Detection of bornavirus-reactive antibodies and BoDV-1 RNA only in encephalitis patients from virus endemic areas: a comparative serological and molecular sensitivity, specificity, predictive value, and disease duration correlation study.

PURPOSE: Human Borna disease virus (BoDV-1) encephalitis is an emerging disease in Germany. This study investigates the spectrum of human BoDV-1 infection, characterizes anti-BoDV-1-antibodies and kinetics, and compares laboratory test performances. METHODS: Three hundred four encephalitis cases, 308 nation-wide neuropsychiatric conditions, 127 well-defined psychiatric cases from Borna disease-endemic areas, and 20 persons with contact to BoDV-1 encephalitis patients or animals were tested for BoDV-1 infections by serology and PCR. RESULTS: BoDV-1 infections were only found in encephalitis patients with residence in, or recent travel to, virus-endemic areas. Antibodies were detected as early as 12 days after symptom onset. Serum antibody levels correlated with disease duration. Serology was ordered after 50% of the disease duration had elapsed, reflecting low awareness. BoDV-1-antibodies were of IgG1 subclass, and the epitope on BoDV-1 antigens was determined. Specificity of the indirect immunofluorescence antibody test (IFAT) and lineblot (LB) from serum and cerebrospinal fluid (CSF), as well as PCR testing from CSF, was 100%. Sensitivity, depending on first or all samples, reached 75-86% in serum and 92-94% in CSF for the IFAT, and 33-57% in serum and 18-24% in CSF for the LB. Sensitivity for PCR in CSF was 25-67%. Positive predictive values were 100% each, while negative predictive values were 99% (IFAT), 91-97% (LB), and 90% (PCR). CONCLUSIONS: There is no hint that BoDV-1 causes other diseases than encephalitis in humans. Awareness has to be increased in virus-endemic areas. Tests are robust but lack sensitivity. Detection of IgG1 against specific peptides may facilitate diagnosis. Screening of healthy individuals is likely not beneficial.

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

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.

Serum cytokine and chemokine changes during Toscana virus meningitis.

Toscana virus is an important arbovirus causing meningitis and meningoencephalitis in countries around the Mediterranean Sea. While the clinical syndrome and laboratory diagnostic procedures have been well described, less is known about the immune response in Toscana virus meningitis and a possible use of cytokine and chemokine changes for the clinical follow-up of patients. We here characterized serum cytokine and chemokine profiles from 37 patients during the acute and convalescent phase of the infection. Only few serum cytokine/chemokine changes were detected during Toscana virus meningitis. Markedly increased concentrations of IP-10, interferon-α, IL-22, and eotaxin were found in the acute phase. Levels of interferon-α, IL-22, and eotaxin remained elevated in the convalescent phase, but decreased concentrations of GM-CSF were detected.

Blood donor screening for West Nile virus (WNV) revealed acute Usutu virus (USUV) infection, Germany, September 2016.

Between 1 June and 31 December 2016, 13,023 blood donations from the University Hospital Aachen in Germany were routinely screened for West Nile virus (WNV) RNA using the cobas TaqScreen WNV Test. On 28 September 2016, one blood donor was tested positive. Subsequent analysis revealed an acute Usutu virus (USUV) infection. During the ongoing USUV epizootics in Germany, blood transfusion services, public health authorities and clinicians should be aware of increased human USUV infections.

Sexual transmission of Zika virus in Germany, April 2016.

Zika virus (ZIKV), an emerging mosquito-borne flavivirus, causes a mild dengue fever-like illness but has recently been associated with neurological disease and severe birth defects. The virus is currently causing a large epidemic in the Americas. Here, we report a male-to-female sexual transmission of ZIKV in Germany in April 2016, following travel to Puerto Rico of the male patient, demonstrated by subsequent seroconversions and molecular identification of identical virus sequences from both patients.