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Volume 27, Number 5—May 2021
Research

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

Philip Eisermann1, Dennis Rubbenstroth1, 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, and Dennis TappeComments to Author 
Author affiliations: Bernhard-Nocht-Institut für Tropenmedizin, Hamburg, Germany (P. Eisermann, D. Cadar, C. Thomé-Bolduan, P. Eggert, A. Schlaphof, J. Schmidt-Chanasit, D. Tappe); Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany (D. Rubbenstroth, M. Beer); University Medical Center Schleswig-Holstein, Kiel, Germany (F. Leypoldt); Medizinische Hochschule Hannover, Hannover, Germany (M. Stangel); Donau-Isar-Klinikum Deggendorf, Deggendorf, Germany (T. Fortwängler); Ludwig-Maximilians-University, Munich, Germany (F. Hoffmann); Max von Pettenkofer Institute, Munich (A. Osterman); German Center for Infection Research, Munich (A. Osterman); Bundeswehr Institute of Microbiology, Munich (S. Zange); Regensburg University Hospital, Regensburg, Germany (H.-H. Niller, K. Angstwurm); Postgraduate Training for Applied Epidemiology, Berlin, Germany (K. Pörtner); European Centre for Disease Prevention and Control, Stockholm, Sweden (K. Pörtner); Robert Koch Institute, Berlin (K. Pörtner, C. Frank, H. Wilking)

Main Article

Table 1

Case definitions for BoDV-1 or VSBV-1 encephalitis/encephalopathy, Germany, 2018–2020*

Case definition
Confirmed case of BoDV-1 or VSBV encephalitis/encephalopathy
Encephalitis or encephalopathy
AND detection of BoDV-1 or VSBV-1 RNA in CSF or CNS 
tissue
OR detection of BoDV-1 or VSBV-1 antigen by IHC with
virus-specific monoclonal antibodies in CNS tissue
Confirmed case of unspecified bornavirus encephalitis/ encephalopathy
Encephalitis or encephalopathy
AND detection of bornavirus antigen by IHC with cross-
reactive monoclonal antibodies or polyclonal serum in CNS 
tissue
Probable case of BoDV-1 or VSBV-1 encephalitis/ encephalopathy
Encephalitis or encephalopathy
AND detection of bornavirus-reactive IgG in a serum or CSF 
sample by screening test (with full virus antigen, e.g., IFAT) 
and suitable confirmation assay detecting antibodies against 
individual bornavirus antigens (derived from infected cells or 
recombinant antigens, e.g., Western blot, immunoblot, or 
ELISA)
AND suitable comparative antibody quantification assay able 
to distinguish antibodies specific for BoDV-1, VSBV-1 or other 
orthobornaviruses (e.g., IFAT, immunoblot, ELISA)
OR exposure to VSBV-1-positive squirrels or epidemiologic 
link to BoDV-1-endemic regions
AND no evidence of other reasons for the clinical picture
Probable case of unspecified bornavirus encephalitis/ encephalopathy
Encephalitis or encephalopathy
AND detection of bornavirus-reactive IgG in a serum or CSF 
sample by screening test (with full virus antigen, e.g., IFAT) 
and suitable confirmation assay detecting antibodies against 
individual bornavirus antigens (derived from infected cells or 
recombinant antigens, e.g., Western blot, immunoblot, or 
ELISA)
AND detection of bornavirus-reactive IgG in a serum or CSF 
sample by screening test (with full virus antigen, e.g., IFAT) 
and suitable confirmation assay detecting antibodies against 
individual bornavirus antigens (derived from infected cells or 
recombinant antigens, e.g., Western blot, immunoblot, or 
ELISA)
Possible case of BoDV-1 or VSBV-1 encephalitis/encephalopathy
Encephalitis or encephalopathy
AND residence in BoDV-1-endemic area or exposure to 
VSBV-1–positive squirrels
AND no evidence of other reasons for the clinical picture

*Case definitions replace those of Tappe et al. (6). Encephalitis or encephalopathy was defined according to Venkatesan et al. (14). BoDV-1, Borna disease virus 1; CNS, central nervous system; CSF, cerebrospinal fluid; IFAT, immunofluorescence antibody test; IHC, immunohistochemical analysis; VSBV-1, variegated squirrel bornavirus 1.

Main Article

References
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1These authors contributed equally to this article.

Page created: February 08, 2021
Page updated: April 20, 2021
Page reviewed: April 20, 2021
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