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Bureau of Disease Control

West Nile Virus

What is West Nile Virus?

West Nile Virus is an illness that can cause encephalitis, an inflammation of the brain. It is a virus that is common in birds, humans and other animals in Africa, Eastern Europe, west Asia and the Middle East. It is very similar to St. Louis encephalitis, which is common in the United States and one that we have lived with for over 35 years.

What are the symptoms?

Most people infected with West Nile Virus have no symptoms of illness. In some people, about 25% of those infected may have a mild illness that includes fever, headache and body ache, sometimes accompanied by a rash or swollen lymph glands.

In less than 1% of the people infected, the severe form of encephalitis will be experienced. Symptoms of the encephalitis could include high fever, convulsions, stiff neck, tremors, headache, coma, stupor, disorientation, muscle weakness or paralysis. In a very few cases, mostly among the elderly, death may occur.

How is West Nile Virus treated?

There is no specific cure for West Nile Virus. In mild cases, you should use the same remedies you would for other virus, such as the flu: drink plenty of water, resting in bed, drinking plenty of fluids, and taking medication such as ibuprofen or acetaminophen to relieve fever and discomfort. In more severe cases treatment may include hospitalization, respiratory support and intravenous therapy.

Anyone experiencing severe or unusual headaches should see a doctor as soon as possible. Also, anyone who has been in an area where the virus has been identified and who experiences high fever, muscle weakness, confusion or severe headaches should see a doctor immediately.

How do people catch this disease?

West Nile encephalitis cannot be passed from person to person. The only way to get the virus is from the bite of an infected mosquito.

The virus actually starts with a bird, usually a crow. It spreads when a mosquito bites a bird that has the virus in their blood. The mosquito then can spread the virus to other birds, animals or people, when it bites during feeding. In areas where the virus has been identified, very few, much less than 1%, of the mosquitoes are infected.

How can we prevent this illness?

There are many things that you can do to help. Key is reducing the breeding grounds for mosquitoes. Be sure to empty any and all containers that hold standing water, and keep them emptied. You can reduce the possibility of this disease spreading even more by taking a few other simple steps:

  • Wear long sleeved shirts and long pants when you go outside
  • Stay inside at mosquito feeding time; dawn, dusk and early evening
  • Spray clothing with a mosquito repellant
  • Apply insect repellant to exposed skin
  • Report any dead birds you find.

The South Carolina Dept. of Health & Environmental Control, in conjunction with the Dept. of Natural Resources, county and local governments, conducts surveillance, tests mosquitoes for the infection, collects dead birds to be sent to the National Wildlife Center for testing, and monitors human illnesses. Mosquito control is key in reducing the impact of West Nile virus. In South Carolina mosquito control is a public service provided by local government mosquito abatement programs.