High titers of infectious SARS-CoV-2 in COVID-19 corpses

Abstract

Background: The prolonged presence of infectious severe acute respiratory syndrome coronavirus (SARS-CoV-2) in deceased coronavirus disease 2019 (COVID-19) patients has been reported. However, infectious virus titers have not been determined. Such information is important for public health, death investigation, and handling corpses. Aim: The aim of this study was to assess the level of SARS-CoV-2 infectivity in COVID-19 corpses. Methods: We collected 11 nasopharyngeal swabs and 19 lung tissue specimens from 11 autopsy cases with COVID-19 in 2021. We then investigated the viral genomic copy number by real-time reverse transcription-polymerase chain reaction and infectious titers by cell culture and virus isolation. Results: Infectious virus was present in 6 of 11 (55%) cases, 4 of 11 (36%) nasopharyngeal swabs, and 9 of 19 (47%) lung specimens. The virus titers ranged from 6.00E + 01 plaque-forming units (PFU)/mL to 2.09E + 06 PFU/g. In all cases in which an infectious virus was found, the time from death to discovery was within 1 day and the longest postmortem interval was 13 days. Conclusion: COVID-19 corpses may have high titers of infectious virus after a long postmortem interval (up to 13 days). Therefore, appropriate infection control measures must be taken when handling corpses.