AVMS

WNV
 

What is West Nile virus (WNV)?  WNV is a virus that is spread by infected mosquitoes. The virus usually infects birds, but it can be spread to humans by mosquitoes that feed on infected birds and then bite humans. The virus is not known to be spread by person-to-person contact. Most people (over 80%) who are infected with WNV will have no symptoms or may have a mild flu-like illness with a fever, headache, and body aches before they recover. In some individuals (less than 1%), the virus can cause a serious illness called encephalitis, which is an inflammation of the brain. People with encephalitis are sick enough that they will seek medical care and be hospitalized. Symptoms of encephalitis may include high fever, severe headache, nausea, stiff neck, confusion, muscle weakness, paralysis, disorientation, convulsions, coma, and rarely, death. The virus was identified in the United States for the first time during 1999.

Is WNV in Alabama?  Yes. The presence of WNV in Alabama was confirmed on August 27, 2001 when it was detected in dead birds. Overall in 2001, WNV was diagnosed in two humans (one died), and detected in four horses and 59 birds. In 2002, WNV was diagnosed in 49 humans (three died), and detected in 194 horses, 597 birds, and 63 mosquito pools. In combination, the 2002 results showed that WNV was confirmed in all 67 Alabama counties last year, and it is expected that WNV will be found throughout the state in 2003.  For 2003, WNV has already been detected in humans, horses, birds, and mosquitoes.

How concerned should I be about WNV in Alabama?  The disease caused by WNV is very similar to the diseases caused by Eastern Equine Encephalitis (EEE), St. Louis Encephalitis (SLE), and La Crosse Encephalitis (LAC).  Like WNV, these diseases are also caused by mosquito transmitted viruses. Though rare, cases of EEE, SLE, and LAC illness have occurred among Alabamians for many years.  Alabamians should be concerned about being infected by WNV, EEE, SLE, and LAC, but remember that such infections are rare. Alabamians have dealt with EEE, SLE, and LAC for many years, and now our state is learning how to deal with WNV.  All mosquito borne diseases can be prevented by taking simple measures to avoid mosquito bites.

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2008 Alabama Vector Management Society
Last modified: 02/04/08