A Winnebago County resident who potentially had a North American strain of hantavirus tested negative, according to the U.S. Centers for Disease Control and Prevention.

The CDC performed confirmatory testing, which did not detect hantavirus, the Illinois Department of Public Health said on Tuesday. Furthermore, the risk of getting hantavirus remains very low for Illinois residents, according to IDPH.

And the long-tailed pygmy rice rat, which is reputed to carry the Andes strain in South America, doesn’t live in the U.S.

The Winnebago County resident had not travelled internationally nor come into contact with anyone associated with the MV Hondius outbreak.

But the resident, whose symptoms were mild and did not require hospitalization, was suspected of contracting the North American strain while cleaning a home containing rodent droppings, according to IDPH.

During the investigation of the potential Winnebago County case, IDPH worked closely with local health departments – including the Winnebago County Health Department – and the CDC.

The Winnebago County resident received an antibody test, which is not considered definitive and requires a more sensitive test by the CDC.

Illinois has only had seven positive hantavirus cases from 1993 to March 2025.

The U.S. has recorded 890 cases of hantavirus from 1993 (the year surveillance began) to 2023.

Hantaviruses are a group of zoonotic viruses that infect rodents. The rodent transmits the virus to humans through their urine, droppings, saliva, or – less commonly – their bites, according to the World Health Organization.

Only the Andes strain – the one associated with the MV Hondius cruise ship – can be spread from person to person. The North American strain of the Hantavirus is not spread from person to person.

Symptoms begin one to eight weeks after exposure. They include abdominal pain, fever, headache, muscle aches, nausea and vomiting.

Unfortunately, hantaviruses found in North America – including the Andes virus – may rapidly progress to hantavirus cardiopulmonary syndrome and cause cough, shortness of breath, fluid in the lungs, and shock, according to WHO.

And although cardiopulmonary syndrome is rare, the fatality rate is up to 50%, according to WHO.

There is no vaccine to prevent hantavirus infection and no antiviral medication to treat it, so care is supportive, according to WHO.