Preprint Concept Paper Version 2 Preserved in Portico This version is not peer-reviewed

The Airborne and Gastrointestinal Coronavirus SARS-COV-2 Pathways

Version 1 : Received: 6 April 2020 / Approved: 9 April 2020 / Online: 9 April 2020 (02:40:16 CEST)
Version 2 : Received: 12 April 2020 / Approved: 13 April 2020 / Online: 13 April 2020 (10:12:52 CEST)

How to cite: Santa-Coloma, T. The Airborne and Gastrointestinal Coronavirus SARS-COV-2 Pathways. Preprints 2020, 2020040133. Santa-Coloma, T. The Airborne and Gastrointestinal Coronavirus SARS-COV-2 Pathways. Preprints 2020, 2020040133.


Since there is not a clear consensus about the possibility for COVID-19 to be an airborne disease, exists a controversy regarding the need to use surgical masks to prevent its spread. Here, using the Kepler conjecture for ideal packaging, the number of virions of different sizes that can be accommodated inside droplets was calculated and are proportional to the 3rd potency of the droplet/virion diameter. The differences between particles of 5 um and 100 μm are around four orders of magnitude, explaining why the airborne spread is much more difficult but still possible. There is no solid evidence yet that the airborne coronaviruses may reach enough concentration to infect, but this may be the case under certain circumstances. The WHO partially recognizes now this fact in a warning to health workers (from my point of view too late, as it was the declaration of a pandemic). Another issue is whether the virus stays infective in aerosols generated from patients. This has not been directly proved yet except with artificial aerosols, but there are no reasons why the virus cannot remain in the air and be infective if the viral charge and time of exposure are enough. We must also consider whether the virus can infect the intestine; there are some signs in this sense. Finally, and most importantly, we need to reduce interactions by using surgical masks to flatten the curve, leave the quarantine and avoid a rebound. For cultural reasons, a social distance of 2 meters (2M) is extremely hard to manage. Surgical masks do reduce the interactions in conditions of proximity and, therefore, help to “flatten the curve”. The WHO and CDC “laissez-faire” on this matter do not help and we are running out of time. Anticipated actions, such as the use of surgical masks for the general population, are critical.


ACE2, airborne; coronavirus; COV-2; COVID-19; food chain; intestinal infection; Kepler conjecture; rebound epidemic; packaging; particle size; SARS; surgical masks.


Biology and Life Sciences, Virology

Comments (1)

Comment 1
Received: 13 April 2020
Commenter: Tomas Santa Coloma
Commenter's Conflict of Interests: Author
Comment: A file with correction label in red was added as supplementary file, not to be published.
Many corrections of style were made.
Some paragraph were added to the text.
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