Delta Airlines said that it has used electrostatic spraying on all its flights since May. The sprayers disinfect aircraft cabins from floor to ceiling, sanitizing areas that employees and passengers frequently touch. The sprayers electrically charge and disperse liquid disinfectant in a fine mist that clings to surfaces. (Delta Airlines)
While airline travel has dropped sharply this year as compared to last year due to the COVID-19 pandemic, travel medicine researchers have plumbed evidence that points to ways to spur safer travel and public confidence in such travel, including testing of all airport personnel, the institution of homogenous safety measures by the airlines, sniffer dogs to detect COVID-19 infected travelers, photo monitoring of mask use at airports, and antigen/saliva-testing methods that offer promise as cheaper alternatives to nasal PCR tests.
"What I found interesting is that essentially airlines are following the rules by the International Air Transport Association [IATA], for example by making people wear masks, disinfecting airplanes, etc., but the way that airlines are following those regulations is strongly dependent on their interpretation," Michel Bielecki, a doctor at the University of Zürich Centre for Travel Medicine, told a recent Connected Aircraft Podcast.
"We have certain airlines who disinfect [planes] before every flight or after every flight, depending on the length of the flight, and you have other airlines who say, 'Ok. We're just going to do it once a day,'" he said. "In general, you have lots of airline-specific differences that make it quite difficult for a passenger nowadays to travel from A to B. I travel quite a lot. Two weeks ago, I was traveling to Greece. A lot of airlines are requesting you to fill out a passenger locator form. What I didn't know was that you didn't only have to fill one out by the airline but also the government. I ended up getting denied boarding because this difference was not clear to me at the gate. I wasn't the only one. There were five or six people who couldn't go on the plane because of that."
Another issue has been the lack of jurisdiction uniformity in the acceptance of at-home, pre-travel COVID-19 screening tests.
An essential factor in rejuvenating safer air travel "is that information has to be conveyed to passengers in a way that is easy to follow, and that is the same across all the airlines rather than having to look up very specific rules that change from week to week [and] from airline to airline," Bielecki said.
The Connected Aircraft Podcast featured Bielecki and Patrica Schlagenhauf, a professor of travel medicine at the University of Zürich, discussing a narrative review of the effectiveness of COVID-19 air travel measures, Air Travel and COVID-19 Prevention in the Pandemic and Peri-Pandemic Period. Schlagenhauf led the researcher team that produced the narrative review.
Schalagenhauf stressed that safer air travel depends on a "curb to curb," multi-pronged approach.
Pre-flight screening of passengers is not enough, as demonstrated after the crash of an Air India re-patriation flight carrying Indian emigrant workers from Dubai to Kozhikode airport in India on Aug. 7. While all 199 passengers had pre-flight negative tests for COVID-19, after the crash the surviving passengers "were exposed to rescue workers, security and government officials, and volunteers who rushed to the scene at the crash site," without any knowledge of their COVID-19 status, according to the narrative review.
"Given the COVID-19 status of the formal and informal responders were unknown and the airport was located in a high transmission area designated as 'hotspot’, all rescued passengers and responders were quarantined and subjected to COVID-19 testing," the review said. "The entire District Government Office and airport emergency staff were quarantined, compromising the capacity of government and airport function in addition to adding to the COVID-19 response burden in the airport vicinity."
Schlagenhauf and Bielecki said that airlines and airports should have protocols that account for emergencies during pandemics, including COVID-19 testing for all airport staff and first responders, triage plans, a maintenance pool of vetted volunteers from the community familiar with disease mitigation concepts who could improve emergency response capacity, and surplus personal protection equipment.
The narrative review casts doubt on the use of temperature scanners for COVID-19 detection. Bielecki said that children, for example, also will not show elevated temperatures or for only a short period of time. Better detection includes pre-flight passenger questionnaires regarding symptoms and antigen, saliva, or PCR tests.
While PCR nasal swab testing is the gold standard that some airports have rolled out, less costly methods, such as antigen or saliva tests, are likely preferred alternatives, as PCR testing can add $150 or more to a passenger ticket and as antigen/saliva testing are a "fraction of the cost" and "just as effective, if not even more sensitive" in detecting the virus than nasal swabs, Bielecki said.
Yet, thus far, it appears that saliva testing, while less time consuming, can be costly as well.
JetBlue, for example, offers a physician-ordered and supervised at home saliva test for prospective passengers through Vault Health, but that test costs $119. A Vault Health supervisor oversees the test via Zoom and lab results are provided within three days, JetBlue said.
Schalagenhauf said that airlines are trying to be innovative in their efforts to ensure safe travel. Turkish Airlines, for example, has significantly altered its inflight meal process. "To minimize contact between crew and passengers in accordance with health recommendations, we have prepared sanitary packed meals for contactless in-flight dining," the company said.
Using sniffer dogs to detect COVID-19 also holds promise as an alternative to the invasive and costly PCR tests. In a pilot project, three dogs at Finland's Helsinki Airport in September have sniffed skin swabs from several thousand arriving passengers since September and the preliminary results look as if the COVID-19 positive rate is on par with that of the PCR tests, which can take a week more for processing than the skin swab samples.
"Dogs are extremely sensitive to detecting infections in people," Schlagenhauf said. "They've been used to detect malaria in people, and they're widely used in airports to detect drug trafficking."