Health officials in northern Illinois said Tuesday they are investigating a potential hantavirus case in Winnebago County, where the person is recovering after a mild illness that did not require hospitalization. The person lives in the county and may have been exposed while cleaning a home where rodent droppings were present.
The case is not tied to the cruise ship outbreak that has drawn attention in recent days. The person has not traveled internationally and had no contact with anyone linked to that outbreak. The Centers for Disease Control and Prevention is testing to confirm whether the person contracted hantavirus, and results could take up to 10 days.
The Illinois Department of Public Health said the risk of contracting hantavirus of any kind remains very low for Illinois residents and said it was releasing the information proactively because interest in the virus has increased. On Monday, the department said it was not aware of any Illinois residents who had been on the cruise ship that experienced the outbreak.
That ship carried 18 passengers, and one had tested positive while another showed mild symptoms. The American passengers returned to the United States and were taken to medical facilities in Nebraska and Georgia. The outbreak involved the Andes strain of hantavirus, which the department said is different from the North American strains more commonly found in North America and not known to spread from person to person.
Hantavirus remains rare in Illinois and across the country. The United States recorded 890 cases from 1993 to 2023, while Illinois saw seven positive cases during that period. The most recent Illinois case was detected in March 2025. For the Winnebago County resident now under review, the question is not whether the virus is widespread, but whether this latest illness is in fact hantavirus at all.
