The chances of a person contracting WNV are very low and most people infected with West Nile virus will not have any symptoms. Those who do become ill may 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. In rare cases, WNV can cause severe disease with symptoms such as muscle weakness, stiff neck, disorientation, tremors, convulsions, paralysis and coma. Older adults and people with compromised immune systems are at an increased risk of severe disease from the virus.
There is no specific treatment for West Nile virus other than to treat symptoms. If you think you have West Nile virus infection, contact your healthcare provider.
WNV is spread to people through the bite of an infected mosquito and is not transmitted person to person. Although few mosquitoes actually carry the virus, the Wisconsin Department of Health Services and your local health department recommend that you follow these tips to minimize your exposure and eliminate breeding grounds for mosquitoes:
- Limit time spent outside at dawn and dusk, when mosquitoes are most active.
- Apply an EPA-registered insect repellant to exposed skin and clothing since 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.
- Clean roof gutters and downspouts for proper drainage.
- Turn over wheelbarrows, wading pools, boats, and canoes when not in use.
- 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 since mosquitoes use these areas to rest during hot daylight hours.
- Landscape to prevent water from pooling in low-lying areas.
DHS has monitored the spread of West Nile virus since 2001 among wild birds, horses, mosquitoes, and people. During 2002, the state documented its first human infections and 52 cases were reported that year. During 2016, 13 cases of West Nile virus infection were reported among Wisconsin residents. West Nile virus infections in humans have been reported from June through October; however, most reported becoming ill with West Nile virus in August and September.