West Nile Virus

What is West Nile Virus?
West Nile virus is a virus that can infect humans, birds, horses and mosquitoes. Infection from this virus is most commonly found in Africa, West Asia and the Middle East. The virus spread to the United States in the summer of 1999, and has now been reported in 48 states.

Avoid Mosquito Bites to Avoid Infection. The best way to avoid infection with West Nile virus is to reduce the number of mosquitoes around your home and neighborhood.

The following are a few things you can do:

  • Apply insect repellent containing 20 to 30% DEET (N,N-diethyl-meta-toluamide) when you're outdoors. Apply it according to the directions on the label. Talk to your doctor before you use insect repellent on your child.
  • Consider staying indoors at dawn, dusk, and in the early evening, which are peak mosquito biting times. If you go outdoors at these times, wear shoes and socks, long pants and a long-sleeved shirt. Loose-fitting, light-colored clothing is best. Spray your clothing with repellent containing permethrin or DEET
  • Mosquito-Proof your home. Limit the number of places available for mosquitos to lay their eggs by eliminating standing water sources from around your home. Get rid of standing water in birdbaths, ponds, flowerpots, wading pools, old tires and other places where mosquitoes might breed. Garden supply stores carry products to keep mosquitoes from breeding in small ponds.
  • Install or repair screens, porch and patio screens.

Is there a vaccine for West Nile virus?

There is no vaccine to prevent West Nile virus in humans yet.

What are the symptoms of West Nile virus infection?

Most people who are infected with West Nile virus have no symptoms. Others may have only mild symptoms, which is called West Nile fever. Symptoms include:
  • Skin rash
  • Fever
  • Headache
  • Nausea
  • Vomiting
  • Diarrhea
  • Loss of appetite
  • Swollen lymph nodes (lymph glands)
  • An achy feeling in the back and muscles

Symptoms usually occur 3 to 14 days after a person is bitten by an infected mosquito and last for 3 to 6 days.

Symptoms of the more severe illness the West Nile virus include:

  • A sudden high fever (above 102°F)
  • Severe headache
  • Stiff neck
  • Feeling disorientated or confused
  • Tremors or muscle jerks
  • Seizures
  • Coma
  • Weakness or partial paralysis
These symptoms may last for several weeks. Contact your doctor if you have any of these symptoms and have recently been bitten by a mosquito.

Is there a treatment for West Nile virus infection?
There is no specific treatment for West Nile virus infection. People who experience mild symptoms usually get better without any medicine after a few days. People who have severe illness may be hospitalized and given intravenous (IV) fluids. They may need to be on a machine called a ventilator to help them breathe. Their doctor also will try to keep them from getting other infections, such as pneumonia.