St. Croix County Public Health is encouraging residents to protect themselves from mosquito bites as they report this year’s first human infections of West Nile virus (WNV) in three residents of the county. Several other people with WNV have been reported in the state this year. WNV activity has also previously been detected in mosquitoes and animals across the state.

West Nile virus is spread to people through the bite of an infected mosquito and is not spread from person to person. Mosquitoes get the virus by feeding on infected birds.

According to the DHS, most people (80%) who are infected with WNV do not get sick. Those who do become ill usually experience mild symptoms such as fever, headache, muscle aches, rash, and fatigue. However, some people (less than 1%) who become infected with the virus get seriously ill with symptoms that include high fever, muscle weakness, stiff neck, disorientation, confusion, tremors, paralysis, and coma. Older adults and those with compromised immune systems are at greater risk of developing severe illnesses that can be fatal. It is important that people contact a health care provider if they suspect they have WNV illness.

WNV illness is most common in Wisconsin during the months of August and September. However, the risk of contracting WNV and other mosquito-borne illnesses such as Jamestown Canyon virus, La Crosse encephalitis virus, or eastern equine encephalitis virus, is present anytime mosquitoes are active. Mosquito activity and the risk of WNV will continue until a hard frost occurs (temperatures below 28 degrees Fahrenheit for at least four consecutive hours.)

The best way to avoid illnesses spread by mosquitoes is to reduce exposure to mosquitoes and eliminate mosquito breeding sites. DHS offers these tips to protect yourself and your family against mosquito bites:

• Apply an insect repellent with DEET, picaridin, oil of lemon eucalyptus, or IR3535 to exposed skin and clothing.
• Prior to heading outdoors, treat clothing with permethrin; do not apply permethrin directly to skin.
• Consider rescheduling outdoor activities that occur during evening or early morning hours, when mosquitoes that spread WNV are most active.
• Wear long sleeves, long pants, and socks when outdoors to help keep mosquitoes away from your skin.
• Prevent mosquitoes from breeding around your home by removing stagnant water from items around your property.
  • Empty standing water that has collected in tin cans, plastic containers, flower pots, discarded tires, roof gutters, and downspouts.
  • Turn over wheelbarrows, kiddie pools, buckets, and small boats such as canoes and kayaks when not in use.
  • Change the water in bird baths and pet dishes at least every three days.
  • Clean and chlorinate swimming pools, outdoor saunas, and hot tubs; drain water from pool covers.
• Make sure window and door screens are intact and tightly fitted to prevent mosquitoes from getting into your home.
• Trim or mow tall grass, weeds, and vines since mosquitoes use these areas to rest during hot daylight hours.

For continued monitoring of WNV activity in St. Croix County and the state, visit the Wisconsin Department of Health Services (DHS) West Nile Virus Data webpage.

Submitted by St. Croix County Public Health