May 15, 2020, ©. Leeham News: In our Corner series about flying during the COVID-19 pandemic, we dig deeper into the knowledge around when a person is infectious and what to do about it in a air travel setting.
The key to getting air travel to restart is to find ways to avoid passengers infecting each other and airport/airliner personnel. This involves the whole event, from leaving the car or public transport at the airport until one enters public transportation or a car at the other end.
IATA (the airline association) has published additional information this week on top of what we referenced last week. We also got a tip of an even deeper information source. The German public broadcaster NDR has made 41 (so far) podcasts around COVID-19 with Professor Drosten, the lead virologist of Berliner Charite’, the top German research hospital.
You find the German podcasts here.
Each interview is transcripted, and all research studies Drosten comments around are referenced in the transcripts. A virus expert condenses decades of worldwide virus research and knowledge around COVID-19 for us.
The key insights that are relevant to air travel from this series:
We now know, according to Drosten, that a person that gets infected with COVID-19 is infectious two days before he gets symptoms, with his most infectious start the day before symptoms. After a week, you don’t infect other people anymore.
But, detailed research, with repeated 100% testing over time in an isolated village in North Italy, shows 44% of infected persons are symptom-free! They have no knowledge they are infectious or have COVID-19.
This explains why IATA, in COVID-19 information issued earlier in the week, says checking the temperature of passengers before they, for instance, pass security has limited value. It might still be done, but more for reassuring passengers than effectively stopping infectious passengers to board planes.
The adequate checks are so-called PCR swab checks that detect the existence of COVID-19 viruses in a person’s nose/mouth. Right now, PCR checks that are practical to use around the check-in at an airport are a few months away.
My comment: When they are with us, they should form the base for a re-established air travel system without the need for further checks and quarantines.
Given that you don’t know if you (or any other person) are infectious, does everyone wearing a mask help? Yes, it does, says Drosten.
A detailed study in Hong Kong found no trace of viruses in the exhaled air from virus-infected persons wearing standard cotton masks.
At the same time, persons without masks had viruses in their exhaled air (the study sucked up all exhaled air during 30 minutes from persons infected with different types of viruses, including Coronaviruses).
Drosten emphasized masks stop you from spreading viruses to others; it’s their most crucial function. Even simple masks diffuse the exhaled air jet, Figure 1. Their stopping of a droplet jet means wearing any mask type is better than none.
My comment: As half of us with infections don’t know we’ve got it, we protect others by wearing masks. Wearing a mask is comforting, as this reduces the risk of me infecting others.
IATA gave further information about the risk to persons working at the airport and in the aircraft.
The airport and airline personnel that are interacting face to face with hundreds of travelers each day need the best possible protection for their nose, mouth, and eyes. Here masks and eye protection to hospital standards are motivated.
The relative safety of the traveling passenger and the risk to the crew we talked about last week is supported by further statistics that IATA provided.
We dig into this data and other studies around the risk of passenger-to-passenger infections next week.