Postmortem swabs in the Sars-CoV-2 Pandemic: Report on 12 complete clinical autopsy cases.

Context Clinical autopsies have historically provided a fundamental contribution in the definition of the clinico-pathological basis of infectious diseases. Even though we are witnessing the decline of the clinical autopsy, its importance remains unchanged as it is the most exhaustive way to investigate diseases. The identification of the virus in postmortem tissues is a fundamental step in the definition of its clinical features. Objective To investigate the presence of Sars-CoV-2 in the postmortem with swabs. Design We performed postmortem swabs in 12 autopsy cases of patients with a clinical diagnosis of Sars-CoV-2 related pneumonia. Our protocol, consisted of a rhino-pharingeal and a tracheal swab in order to search for the virus in the upper airways and of two swabs on the parenchyma of each lung. We also performed a fifth swab on the parenchyma of both lungs in order to search for other viruses that could evolve in a clinical picture of interstitial pneumonia Results Overall we found that 9 out of 12 cases had at least one postmortem swab to be positive for Sars-CoV-2. Moreover we evaluated the time lapse between the antemortem and the postmortem swabs, the time between death and the postmortem swabs, and the time lapse between the postmortem swabs and the acceptance to the microbiology laboratory. Interestingly we did not find a relation neither between the results of the swabs and the time lapsed from their collection, or with the time lapsed before their acceptance in the microbiology laboratory. Conclusions A thorough knowledge of the eventual persistence of pathogens in deaths related to infectious diseases is fundamental for the safety of the operators during the autopsy practice, especially when referring to emergent pathogens like Sars-Cov-2. Our study highlights the importance in performing multiple swabs in the postmortem, since Sars-CoV-2 swab positivity can be limited to only a single swab.