The U.S. Centers for Disease Control and Prevention said on Friday that the outbreak of Seoul virus infection in Illinois and Wisconsin, which has so far affected eight individuals, was caused by pet rats.
First Known Seoul Virus Outbreak In U.S Linked To Pet Rats
Previous outbreaks of the disease in the United States occurred in wild rats but the newly identified cases are the first known in the country that have been linked to pet rats.
Veterinarian Jennifer McQuiston of CDC's Division Of High Consequence Pathogens and Pathology, however, said that a similar outbreak related to pet rats has also been reported previously in Europe so this is not the first to be associated with pets worldwide.
McQuiston said that people who have purchased rats in affected areas and observed symptoms of the virus need to contact their healthcare provider.
The first identified patient in the current outbreak visited a hospital suffering from flu-like symptoms. Because the patient, a resident of Wisconsin, was a home-based rodent breeder, the doctor decided to test for hantavirus, which is often carried by rodents.
Following the result in late December which revealed the patient was positive of hantavirus, health officials in Wisconsin sent CDC a sample from the patient along with another sample from the patient's family member who also worked with rodents.
Symptoms Of Seoul Virus Infection
On Jan. 11, CDC confirmed that both patients were infected with Seoul virus, a rodent-borne hantavirus characterized by fever, chills, nausea, abdominal pain, and pink eye-type infection.
The symptoms of Seoul virus, which is carried by wild Norway rats worldwide, typically develop one to two weeks after contact but may take as long as eight weeks to emerge. Most people who get infected with the virus recover but in rare cases, a simple infection can lead to hantavirus pulmonary syndrome, which starts off with fever, fatigue and severe aches but may turn fatal.
Eight Individuals Positive For Seoul Virus
Both of the patients in Wisconsin recovered but the discovery of their illness prompted follow-up investigations at several rat suppliers leading to the identification of six other cases among those working at two breeding facilities in Illinois.
Of the six who tested positive, only one experienced illness. The five other did not show symptoms of the virus, which cannot be transmitted among people regardless if there are symptoms or none. People typically get infected when they come in contact with infected blood, urine, and saliva of infected rats or get bitten by them. The infected rats often do not appear sick.
More Cases Expected To Be Identified As Investigation Continues
Public health authorities expect to identify more ratteries and more infected individuals as the investigation progresses.
"CDC has deployed two epidemiologists to work with local and state health authorities to determine if any customers who bought rats have become ill," CDC said in a statement. "Human and animal health officials are working together to make sure infected rats are not distributed further."
