With the H7N9 and HPAI H5 stories capturing most of my attention the past few days I haven't taken the time to write about an outbreak - reported late last week by the CDC - of the Seoul virus among pet rats (and a number people exposed to them) in the upper Midwest.
While North American wild brown or Norway rats are known to harbor this type of hantavirus, this is the first known outbreak of human cases in the United States.
Like the majority of emerging infectious diseases, Hantavirus is a zoonotic disease; one that can be transmitted between (or are shared by) animals and humans.
The clinical symptoms of Hantavirus were first recognized by western medicine back in the early 1950s during the Korean war, when 3,000 UN troops stationed there were infected with a mysterious viral illness. The mortality rate was 10%-15%, with patients experiencing fever, hypotension, renal failure, and internal bleeding (disseminated intravascular coagulation).
Originally called Korean Hemorrhagic Fever, this condition is now known as Hemorrhagic Fever with Renal Syndrome (HFRS). Although it was suspected that rodents were the main epidemiological vector, the pathogen responsible wasn’t isolated until the 1970s.Scientists have since identified dozens of viruses within the genus Hantavirus (named after the Hantaan River of Korea) from all around the world, with mortality that varies from 1%-2% for some varieties (i.e. Seoul Virus, Puumala Virus) to more than 30% for the North American Sin Nombre and South American Andes Virus.
Today, as the investigation into potential chains of exposure to these rats continues, the CDC has published a HAN Advisory, in part to alert medical professionals to be alert to the possibility of seeing cases, and to alert the public as well.
I've only posted some excerpts, so follow the link to read it in its entirety.
Distributed via the CDC Health Alert Network
January 24, 2017, 14:00 ET (2:00 PM ET)
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. Seoul virus is a member of the hantavirus group of rodent-borne viruses. Trace-back and trace-out investigations of possibly infected rodents have identified distribution chains in other states that may require additional investigations. 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 United States.
- As part of the outbreak investigation, CDC and Illinois and Wisconsin health officials are conducting trace-back and trace-out investigations to determine where rodents from confirmed-positive facilities may have been distributed.
- CDC currently recommends testing of all persons who report recent or current illness after (1) handling rats from a facility with Seoul virus infection that was confirmed by laboratory testing (either rat or human), or (2) handling rats from a facility that sold rats to a facility with Seoul virus infection. Testing is also offered to persons without illness but (1) who are reporting exposure to rats from a facility with Seoul virus infection that was confirmed by laboratory testing, or (2) who are reporting exposure to rats from a facility that sold rats to a facility with Seoul virus infection but where no illness has been reported.
- In general, CDC recommends consideration of hantavirus testing in all persons with symptoms of Seoul virus infection and rat contact, even if the rat was not associated with a facility where a confirmed infection in a rat or human was reported.
- In the United States, hantavirus infections in people are notifiable conditions. Healthcare providers who suspect hantavirus infection in a patient should contact their state or local health department.
For More Information:
- CDC currently recommends laboratory testing for all persons who report recent or current illness after (1) handling rats from a facility with Seoul virus infection that was confirmed by laboratory testing (either rat or human), or (2) handling rats from a facility that sold rats to a facility with Seoul virus infection. Testing is also offered to persons with exposure to rats from a facility with Seoul virus infection that was confirmed by laboratory testing, or to persons with exposure to rats from a facility that sold rats to a facility with Seoul virus infection but where no illness was reported. All testing should be coordinated with the healthcare provider’s local or state health department.
- Persons with potentially infected rats should not sell, trade, or release their rats. They should contact their state health department with any questions. Healthcare providers should emphasize the importance of safe animal practices with their patients (https://www.cdc.gov/healthypets/pets/small-mammals/petrodents.html).
- Health care providers may also consider laboratory testing of patients with symptoms suggestive of Seoul virus infection and a history of rat contact, regardless of whether there is known interaction with rats or rat facilities with laboratory confirmed Seoul virus infections.
- As with all human hantavirus infections, Seoul virus infection is a notifiable disease. Healthcare providers who suspect Seoul virus infection in a patient should report it to their local health department.
- For laboratory testing inquiries, healthcare providers should contact their state or local health department. Prior approval is required by the state health department.
CDC Seoul virus FAQs: https://www.cdc.gov/hantavirus/outbreaks/seoul-virus/faqs.html
CDC healthy pets website: https://www.cdc.gov/healthypets/pets/small-mammals/petrodents.html