Investigation of fatal human Borna disease virus 1 encephalitis outside the previously known area for human cases, Brandenburg, Germany – a case report
Dennis Tappe, Kirsten Pörtner, Christina Frank, Hendrik Wilking, Arnt Ebinger, Christiane Herden, Christoph Schulze, Birgit Muntau, Petra Eggert, Petra Allartz, Gerlind Schuldt, Jonas Schmidt‐Chanasit, Martin Beer, Dennis Rubbenstroth
Abstract
BACKGROUND: The true burden and geographical distribution of human Borna disease virus 1 (BoDV-1) encephalitis is unknown. All detected cases so far have been recorded in Bavaria, southern Germany. CASE PRESENTATION: A retrospective laboratory and epidemiological investigation of a 2017 case of fatal encephalitis in a farmer in Brandenburg, northeast Germany, demonstrated BoDV-1 as causative agent by polymerase chain reaction, immunohistochemistry and in situ hybridization. Next-generation sequencing showed that the virus belonged to a cluster not known to be endemic in Brandenburg. The investigation was triggered by a recent outbreak of animal Borna disease in the region. Multiple possible exposures were identified. The next-of-kin were seronegative. CONCLUSIONS: The investigation highlights clinical awareness for human BoDV-1 encephalitis which should be extended to all areas endemic for animal Borna disease. All previously diagnosed human cases had occurred > 350 km further south. Further testing of shrews and livestock with Borna disease may show whether this BoDV-1 cluster is additionally endemic in the northwest of Brandenburg.