West Nile Virus Information

West Nile virus exists in nature through a transmission cycle involving mosquitoes and birds. Mosquitoes become infected with West Nile virus when they feed on infected birds, which may carry the virus in their blood for a few days. Infected mosquitoes can then transmit West Nile virus to humans and animals when biting to take a blood meal. In rare instances, West Nile virus may be transmitted from human to human through organ donation or blood transfusion or from pregnant mother to fetus. These new modes of transmission are still under investigation.

Most individuals infected with West Nile virus will not have any symptoms or signs of illness. People who develop illness may experience mild symptoms such as fever, headache, and body aches; occasionally a skin rash and swollen lymph glands may be noticed. Less than 1% of persons infected with the virus may develop a more severe disease with symptoms including high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, paralysis and, rarely, death. If you are concerned that you may have been exposed, please contact your healthcare provider.

The following steps may help you avoid contact with mosquitoes:

• Stay indoors at dawn or early evening
• Wearing long-sleeved shirts and long pants when outdoors
• Use insect repellent containing an EPA-registered insect repellent and following package instructions
• Get rid of mosquito breeding sites by:
  • Removing all discarded tires from your property
  • Disposing of any water-holding containers
  • Changing the water in pet dishes and replacing the water in bird baths weekly
  • Drilling holes in tires swings so water drains out
  • Keeping children's wading pools empty and on their sides when they aren't being used

Dead bird surveillance during the past years has provided valuable information on the spread of WNV in Maryland. West Nile virus has now been detected in human and animal populations in nearly all jurisdictions in Maryland, and is expected to return each year.

If you find a dead bird, please dispose of it as follows:

• Wear plastic or latex gloves or use a plastic bag as a glove
• With your gloved hand, place or wrap the bird in a plastic bag and tie the bag securely
• Dispose of the bag (and gloves) in an outdoor trash receptacle
• Wash your hands with soap and water

Sick or injured birds should be reported to your local wildlife rehabilitator (call 1-877-463-6497 for a list of licensed rehabilitators).

For more information on West Nile virus visit:

Maryland West Nile Virus Information Page
Maryland Department of Agriculture - Office of Plant Industries and Pest Management
Office of Environmental Health
Centers for Disease Control - West Nile Virus Page