Emerging Infectious Diseases (May 2021)

Active Case Finding of Current Bornavirus Infections in Human Encephalitis Cases of Unknown Etiology, Germany, 2018–2020

  • Philip Eisermann,
  • Dennis Rubbenstroth,
  • Daniel Cadar,
  • Corinna Thomé-Bolduan,
  • Petra Eggert,
  • Alexander Schlaphof,
  • Frank Leypoldt,
  • Martin Stangel,
  • Thorsten Fortwängler,
  • Florian Hoffmann,
  • Andreas Osterman,
  • Sabine Zange,
  • Hans-Helmut Niller,
  • Klemens Angstwurm,
  • Kirsten Pörtner,
  • Christina Frank,
  • Hendrik Wilking,
  • Martin Beer,
  • Jonas Schmidt-Chanasit,
  • Dennis Tappe

DOI
https://doi.org/10.3201/eid2705.204490
Journal volume & issue
Vol. 27, no. 5
pp. 1371 – 1379

Abstract

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Human bornavirus encephalitis is a severe and often fatal infection caused by variegated squirrel bornavirus 1 (VSBV-1) and Borna disease virus 1 (BoDV-1). We conducted a prospective study of bornavirus etiology of encephalitis cases in Germany during 2018–2020 by using a serologic testing scheme applied along proposed graded case definitions for VSBV-1, BoDV-1, and unspecified bornavirus encephalitis. Of 103 encephalitis cases of unknown etiology, 4 bornavirus infections were detected serologically. One chronic case was caused by VSBV-1 after occupational-related contact of a person with exotic squirrels, and 3 acute cases were caused by BoDV-1 in virus-endemic areas. All 4 case-patients died. Bornavirus etiology could be confirmed by molecular methods. Serologic testing for these cases was virus specific, discriminatory, and a practical diagnostic option for living patients if no brain tissue samples are available. This testing should be guided by clinical and epidemiologic suspicions, such as residence in virus-endemic areas and animal exposure.

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