Scientists have reported the first case of a hantavirus — also known as the ”Seoul virus” — being transmitted from an animal to a human in Germany after a young woman contracted a hantavirus infection from her pet rat.
However, there’s no need to panic. Reports about unusual viruses jumping from animals to humans are likely to push a few hot buttons given the current Covid-19 pandemic, but this case is extremely unlikely to signify a major risk to global health.
Hantaviruses are a family of rodent-borne viruses that have caused minor disease outbreaks before, most notably in Asia where the virus is thought to have originated. There have also been cases in the US, such as the outbreak of hantavirus at Yosemite National Park in 2012. Between 1993 and 2017, there were 728 cases of hantavirus disease in the US, according to the Centers for Disease Control and Prevention (CDC). However, this is the first time the viral infection has been seen in Germany. As such, they suspect that the infected rat, which had been bred for the pet trade, was imported from a different country.
“The virus originally comes from Asia and was probably carried to Europe by wild rats on ships. However, it had not previously been observed in Germany," Professor Dr Jörg Hofmann, first study author and head of the National Consultant Laboratory for Hantaviruses at Charité's Institute of Virology, said in a statement.
"Until now, only contact with mice would result in a suspected diagnosis of hantavirus infection. It will now be necessary to consider the possibility of infection after contact with either wild or domesticated rats as well," added the study's authors. "The fact that this pathogen has been confirmed in a pet rat also means that the virus is capable of being exported, via the trade in these animals, practically anywhere in the world."
As reported in the journal Emerging Infectious Diseases, researchers from Charité – Universitätsmedizin Berlin in Germany explained that the 18-year-old patient required intensive care treatment after developing symptoms of acute kidney failure. The cause of the illness was initially unclear, but blood tests later confirmed a suspected diagnosis of hantavirus infection. Genetic analysis of the virus revealed it was an orthohantavirus, although the species remained uncertain. This analysis also affirmed the suspicion that the woman’s infection came from her pet rat.
"Both viral sequences — the patient's and the rat's — were identical. This confirms that the disease was transmitted by an animal to a person, which means it is a zoonotic disease,” added Professor Hofmann.
Fortunately, although there are rare cases of person-to-person transmission, it appears that hantaviruses rarely spread from one person to another.