Chicago Reports Its First West Nile Virus Death for 2026

Authorities in Chicago this week announced the city and state’s first fatal case of West Nile virus this year.

The Chicago Department of Public Health said on Sept. 1 that two cases of West Nile virus and one death have been reported so far in 2026 in the city, while the Illinois Department of Health confirmed its first case in the state in August.

West Nile virus is commonly spread to people through infected mosquitoes, according to the Centers for Disease Control and Prevention. Infections are most often reported in the summer and fall—June through October.

Approximately 2,000 people are diagnosed with the virus each year in the United States, the agency said. However, that figure may be lower than the actual number because many people do not report significant symptoms.

In a statement, Chicago Department of Public Health Commissioner Garth Walker said “2026 has seen the rainiest summer in Chicago in years, giving mosquitoes ample opportunities to breed.” He added that the best way to avoid West Nile is to prevent mosquito bites and stop the insects from breeding around dwelling areas. Mosquitoes breed in stagnant water.

Officials urged Illinois residents to wear protective clothing, use insect repellent, and make sure screens are installed to keep mosquitoes away. They were asked to report the presence of pools of stagnant water.

“The year’s first death in Illinois related to West Nile virus is a sobering reminder to take mosquito-borne illness seriously,” said Illinois Health Department Director Dr. Sameer Vohra in a statement.

”While most people won’t experience serious symptoms, West Nile virus can lead to severe illness in high-risk groups such as older adults, individuals with chronic medical conditions, and immunocompromised persons.”

Recent data published by the CDC as of Sept. 1 show that 407 cases of the virus have been confirmed across the United States this year, with 40 states reporting at least one case. The most cases are located in the southern United States, namely Arizona, California, and Texas.

While most people who contract West Nile virus don’t develop any symptoms, the CDC said, those who do get symptoms generally see them start two to six days after being bitten by a mosquito infected with the virus, while in some cases it could take two to 14 days.

Around 1 in 5 people, or 20 percent, develop a fever and other symptoms after contracting West Nile, while a smaller number of individuals develop a severe and sometimes fatal illness, including encephalitis or meningitis, the CDC said. Some symptoms other than fever include a headache, body aches, joint pains, vomiting, diarrhea, or rash.

The health agency advises that anyone experiencing a stiff neck, high fever, confusion, tremors, or muscle weakness should seek immediate medical attention. There are no currently available medicines designed to treat West Nile.