Tested for Covid before flying, number of travelers infected reduces to just 0.05% – one in 2,000 – study suggests
- A new study looked at 10,000 passengers tested to fly from the US to Italy between December 2020 and May 2021
- Not being tested was linked to estimated prevalence of COVID-19 infection on flights of up to 0.2% or one in every 500 people
- Getting a nose swab up to 72 hours before the flight and an airport test led to a prevalence of 0.05% or one in 2,000 travelers
- Researchers say findings show preflight testing programs can dramatically reduce risk of cases and lead to safer flights
Testing for COVID-19 before a flight could significantly reduce the number of travelers infected, a new study finds.
Researchers from the Mayo Clinic, the Georgia Department of Public Health and Delta Air Lines looked at different testing strategies for air passengers.
They found that getting a nose swab up to 72 hours before the flight reduced the number of infected customers to about 0.05 percent.
That equates to about one in 2,000 people who test positive for the virus.
The team says the findings show that preflight testing programs can help dramatically reduce the risk of infection and lead to safer flights.
A new study from the Mayo Clinic examined 10,000 passengers who were tested to fly from the US to Italy between December 2020 and May 2021. Pictured: A man receives a COVID-19 test from a nasal swab at Tom Bradley International Terminal at Los Angeles International Airport, December 2020
Not being tested was linked to the estimated prevalence of COVID-19 infection on flights of up to 0.2% or one in every 500 people. Getting a nose swab up to 72 hours before the flight and an airport test led to a prevalence of 0.05% or one in 2,000 travelers
For the study, published in Procedures Mayo Clinic, the team looked at Delta’s preflight testing program that ran from December 2020 to May 2021.
The program allowed people to travel internationally and avoid quarantine if they tested negative before arrival.
Data was examined from 9,853 people traveling from Hartsfield-Jackson Atlanta International Airport in Atlanta or John F Kennedy International Airport in New York City to Rome or Italy.
There were five different testing options: a 72-hour pre-flight molecular test and an airport molecular test; 72-hour pre-flight molecular test and an airport antigen test; antigen test only at airport; molecular test only at airport; or don’t test.
Molecular testing, also known as polymerase chain reaction (PCR) testing, is considered the gold standard in COVID-19 testing.
They are considered very accurate because they detect coronavirus genetic material in a patient’s mucus or saliva.
However, they are expensive and have a long lead time because the sample must be sent to a lab and analyzed by a professional.
It generally takes at least two days for results to be returned, making it difficult to use PCR testing for widespread surveillance.
Meanwhile, rapid tests look for antigens or proteins found on the surface of the coronavirus.
This screening method is faster, with results coming back within 15 minutes, but less accurate, as patients are more likely to have false negatives — getting a negative result even though they are actually infected.
Of the nearly 10,000 passengers who underwent testing, four — 0.04 percent — who tested positive by both the molecular test and the rapid antigen and were not allowed to fly.
There were no false positive rapid antigen tests.
That means only one in about 2,000 people flying with Delta Air Lines is likely to be infected with COVID-19
“That’s a damn low number,” lead author Dr. Aaron J Tande, an infectious disease specialist at the Mayo Clinic, told me. CNBC.
The no-test option — for those who chose to quarantine abroad — was most likely to be infected on board at 0.2 percent, or one in every 500 people.
The authors say there are restrictions, including those who suspected they were infected and did not fly and those who are more careful about wearing masks and social distancing because they knew they couldn’t fly if they caught the virus.
“I can’t say that’s why the positive test rate was so low — or was it really that the 72-hour test was so good,” Tande told CNBC.
“But… the end result is that it’s a safer flight for people, and that’s what we want.”