ASSISTANT DIRECTOR PENNSYLVANIA DEPARTMENT OF AGRICULTURE
In response to the recent finding of Seoul virus in domestic rats in several states, including Pennsylvania, we are providing practitioners with information about this zoonotic disease, including the attached Centers for Disease Control and Prevention (CDC) Health Advisory for Seoul Virus. The CDC provides FAQs about Seoul Virus and Guidelines for the Sanitary Management of Pet Rodents.
During early December 2016, a home-based rat breeder in Wisconsin developed an acute febrile illness. During late December 2016, CDC tested a blood specimen from the patient and confirmed that the infection was caused by Seoul virus, a member of the hantavirus family of rodent-borne viruses. A family member who worked with rodents also tested positive for Seoul virus. Both people have recovered. A follow-up investigation of rat breeders who supplied the initial patient's rats revealed six additional human cases of Seoul virus infections occurring at two Illinois rat-breeding facilities. Of the eight confirmed cases in Wisconsin and Illinois, two were hospitalized. Rats at these facilities have also tested positive for Seoul virus.
CDC and health officials from Wisconsin and Illinois are conducting an investigation of Seoul virus infections among pet rats and persons exposed to rats at rat-breeding facilities in Wisconsin and Illinois. Trace-back and trace-out investigations of possibly infected rodents have identified distribution chains in other states that may require additional investigation.
People who become infected with this virus often exhibit relatively mild or no symptoms, but some will develop a form of hemorrhagic fever with renal syndrome (HFRS) with death in approximately 1-2% of HFRS cases. Although serologic studies have indicated the presence of Seoul virus in wild rats in the United States, this is the first known outbreak associated with pet rats in the US.
Human and animal health officials are working together to identify the sources of infected rats, and to trace-out where potentially infected rodents may have been distributed. People at risk of Seoul virus infection due to exposure to infected rats are also being identified. To date, state health officials in Alabama, Arkansas, Colorado, Illinois, Indiana, Louisiana, Michigan, Minnesota, Pennsylvania, South Carolina, Tennessee, Utah, and Wisconsin have been notified that infected rats may have been moved into these states. Those receiving potentially infected rats will be contacted by the PA Department of Health, and should not distribute these rats further.
The Pennsylvania Department of Agriculture received word this week that a rattery in Lancaster County, PA had received rats from a Tennessee rattery in the recent past and this Tennessee rattery has since tested positive for Seoul Virus. The Lancaster County rattery voluntarily depopulated the remaining rats in their facility and the Bureau of Animal Health is in the process of tracking any rat movements from this rattery after the arrival of these rats from Tennessee. This information is being shared with the Pennsylvania Department of Health and they will be contacting the owners regarding questions concerning human exposure to rats from this premises. The Pennsylvania Department of Agriculture is working cooperatively with the Department of Health to get word out to owners of rats that originated from this Lancaster County rattery to ensure that owners receive pertinent human health information.
Practitioners who receive questions regarding rats purchased from Happy-Go-Ratty Rattery of Lancaster County should instruct clients to seek advice from the PA Department of Health. At the discretion of the owner and veterinarian the owner may opt to euthanize these rats or exposed rats due to the human health concerns associated with infected rats. Serological testing can confirm infection in rats, and testing is available at IDEXX reference laboratories. If the animals are test-positive or euthanized without testing, the owners should be encouraged to talk with the Department of Health at 877.724.3258 about appropriate precautions for their family.