Scientists identify more infections with classical Borna disease virus
Newly published study in „The Lancet Infectious Diseases“ provides insights into human infections with Borna Disease Virus (BoDV-1)
Insel Riems, 8 January 2020. The study published today in the renowned medical journal „The Lancet Infectious Diseases“ collects and characterizes known human infections with Borna Disease Virus (BoDV-1). So far, a total of 14 cases have been detected in Bavaria between 1996 und 2019.
For this study, research groups from the universities of Regensburg, Munich, Giessen, and Freiburg, the Bernhard Nocht Institute for Tropical Medicine in Hamburg and the FLI on the island of Riems worked together.
BoDV-1, which has long been known as the causative agent of Borna disease in horses, sheep and other mammals, was first identified as the cause of severe human encephalitis in 2018. Within the framework of the current study published by the FLI and the University of Regensburg, presence of the virus could be confirmed in current as well as in archived cases. The most recent known case occurred at the end of 2019.
The reservoir of the pathogen is the bicolored white-toothed shrew. According to the study, infection through contact with an infected bicolored white-toothed shrew or its excrements can be assumed in the majority of cases. However, the exact transmission route is still unknown. Natural human-to-human, horse-to-horse, or horse-to-human transmission can be ruled out according to current knowledge.
The results of the cooperating research groups and treating physicians in the surrounding hospitals in Bavaria make it clear that BoDV-1 is a virus with a very high death rate. However, the absolute number of infections and hence the risk of infection is estimated to be very low. An increase in the number of cases in recent years has not been observed. However, it is unclear whether there are more cases that have not yet been diagnosed.
In order to create a better data situation regarding the occurrence of human infections, compulsory notification of BoDV-1 infections will be introduced in March of this year in Germany.
„It is important that in particular unclear cases of encephalitis in regions where BoDV-1 occurs are investigated for presence of the virus“ says Prof. Dr. Martin Beer, head of the Institute of Diagnostic Virology of the FLI. In addition to fever and severe headaches, the disease manifests itself through severe neurological symptoms such as speech and gait disorders and leads to coma within days or a few weeks. The main risk areas are Bavaria, Thuringia, Saxony-Anhalt as well as parts of adjoining federal states.
A leaflet published by FLI, Bernhard Nocht Institute for Tropical Medicine, and Robert Koch Institute describes how infections can be prevented.
Within the framework of the consortium „ZooBoCo“ funded by the Federal Ministry of Education and Research with the associated project „Borna-Fokus-Bayern“, the disease is being further investigated and research is done in particular with the aim to identify transmission pathways and treatment options.
Prof. Dr. Martin Beer
The Lancet Infectious Diseases: Zoonotic spillover infections with Borna disease virus 1 leading to fatal human encephalitis, 1999–2019: an epidemiological investigation
https://www.rki.de/DE/Content/InfAZ/B/Bornavirus/Merkblatt.pdf?__blob=publicationFile Leaflet Prevention of infections (German language)