(SPRINGFIELD) Six cases of Seoul virus in people who were directly exposed to rats were reported by the Illinois Department of Public Health on Thursday.

People were contracted the virus at two different Illinois facilities where rats are bred, according to a statement from IDPH. Two Wisconsin residents tested positive for the virus after a rattery in Wisconsin purchased rats from two Illinois ratteries.

Seoul virus is not transmitted from person to person and cannot infect other animals, IDPH said. Diseases that are carried by rodents can only be transferred from direct contact with rat urine or feces. It is a type of hantavirus carried by brown or Norway rats. Only a few cases of the virus have been reported in the U.S.

Symptoms of those infected may include fever, severe headache, back and abdominal pain, chills, blurred vision, redness of the eyes or rash, according to IDPH. Although, not all people infected show any signs of illness. Five of the six cases in Illinois did not experience symptoms.

“The general public is at an extremely low risk. Out of an abundance of caution, we want to let the public know in the event they have recently purchased rats from an affected facility and become ill,” IDPH Director Nirav D. Shah, M.D., J.D. said.

The rats at each facility were tested and those results were pending, IDPH said. Authorities are working to identify others who might be exposed and locate the source of the virus.