First bird in Wisconsin tests positive for West Nile virus
State and county health officials announced that a dead crow found in Washington County has tested positive for West Nile virus. This is the first bird to test positive for the virus in Wisconsin this year.
Although very few mosquitoes actually carry West Nile virus, infected birds serve as an early warning that the virus is present in the area and that people should be more vigilant in protecting themselves against mosquito bites.
West Nile virus is spread to people through the bite of an infected mosquito. 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 Department of Health Services 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 2012, 57 cases of West Nile virus infection were reported among Wisconsin residents, the highest annual number of cases reported since surveillance began in Wisconsin.
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.
Measures to help decrease exposure to mosquitoes and prevent West Nile virus and other mosquito-borne infections include:
• Limit time spent outside at dawn and dusk, when mosquitoes are most active.
• Apply insect repellent to clothing as well as exposed skin.
• Make sure window and door screens are in good repair to prevent mosquito entry.
• Reduce mosquito breeding sites by properly disposing 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 so they will not collect water.
• 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.
The chances of a person becoming infected with the West Nile virus are 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.
Neurologic problems may occur in a small percentage of infected people. Symptoms may begin between three-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.
There is no specific medication for West Nile virus other than supportive treatment to help alleviate symptoms.
Statewide surveillance activities for West Nile virus began on May 1. People who find a dead bird in their yard or who have a question about a dead bird should call the Dead Bird Reporting Hotline at 1-800-433-1610.
People should not handle dead birds with their bare hands but should use gloves or a clean plastic bag to pick up the bird through the bag. Horse owners should contact their veterinarian to get their horse vaccinated or if they suspect their horse is ill with West Nile virus infection.
For more information on West Nile virus, go to