German study shows ‘lower than expected’ risk of coronavirus transmission on planes

Wearing masks to prevent the spread of the coronavirus was not widespread in March, when a group of German tourists took a long flight home from Israel – but researchers were surprised to find only two passengers outside the group had been infected.

German study shows 'lower than expected' risk of coronavirus transmission on planes
A plane in Bavaria. Photo: DPA

In a short study published Tuesday in the US medical journal JAMA Network Open, virologists at a university hospital in Frankfurt, Germany meticulously contacted all of the passengers from the flight – none of whom had worn masks at the time – to examine the actual risk posed by the presence of travelers infected with COVID-19.

On March 9th, 102 passengers boarded the Tel Aviv-Frankfurt flight that lasted four hours and 40 minutes, including a group of 24 tourists.

German authorities were alerted that the group had come into contact with an infected hotel manager in Israel, and decided to test the 24 tourists upon their arrival in Frankfurt.

Seven of them tested positive, as did another seven later on.

Four to five weeks later, researchers contacted the 78 other passengers from the flight, 90 percent of whom responded. The researchers asked them whom they had come into contact with and what symptoms they had, and tested several
of them.

READ ALSO: Germany plans to make face masks mandatory at airports

They found two passengers were most likely infected during the flight: the two people sitting across the aisle from the original seven cases.

For respiratory viruses, experts traditionally consider the contagion zone in an airplane to extend two rows of seats in front of the infected person and two rows behind.

But shockingly, a person seated in the row (seat 44K) directly ahead of two of the infected tourists (seats 45J and 45H) was not infected.

“This person from row 44 told us that he had a long conversation, and was speaking a long time with both of row 45,” Sandra Ciesek, the head of the Institute of Medical Virology in Frankfurt, told AFP, noting that made it all the more surprising he was not infected.

READ ALSO: How face masks have helped slow down the spread of coronavirus in Germany

The two passengers seated directly behind another infected tourist also did not contract COVID-19.

“We were surprised to only find two likely transmissions,” said Sebastian Hoehl, from the same Frankfurt institute.

All of the other passengers were not tested, so researchers could not exclude that some of them might have been infected. The study stresses that, in any case, viral transmission on an airplane is indeed possible if passengers do not wear masks.

But, Hoehl noted, “as the rate was lower than what we expected, and as none of the passengers wore masks, I think it is reassuring that we could not detect more” cases.

The researchers also said that multiple studies on repatriation flights from Wuhan, China at the start of the pandemic found that no transmissions occurred on board while passengers were masked.

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Pandemic in Germany unlikely to end this year, says top virologist

High profile German virologist Christian Drosten believes Germany will see a severe spike in Covid infections after summer, and that the pandemic will not become endemic this year.

Pandemic in Germany unlikely to end this year, says top virologist

Drosten previously said that Germany would probably be able to declare the end of the pandemic this year.

But in an interview with Spiegel, Drosten said he had reevaluated his opinion. 

“When the Alpha variant came, it was very surprising for me. When Delta appeared I was sceptical at first, then with Omicron we had to reorient ourselves again. And since January there have already been new Omicron subtypes.

“So I would actually like to correct myself: I no longer believe that by the end of the year we will have the impression that the pandemic is over.”

READ ALSO: End is in sight for pandemic in Germany, says virologist 

Drosten also said that Germany will not see a largely Covid-free summer, which has been the case in previous years, and a further increase in infections in autumn. 

“We are actually already seeing an exponential increase in case numbers again,” Drosten said.

“The BA.5 variant (of Omicron) is simply very transmissible, and people are losing their transmission protection from the last vaccination at the same time.”

In other countries, he said, when the number of cases become high, hospitalisation and death rates also rise again. “Unfortunately, that will also be the case here,” said Drosten, but added: “Overall, however, far fewer people will become seriously ill and die than in 2021.”

Drosten said he expected many more infections from September.

“I hope that the school holidays will dampen the increase in cases somewhat. But from September, I fear we will have very high case numbers,” the head of the virology department at Berlin’s Charité hospital told Spiegel.

READ ALSO: German Health Minister lays out autumn Covid plan

Virologist Christian Drosten at a Covid press conference in 2021.

Virologist Christian Drosten at a Covid press conference in 2021. Photo: picture alliance/dpa | Kay Nietfeld

If the government does not take any action, he predicted there would be a lot of sick leave across all industries. “That will become a real problem,” he said.

Drosten said he did not expect overcrowded intensive care units in Germany.

But the new BA.5 sub-variant, which is becoming dominant in Germany, may affect people more strongly. 

“The wheel is turning more towards disease again,” said Drosten. It is not true that a virus automatically becomes more and more harmless in the course of evolution. “That makes me even more worried about the autumn,” he said.

Drosten recommends wearing masks indoors during the colder months, saying it is “the least painful” measure.

If, in addition, “up to 40 million people could be immunised or given a booster vaccination” before winter, for example by urgently calling for company vaccinations, that would “really make a difference”, Drosten said.

In the long term, he said it’s inevitable that people will become infected with coronavirus.

He said the population immunity due to vaccinations and infections will at some point be so strong that the virus will become less important. “Then we will be in an endemic state,” said Drosten. In the worst case, however, this could take “several more winters”.

However, Drosten warned against people trying to deliberately infect themselves with Covid, saying getting the infection in summer doesn’t mean people will be protected in winter. 

Drosten himself said he has not yet contracted Covid-19.

“So far, I guess I’ve just been lucky,” he said. “I rarely put myself in risky situations, but I’m not overly cautious either.”

‘Pandemic depends on behaviour’

According to the Robert Koch Institute (RKI)’s latest weekly report, more outbreaks are occurring in care homes, and the number of patients in intensive care units is slightly rising as infections go up. 

The institute said there had been a 23 percent increase in the 7-day incidence compared to the previous week. On Friday the 7-day incidence stood at 618.2 infections per 100,000 people. There were 108,190 infections within the latest 24 hour period and 90 deaths. 

“The further course of the pandemic depends not only on the occurrence of new virus variants and the uptake of vaccinations on offer, it also depends to a large extent on the behaviour of the population,” said the RKI.

According to the DIVI intensive care register, the number of Covid-19 patients in ICUs had increased to 810 on Thursday this week, from about 600 at the beginning of the month.

However, that number is still low compared to previous Covid peaks when thousands of people were in intensive care in Germany.