Seoul Hantavirus and Pet Rats in the Pacific Northwest

Summary (the tl;dr version):

• Seoul hantavirus is a zoonotic virus that is transferrable to humans from pet rats; humans sometimes get sick, rats don't

• The CDC is currently investigating cases of it in humans in other parts of the US but NOT in the Pacific Northwest

• Seoul hantavirus is MUCH milder than Sin Nombre hantavirus, which is the deadly one caught from wild mice

• Testing at this time would have to be privately done and is prohibitively expensive in this area for an accurate assay

• It is highly unlikely this rattery or others we work with has been exposed to the virus via any ratteries being investigated

• If you have concerns, read this article and the links below to help yourself make good choices about adopting rats

The Longer, More Informational Version With Links

As you may have seen on the news, there has been an outbreak of Seoul hantavirus linked to pet rats sold from a couple of breeding facilities in Illinois and Wisconsin that began last December. The CDC (Center for Disease Control) has been investigating the outbreak and has traced some infected rats and people to 9 other states. 18 states in total have been investigated. There has been NO investigation or link to WA, OR, ID or BC at this time.  States with ratteries currently under investigation include AL, CO, DE, GA, IL, IA, LA, MD, MI, MN, MO, ND, NJ, PA, SC, TN, UT, WI. The current number of laboratory confirmed cases of Seoul hantavirus in humans is 16 and, of those, only two showed symptoms and were hospitalized. Both have since recovered.

Seoul hantavirus is carried by rattus rattus, the black or roof rat, and by rattus Norvegicus, the brown or Norway rat, which is the species our domestic pet rats are derived from. Rats show NO sign of illness and only carry the disease, which they can transfer between themselves and other rats or to humans. Humans can show signs of illness, though in many cases, an infected person will show no or very mild symptoms that they attribute to a cold or flu virus. In rare cases, Seoul hantavirus can result in kidney failure, particularly if a person who already has a compromised immune system or kidney issues, contracts it. There are no specific treatments for the virus in infected individuals, only supportive care, and there is currently no vaccine available for the disease. Seoul hantavirus is not to be confused with the much more deadly Sin Nombre hantavirus, which causes severe illness and even death in many people who come in contact with it. Pet rats cannot carry Sin Nombre – it is found only in wild mouse species. Seoul hantavirus is endemic throughout many parts of Asia and cases of it have been seen across the world. This is the first instance of it being found in pet rats in North America, though it has been previously found in wild populations on the continent.

It is currently thought that rats can shed Seoul hantavirus their entire lives, going in and out of cycles of infectiousness. Humans, once infected, cannot transmit the virus to other humans. The virus is shed through urine, feces and other bodily fluids. The CDC and the state/provincial health departments in the Pacific Northwest - WA, OR, ID and BC - are not currently providing testing for our area nor are they recommending that pet owners test unless they suspect they have had contact with a rattery currently under investigation. It is possible to privately test via an independent laboratory such as IDEXX. However, to test the number of rats necessary to get an accurate assessment of our status, we'd need to spend hundreds of dollars to go through our vet and get blood samples taken and sent to the lab. Even then, unless every single rat in our rattery was tested, we could never 100% say that we were free of the virus as it seems that it doesn't spread with extreme ease, even inside a closed rattery.  Our rattery has had no rats in from any facilities currently under investigation. We also work solely with a closed circle of other ratteries in our area that only trade among ourselves, thus limiting our exposure to potential diseases and keeping close track of genetic health of our various lines while also making it easier for us to keep a good level of genetic diversity in our population.

With all this in mind, we’ve decided to continue with our breeding plans this year and with placing rats in pet homes. Should any cases be investigated in our state or among ratteries we do work with, that will change and we will temporarily cease placement until we are certain we’re not exposing anyone to potential issues. Our regular quarantine procedures will continue to be in effect as always as we still need to guard against viruses that can harm rats like SDA and Sendai. We will have the most up to date information posted on this site about zoonotic diseases (diseases that can be passed between animals and humans) letting potential adopters know that it’s a possibility, however remote, and allowing them to make their own good choices. We also stress that good sanitation is SO important when dealing with cage cleaning and keeping rats off of surfaces where food prep happens. It’s also strongly suggested that people wash their hands and, especially, get children in the habit of handwashing, after handling their pets of all kinds. It is also recommended by the CDC that people not kiss or closely cuddle their rats, but realistically, just use your best judgment on that. Remember that many animals can put humans at risk for illness besides rats – cats, dogs, birds and lizards all have their special issues – but that we all have to make our own cost/benefit risk analyses. Currently, the risk of pet rats in the Pacific Northwest having Seoul hantavirus appears to be low but there are no guarantees that it is zero. It’s up to us as rat fanciers to educate ourselves and make the best choices we can for our safety and our pets’ safety.
Here are a list of reliable informational links. The AFRMA page has a ton of articles from many sources and currently has the most up to date collection of information as it is published online.  The CDC posts regular updates, and has a very good FAQ about Seoul hantavirus and how to deal with it. There is, unfortunately, a lot of panic and misinformation out there on the internet, so keeping abreast of official information about the outbreak is really crucial to making good choices and staying calm. A similar situation to this one occurred a couple years ago in the UK and their rat fancy got through it with minimal problems and is back to regular shows and events. We are all hoping to follow their “keep calm and carry on” example here in the Northwest.

AFRMA Links (kept really up to date):
CDC Info on Hantavirus and their investigation:
Washington State Veterinary Medical Association link: