An outbreak of rat virus has been linked to facilities in two states in the U.S., and it’s the first outbreak of this virus linked to pet rates in the States. A total of eight people have gotten sick in Illinois and Wisconsin, and public health officials believe that all of them got sick because they worked at ratteries in those states.

Health officials were tipped off to the virus’ presence when two people in Wisconsin who worked at a facility for the breeding of rats got sick in December, requiring hospitalization for one of thing. Tests turned up positive for the Seoul virus, which is found in rodents. Health officials then found six people who worked at rat-breeding facilities in Illinois who were also infected.

The virus is found in the Norway or brown rat, found around the world. It’s rare for people to catch the virus from rats, and when it does it usually happens in Asia.

“Seoul virus is not known to be transmitted from person to person. Therefore, the general public is at extremely low risk,” said IDPH Director Nirav D. Shah, M.D., J.D. “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.”