The risk of in-flight transmission of novel coronavirus among passengers is considered to be low. But studies published recently show that the virus can spread to other passengers.
In one study, the researchers found one symptomatic passenger seated in business class had transmitted SARS-CoV-2 virus to at least 15 other passengers during a direct flight from London to Hanoi.
- Though no genome sequencing study was undertaken to confirm in-flight transmission, the researchers undertook in-depth analysis.
- Epidemiological upstream and downstream investigations, quarantining the passengers, and laboratory testing were undertaken to support their hypothesis of spread during the 10-hour flight.
- The interviews did not reveal that any of the additional persons with flight-associated cases had been exposed to SARS-CoV-2 before or after the flight during their incubation periods other than having taken the same flight as the index case.
- The most likely route of transmission during the flight is aerosol or droplet transmission from index case, particularly for persons seated in business class.
- Besides thermal imaging, current guidelines recommend only the use of face masks with no additional measures to increase physical distance on board, such as blocking the middle seats.
- While masks can cut the risk of transmission, the absence of physical distancing, especially in economy class may increase the risk of virus spread.
- The findings challenge these recommendations. Transmission on flight was clustered in business class, where seats are already more widely spaced than in economy class.
- Infection spread much further than the existing two-row or two-metre rule recommended for COVID-19 prevention on airplanes.
- They also note limitations of thermal imaging and self-declaration of symptoms. They also note that it has been hypothesised that a combination of environmental factors on airplanes can prolong the presence of SARS-CoV-2 in flight cabins.
