SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a coronavirus responsible for COVID-19 (coronavirus disease 2019) which resulted in a cluster of cases of pneumonia that originated in China around 31 December 2019 and has subsequently spread across the globe. Currently, COVID-19 represents a health emergency worldwide, leading, in severe cases, to pneumonia, severe acute respiratory syndrome, multiorgan dysfunction or failure, and death. In the context of limited scientific knowledge and evidence of SARS-CoV-2 infection, guidance is becoming increasingly necessary for pathologists who have to perform postmortem investigations on COVID-19 cases. The aim of the present report is to share a procedure applicable to cases of COVID-19-related death, particularly in cases of death without medical intervention and in the absence of an ascertained SARS-CoV-2 infection and/or COVID-19 diagnosis, therefore providing support for diagnostic activity in the present COVID-19 pandemic. For this purpose, a standard operating procedure for correct swab collection, autopsy investigation and tissue sampling is provided.
Hic est locus ubi mors gaudet succurrere vitae
“This is the place where death delights in helping life”
SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a coronavirus responsible for COVID-19 (coronavirus disease 2019) which resulted in a cluster of cases of pneumonia that originated in China around 31 December 2019 and has subsequently spread across the globe. Currently, COVID-19 represents a health emergency worldwide, leading, in severe cases, to pneumonia, severe acute respiratory syndrome, multiorgan dysfunction or failure, and death .
Measures and recommendations have been developed to help healthcare personnel prevent the spread of the virus and to properly manage COVID-19 cases, advising on possible risks and preventive measures . In the context of limited scientific knowledge and evidence of SARS-CoV-2 infection, guidance is becoming increasingly necessary for pathologists who have to carry out postmortem investigations on COVID-19-related deaths [3–5].
The aim of the present report is to share a procedure for correct swab collection and autopsy investigations, offering technical support to professionals involved in these activities during the SARS-CoV-2 pandemic outbreak.
In each of the phases, the described procedure is carried out with the involvement of an operating pathologist and a support pathologist appointed to manage the samples and document the findings.
Such an approach can be used in cases of both suspected and probable COVID-19. The strength of this method is the development of a standard operating procedure for sampling and autopsy investigation in conditions of high biological risk.
Before the autopsy investigation, swabs of the upper respiratory tract (nasopharyngeal and oropharyngeal) are collected for virological SARS-CoV-2 research.
Collection of nasopharyngeal swabs is performed as follows (Fig. 2A):
Collection of oropharyngeal swabs is performed as follows (Fig. 2B):
For safe sample preparation, after collection each of the swabs is placed in a sterile tube containing 2–3 mL of viral transport medium or sterile saline. The sterile tubes are then inserted into two different Falcon® tubes, which are placed into a plastic bag with adhesive closure and, subsequently, into a plastic bag with zip closure. Each container is labeled to indicate the identification number of the subject, the identification code of the sample, the type of sample and the date of collection.
Immediately after sampling, the swabs are sent to the laboratory for subsequent processing by real-time PCR.
In the autopsy investigation of COVID-19 cases (suspected or probable) “en bloc” extraction (evisceration according to Ghon) of the cervicothoracic organs is performed.
According to this technique, “en bloc ” extraction of the oral (tongue, oropharynx, hypopharynx), cervical (larynx, trachea) and thoracic (tracheal bifurcation, major bronchi, lungs) respiratory structures is performed, with final resection from the surrounding structures (aorta, inferior vena cava and esophagus) .
The basic steps for Ghon block removal are briefly described below:
As an alternative to steps 2 and 3, the cervical block can be dissected above the thyroid cartilage to avoid the risk of sharp injury and to facilitate the maneuver for less experienced operators.
Intra-autopsy swab collection for virological SARS-CoV-2 research is performed after the removal and opening of the respiratory block from the lower respiratory tract (primary bronchi).
Collection of the lung swabs is performed as follows:
For safe sample preparation for transport and processing, the procedure is the same as that mentioned above for the nasopharyngeal and oropharyngeal swabs.
Standard samples collected for histopathological investigation of COVID-19 cases include the following:
The present procedure was designed according to a step-by-step diagnostic approach (Fig. 5). In particular, postmortem sampling for SARS-CoV-2 virological research by real-time PCR is always carried out in cases of a decedent with suspected or probable COVID-19 in two steps:
For this purpose, a complete autopsy with extraction of the Ghon respiratory block is therefore of considerable importance, as it allows preservation of the anatomical integrity of the upper and lower airways and correct sampling of the primary bronchi for virological confirmation/exclusion.
The correct visualization of the whole respiratory tract, as well as the description and evaluation of its macroscopic characteristics (caliber, width, intraluminal content), are also facilitated. Furthermore, the advantages of the described technique include the possibility of proceeding with complete and accurate sampling, which is useful for a definitive pathological diagnosis through histological and immunohistochemical investigations [8–11].
In conclusion, the present procedure is applicable in cases of COVID-19-related death, particularly in cases of death without medical intervention and in the absence of an ascertained SARS-CoV-2 infection and/or COVID-19 diagnosis, therefore providing support and an approach for the diagnostic activity in the present COVID-19 pandemic.
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All the authors contributed equally to the conception and design of the study, acquisition of data, or analysis and interpretation of data, drafted and revised the article critically for important intellectual content, and approved the final version before its submission.
Authors and corresponding author don’t have conflict of interests in writing and submitting for publication the manuscript.