Please see the comment at the end of this post regarding conflict of interest for the authors. Thanks to our readers for pointing out that I missed some fine print.
Written by Clay Smith
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”The risk of contracting coronavirus disease 2019 (COVID-19) during air travel is lower than from an office building, classroom, supermarket, or commuter train.”
Why does this matter?
This was a patient information page in JAMA, which we usually don’t cover, but this is of such import for our patients and our own personal lives that I thought we should review it. Anyway, I learned a lot…
Flying tube of germs or flying HEPA filter?
COVID-19 is primarily transmitted via respiratory droplets. Before you aerosol scientists send me hate mail – SARS-CoV-2 simply does not behave like true airborne pathogens, such as measles, varicella, or TB. But it is well known it may spread further than 6 feet under the right circumstances. So, what’s the risk on a plane? There are only 42 known cases of COVID-19 related to air travel across the globe. Contrast that to a transmission rate of 0.3% on high speed trains in China, with 2,300 infected. On a plane, air flows from numerous overhead vents to floor-level air returns, 50% fresh outside air is introduced, and all return airflow passes through a HEPA filter (see figure). Transmission of COVID row to row is unlikely, as there is little airflow between rows. All cabin air is completely exchanged every 2-3 minutes in modern aircraft. Masks, temperature/symptom screening, disinfection, hand-washing, and physical distancing mitigate the risk further. The best thing to do if you need to fly is wear a mask, point the overhead vent at your face, and turn it on full blast. Oh…and wash your hands often.
Source
Risk of COVID-19 During Air Travel. JAMA. 2020 Oct 1. doi: 10.1001/jama.2020.19108. Online ahead of print.
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Clay!
I hope this piece is true and logically it makes sense from an airflow point of view, and I really want it to be true, but you make no mention of the conflicts of interest in the article. Namely, that "Dr Pombal reported being an employee of TAP Air Portugal Group Health Services and is chairperson of the Aerospace Medical Association Air Transport Medicine Committee. Dr Hosegood reported being an employee of Qantas Airways and is president of the International Airline Medical Association. Dr Powell reports receipt of personal fees from the IATA." While I believe that their qualifications place them in a strata capable of being able to discuss such matters, it also calls into question their analysis as the financial implications to the airline industry are immense as is being able to have this published in JAMA as part of their Patient Page series.
Ian C. May, MD FACEP
Great point. I missed the fine print at the bottom. Thanks for bringing that to my attention. Seems like more disinterested parties would have made a more compelling case.