West Nile Virus: 3 Deaths Reported in Wisconsin, Illinois, Health Officials Say

Mosquitoes in a container in a laboratory in Germany, which saw its first case of West Nile virus in 2019, in a 2019 file photograph. Steffen Kugler/Getty Images

Two people have died and another has been hospitalized in Wisconsin after contracting West Nile virus (WNV) illness, health officials have confirmed, just one day after a man died in Illinois from the same pathogen.

The Wisconsin Department of Health Services (DHS) confirmed the two deaths in the state in an Aug. 29 press release, noting that the three cases involved residents in Outagamie, Fond du Lac, and Brown counties.

Health officials did not release the identity of the individuals.

In addition to the human cases, the virus has also been detected this year in mosquitoes, animals, and healthy blood donors whose blood screened positive for WNV, the department said.

“DHS is saddened to hear about the deaths of Wisconsin residents from West Nile Virus,” DHS Bureau of Communicable Diseases Director Traci DeSalvo said. “Although people with weakened immune systems tend to be at greatest risk, severe West Nile virus can occur in people of all ages. It is important for all Wisconsinites to take steps to prevent mosquito bites when outdoors.”

According to the Wisconsin DHS, around 18 cases of WNV illness are reported in the state every year.

While transmission of the virus can occur any time that mosquitoes are active, most people with WNV typically become ill around August or September.

On Aug. 29, the Illinois Department of Public Health (IDPH) announced the first death of a resident this year from the virus.

According to IDPH, the individual was in their 80’s and lived in Lake County. They had an onset of symptoms of WNV in mid-August and died soon after.

Symptoms of West Nile Virus

The IDPH said there have been nine non-fatal cases of WNV confirmed to date this year, the majority of which were reported in Cook County, with others in DuPage, Will, Winnebago, and Tazewell counties.

“This death—and the six that occurred last year in Illinois—are a stark reminder that West Nile virus poses a serious risk, especially to older people and those with weakened immune systems,” IDPH Director Sameer Vohra said.

There is currently no vaccine or specific treatment for West Nile Virus, which is spread to humans, birds, and other animals through the bite of an infected mosquito.

While most people infected with WNV people do not develop any symptoms, some people may experience symptoms such as fever, headache, body aches, joint pains, vomiting, diarrhea, or a rash, according to the Centers for Disease Control and Prevention (CDC).

In more severe cases, infected individuals may develop a serious or fatal illness affecting the central nervous system such as encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes that surround the brain and spinal cord).

While the virus can infect people of all ages, those above the age of 60 and those with underlying health risks such as cancer, diabetes, hypertension, or kidney disease, are at a higher risk of severe disease, according to the CDC.

The health agency has recorded 289 West Nile Virus cases across 33 states so far in 2024. Approximately 195 of those cases have been neuroinvasive, meaning the virus infected the brain and nervous system.

In 2023, the CDC recorded 2,566 cases of WNV and 182 deaths from the virus.

In the wake of the deaths, health officials are urging Americans to take steps to protect themselves from mosquito bites, including reducing exposure, repelling insects with clothing and repellents, and rescheduling outdoor activities that occur in the evening or early morning, when mosquitoes that spread the virus are most active.

They are also encouraging Americans to report locations that are at high risk for producing mosquitoes.

The Associated Press contributed to this report.