Thursday, September 9, 2004

Midsummer and early fall are beautiful times of year here in Pennsylvania. They are also the times for the presence of West Nile Virus in this area. West Nile virus is a mosquito-borne disease that can cause encephalitis, an inflammation of the brain. Human infection with the virus is usually through the bite of an infected mosquito.

In most areas where the virus is established, only 1% of the area's mosquitoes carry the virus. Most people who are infected with the West Nile virus will not have any symptoms of illness. It is estimated that 20% of those infected will develop symptoms, including fever, headache, body aches, rash, and swollen lymph glands. The symptoms will generally last a few days. There is no specific treatment and it cannot be spread from person to person. Only 1 in 150 persons infected with the virus will develop a more severe form of disease.

Those developing this severe form (symptoms include headache, high fever, neck stiffness, stupor, disorientation, coma, convulsions) will require hospitalization and intense treatment.

Prior to 1999, no West Nile virus cases had been reported in the United States. Since 2000 the number of both mild and severe cases reported has increased each year. In 2003 in Pennsylvania there were 247 human cases and 8 deaths reported. All residents of areas where virus activity has been noted are at risk of getting West Nile virus; however, persons over 50 years of age have the greatest risk.

You can protect yourself and reduce your risk of being bitten by mosquitoes by doing the following:

  • Wear shoes, sock, long pants and a long-sleeved shirt when outdoors for long periods of time, or when mosquitoes are most active.
  • Consider the use of mosquito repellent containing DEET.
  • Take extra care to use repellent and protective clothing or consider avoiding outdoor activities doing the peak mosquito hours from dawn to dusk.
  • Eliminate areas of standing water around your residence, thereby limiting the number of places for mosquitoes to breed.

For more information about West Nile virus visit the Pennsylvania West Nile Control Program website at