Health officials in the United States and Canada are trying to get to the bottom of recent outbreaks of Seoul virus, a potentially serious illness to humans that is transmitted by rats.
Both the Centers for Disease Control in the US and Ontario’s Ministry of Health and Long-Term Care are investigating cases, three of which have been identified in Ontario and 16 in the US.
In Kitchener, Ontario, one local rat-breeding operation has been closed due to the discovery that two humans connected to the business contracted Seoul virus, a form of hantavirus that is carried by Norway rats. Although the rats themselves are immune to it and show no symptoms, humans can contract the virus through exposure to rat bodily fluids, rat faeces, contaminated bedding or bites from infected rats.
Seoul virus typically presents as flu-like symptoms such as fever, headache, back and abdominal pain, chills and redness of the eyes. In rare cases, the virus can lead to acute renal disease and kidney failure. Yet, the health risk to the general population is said to be low as the virus does not spread from person-to-person.
“If people have a pet rat, or work in the rat industry and are concerned about their health, they really should be seeking medical attention,” said Brenda Miller, manager of health protection and investigation with the Region of Waterloo Public Health unit. “We don’t know there are not other cases out there, but we will know if people go to seek medical attention.”
As reported in the Waterloo Region Record, other rat breeders are taking steps to prevent the virus’ spread.
”It’s very serious … it spreads like wildfire. If one were to catch it, it would wipe out our entire colony,” said Chantal Warner, owner of Rattastic Ratteries in Kitchener. “They’d all have to be euthanized. That would kill our business.” Warner says that all of her animals have been tested for the virus and she advises anyone planning on buying a pet rat to make sure the rat comes from a reputable breeder whose rats have been cleared by a veterinarian.
In the US, the first two cases of Seoul virus were reported in December 2016 from two home-based rat breeders in the state of Wisconsin. Since then, 14 other cases have been confirmed across a total of 9 states, with rat facilities in 18 other states currently being investigated. So far, two people have been hospitalized in the US as a result of contracting the virus and none have died.
The World Health Organization reports that as there is presently no effective treatment for Seoul virus, prevention of infection is key. Worldwide, most cases of the disease have surfaced in Asia where about one-quarter of cases of hemorrhagic fever with renal syndrome are attributed to Seoul virus.
The human infections under investigation in Canada and the US are the first known cases in the two countries for the virus. An outbreak of Seoul virus had been previously reported in Europe.