Rats can also transmit hantavirus

Photo: csm/Charite

Infection by Asian virus type detected in Germany

Asia 728x90

A research group at Charité – Universitätsmedizin Berlin was the first in Germany to prove the transmission of a certain virus species – the Seoul virus – from an animal to humans. In cooperation with the Friedrich-Loeffler-Institute, the pathogen was detected in a young patient and her pet rat. This could have an impact on how wild and domestic rats are handled, as now described in the journal Emerging Infectious Diseases*.

After several outbreaks in the 21st century, hantavirus diseases are more in the public focus and have been subject to compulsory notification in Germany since 2001. Various mouse species can be used to transmit, for example, the Puumala and Dobrava-Belgrade viruses, which are widespread in Central Europe. These usually lead to febrile diseases, but in some cases also to HFRS syndrome, which is associated with fever, a drop in blood pressure and acute kidney failure. In contrast, the Seoul virus, which is mainly spread in Asia and which far more frequently leads to severe courses of disease, is found exclusively in rats. Transmission of the highly virulent Seoul virus from rats to humans has already been documented in several cases outside Asia.

The team around Prof. Dr. Jörg Hofmann, head of the National Conciliary Laboratory for Hantaviruses at the Institute of Virology of the Charité, has now been able to show for the first time a so-called autochthonous – i.e. acquired in Germany – infection by the Seoul virus, the origin of which was a rat. In close cooperation with the research group of Prof. Dr. Rainer G. Ulrich at the Friedrich-Loeffler-Institute (FLI) in Greifswald as well as local and regional health authorities, the researchers have detected the virus in a young female patient from Lower Saxony and one of her home rats. “This virus originally comes from Asia and probably arrived in Europe through infected wild rats on ships, but has never been observed in Germany before,” says Prof. Hofmann, first author of the study. The patient’s infected breeding rat was probably imported into Germany from another country.

The young patient had to receive intensive medical care for several days after she showed symptoms of acute kidney failure. Serological laboratory tests quickly confirmed the suspected hantavirus infection – but it was not clear what type of virus it was.

Prof. Hofmann’s team at the Charité developed a special molecular diagnostic technique that helped identify the Seoul virus in the patient. The experts at the Friedrich-Loeffler-Institute were able to detect the same virus in the affected pet rat using the test. Prof. Hofmann explains: “Both virus sequences, the patient’s, and the rat’s, were identical. This confirms a disease caused by transmission of the pathogen from animal to human – a so-called zoonosis”.

“Until now, hantavirus infections were only thought to occur in contact with mice. Now one must consider the possibility of infection even in contact with wild or domestic rats,” the authors warn. “Detection in a pet rat also means that the virus can be exported practically anywhere by selling these animals”. Caution is therefore required when keeping rats.

*Hofmann J et al Autochthonous ratborne Seoul virus infection in woman with acute kidney injury. Emerg Infect Dis (2020), DOI: 10.3201/oath2612.200708