[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]
Volume 25, Number 6—June 2019 / Synopsis
Immunopathology of Fatal Human Variegated Squirrel Bornavirus 1 Encephalitis, Germany, 2011–2013
Dennis Tappe , Jonas Schmidt-Chanasit, Jessica Rauch, Petra Allartz, and Christiane Herden
Author affiliations: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany (D. Tappe, J. Schmidt-Chanasit, J. Rauch, P. Allartz); German Centre for Infection Research, Hamburg (J. Schmidt-Chanasit); University of Giessen, Giessen, Germany (C. Herden)
Variegated squirrel bornavirus 1 (VSBV-1) is a zoonotic virus that causes fatal encephalitis in humans who are infected after contact with exotic squirrels. We analyzed the brain lesions and the immune responses in all 4 known human cases that showed panencephalitis. Inflammatory infiltrates in areas positive for VSBV-1 RNA and antigen consisted of CD4+ and CD8+ T cells, with perivascular B-cell accumulation. Strong microglial response and bizarre astroglial expansion were present. Areas of malacia contained neutrophils and foamy microglia and macrophages. Immunopathologic examination during infection showed cleavage of caspase 3 in brain cells adjacent to CD8+ cells and widespread p53 expression, hallmarks of apoptosis. Cerebrospinal fluid analyses over time demonstrated increasing protein concentrations and cell counts, paralleled by pathologic lactate elevations in all patients. The most severe cerebrospinal fluid and histologic changes occurred in the patient with the highest viral load, shortest duration of disease, and most medical preconditions.
Keywords: Variegated squirrel bornavirus 1; Encephalitis; Human; Germany; Immunopathology.