In March, before the masks became commonplace, German tourists infected with the coronavirus returned from Israel on a flight lasting more than four hours, from which, to the surprise of a group of researchers, only two infections from other passengers were identified.
In a brief study published Tuesday in the American journal Jama Network Open, virologists at Frankfurt University Hospital meticulously contacted all the flight’s passengers in order to discover the real risk posed by the presence of passengers infected with the virus responsible for covid-19.
On 9 March, the Tel Aviv-Frankfurt flight, which lasted 4 hours and 40 minutes, had 102 passengers on board, including a group of 24 tourists.
The German authorities, after receiving information that the group had been in contact with a contaminated hotel manager in Israel, decided to test the 24 tourists upon their arrival in Frankfurt.
Seven of them tested positive (seven more would later report it).
Four to five weeks later, the researchers contacted the remaining 78 passengers, 90% of whom responded.
When asked about their contacts and symptoms, and testing several of them, they found two passengers who probably became infected during the flight: two people sitting across the aisle from the original seven cases.
For respiratory viruses, virologists traditionally consider the contamination zone on an airplane to extend two rows forward and two rows back.
But surprisingly, one person sitting in the row (seat 44K) immediately in front of two tourists carrying the virus (seats 45J and 45H) was not infected.
“The person in row 44 told us that he had had a long talk with the two in row 45,” Sandra Ciesek, director of the Institute of Medical Virology in Frankfurt, told AFP.
Nor was there any infection in two passengers sitting right behind another infected tourist.
“We were surprised to find only two transmissions,” said Sebastian Hoehl, from the same institute.
However, all other passengers were not tested, so it cannot be ruled out that others were infected. The study confirms in all cases that transmissions on an airplane, in the absence of masks, are indeed possible.
But, the researcher stresses, “being the rate lower than expected, and being that none of the passengers were wearing masks, it is reassuring that we have not detected others”.
And the researchers point out that several studies of repatriation flights from Wuhan, China, at the start of the pandemic established that no contagion had occurred on board, although on those trips passengers wore masks.
By AFP
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