PRESENCE OF HUMAN HERPESVIRUSES INFECTION MARKERS IN HOSPITALIZED COVID-19 PATIENTS IN LATVIA

Herpesviruses share ability of persistence in latent state after primary infection which can switch to reactivation due to factors including other infections and altered state of immune system. Some studies have associated the reactivation of human herpesviruses with the severity and length of COVID-19. Viruses may under certain conditions escape the immune system response and hide in tissue reservoirs while maintaining possibility to reactivate, thus facilitating the entry of the SARSCoV-2 into cells, enhancing viral load and aggravating the severity of symptoms. The aim of this work was to determine the presence of human herpesviruses infection markers in COVID-19 patients. The study included 86 hospitalized COVID-19 patients aged 18 – 93 years. Presence of human herpesviruses infection markers were determined by multiplex real-time and nested PCRs using peripheral blood and cell-free blood plasma DNAs as the templates. For 48/86 patients, repeated samples in dynamics were available at two or three timepoints. Levels of anti-EBV-CA IgG, anti-EBV-EA-D IgG and anti-HHV-6 IgG was determined by ELISAS. 37.2% of blood but none of the plasma DNA samples were positive for the presence of EBV genomic sequences;
10.47% of blood DNA samples were positive for HHV-6A/B, and 20.9% blood and one plasma DNA sample were positive for HHV-7 genomic sequences. In dynamics, EBV genomic sequences were detected in 31.25% of blood DNA samples, HHV-6A/B sequences – in 8.3% of blood and in 4.2% of plasma DNA samples, HHV-7 genomic sequences – in 16.7 % of blood and in 6.25% of
plasma DNA samples. Preliminary results show that anti-EBV-CA IgG, anti-EBV-EA-D IgG and anti-HHV-6 IgG are present among COVID-19 patients. This study shows that human herpesviruses infection markers are present in COVID-19 patients and could indicate to the reactivation of these viruses that can affect the course and recovery of COVID-19.