If flying is so dangerous right now, why do airline workers have lower overall infection rates than the general population? This is one of many questions being asked, as the world weighs travel restrictions, and the devastating effects covid-19 are having not only on the population, but economies worldwide.
The CDC just released a lengthy report on covid-19 transmission on board long haul flights from the days before masks were made mandatory onboard, and even then, transmission wasn’t nearly as bad as many would think.
But let’s start with the sobering reality. As surmised in the study: the risk of covid-19 transmission on planes is “real”. Also in reality, the risk of covid-19 transmission is real virtually anywhere that isn’t your own personal space, and therefore a trip to a local coffee shop may be a level of risk that’s understandably unacceptable for many.
For many people, travel is a risk too great right now, and there’s zero judgement on that front. People must assess risk as it applies to them, using as much scientific data as possible. Many travelers will be encouraged by the report in the sense that finding a spreader event was noteworthy, rather than “not” finding being of note.
Covid-19 Transmission On Long Haul Flights
The CDC studies examined a variety of flights from February, March and April, during peak covid-19 infection periods, and tested and traced not only passengers on board, but nearly all close contacts prior to, and after the flight.
Notably, the study followed these flights in February, March and April, long before masks were made mandatory or used at all, and before airlines stepped up cleaning measures.
Perhaps crucially, no pre flight covid-19 testing for international travel was in effect at this point either, and could have made all the difference in the worst case results. For symptomatic travelers, access to covid-19 testing was also scarce at the time, and in many cases, full symptoms hadn’t been addressed to the public yet.
The tl:dr story is that a flight had covid-19 spread to other passengers during this time, but others, even ultra long haul flights did not.
On a 15 hour flight from China to Canada, one person was known to be infected with covid-19 during the journey, but is not believed to have infected anyone on board the flight. After testing and tracing, not a single other person is known to have contracted covid-19, though limitations are noted. The CDC report states…
In January 2020, no secondary cases were detected after a 15-hour flight to Canada with a symptomatic person with COVID-19 on board (29), although contact tracing and monitoring were limited (30). Similar results with similar limitations have been reported from flights arriving in France (31,32) and Thailand (33) in January and February.CDC Report
Basically, before masks on board became a thing and airlines started handing out sanitizing kits for your seat and belongings, a variety of flights had infected passengers and after exhaustive research, the best conclusion was that no other flight passengers became infected on the majority of sampled flights.
The study woefully omits any recent data on flights in the following months since health and hygiene measures were introduced on board. A central focus of the CDC study was instead an outlier of spread from a flight in March, during the height of viral intensity in which a passenger knowingly put others at risk, and did.
Of the 5 main flights studied by the CDC, only one had defined covid-19 spread. A sixth flight from Singapore was also examined, where 16 covid-19 infected passengers were on board, but are believed to only have infected one additional person during the trip.
The flight from London to Hanoi in early March saw one passenger infect up to 16 people is believed to be the worst covid-19 spreader event in air travel studied. Those who were infected were almost all within close proximity to the spreader for the flight, which is legitimate reason to add pause, for some.
The passenger, which the CDC believes to be the “Case 1”, did not wear a mask or limit their movements while on board. Somewhat buried in the CDC report, the person was also knowingly symptomatic when they embarked on their travel journey, and ignored all warnings not to travel despite experiencing severe cough, shortness of breath and fever prior to flight.
The person was also in direct contact with someone who had just been in a highly infectious area, which is why country efforts to require covid-19 testing or additional quarantine restrictions for flights embarking from certain departure points adds a vital level of security.
Effectively, the spreader on this flight lied at check in when questioned about any of these symptoms, or their contact with people from high risk areas. In the least surprising news of 2020, people simply can’t be trusted to self isolate or cancel plans, no matter how much we wish it not to be that way.
Country or airline insistence on mandating recent negative covid-19 tests prior to flight could absolutely help in further mitigation of any travel related risks. Both Dubai and Emirates currently require a negative covid-19 test prior to flight, and before entry into the UAE, and after months of tourism has yet to experience a significant spike in cases. In Bahrain, of 713 new cases, 4 were believed to be travel related.
The airline doubled down by offering all passengers up to €150 in covid-19 related coverage, even for destinations beyond where they fly with Emirates for a period of 30 days. Virgin Atlantic and Etihad recently followed, with their own complimentary covid-19 cover for passengers.
But, what about short haul flights?
Short haul flights were recently hypothesized by MIT studies to carry a chance of covid-19 infection of between 1:4400 – 1:7700. The study gained traction with a separate new study suggesting cabin crew and customer facing airline staff in the USA have a .08% instance of covid-19 infection, compared to 2% for the general population.
Rather than being worse off for covid-19 infection, the data puts customer facing airline employees more than a single percentage point less likely to become infected.
Health officials currently recommend at least one fresh mask for every 4 hours of potential exposure, so if you’re taking a 10 hour flight, and have 4 hours of transit and airport time, plan to bring 14 hours worth of masks on board. That’s four masks, by the way. Regular hand washing and sanitizing of surfaces is also crucial.
The CDC report is far from a happy go lucky endorsements for a return to travel. However, the relatively low instance of new infection on flights, even in March before face masks, sanitizing products or mandatory covid-19 testing restrictions were added on board is encouraging. Use widely accepted available data to create your own risk assessment in travel.
For many, it’ll be a while before a long haul flight is appealing, either due to the risk or the restrictions, but for those who do travel responsibly it could be a lot worse right now.