‘Bad math’: Airlines’ COVID-19 safety analysis challenged by expert

Scientists are poring over dozens of on-board infection cases, as well as flights with contagious passengers but no known transmission. (AP)
Short Url
Updated 19 October 2020

‘Bad math’: Airlines’ COVID-19 safety analysis challenged by expert

  • Key assertion about the improbability of catching COVID-19 on planes was based on ‘bad math’
  • ‘Long flights ... can provide conditions for superspreader events’

PARIS: A campaign by coronavirus-stricken aviation giants to persuade the world it’s safe to fly has been questioned by one of the scientists whose research it draws upon.
Dr. David Freedman, a US infectious diseases specialist, said he declined to take part in a recent presentation by global airline body IATA with planemakers Airbus, Boeing and Embraer that cited his work.
While he welcomed some industry findings as “encouraging,” Freedman said a key assertion about the improbability of catching COVID-19 on planes was based on “bad math.”
Airlines and planemakers are anxious to restart international travel, even as a second wave of infections and restrictions take hold in many countries.
The Oct. 8 media presentation listed in-flight infections reported in scientific studies or by IATA airlines – and compared the tally with total passenger journeys this year.
“With only 44 identified potential cases of flight-related transmission among 1.2 billion travelers, that’s one case for every 27 million,” IATA medical adviser Dr. David Powell said in a news release, echoed in comments during the event.
IATA said its findings “align with the low numbers reported in a recently published peer-reviewed study by Freedman and Wilder-Smith.”
But Freedman, who co-authored the paper in the Journal of Travel Medicine with Dr. Annelies Wilder-Smith of the London School of Hygiene and Tropical Medicine, said he took issue with IATA’s risk calculation because the reported count bore no direct relation to the unknown real number of infections.
“They wanted me at that press conference to present the stuff, but honestly I objected to the title they had put on it,” the University of Alabama academic said.
“It was bad math. 1.2 billion passengers during 2020 is not a fair denominator because hardly anybody was tested. How do you know how many people really got infected?” he said. “The absence of evidence is not evidence of absence.”
IATA believes its calculation remains a “relevant and credible” sign of low risk, a spokesman said in response to requests for comment from the industry body and its top medic Powell.
“We’ve not claimed it’s a definitive and absolute number.”
Wilder-Smith could not be immediately reached for comment.
While the pandemic has seen some airlines leave middle seats empty to reassure customers, the industry has opposed making such measures mandatory.
Plane cabins are considered lower-risk than many indoor spaces because of their powerful ventilation and their layout, with forward-facing passengers separated by seat rows. Ceiling-to-floor airflows sweep pathogens into high-grade filters.
That understanding is supported by simulations and tests run by the aircraft makers as well as a US Defense Department study released on Thursday.
The joint presentation with all three manufacturers signaled a rare closing of ranks among industrial archrivals, behind a message designed to reassure.
Sitting beside an infected economy passenger is comparable to seven-foot distancing in an office, Boeing tests concluded, posing an acceptably low risk with masks. Standard health advice often recommends a six-foot separation.
Airbus showed similar findings, while Embraer tested droplet dispersal from a cough. Some 0.13 percent by mass ended up in an adjacent passenger’s facial area, falling to 0.02 percent with masks.
Dr. Henry Wu, associate professor at Atlanta’s Emory School of Medicine, said the findings were inconclusive on their own because the minimum infective dose remains unknown, and risks increase in step with exposure time.
“It’s simply additive,” said Wu, who would prefer middle seats to be left empty. “A 10-hour flight will be 10 times riskier than a one-hour flight.”
Nonetheless, a commercial jet cabin is “probably one of the safer public settings you can be in,” he added. “Sitting at a crowded bar for a few hours is going to be much riskier.”
Scientists are poring over dozens of on-board infection cases, as well as flights with contagious passengers but no known transmission.
In March, 11 infectious passengers on a five-hour Sydney-Perth flight passed the virus to 11 others, according to a paper in the Emerging Infectious Diseases journal.
Among those infected, two were seated three rows away from a contagious passenger and one was six rows away, suggesting that typical two-row contact-tracing might have missed them.
One sufferer on a 10-hour London-Hanoi flight the same month infected 16 others including 12 in her business-class cabin, according to a study by Vietnamese and Australian academics.
“Long flights ... can provide conditions for superspreader events,” the study said, adding that its findings “challenge” the airlines’ assertion that on-board distancing is unnecessary.
IATA points out that many of the flights examined by scientists in published studies occurred before mask-wearing became widespread and reduced infection risks.
Its presentation conceded that the 1-in-27 million statistic “may be an underestimate,” while maintaining that in-flight infections remained less likely than a lightning strike, even if only 10 percent of actual cases had made the count.
“That’s misleading,” Emory’s Wu said. “Thinking about how hard it is to identify them, I wouldn’t be surprised if it’s far less than 1 percent. The only thing I’m sure of is that it’s a fantastic underestimate.”

US sanctions Chinese and Russian firms over Iran trade

Updated 27 min 33 sec ago

US sanctions Chinese and Russian firms over Iran trade

  • Four companies accused of ‘transferring sensitive technology and items’ to missile program

LONDON: The US has slapped economic sanctions on four Chinese and Russian companies that Washington claims helped to support Iran’s missile program.

The four were accused of “transferring sensitive technology and items to Iran’s missile program” and will be subject to restrictions on US government aid and their exports for two years, Secretary of State Mike Pompeo said in a statement.

The sanctions, imposed on Wednesday, were against two Chinese-based companies, Chengdu Best New Materials and Zibo Elim Trade, as well as Russia’s Nilco Group and joint stock company Elecon.

“These measures are part of our response to Iran’s malign activities,” said Pompeo. “These determinations underscore the continuing need for all countries to remain vigilant to efforts by Iran to advance its missile program. We will continue to work to impede Iran’s missile development efforts and use our sanctions authorities to spotlight the foreign suppliers, such as these entities in the PRC and Russia, that provide missile-related materials and technology to Iran.”

The Trump administration has ramped up sanctions on Tehran after withdrawing from the Iran nuclear deal in 2018.

Earlier this week, Pompeo met Kuwaiti Foreign Minister Sheikh Ahmad Nasser Al-Mohammad Al-Sabah, when the campaign of pressure on the Iranian regime was also discussed.

“I want to thank Kuwait for its support of the maximum pressure campaign. Together, we are denying Tehran money, resources, wealth, weapons with which they would be able to commit terror acts all across the region,” he said.

It is not yet clear how the incoming administration of Joe Biden will deal with Tehran and whether it wants to revive the nuclear deal which would be key reviving the country’s battered economy. The Iranian rial has lost about half of its value this year against the dollar, fueling inflation and deepening the damage to the economy.

Iran’s economy would grow as much as 4.4 percent next year if sanctions were lifted, the Institute of International Finance (IIF) said last week. 

The economy is expected to contract by about 6.1 percent in 2020 according to IIF estimates.