First Human Case of West Nile Virus Disease in Dane County in 2006

August 31, 2006
Amanda Kita-Yarbro Communicable Disease Epidemiologist 294-5314 or 235-4067
Badger Prairie

A resident of Dane County has tested positive for West Nile virus (WNV) infection. This is the first case of WNV disease in Dane County in 2006. This individual was a male between the ages of 18 and 50. He had WNV encephalitis and is expected to fully recover from the disease. The individual most likely contracted the illness in Dane County, as he has not traveled outside the area for at least six months. There have been two other reports of human WNV disease in Wisconsin in 2006.
West Nile Virus is spread to humans through the bite of an infected mosquito. Mosquitoes acquire the virus by feeding on infected birds. Madison and Dane County residents are being reminded of steps they can take to lessen their chances of contracting West Nile Virus (WNV) by taking precautions to prevent bites and eliminate areas where mosquitoes can breed. The actions to take include:
Avoid mosquito bites:

• Maintain window screens in good repair to decrease indoor contact with mosquitoes.
• When outdoors, wear an effective mosquito repellant containing an active ingredient registered by the EPA, such as DEET, picaridin, or oil of lemon eucalyptus.
• When outdoors, wear light-colored protective clothing such as long pants and loose-fitting long-sleeved shirts, and tuck pants into socks.
• Avoid being outside during times of high mosquito activity, specifically around dawn and dusk.

Eliminate standing water:

• Clean out rain gutters to prevent water from collecting after a storm.
• Remove containers, old tires, and other objects that may collect water.
• Change the water in bird baths and wading pools every three to five days.

West Nile virus infections can range in severity from no symptoms to severe disease that can lead to death. Most people (80%) who become infected with WNV never have any symptoms. About 20% of people infected with WNV develop a mild illness called West Nile fever from which they recover in a few weeks. The most common symptoms of West Nile fever include fever, headache, and fatigue and some people have a rash or swollen lymph glands. Less than 1% of people infected with WNV develop more severe symptoms, which can include headache, high fever, stiff neck, disorientation, and paralysis. These forms of WNV disease can be fatal or have long lasting health effects. People who think they might have symptoms of WNV disease should call their health care providers.
In 2005, a total of 17 Wisconsin residents became ill from West Nile Virus. Two people who had the virus died, including a Madison resident. More information on WNV can be found on the Wisconsin Department of Health and Family Services wesite.
Public Health Madison and Dane County in cooperation with the Wisconsin Division of Public Health will continue surveillance for West Nile virus in until the end of the mosquito season. Madison and Dane County residents should report sick or dead crows and blue jays to the Dead Bird Hotline, 1-800-433-1610.