Reactivation of Epstein-Barr virus (EBV) has been suggested to play role in long lasting multiorgan symptoms months after the initial COVID-19 illness. The aim of our prospective multicenter study was to 1) to evaluate the reactivation of several DNA viruses of the Herpes virus family (Herpes simplex /HS/, Varicella zoster (VZ), Cytomegaovirus (CMV) and EBV) and Parvovirus-B19 by SARS-CoV-2 in patients with the diagnosis of long-COVID syndrome, 2) to investigate the effect of supposed virus reactivation on clinical conditions and long COVID syndromes. Viral IgG and IgM titer of the selected DNA viruses of 105 consecutive patients were compared with age and sex-matched healthy (non-infected, non-vaccinated, n=105) controls. Long Covid patients had significantly higher summarized number of IgM positivity of the DNA viruses, and significantly elevated EBV IgG and Parco-B19 IgM titer as compared to healthy controls. Significantly more patients with long COVID symptoms had an EBV IgG titer above the detection limit as compared with healthy controls, suggesting EBV virus reactivation and chronic EBV infection. EBV IgG titer was significantly higher in patients with dominant pneumological symptoms, while elevated Parvo-19 IgM titer was observed in patients with dominant cardiovascular complaints. In patients with long-COVID syndrome the quantitative EBV IgG titer increased with the time between infection and blood sampling, suggesting the subclinical continuous DNA virus activation by the SARS-CoV2 RNA virus. 

Mariann Gyöngyösi completed her medical studies and PhD at the Albert Szent-Györgyi Medical University, Szeged, Hungary 1995, followed by habilitation at the Medical University of Vienna (Cardiology) in 2002. Her present position is professor at the Dept. Cardiology, Medical University of Vienna, Austria, leader of the cardiologic Long-COVID Ambulance, and leader of the Translational Cardiology Group. Her most important awards are Pfeiffer-Competition Austria, 1. Price, Austrian Society of Cardiology 1. Price, Billroth Preis of the Österreichisches Ärztekammer. Most important grants: LifeValve, Fibro-targets, Science, ReGenHeart, CresPace EU projects, numerous unrestricted research grants and contracts for experimental invasive cardiology projects. Her research and clinical interest involves ischemic heart disease, interventional cardiology, cell- and gene-based therapy, heart failure, cardiotoxicity, H-index: 40, Original papers (per reviewed): 245 (212 in PubMed), citation 5845.