State regulators say half a dozen Illinoisans have developed a virus linked to rats at two Illinois rat farms.
The Illinois Department of Public Health reported Thursday that there have been six confirmed cases of Seoul virus in Illinoisans who had direct exposure to rats in two different Illinois ratteries, including one in east-central Illinois. Ratteries are facilities where rats are bred.
A rattery in Wisconsin purchased rats from the two Illinois ratteries, and two Wisconsin residents have also tested positive for Seoul virus. Results of laboratory testing of rats at these facilities are pending.
The agency said it is working closely with the Wisconsin Department of Health Services, the Centers for Disease Control and Prevention, and local health departments to investigate the source of the Seoul virus infections, coordinate testing and prevent possible future cases.
The IDPH has contacted both Illinois ratteries to identify people who may have been exposed and to follow up on any additional potential illnesses. The ratteries are located in northwest Illinois and east-central Illinois. An IDPH spokeswoman declined to further specify the location of the ratteries. Neither rattery was selling rats as of Thursday, the agency reported.
“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. “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.”
Seoul virus, a type of hantavirus, is carried only by brown or Norway rats. Other pets and animals cannot be infected. Only a few cases of Seoul virus have been reported in the U.S.
Symptoms may include fever, severe headache, back and abdominal pain, chills, blurred vision, redness of the eyes or rash. In severe cases, infection can also lead to acute renal disease. However, not all people infected with the virus experience symptoms. Five of the six Illinois cases showed no signs of illness.
As the investigation continues, more ratteries or people who have purchased rats at affected ratteries may be identified, the agency said. The agency asked that people take precautions to avoid becoming infected. The agency said anyone concerned about a recent rat purchase should make sure to follow good pet hygiene practices, and contact a local health department or health care provider if you recently purchased or handled rats from an Illinois rattery and are experiencing symptoms of Seoul virus.
As with other diseases carried by rodents, Seoul virus is transmitted to people from direct contact with rat urine or feces, contaminated materials like bedding, and possibly by aerosolized feces, urine or saliva. It can also be transmitted through a bite from an infected rat.