avoiding areas of high mosquito activity.
  • Avoiding unnecessary outdoor activities at dawn and dusk when mosquitoes are most active.
  • Wearing long pants, long-sleeved shirts and hats when concerned about mosquito exposure. 
  • Using an EPA-registered insect repellent according to package directions.

Most individuals infected with WNV will not have any symptoms. People that do develop illness will usually have any combination of fever, headache, body aches, skin rash and swollen lymph glands. These symptoms generally appear two to 14 days following the bite of an infected mosquito.  

Less than one percent of persons exposed to the virus will develop more severe infections, with symptoms such as headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. 

In rare instances, WNV can be fatal.  People older than 50 and those who have compromised immune systems (such as organ transplant recipients) are at greatest risk of developing severe disease when infected with WNV.  

Residents are urged to monitor their own yards and gardens for standing water that can serve as a breeding ground for mosquitoes. Small amounts of water in a discarded can or container will support dozens of mosquitoes. 

To eliminate mosquito-breeding areas:
  • Clean rain gutters to allow water to flow freely.
  • Remove old tires or drill drainage holes in tires used as playground equipment.
  • Turn over wading pools, wheelbarrows, wagons and carts when not in use. Flush water from bottom of plant holders twice a week.
  • Replace water in birdbaths at least twice a week.
  • Turn garbage can lids upside down and make sure trash receptacles are empty of water.
  • Fix dripping faucets.
  • And aerate ornamental pools and water gardens or stock with fish and use a circulating filter system.

For information, including weekly updates after a confirmed case, visit the Maryland Department of Health & Mental Hygiene at http://phpa.dhmh.maryland.gov/OIDEOR/CZVBD/SitePages/west-nile.aspx.