MADISON, Wis. -

Despite the cold spring, public health officials are warning residents of the impending mosquito population that may be carrying West Nile virus.

An infected mosquito can transmit the disease to humans or other mammals by biting them, according to a Public Health of Madison and Dane County release. After humans are infected the disease cannot be transmitted person to person.

To reduce the impact of West Nile Virus, public health officials ask residents to try to prevent mosquito bites and to report any sick or dead blue jays or crows to the Dead Bird Hotline at 1-800-433-1610.

Tips to prevent mosquito bites

  • Limit time spent outside at dawn and dusk, when mosquitoes are most active.
  • Apply insect repellent to exposed skin, as well as clothing, 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 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.

Last year four cases of West Nile Virus were reported in Dane County during mosquito season, officials said. Twenty-three cases have been reported in Dane County since 2002.

Most people infected will not show symptoms, officials said. For those who do show symptoms, they may develop a fever, headache, rash, muscle and joint aches, nausea, vomiting and fatigue that can last a few days.

Officials encourage anyone who thinks they are infected with West Nile Virus to contact their health care provider.

PHMDC works with the city of Madison, six neighboring communities and the University of Wisconsin campus to implement mosquito larvae monitoring and control activities in the Madison area, according to the release. Last year almost 9 percent of the ditches and ponds monitored by PHMDC staff produced high numbers of West Nile Virus carrying mosquitoes and were treated to prevent them from becoming adult mosquitoes.