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Are airplanes a COVID19 transmission nightmare? A thread (because I am asked this a lot ) People don’t realize that air exchanges and HEPA filtration in an airplane provide better than average indoor air quality - you aren’t just all breathing the same tube of contaminated air.
The environmental control system used in commercial aircraft generally reduces spread of airborne infection -perceived risk is greater than the actual risk. Points: 1`)TB transmission -within 2 rows and spending >8h = higher risk, overall < or = spread versus other small spaces.
2) SARS 2004 -was thought to be spread on 5/40 investigated flights, mostly within 5 rows of the index case –the worldwide total infection was only ~8000, so these numbers were from very few infected travelers. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7134995/.
3) Pandemic influenza on planes: 4/18 reported studies, no secondary cases but ?publication bias. Secondary cases estimated 3.7 to 5.3 dep on time/flight size, so a pretty low attack rate and presumably no precautions were used. (refs from https://www.medrxiv.org/content/10.1101/2020.04.01.20049528v1.article-info)
5) COVID-19: one flight (index patient with dry cough) resulted in 0/350 infections in other passengers, and other flights with an infected person, no transmission. One UK to Vietnam flight-14 infections, handful of other cases on survey of 4 airlines. Just a handful documented.
Airplane transmissions are dwarfed by outbreak volumes from nightclubs and churches…context is important: worldwide cases are climbing by a million a week right now, and there are >50,000 flights a day (Normal was >100,000/d and the lowest in April was still around 30,000/day.
Beyond plane risk, I think we need to be careful about travelling across risk gradients (wouldn’t want to introduce infection in a lower risk area or bring it back from a higher risk area.) Travel involves lineups, ground transport, getting food in public spaces...
...these risks to and fro that may be more worrisome than an airplane itself, although could be manageable between low risk areas. I also am somewhat disappointed that low density/distanced seating appears to have fallen by the wayside.
We’ll need to keep track of the COVID-19 contact tracing experience around air travel with screening, hand hygiene, and masks. But - the airport bar may be higher risk, and airplanes themselves are really not as bad as they intuitively seem.
So – am I flying? I *might* (Maybe. Perhaps.) for a really serious family reason, depending on destination...for now we’ll stick with local tourism/camping. But I am sure I am not alone in wishing we could return to good old “precedented times.” /end
Woops wrong reference the plane summary stuff was drawn from the research they used in this modelling paper: https://www.medrxiv.org/content/10.1101/2020.06.10.20127977v2.full.pdf
