Today, Dr. David Williams, Ontario's Chief Medical Officer of Health, issued a statement following the identification of three human cases of Seoul virus infection linked to rat exposure in Ontario:
"The Ministry of Health and Long-Term Care, in collaboration with public and animal health partners at a variety of government levels, are investigating three human cases of Seoul virus infection in Ontario. All three individuals had prolonged contact with rats. No serious health outcomes have been reported for the cases.
The ministry and its partners are investigating the source of the illnesses including links to a multi-state investigation in the United States involving ratteries. As of February 24, 2017, the Center for Disease Control and Prevention is investigating a similar Seoul virus outbreak associated with rat exposure that involves 16 positive human cases and ratteries located in 15 states.
To date, laboratory testing of rats from some Ontario ratteries have identified positive results for Seoul virus. Further testing of rats is ongoing.
Seoul virus is a type of hantavirus that can be transmitted from rats to people through bite wounds or exposure to urine, feces, saliva or contaminated bedding.
The health risk to Ontarians is considered low and Seoul virus is not spread from person to person.
However, people who come in contact with rats and materials contaminated with urine, droppings or saliva should educate themselves about potential diseases they could be in contact with, including Seoul virus, and take the appropriate precautions.
A person that is infected with Seoul virus may not develop symptoms or will only develop very mild symptoms. However, in some instances, more severe symptoms may include fever, severe headache, back and abdominal pain, chills, blurred vision, redness of the eyes, or rash.
The majority of cases recover with no long-term health effects. In rare cases, infection can lead to a type of acute renal disease called Hemorrhagic Fever with Renal Syndrome (HFRS), which might include low blood pressure, shock, and acute kidney failure.
People who have had prolonged exposure to rats and are concerned that they may be infected with Seoul virus are advised to contact their health care provider. Further information on Seoul virus can be found at Public Health Ontario (PHO)'s website, including lab testing criteria.
Rats do not show symptoms of disease when they are infected with Seoul virus.
People who are concerned that their pet rat may be infected should consult with their veterinarian who can offer advice and possible testing for Seoul virus infection through a commercial laboratory.Owners of rat breeding facilities in Ontario who have sent rats to or received rats from facilities involved in the investigation may be offered testing by the Public Health Agency of Canada (PHAC) to determine if they and/or their rats have been exposed to Seoul virus.
Rats infected with Seoul virus can continue to shed virus throughout their lives, and therefore pose an ongoing risk to humans and other rats they contact. There is no way to treat them for their infection.
The ministry will continue to work collaboratively with public health units, PHO, the Ontario Ministry of Agriculture, Food and Rural Affairs, PHAC, and key stakeholders to investigate and mitigate the risk from Seoul virus infections in the province."