Mosquitoes In Milwaukee County Test Positive For West Nile Virus

MILWAUKEE, WI — Health officials in Milwaukee are urging residents to protect themselves against mosquito bites after samples of the insects from the city and the north shore tested positive for West Nile virus.

Surveillance for the virus began in early July and this is the first detection, but no confirmed cases have been reported in humans so far in 2023, the City of Milwaukee Health Department said in a news release Tuesday. The virus can spread to humans and animals through a bite from a mosquito, which picks the virus up from birds, but it cannot be spread between people or animals, the health department said.

In a news release, the North Shore Health Department said mosquitoes tested in Milwaukee County at Jackson Park and in Glendale near Bender Road tested positive for the virus.

“Though there have not been any confirmed human cases of West Nile virus yet this year, the positive mosquitoes mean that Milwaukee residents need to be more vigilant in their personal protective measure to prevent bites,” said Milwaukee Health Commissioner Mike Totoraitis in a news release.

The majority of people who get infected by WNV, around 80 percent, do not get sick, the health department said. But others can experience mild symptoms ranging from fever, headache, muscle aches, rash and fatique, while less than 1 percent of people who are infected can get seriously sick with a high fever, weakness, stiff neck, confusion, tremors, paralysis and even coma, the health department said.

People who have compromised immune systems and older adults are at a higher risk of more severe symptoms, which can be fatal, so health officials are noting the importance of calling a healthcare provider if they suspect West Nile virus.

“Though there are no confirmed human cases of West Nile virus yet this year, the positive mosquitoes mean that residents of Milwaukee County should be more vigilant in efforts to prevent bites. The best prevention is not getting bit! Wear insect repellant, long sleeves and pants, and take steps to control mosquitos, like using screens in your windows and emptying items that have standing water (like bird baths and planters),” said North Shore Health Department Health Officer Becky Rowland in a news release.

The virus' spread in Wisconsin has been under monitoring since 2001 and an average of 17 cases are reported across the state yearly with infections most likely between August and September but also possible throughout much of summer and fall, the health department said.

Public health officials said the best way to avoid illness from mosquitos is to eliminate their breeding sites and reduce your exposure to them. Wisconsinites can expect mostquitoes to linger around, and continue to pose the risk of West Nile virus until a hard frost comes and drops temperatures below 28 degrees for at least four hours straight.

Here are some tips from the Department of Health Services to prevent mosquito bites:

• Avoid 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.
• Mosquito-Proof Your Home
  • 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.