Detection and infectivity of SARS-CoV-2 in exhumated corpses

Abstract

Postmortem detection of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) after the exhumation of a corpse can become important, e.g. in the case of subsequent medical malpractice allegations. To date, data on possible detection periods [e.g. by reverse transcription polymerase chain reaction (RT-PCR)] or on the potential infectivity of the virus after an exhumation are rare. In the present study, these parameters were examined in two cases with a time span of approximately 4 months between day of death and exhumation. Using SARS-CoV-2 RT-PCR on swabs of both lungs and the oropharynx detection was possible with cycle threshold (Ct) values of about 30 despite signs of beginning decay. RT-PCR testing of perioral and perinasal swabs and swabs collected from the inside of the body bag, taken to estimate the risk of infection of those involved in the exhumation, was negative. Cell culture-based infectivity testing was negative for both, lung and oropharyngeal swabs. In one case, RT-PCR testing at the day of death of an oropharyngeal swab showed almost identical Ct values as postmortem testing of an oropharyngeal swab, impressively demonstrating the stability of viral RNA in the intact corpse. However, favorable climatic conditions in the grave have to be taken into account, as it was wintertime with constant low temperatures. Nevertheless, it was possible to demonstrate successful postmortem detection of SARS-CoV-2 infection following exhumation even after months in an earth grave.

The Impact of the COVID-19 Pandemic on the Practice of Forensic Medicine: An Overview

“…In the first group, there are a great number of published studies: the positivity persistence to RT-PCR tests has been demonstrated in post-mortem samples ranging from a few hours after death [ 84 ] to 78 days after death [ 85 ]. Moreover, the positivity test has been demonstrated under different conditions: both in samples from corpses stored refrigerated (cold room) [ 86 , 87 ] and in exhumed corpses [ 88 ]. Nevertheless, it has been demonstrated too, that by applying specific procedures during the autopsy, infection risks may be minimized for the personnel involved in post-mortem investigations [ 89 ].…”

Postmortem Stability of SARS-CoV-2 in Mouse Lung Tissue

“…Furthermore, infectious virus was isolated in 2 of 4 cases at 4–17 days postmortem; however, this study did not quantify virus titers to determine the loss of virus infectivity ( 6 ). A separate study found that infectious virus was undetectable after exhumation at 3–4 months postmortem ( 7 ). Overall, RNA detection by RT-PCR might not directly correlate with virus infectivity or duration of symptomatic disease.…”

“…At day 14 only 0.7% of the initial infectious virus and 17% of viral RNA remained. Plenzig et al ( 7 ) detected viral RNA in 2 exhumed corpses at 3 months postmortem, despite an absence of infectious virus. We used hematoxylin and eosin staining to detect viral nucleoprotein in lung tissue.…”

Spread of COVID-19 Infection in Long-Term Care Facilities of Trieste (Italy) during the Pre-Vaccination Era, Integrating Findings of 41 Forensic Autopsies with Geriatric Comorbidity Index as a Valid Option for the Assessment of Strength of Causation

“…Before and during autopsies, multiple swabs were collected at identical sites from rhynopharinx, oropharynx, trachea, right and left bronchus, and rectum, which were examined by Real Time Polymerase Chain Reaction (RT-PCR). Positive results were reported as semi-quantitative Cycle Threshold (Ct) values [ 56 ]. The Ct values, collected and grouped into three categories, were defined as follows: <25 strongly positive, 25–35 moderately positive, and >35 weakly positive [ 57 ].…”