In March 2024, a 44-year-old resident of central Germany was hospitalized with a high fever, severe fatigue, diarrhea, and acute kidney failure. She required temporary dialysis therapy, but ultimately made a full recovery.

Laboratory tests revealed that the cause of her illness was the Seoul virus — a subtype of hantavirus that, according to researchers, she most likely contracted during a visit to a private breeding facility for pet rats several weeks before the onset of symptoms.

The report on this rare virus was published in the journal Emerging Infectious Diseases.

A joint investigation conducted by local health authorities, the Friedrich-Loeffler-Institut (FLI) and the Bernhard Nocht Institute for Tropical Medicine (BNITM) found that several rats from this breeding facility tested positive for the virus. Genetic analysis showed a high degree of similarity between the viral sequences found in the animals and in the patient. Although the Seoul virus is present worldwide, human infections in Germany have been extremely rare until now.

The primary transmission route is inhalation of tiny particles contaminated with the urine, feces, or saliva of infected rats. Human-to-human transmission has not been documented.

“Many people are unaware that pet rats can carry pathogens capable of causing serious disease,” noted Professor Rainer Ulrich.

He stresses that responsible pet ownership and good hygiene are essential for preventing new cases.

Meanwhile, Mario Hönnemann, a microbiology specialist at the Institute of Infection Epidemiology, pointed out that cooperation between medical and veterinary services played a key role in uncovering the circumstances of this case.