Comprehensive Severe Acute Respiratory Syndrome Coronavirus 2 Detection Using Polymerase Chain Reaction and Rapid Antigen Testing in Postmortem Specimens

Abstract

Polymerase chain reaction (PCR) is indispensable for diagnosing coronavirus disease 2019 (COVID-19) in autopsy cases. In this study, we performed comprehensive reverse transcription quantitative PCR (RT-qPCR) and rapid antigen tests for COVID-19 on forensic postmortem specimens, regardless of the antemortem symptoms and causes of death. Immediately before forensic external examination and autopsy, a wiping solution was collected from the nasopharynx with a dry swab, and rapid antigen testing and RT-qPCR were performed. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was detected by RT-qPCR in 12 of the 487 cases; the infection rate was 2.46%. Of the RT-qPCR–positive cases, 7 were associated with COVID-19–related deaths. Cycle threshold values were not correlated with the cause of death or postmortem time. The sensitivity and specificity of the rapid antigen test were 91.67% and 100.00%, respectively. The RT-qPCR positivity rate of forensic cases was higher than the cumulative infection rate for the entire population. SARS-CoV-2 could be detected with the rapid antigen test and RT-qPCR within 216 hours of death. Because the rapid antigen test showed the same sensitivity and specificity as those observed in clinical practice, the test combined with RT-qPCR may be useful for diagnosing COVID-19 even in postmortem specimens.