[Detection rates and high concentration of herpesvirus (Orthoherpesviridae) DNA in autopsy materials from patients with COVID-19 fatal outcome].

Introduction: SARS-CoV-2 infection causes immune disorders that create conditions for the reactivation of human herpesviruses (HHVs). However, the estimates of the HHVs effect on the course and outcome of COVID-19 are ambiguous. Аim - to study the possible relationship between the HHV reactivation and the adverse outcome of COVID-19.
Materials and Methods: Postmortem samples from the brain, liver, spleen, lymph nodes and lungs were obtained from 59 patients treated at the Moscow Infectious Diseases Hospital No.1 in 2021-2023. The group 1 comprised 39 patients with fatal COVID-19; group 2 (comparison group) included 20 patients not infected with SARS-CoV-2 who died from various somatic diseases. HHV DNA and SARS-CoV-2 RNA were determined by PCR.
Results: HHV DNA was found in autopsy samples from all patients. In group 1, EBV was most often detected in lymph nodes (94%), HHV-6 in liver (68%), CMV in lymph nodes (18%), HSV in brain (16%), VZV in lung and spleen (3% each). The detection rates of HHVs in both groups was similar. Important differences were found in viral load. In patients with COVID-19, the number of samples containing more than 1,000 copies of HHV DNA per 100,000 cells was 52.4%, in the comparison group - 16.6% ( p < 0.002). An association has been established between the reactivation of HSV and HHV-6 and the severity of lung damage. Reactivation of EBV correlated with increased levels of liver enzymes.
Conclusion: Reactivation of HHVs in patients with fatal COVID-19 was associated with severe lung and liver damages, which indicates a link between HHV reactivation and COVID-19 deaths.