According to a survey conducted earlier this year, there may be a way to reduce the number of Covid infections on commercial aircraft to almost zero.
The study results were published September 1 in a peer-reviewed article published in the Mayo Clinic Proceedings Medical Journal. This article, in collaboration with Georgia’s Department of Public Health and Delta’s Mayo Clinic, found that a single polymerase chain reaction (PCR) test performed within 72 hours of flight showed the percentage of infected passengers on board. It was reduced to 0.05%. It is 5 for every 10,000 passengers.
At the time of the survey, the infection rate in the United States was 1.1%, or about 1 in 100.
The findings analyzed data from Delta’s pre-flight test program, which ran from December 2020 to May 2021.
Here’s how Delta’s testing program works: Passengers on some flights from New York City and Atlanta were able to fly to Italy without quarantine upon arrival if they tested positive for COVID-19 within 72 hours of the flight. The test was negative. Antigen test before departure and rapid antigen test on landing.
Data from Delta’s pre-flight test program provides new information on test feasibility, test accuracy and passenger infection rates on commercial flights.
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Of the 9,853 people who tested negative in the PCR test, four tested positive on the rapid antigen test at the airport. The diagnosis was confirmed by rapid molecular testing and these people were not allowed to fly.
One of the passengers on the flight to Italy was positive at the time of landing.
According to the article, this corresponds to the detection of one case per 1,970 travelers during a “high prevalence of active infection in the United States”.
Dr. Aaron J. Tande, an infectious disease specialist and lead author of the article at the Mayo Clinic in Rochester, Minnesota, said:
The study shows that a single PCR test within 3 days of flight eliminates the need for subsequent tests at the airport.
“Borders” of Research
Journal articles list some “limitations” that may have affected the results of the study, such as the role of pre-flight testing in passenger behavior. Participants who were suspected of having a COVID infection may have opted not to travel. According to Tande, others may be more excited about wearing a mask and self-isolating, knowing they had to test negative to fly.
“I can’t say that we have reduced the number of positive tests that much, or that it was really true that the 72-hour test was so good,” he told CNBC. “But … the end result is that it’s a safe flight for people and that’s what we want.”
According to Tande, the findings are based on the COVID-19 strain that was prevalent in the United States in early 2021 and not the more infectious delta mutants that are currently mainstream.
“I don’t think we’ll get exactly the same results if we replicate this study now that community infection rates and viruses are different,” he told CNBC. “I think the infection rate on board will drop significantly.”
Safer but less viable option
The pilot program considered five testing strategies, two of which may have detected more infected leaflets.
For example, a rapid molecular test at an airport can detect more infections as the time between test and flight is shortened and infections that occur during that time can be detected. Studies show that adding a 72-hour PCR preflight test can find even more.
Although the airport was not designed for large-scale medical examinations, several airports set up temporary facilities last year, including Fiumicino International Airport in Rome.
Alessia Pierdomenico | Bloomberg | Getty Images
However, one of the pre-flight PCR tests is a “better approach” because it is more feasible, Tande said. He said PCR tests are widely available and more “sensitive”, meaning they are better at detecting positive cases and removing the logistics of testing from the airport. The initial test gives infected passengers time to reorganize their plans instead of being surprised just before the flight’s departure.
Flight test or vaccination?
Pre-flight PCR testing can make a flight safer, but most passengers are currently flying without it. And airlines are tight-lipped about mandating them in the future.
However, testing international flights may become a de facto rule if the country of arrival requires passengers to enter the country. A Delta spokesperson did not say whether it would require screening of passengers, but said that “governments are responsible for setting their own requirements.”
Tande said that when passengers need to pass a pre-flight PCR test, they find it safer to fly. Still, he said he would prefer only vaccinated flights if given the option.
“I would definitely go on a vaccination flight – and (I) would wear a mask,” he said.
According to news.com.au, Qantas CEO Alan Joyce said last week that passengers on international flights need to be vaccinated. As The Washington Post reported this week, US officials are currently debating whether vaccinations are required to fly domestically and internationally.
“Unfortunately, because of the vaccination attitude, COVID will be with us for a long time,” Tande said. “Consistent masking and testing before flight will improve safety and allow us to continue to function as a normal society.”