COVID-19 in the autopsy room–requirements, safety, recommendations and pathological findings

The COVID-19 pandemic, also known as ‘coronavirus disease of 2019′, has become a worldwide concern due to severe acute respiratory syndrome with coronavirus 2 (SARS-CoV-2), going far beyond the actual capabilities of local healthcare systems [1‐3]. A global shortage of diagnostic tests that many countries faced once the World Health Organization (WHO) declared that the outbreak of the pandemic was overwhelming and the limited capabilities to perform such tests by the medical staff overstretched the potential of health care systems worldwide. At the same time, researchers and clinicians continuously sought the most effective drugs against SARS-CoV-2 [4‐6].

Diagnostic procedures depend on the degree of disease severity, and they are different for asymptomatic but suspected patients and for those who present with specific clinical manifestations. In addition, tests for influenza or other pathogens can cause respiratory infections, and specific laboratory tests (complete blood count (CBC), arterial blood gas assessments) and radiological tests (primarily computed tomography (CT), RTG, or ultrasonography (USG)) are performed on a regular basis. The three diagnostic strategies – genetic tests, antigen tests, and antibody tests – currently constitute a routine laboratory diagnosis of SARS-CoV-2 infection. Reverse transcription real-time polymerase chain reaction (rRT-PCR) is currently a basic technique that enables a relatively quick detection of SARS-CoV-2 infection [7].

SARS-CoV-2, recently categorized as an HG3 organism, constitutes a significant risk for employees who face infected patients [8‐10]. The emergency measures that aim to minimize the epidemiological risk of SARS-CoV-2 spread must be maintained at all levels of the healthcare system. Therefore, it is of great importance to implement strict requirements concerning the management of the deceased who died because of COVID-19. Regarding the high risk of infection of medical personnel, primary care staff, morgue staff, and funeral and transportation agency workers, the implementation of specific safety requirements appears to be crucial. To date, numerous scientific organizations and societies worldwide have prepared specific recommendations regarding postmortem examinations and autopsies. These are highly differentiated and have been implemented with different aims and scopes – from underestimating the safety requirements to extreme precautions that aim to minimize the risk of infection.

Although the clinical features and radiological findings of SARS-CoV-2 infection have been well described so far, the early detection of potential SARS-CoV-2 infection would significantly minimize the epidemiological risk. Invariably, a classical autopsy remains the gold standard for determining the causes and mechanisms of death, as it also allows a gross examination and microscopic examination [11]. It is crucial to perform an autopsy to provide insight into the possible mechanisms of SARS-CoV-2 action and the extent of organ involvement targeted by the virus [12].

Safety requirements and proper techniques for the autopsy would significantly improve the management of a continually increasing number of deceased individuals with COVID-19. In addition, a full autopsy with both macroscopic and microscopic examinations would provide insight into manifestations of SARS-CoV-2 infection that might not be easily detected ante mortem. According to the WHO, bodies are generally not infectious except for patients with hemorrhagic fever (such as Ebola or Marburg) and cholera; however, there is no evidence of whether the deceased with COVID-19 might constitute a possible source of infection [13]. Furthermore, a history of no exposure does not completely guarantee that the deceased is not infected with SARS-CoV-2. Therefore, the early detection of an infection in a deceased individual who was suspected of having COVID-19 would significantly decrease the epidemiological risk associated with potential exposure to medical personnel and the family and acquaintances of the deceased and enable an efficient identification of a possible source of infection. Therefore, it is crucial to provide security measures that minimize the risk of exposure and at the same time respect the rights of the families of the deceased while providing the option to investigate the actual cause of death.

Knowledge about the persistence of SARS-CoV-2 on different surfaces is limited only to laboratory settings, with no precise confirmation in reality. It is yet unknown how long SARS-CoV-2 can persist on the clothes and bodies of the deceased. It was found that the stability of SARS-CoV-2 is similar to that of SARS-CoV-1; however, this was proven only under experimental conditions [29]. According to Kampf et al., human coronaviruses remain infectious on inanimate surfaces for up to 9 days [30]. Furthermore, it is estimated that coronavirus infectivity can be significantly reduced upon applying 0.1% sodium hypochlorite or 62–71% ethanol to surfaces. Copper also exhibits antiviral properties [31]. However, it is has not yet been confirmed whether the abovementioned findings apply specifically to SARS-CoV-2. Coronaviruses are sensitive to increased temperatures, detergents and commonly used disinfectants [30]. Viral transmission, usually on items via the airborne route, results in viral persistence on those surfaces, usually up to several hours. On cardboard surfaces, viruses can persist up to 24 h, whereas on stainless steel and artificial materials, viral persistence might last up to 2–3 days [29]. Viruses that are closely related to SARS-CoV-2 – SARS and MERS – can persist for a long time in humid and shaded environments – up to 2 days in tap water and sewage, up to 3 days in feces, up to 14 days in saline, and up to 17 days in urine [32]. MERS-CoV might be detected in nasal swabs up to 3 days after death [33]. SARS-CoV-2 can also be detected in cerebrospinal fluid; however, such results are limited to ante mortem studies [34].

The results of available studies show that SARS-CoV-2 detection is possible mainly in secretions from the respiratory tract. The highest positive rates of SARS-CoV-2 detection are noted in bronchoalveolar lavage fluid, followed by sputum, nasal swabs, fibrobronchoscope brush biopsy, pharyngeal swabs, feces, and blood (Table 2) [35‐37].

The highest sensitivity of SARS-CoV-2 detection is obtained via the collection of swabs from both the upper and lower respiratory tracts (among which bronchoalveolar lavage fluid and sputum are the most highly recommended) [38, 39]. An autopsy allows the collection of swabs from the lower respiratory tract, which provide a higher probability of viral RNA detection than swabs from the nasopharynx.

Before an anatomical examination and autopsy, all the samples for further testing should be collected to minimize the risk of potential contamination [32]. Generally, there are several rules regarding sample collection:

Samples that are recommended to be obtained during an autopsy include 2 samples from the peripheral blood, 1 sample from the blood containing an anticoagulant for genetic examinations, 1 sample from urine, 1 sample from cerebrospinal fluid, and 2 samples from vitreous humor, as well as pleural, pericardial, or peritoneal fluid, if possible [40, 41]. SARS-CoV-2 might also be detected in the feces of patients who do not present with any gastrointestinal symptoms. Viral detection limited only to oral swabs is not recommended since the virus is detected only in anal or blood samples and is not detected in oral swabs. Furthermore, oral swabs that are positive during the early stages of infection can become anal swabs that are positive during the late stages of infection [42]. Respiratory tract samples can be easily collected with ready-to-use swabs; blood, cerebrospinal fluid, or urine samples should be taken prior to the opening of body cavities to minimize the risk of contamination. Blood cultures can be preferentially obtained from the subclavian vein, jugular vein, or left ventricle [43]. It has been suggested that the pooling of samples before RT-PCR amplification might reduce the number of further tests needed [44]. Cryopreservation allows the rapid and deep freezing of tissues (at a minimum temperature of -80 °C) and thus the collection of samples with viruses for further diagnostic tests. This is highly beneficial, especially where tests are limited and cannot be performed immediately after sample collection. In COVID-19 patients, bronchial tissue samples can be collected for cryopreservation. However, since different samples were reported to be obtained from the deceased so far, it should be taken into consideration that standardized autopsy procedures (including sample collection) are crucial to facilitate a postmortem diagnosis.

The rooms where autopsies are performed should meet specific technical requirements, with a particular emphasis on the ventilation devices. First, two zones should be designated – a 'clear area' and a 'dirty area' – and an additional 'intermediate zone' for the removal of protective clothing after the autopsy [37]. Autopsies should be performed in airborne infection isolation rooms (AIIRs), which should provide negative pressure compared to the surrounding areas [22]. When such rooms are unavailable, negative pressure should be provided, and air recirculation to other rooms should be restricted. It is recommended to provide air exchange (a minimum number of 6 changes per hour); air should be exhausted either outside or through a high-efficiency particulate aerosol (HEPA) filter. Equipment in the autopsy room dedicated for COVID-19 autopsies should include:

Three major examinations are the most important regarding COVID-19 confirmation: real-time polymerase chain reaction, immunochemistry, and electronic microscopy. Serological tests depend on the so-called ‘serological window’, which, in the case of SARS-CoV-2, lasts for 7 to 14 days [48]. Both molecular and serological tests are crucial to confirm viral presence since SARS-CoV-2 can be transmitted through various routes [49]. Postmortem examinations raise numerous concerns not only in patients with confirmed COVID-19 but also in patients with suspected or probable COVID-19. This is mainly due to limited possibilities of performing extensive population screening tests that exceed logistical and financial capabilities even in highly developed countries. Postmortem examinations and tests for SARS-CoV-2 are highly important, as they enable the maintenance of proper precautions adjusted to the actual threat level not only during the autopsy but also in the further management of the deceased [50]. Given the current epidemiological situation, autopsies, even in patients with unknown or uncertain causes of death, should be performed with extreme precautions following an appropriate preventive policy, as unconfirmed cases create a source of potential contamination [8]. Therefore, it is proposed that computed tomography (CT) might constitute an alternative method of COVID-19 detection and significantly minimize the risk of potential infection in medical personnel. The usefulness of CT has been documented by many ante mortem studies, and its sensitivity is believed to be even higher than that of genetic or immunoenzymatic tests [51‐57]. The application of CT is crucial since radiological changes might appear as the first signs, preceding clinical manifestations in some cases. In Italy, a country with one of the highest mortality and incidence rates of SARS-CoV-2 infection, postmortem computed tomography (PMCT) is recommended as a primary diagnostic tool for COVID-19, being equally as important as genetic tests [28]. In addition, PMCT is considered a highly sensitive diagnostic method, especially in patients who did not receive cardiopulmonary ante mortem resuscitation [58]. While performing PMCT in suspected or confirmed COVID-19 cases, it is important to consult a radiologist who specializes in postmortem imaging, as it is crucial to distinguish between naturally occurring postmortem changes in the lungs and those that were induced by SARS-CoV-2 infection and COVID-19 [51, 59]. PMCT might be a useful tool during the autopsy of confirmed and suspected COVID-19 cases; however, the utility of this examination should be further evaluated. In addition, lung ultrasound can be used in children with pneumonia, for instance. However, such findings should be cautiously interpreted with the clinical and laboratory findings [60]. To the best of our knowledge, it has been unknown whether USG can be applied as a postmortem diagnostic tool in patients with SARS-CoV-2 infection. Although there are several preliminary studies on USG as a tool for forensic purposes, knowledge of its usefulness in COVID-19 patients is lacking [61‐65]. In addition, specific procedures regarding the handling of corpses require appropriate PPE that minimizes the risk of potential viral transmission (Table 3).

The two most common imaging characteristics of COVID-19 are ground-glass opacities and lung consolidation [66, 67]. Lesions that are found via CT are primarily in the middle and lower lung sites and present a multifocal distribution [56]. Bai et al. showed that the prevalent features of COVID-19 found via CT also include a peripheral distribution of pneumonia (80%) and vascular thickening (58%) [68]. However, CT findings vary in different patients and stages of COVID-19. Pleural thickening and extensive adhesion have been reported in COVID-19 patients, consistent with PMCT and autopsy findings [69]. The most common pulmonary imaging features observed by Zhao et al., who performed CT on 101 individuals with COVID-19, were ground-glass opacities (86%), ground-glass opacities with consolidation (64%). vascular enlargement (71%) and traction bronchiectasis (53%) [70]. Other prevalent findings observed via PMCT include mixed patterns of reticular infiltrations [71]. Such findings are distributed mostly peripherally in the lower lobes and usually involve both lungs. In addition to CT, X-ray can also be performed in COVID-19 patients and demonstrates patchy, high-density opacities or consolidation in the lungs with high accuracy [72]. Conventional chest CT or X-ray is sufficient to identify typical characteristics of COVID-19-associated pneumonia.

Currently, there are no sufficient data on the viability of PMCT as a postmortem diagnostic tool for patients with suspected or confirmed COVID-19. However, according to Italian recommendations, PMCT has been included in the decision tree of the autopsy, and its utility is equal to that of swab collection [28]. The sensitivity and specificity of this method are yet unknown in postmortem studies. However, if there is a limited number of diagnostic tests, PMCT and radiological findings might constitute a solution that could minimize the risk of infection. However, there is a need for further validation studies to verify the utility of PMCT application during the autopsies of patients with suspected/confirmed COVID-19. Importantly, even in asymptomatic patients with yet unconfirmed or suspected COVID-19 pneumonia, CT can reveal typical abnormalities [67].

Patients who die because of COVID-19 can be embalmed, buried or cremated depending on the preferences [93]. As people from different religions have numerous traditions, the burial, cremation, or embalming tends to differ. Embalming is the injection of a preservative solution that replaces the blood and fills the body cavities and organs [94]. Since embalming involves contact with the body, blood, and other fluids, this process should be undertaken with extreme precautions to minimize the risk of infection.

The Catholic Cemeteries & Funeral Services (CCFS) prepared protocols to handle individuals who died because of COVID-19 that were adjusted for specific situations; mortuary services have continued without interruption in Catholic Church, and the procedures might involve traditional burial, cremation or embalming [95]. The European Centre for Disease Prevention and Control (ECDC) allows burial, cremation, or embalming of the deceased with either suspected or confirmed COVID-19 [93]. The ECDC states that the families are allowed to view the body. Additionally, permission is granted for physical contact with the body; however, following standard precautions and applying PPE – gloves and long-sleeved water-resistant gowns are the minimum requirements. In cases of a PPE shortage, physical contact with the body should be restricted. According to Red Cross guidelines, burial in a single grave is preferred, whereas mass graves are discouraged; the body should also be double bagged [96]. In Jewish culture, regardless of the burial method performed, the seventh day following a burial – shiva – is the day at which the grieving process begins and is very important in Jewish culture; however, due to the need for social distancing and gathering prevention – it has to be canceled or postponed [97, 98]. In addition, according to Jewish religious law, burial must be undertaken within 48 h of death, which might be naturally restricted during the SARS-CoV-2 pandemic. In Islamic law and Muslim culture, each individual should be buried in a separate grave; however, in cases of a massive SARS-CoV-2 infection, collective graves are permitted by the law [99]. Buddhists perceive an autopsy as beneficial; however, they usually prefer to prolong the examination for 3–4 days to ‘give time for the soul to leave the body’; during the COVID-19 pandemic, these timelines have to be shortened [100].

Generally, families and friends may see the body before the burial; however, the restrictions concern physical contact. In addition, under the principles of social distancing, the number of mourners must be limited. Individuals who have certain respiratory diseases should not be allowed to see the body; however, it is possible only if the person wears a protective mask. Furthermore, children, adults over 60 years old, and immunosuppressed individuals should not have contact with the body. During all the activities associated with body preparation for burial, the usual principles of Standard Infection Control Precautions and Transmission-based Precautions should be followed. The risk assessment regarding the funeral premises should include known or suspected infection hazards, the timing of procedures, the number of required staff, and whether additional observers should be excluded [9]. Burial procedures are not systematized, but they should be since the lack of proper and sufficient protective precautions might be associated with an increased epidemiological risk.

SARS-CoV-2 has been reported to present certain survivability in the bodies of infected patients. There are still speculations as to whether individuals with confirmed COVID-19 should receive an autopsy. However, during times of rapid pandemic expansion and the urgent need for epidemic preservation, the need for an autopsy in both suspected and confirmed cases seems rational since it expands our knowledge of the mechanism of action of SARS-CoV-2 and organs that are targeted by the virus. An autopsy allows the exact macroscopic and microscopic examinations of suspected and confirmed cases. In addition, an autopsy provides an accurate diagnosis and confirms ante mortem laboratory and radiological findings, especially in suspected cases. Furthermore, an autopsy allows the detection of coexisting diseases as well as the assessment of the extent of SARS-CoV-2 infection. Although there have been an increasing number of studies regarding the clinical manifestations and complications of COVID-19, knowledge about the pathologic postmortem manifestations, both macroscopic and microscopic, is still scarce. Since the pandemic is still expanding and the number of infected patients is continually increasing, there is an urgent need to report postmortem findings to expand our knowledge on the pathology of COVID-19. To increase the efficiency of work while minimizing the risk of exposure of medical personnel to the potential source of infection, it is highly recommended to introduce PMCT on a regular basis while simultaneously performing needle biopsy to collect lung parenchyma specimens instead of opening all body cavities. For forensic experts and pathologists, it seems necessary to collect different samples because viral detection might differ depending on the stage of the disease. Minimally invasive biopsy for a postmortem histological examination and the application of a virtual autopsy (so-called virtopsy) might constitute alternatives for a typical autopsy, significantly minimizing the risk of potential infection.

1. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by survivability in the bodies of the deceased who died because of SARS-CoV-2 infection.

2. Autopsies are rational for patients with both suspected and confirmed SARS-CoV-2 infection.

3. Postmortem findings of SARS-CoV-2 infection include macroscopic and microscopic changes, as well as altered radiological findings.

4. SARS-CoV-2 might be detected in various samples obtained postmortem, such as respiratory tract samples, blood, feces, cerebrospinal fluid, or urine.