Several people in Wisconsin and Illinois have contracted a rare rodent virus.
The Wisconsin Department of Health Services made the announcement Thursday, saying the state's had two confirmed cases of the Seoul virus, which is a rare type of hantavirus carried by wild Norway rats across the world.
The people infected had been exposed to the rodents at a rat breeding facilities – or ratteries – in northeastern Wisconsin. Apparently the rattery owner purchased rats from two breeding facilities in Illinois.
Six people exposed to rats at the Illinois facilities have also been infected with the Seoul virus.
"Because rats from ratteries are sold to and swapped among individuals, we are working with local health departments and the Centers for Disease and Prevention to determine if there are additional cases," said State Health Officer Karen McKeown.
Two CDC epidemiologists arrived in Wisconsin to trace out clients who bought rats from or were exposed to the breeding facility.
None of the ratteries involved are currently selling rats.
About the Seoul virus
The Seoul virus is a rare form of of hantavirus – really, any form of hantavirus is pretty rare in the U.S.
Hantavirus is typically spread by rodents – however infected rats will likely look healthy. People can get sick having contact with, or being in close proximity to infected rodents, or their urine and droppings. You can also get it from being bit by an infected animal. It's not spread from person to person, though.
The U.S. had it's first known hantavirus outbreak in 1993, and several otherwise healthy people died from it. But that was a totally different form of the disease called Sin Nombre.
According to the CDC, the Seoul virus only has a 1 percent mortality rate, compared to the Sin Nombre virus' 50 percent.
The Wisconsin Department of Health Services says symptoms may include fever, chills, nausea, intense headaches, back and abdominal pain, chills, blurred vision, redness of the eyes, flushed face, or rash. In severe cases, infection can lead to renal disease. However, some people don't experience any symptoms.
Of the cases so far, one person in Wisconsin had to be hospitalized, but has since recovered. In Illinois, five of the six cases showed no signs of illness.
If you've had contact with rats recently obtained from a rat breeder and are experiencing any of these symptoms, call your doctor immediately.
Wisconsin health officials recommend practicing good hygiene with pets, like washing your hands after playing. You can get more tips here.