Three cases of Seoul virus have been confirmed in Ontario recently, and two of them come from Waterloo Region.

Seoul virus is mostly known to infect rats. While it can be transmitted from rats to humans in certain circumstances, it cannot be transmitted from humans to other humans.

“You have to have contact with a rat, and you have to have contact with its urine or feces or droppings,” says Brenda Miller, Region of Waterloo Public Health’s manager of health protection investigation.

An investigation into Seoul virus began in the United States in late 2016. That investigation was traced back to multiple Ontario rat farms, including one in Waterloo Region.

Miller says two people at that rattery have tested positive for the virus.

Many people who contract Seoul virus never show any symptoms. Those who do show symptoms may experience fever, headaches, or pain in their neck, back and/or abdomen.

With reporting by Marc Venema