Japan’s National Institute for Infectious Diseases published an epidemiological investigation showing long range airborne transmission on a plane. It occurred in Mar 2020. It was published in Oct 2020, in Japanese only. Google translate makes it pretty readable.
Main takeaways:
- started off following the “2 row rule” but after finding a bunch of infections near the index case they expanded and expanded and eventually tested 122 out of 141 passengers.
- found 14 PCR positive passengers.
- found several others with symptoms who they did not test.
- confirmed that all positives were an RNA match for the index case.
- it travelled far - furthest infection was 16 rows in front of index case with another 4 infections 9 rows in front and one 6 rows behind. Also, some of the symptomatic, untested people were far from the index case.
- index case had a severe cough but did not wear a mask
I have translated the seating diagram published in the report from Japanese to English. I don’t know why there are 2 “3rd tests”, that was in the original Japanese.
In the discussion they mention droplet and “マイクロ飛沫感染” - micro-droplet - infection in-flight. They also say that they didn’t have aircondtioning and ventilation information or pre-boarding passenger interaction information.
I often hear that “Japan understood this was airborne from the start” and it’s half true - some scientists here knew and the “3 Cs” guidance has been good but a lot of the response has been focused on droplets and fomites, cleaning and perpex barriers.
All of the information in this report was available in March 2020. It’s really disappointing that this was not published sooner and more broadly as it seems like it would have been strong evidence for airborne spread and also strong evidence against the safety of air travel. Especially given the full RNA analysis and almost complete test coverage os passengers
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