Prevention SARS-CoV-2 virus aerolization during an autopsy

This post is concentrated only on prevention SARS-CoV-2 virus aerolization during an autopsy. Proper autopsy technique and air flow engineering controls in the morgue’s room are the subject of discussion.

It would be a shame that anatomic pathology is losing such precious learning material as COVID-19 autopsy data. Stifled by regulators and the fear of unknown, pathologists delayed their autopsies activities in the beginning of the COVID-19 epidemic outbreak. Although now the OSHA’s position has been changed, in the beginning of the epidemic the agency had not recommended autopsies.

There is no any scientifically supported evidence that COVID-19 is different from other respiratory infections initiated by corona viruses as far as transmission is concerned. The main way of transmission is by droplet nuclei containing viruses through mucous excretions from infected person with or without disease symptoms. The decedent does not sneeze, cough, speak, or shed viruses in the environment. Although the aerosol component in transmission is still disputed, this is only one possible way of become an infection source during the autopsy performance.

To be on more or less scientific ground in understanding of the mechanism of the virus aerolization, it is necessary to touch some biology and physics basics. We are going to do with maximal simplification.

 A viable SARS-CoV-2 virus cannot exist without its protein-lipid envelop. The virus is dwelling in the mucus which is made up of 95% water, although mucus contains other ingredients such as mucin (2%–3%), proteoglycans, lipids proteins, and DNA. Virus has the binding attachment to specific molecules on the surface of the cells. Molecules in water content follow the kinetic energy random motion when the the fastest can overcome Van der Walls power and escape from the surface in vapor. The speed and intensity of evaporation increases with velocity, temperature and diminished humidity. It means that air circulation even 6 per hour, never mind 12 per hours as CDC suggests, only increases possibility of viruses aerosolization. Horizontal laminate airflow with 6 or 12 per hour circulations has been  developed for diminishing gas (formaldehyde, for instance) and fumes, but in the case of the autopsy procedure such design contributes to aerosol formation just at the zone of the work.

This is my understanding of the infectious aerosol’s development during an autopsy. Moreover, the conditions for aerosol development is more possible than in a patient’s ward during a ventilator handling. During an autopsy, the large surfaces of respiratory tract, including bronchi and lung, digestive tract are open. Under certain conditions, evaporation and aerolization of light droplet nuclei might be possible. Of course, if the virus exists in the body. However, we have to assume that it is just in case.

My practical recommendations

Delay of the autopsy is not only unnecessary but contra productive because SARS-CoV-2 virus needs only mucous epithelial cell for reproduction. The body becomes more favorable without immunology mechanisms of the living organism. The viral load increases during the delay. This is in contrast with HIV which is a blood infection.

The autopsy room should be prepared by vacuuming. Floors, walls, and tables should be cleaned by water horse spray without using any disinfectant because the goal is to diminish the amount of dust though it will remain anyway. Disinfection would be obligatory after the autopsy procedure.

The body should be washed, especially the upper part (face, shoulders).

Every splash outside the body on the table and the floor should be immediately washed off to prevent evaporation and as a result the virus aerolization .

Minimal use of sawing that create particles which can be loaded with evaporating/aerolized infectious material. Open the chest cage through the cartilages of sternum ribs junctions cut by dissection knife. CDC’s recommendation for using hand shears as an alternative cutting tool is ineffective and wrong because some particles are generated and they fall down into the thorax cavity.

The pathologist should see the organs with no delay after evisceration.

The body should be closed as much as possible fast.

Personal Protective Equipment (PPE) is discussed in a special post. Again, the main thing is not donning, which is completely adequate according OSHA regulations, but careful professional donoff is essential. Double gloves, although OSHA does not require them, are always reasonable during an autopsy with immediate replacement after any evidence or suspicion of a tear.

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