The Illinois Department of Public Health said it is investigating a potential case of hantavirus in an Illinois resident that they said is not linked to the deadly cruise ship outbreak.
Three people aboard the MV Hondius died from hantavirus, which is rare, and at least three more were sickened. A total of 16 American passengers are being monitored and quarantined in Nebraska after getting off the ship.
Illinois public health officials said the Centers for Disease Control and Prevention is doing additional testing to confirm the resident is positive for hantavirus, and it could take up to 10 days to get results.
IDPH said the patient is a resident of Winnebago County, close to the Rockford area, who had not traveled internationally and had not had any contact with any of the cruise ship passengers. They believe the patient contracted the virus in a home with rodent droppings and that it is the North American strain of hantavirus — not spread from person to person, unlike the Andes strain associated with the MV Hondius outbreak.
“It’s (spread) by breathing it in, it’s by inhaling it or by ingesting it,” said Dr. Michael Angarone with Northwestern Medicine.
Health officials also emphasized that the rodent species known to carry the Andes strain of the virus in South America isn’t found in the U.S.
IDPH, along with some Chicago-area doctors, said the risk of contracting any strain of hantavirus remains very low in Illinois.
What are the symptoms of hantavirus?
Common hantavirus symptoms include fever, muscle aches, stomach pain, and nausea.
“But then very quickly, after the symptoms set on, there is a dramatic respiratory component that is life-threatening,” said Dr. Mia Taormina, who is with Duly Health and Care.
She says incubation could last at least eight weeks. A patient may be put on a breathing machine, medications to reduce inflammation, or told to wait it out for weeks, even months.
Again, health officials say the chances of the virus popping up in Chicago are very low. Only seven cases have been confirmed since 1993. The last detected was in March 2025.
How can hantavirus be prevented?
As for prevention, doctors say if you are around rodent feces, keep a few precautions in mind.
“Some recommend either watering down the area before sweeping up, making sure it’s very well ventilated, wearing a mask or even eye covering just because all of that stuff is blowing around,” Dr. Angarone said.
Doctors say that while there are a lot of rats and mice in Chicago, hantavirus has not been detected in the city’s rodent population. About 95% of the North American strain tends to be west of the Mississippi River in places such as California, Arizona, and New Mexico.