WINNEBAGO COUNTY, ILLINOIS — An Illinois resident who was initially suspected of having hantavirus has tested negative for the rare rodent-borne illness, health officials said Monday.
Illinois Department of Public Health officials said the Winnebago County resident, who underwent additional testing last week, experienced mild symptoms following possible exposure to rodent droppings, according to the Chicago Sun-Times. The testing done by the Centers for Disease Control and Prevention ultimately did not detect hantavirus in the patient, health officials said Monday.
The Illinois Department of Public Health launched an investigation last week into the "potential" hantavirus case. At the time, health officials said the case was not connected to the recent outbreak on the MV Hondius cruise ship, IDPH said in a news release.
Health officials believed the resident may have contracted a North American strain of the virus while cleaning a home where rodent droppings were present. The resident's mild symptoms did not require hospitalization, health officials said last week.
The IDPH worked with the CDC to conduct the additional testing, which ultimately revealed the resident did not have hantavirus.
Health officials are closely monitoring concerns surrounding hantavirus after several passengers aboard a Dutch cruise ship in South America became ill with the rare rodent-borne disease. At least three people died in connection with the outbreak aboard the MV Hondius, prompting investigations into how passengers may have been exposed during the voyage.
Illinois has had seven positive cases of hantavirus since 1993, including one death in 1996. The most recent case in Illinois was in March 2025.
According to IDPH, the hantavirus strain most commonly seen in the U.S. is caused by exposure to rodent droppings and is not contagious from person to person.
Hantaviruses are a group of viruses found in wild rodents, according to IDPH. Humans can contract a hantavirus infection by breathing dust contaminated by the urine, saliva or feces of an infected rodent.
"Cases are most likely to occur in rural areas where the deer mouse, which appears to be the main source of the virus in the United States, primarily lives," according to information from IDPH. "Buildings, barns, garages, areas where rubbish or wood piles exist, or similar locations can serve as potential settings of Hantavirus infection if such sites are inhabited by infected rodents and conditions favorable for transmission (dry, dusty areas contaminated with rodent excreta) exist. Keeping homes and buildings rodent-free is a primary prevention measure against this group of viruses."
The Associated Press contributed to this article.
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