Bird Tests Positive for West Nile Virus in Dane County

Monday, June 20, 2016 - 11:43am

Take Measures to Prevent Mosquito Bites and Eliminate Breeding Sites

A bird found in Dane County has tested positive for West Nile virus.  This is the first bird that tested positive for West Nile virus in Wisconsin since surveillance for the mosquito-transmitted virus began May 1.  West Nile virus is spread to humans through the bite of an infected mosquito. Mosquitoes acquire the virus by feeding on infected birds.

“West Nile virus seems to be here to stay, so the best way to avoid the disease is to prevent mosquito bites and eliminate breeding grounds for mosquitoes,” says Janel Heinrich, Director of PHMDC (Public Health Madison and Dane County).

PHMDC recommends the following:

  • Limit time spent outside at dawn and dusk, when mosquitoes capable of transmitting West Nile virus are most active.
  • Apply insect repellant to clothing as well as exposed skin since mosquitoes may bite through clothing.
  • Make sure window and door screens are in good repair to prevent mosquito entry.

To help reduce potential breeding sites:

  • 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.

The majority of people (80%) who are infected with West Nile virus do not get sick. Those who do become ill usually experience mild symptoms such as fever, headache, muscle ache, rash, and fatigue. Less than 1% of people infected with the virus get seriously ill with symptoms that include high fever, muscle weakness, stiff neck, disorientation, tremors, confusion, paralysis, and coma. Older adults and those with compromised immune systems are at greater risk of developing central nervous system illness that can be fatal.

The Department of Health Services has monitored the spread of West Nile virus since 2001 among wild birds, horses, mosquitoes, and people. During 2015, seven cases of West Nile virus infection were reported among Wisconsin residents.

PHMDC continues to maintain partnerships with City of Madison agencies, six neighboring communities, and the University of Wisconsin to carry out mosquito larvae monitoring and control activities in the Madison metropolitan area. Additionally, new monitoring is underway to detect the presence of the mosquito species that transmits the Zika virus.
Last year, approximately 9% of the ditches and ponds monitored by PHMDC staff produced high numbers of the breed of mosquitoes capable of carrying West Nile virus.  These sites were treated with larvicide to prevent the larvae from becoming adult mosquitoes.

The Wisconsin Division of Public Health will continue surveillance for WNV until the end of the mosquito season. However, with the confirmation of the infected dead bird in Dane County, no further testing will be done here.  You can still report sightings of sick/dead birds to the Dead Bird Reporting Hotline at 1-800-433-1610.
For more information on West Nile virus

For a list of frequently asked questions on WNV




Health & Safety