Quantification and persistence of COVID-19 virus in recently deceased individuals before and after embalming

The COVID-19 pandemic severely affected the medical education worldwide. The infection risk for medical students and healthcare personnel who work with COVID-19 positive cadavers or tissues remains unclear. Moreover, COVID-19 positive cadavers have been rejected by medical schools, adversely impacting the continuum of medical education. Herein, the viral genome abundance in tissues from four COVID-19 positive donors before and after embalming were compared. Tissue samples were collected from the lungs, liver, spleen, and brain both pre- and postembalming. The possible presence of infectious COVID-19 was determined by inoculating human tissue homogenates onto a monolayer of human A549-hACE2 cells and observing for cytopathic effects up to 72 h postinoculation. A real- time quantitative reverse transcription polymerase chain reaction was performed to quantify COVID-19 present in culture supernatants. Fully intact viral genome sequence was possible to obtain in samples with higher levels of virus, even several days postmortem. The embalming procedure described above substantially reduces the abundance of viable COVID-19 genomes in all tissues, sometimes even to undetectable levels. However, in some cases, COVID-19 RNA can still be detected, and a cytopathic effect can be seen both pre- and postembalmed tissues. This study suggests that embalmed COVID-19 positive cadavers might be used safely with appropriate precautions followed in gross anatomy laboratories and in clinical and scientific research. Deep lung tissue is the best specimen to test for the virus. If the tests on the lung tissues are negative, there is a very low likelihood that other tissues will show positive results.