A team of German researchers identified eight cases of Borna virus (Bornaviridae family), a virus transmitted by shrews, in eight patients hospitalized between 1999 and 2019 for encephalitis. As reported in the study in The Lancet Infectious Diseases, these cases were all recorded in southern Germany. In particular, cases would have spread mainly among people in rural areas.
The virus is transmitted by the shrew (family of soricides), a rat-like mammal that is spread a little bit around the globe. It is considered one of the smallest mammals in existence. According to the researchers, these animals transmitted the virus to domestic cats, which in turn transmitted it to their owners or humans.
Symptoms of the infection include headaches, confusion, fever, convulsions and memory loss as well as, in the most serious cases, loss of consciousness. All eight patients examined by the researchers died between 16 and 57 days after admission.
This is precisely why the researchers believe that Borna virus infection should be considered a serious and potentially lethal disease for humans, as Barbara Schmidt of the University of Regensburg reports. Moreover, it is not known why, it seems to have gone completely unnoticed as far as infections in humans are concerned.
Although rare, this virus could still be the cause of unexplained cases of serious encephalitis, as Martin Beer of the Friedrich-Loeffler Institute, another author of the study, points out.