Arboviruses

West Nile virus (WNV) is a potentially serious illness that is spread by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. The infected mosquitoes can then spread WNV by biting humans and other animals, such as horses. First appearing in the U.S. in 1999, WNV has now spread through most of the country. North Carolina found its first case in a bird in 2000 and its first human case in 2002.

WNV flares up during mosquito season - summer and early fall. People typically develop symptoms between 3 and 14 days after being bitten by an infected mosquito, if they develop any symptoms at all. Most people who are infected with West Nile - approximately 80 percent - will not become ill. Up to 20 percent of the people who become infected will display mild symptoms, including fever, headache, and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms typically last a few days. About one in 150 people infected with WNV will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis, and often require hospitalization. These symptoms may last several weeks, and neurological effects may be permanent. People over the age of 50 are more likely to develop serious symptoms of WNV if they do get sick. Anyone who may be ill with WNV should see a doctor as soon as possible.

The best way to avoid West Nile virus is to prevent mosquito bites.

There is no specific treatment for WNV infection. In mild cases, people experience symptoms such as fever and aches that pass on their own. In more severe cases, people usually need to go to the hospital for treatment.

West Nile virus is fatal to several species of birds, including blue jays, crows, cardinals and raptors like hawks and owls. Since 1999, North Carolina and other states have tested dead birds and sentinel flocks of chickens to track WNV activity. By the end of 2002, WNV had been found in virtually every county in North Carolina. Extensive bird testing is no longer necessary, as it is clear that WNV is here to stay. However, the state still tracks reports of dead blue jays, crows, cardinals, hawks and owls to monitor virus activity. If you find a dead bird, don't handle the body with your bare hands. For directions and a reporting form, see Public Health Pest Management's reporting web page. You may also contact your local health department or local animal control office for instructions on reporting and disposing of the bird.

Brochures

• What is West Nile virus? (pdf)
• ¿Qué es el virus West Nile, conocido como Virus del Nilo Occidental? (pdf)
• Mosquito Problems Start at Home (pdf)
• Las problemas con los mosquitos empieza en casa (pdf)
• West Nile Virus FAQs (Frequently Asked Questions) (pdf)
• Recommendations for safe use of personal insect repellents

West Nile Response Plan and Procedures for North Carolina

• Response Plan (pdf)
• Attachments (pdf)

Press Releases

Related Links

• West Nile Virus Alert, NC Department of Agriculture and Consumer Services
• North Carolina Public Health Pest Management (Division of Environmental Health)
• Ways to Avoid West Nile Virus Risk in Outdoor Work, National Institute for Occupational Safety and Health (NIOSH)
• West Nile Virus information Centers for Disease Control and Prevention (CDC)
• West Nile Virus and Wild Game Hunters Centers for Disease Control and Prevention (CDC)
• WNV in horses and other equines: Veterinary Division Disease Alerts, N.C. Department of Agriculture and Consumer Services

*Some resources are in a pdf format to make reading and printing easier. You may need to download the free software Adobe Reader 9.0 (or higher) to access them.

Arbovirus Topics

• Arboviruses
• Eastern equine encephalitis (EEE)
• La Crosse encephalitis (LAC)
• Precautions for minimizing pesticide exposure during mosquito-control spraying
• Preventing Mosquito Bites
• Safe Use of DEET Insect Repellent (for Adults and Children)
• School Use of DEET Insect Repellent

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