Association between Epstein-Barr-Virus reactivation and development of Long-COVID fatigue

Abstract

In the present prospective study, we analysed whether Long-COVID fatigue may be triggered by SARS-CoV-2 persistence in the gastrointestinal or respiratory tract after acute disease, or by COVID-19-associated reactivation of EBV. We tested for SARS-CoV-2 RNA in stool and throat washings, and for EBV DNA in stool, throat washings and blood by real-time PCR (EBV) and real-time RT-PCR (SARS-CoV-2) as described before. The experimental procedures were performed with permission of the human ethics committee of the Medical University of Vienna (vote number: 2281/2020). All patients provided written informed consent. Samples were collected between 74 and 471 days (median: 235 days) after beginning of acute SARS-CoV-2 infection in 30 Long-COVID patients characterized by persistent fatigue, post-exertional malaise (PEM), autonomic dysfunction and/or orthostatic intolerance. Twenty age- and sex-matched patients, who have fully recovered after the SARS-CoV-2 infection, were recruited for control purposes. Samples were collected between 106 and 571 days (median: 275 days) after beginning of acute SARS-CoV-2 infection. All patients had mild infections, were not hospitalized and were infected between spring 2020 and autumn 2021. We further analysed virus-specific antibodies including SARS-CoV-2 IgA and IgG with commercial ELISA assays (Euroimmun). As Long-COVID patients showed a higher frequency of positive titres for specific EBV antibodies compared with controls in earlier studies, the patients' EBV IgM and IgG were tested by a commercial microarray (ViraMed). Demographic data as well as inclusion and exclusion criteria are depicted in Table S1. More detailed information on the methodological procedures is listed in the Supporting Information.