Wisconsin health officials announced Wednesday that a bird recently tested positive for West Nile virus in Dane County, the first to do so in Wisconsin this year.
In Michigan, West Nile activity was identified earlier this summer in Saginaw and Washtenaw counties.
Although very few mosquitoes actually carry West Nile virus, infected birds serve as an early warning by indicating the virus is present in the area and people should be more vigilant in protecting themselves against mosquito bites.
West Nile virus is spread to people and horses through the bite of an infected mosquito. People must be bitten by an infected mosquito in order to contract the virus. Mosquitoes become infected with West Nile virus by feeding on infected birds and then potentially transmit the virus by biting other animals or people.
The positive West Nile virus finding emphasizes the ongoing need to take precautions against mosquito bites. Follow these measures to help reduce exposure to mosquitoes and prevent West Nile virus infection:
- Limit time spent outside at dawn and dusk, when mosquitoes are most active.
- Apply insect repellant to clothing as well as exposed skin because mosquitoes may bite through clothing.
- Make sure window and door screens are in good repair to prevent mosquito entry.
- Properly dispose of items that hold water, such as tin cans, plastic containers, ceramic pots or discarded tires to prevent mosquito breeding. Turn over wheelbarrows, wading pools, boats and canoes when not in use.
- Clean roof gutters and downspouts for proper drainage.
- Change the water in birdbaths and pet dishes at least every three days.
- Clean and chlorinate swimming pools, outdoor saunas, and hot tubs; drain water from pool covers.
- Trim tall grass, weeds and vines because mosquitoes use these areas to rest during hot daylight hours.
- Landscape to prevent water from pooling in low-lying areas.
The chances of a person becoming infected with the West Nile virus are very low and most infected people will not have any symptoms. Those who do become ill typically develop a fever, headache, and rash that lasts a few days.
Symptoms may begin between three to 15 days after being bitten by an infected mosquito. Older adults and people with compromised immune systems are at an increased risk of severe disease from the virus and can develop neurologic illness such as meningitis, seizures, and paralysis.
There is no specific treatment for West Nile virus other than to treat symptoms. If you think you have a West Nile virus infection, contact your health care provider.
Horse owners should contact their veterinarian to get their horse vaccinated or if they suspect their horse is ill.
The Wisconsin Department of Health Services has monitored the spread of West Nile virus since 2001 among wild birds, horses, mosquitoes and people. In 2002, the state documented its first human infections, with 52 human cases. In 2011, three human cases of West Nile virus were reported throughout Wisconsin.
Last year, West Nile virus was responsible for 34 serious illnesses and two fatalities in Michigan. For up to date information about West Nile activity in Michigan, precaution and treatment information, or to report sick or dead birds, visit www.michigan.gov/westnile.