A report published by members of Ireland’s Department of Public Health suggests that 59 cases of COVID-19 infection over the summer, including one ICU admission, were tied to a single long-haul flight arriving in the country over the summer. While stopping short of explicitly confirming the transmission on the plane, the report notes “the potential for in-flight/airport transmission exists in this outbreak.”
In-flight transmission is a plausible exposure for cases in Group 1 and Group 2 given seating arrangements and onset dates. One case could hypothetically have acquired the virus as a close household contact of a previous positive case, with confirmed case onset date less than two incubation periods before the flight, and symptom onset in the flight case was 48 h after the flight. In-flight transmission was the only common exposure for four other cases (Flight Groups 3 and 4) with date of onset within four days of the flight in all but the possible tertiary case. This case from Group 3 developed symptoms nine days after the flight and so may have acquired the infection in-flight or possibly after the flight through transmission within the household.
Only 17% of seats were occupied during the flight and most passengers wore masks on board. Still, 13 of the 49 passengers eventually tested positive; at least nine reported to be wearing masks throughout the flight.
They also transmitted the virus to 46 other people in Ireland. In one case a passenger transmitted it to a family member who then infected 25 of 34 other people in a shared accommodation facility.
Are masks and social distancing enough?
The researchers acknowledge existing reports suggesting “distancing and restricted crew/passenger interaction can contribute to prevention of COVID-19 transmission in-flight.” At the same time, the group notes, “It is interesting that four of the flight cases were not seated next to any other positive case, had no contact in the transit lounge, wore face masks in-flight and would not be deemed close contacts under current guidance from the European Centre for Disease Prevention and Control (ECDC).”
The country used the incident as the catalyst for increasing its restrictions, including informing all passengers when a positive case is reported on board and emphasizing Ireland’s 14-day restriction-of-movement policy for nearly all international arrivals.
Moreover, the researchers provided additional recommendations:
- When a positive COVID-19 case is linked to a flight, rapid flight contact tracing may prevent onward spread and we support the proposed EU digitalised public health passenger locator form and development of improved systems of tracing.
- Swift action is needed where cases with no other link emerge beyond the close contact two-seat radius to instigate early investigation and control measures.
- Enhanced surveillance should include transiting/transfer information to identify potential common links.
The flight in question appears – based on the seat map, cabin capacity and flight duration – to have been an A350-900 operated by Qatar Airways from Doha to Dublin.
A favor to ask while you're here...
Did you enjoy the content? Or learn something useful? Or generally just think this is the type of story you'd like to see more of? Consider supporting the site through a donation (any amount helps). It helps keep me independent and avoiding the credit card schlock.
Paging United Airlines and DoD to explain this…
No wonder Qatar offered those Covid insurance policies…
They didn’t take a hard enough look at the transit lounges or employee interactions on the ground. Doesn’t say whether these pax wore masks during transit or prior flights.
Also doesn’t trace back to prior flights.
The recommendations are fine – notify if there’s a case onboard. But really hard to judge in-flight transmission here.
The research does not explicitly state in-flight transmission, though it remains possible given the limited other interaction points for at least some of the passengers on this flight.
And the risk of transmission via travel in general is still very real.
Interesting – I guess if you wear a mask and board a plane you need the luck of the Irish to avoid getting Covid-19. Airplanes are still in the no fly zone for me until a vaccine is out and distributed. May the odds ever be in your favor for those of you fliers.
Just recently there was a contradicting bit of news/study about how commercial airplanes do not further the spread of coronavirus among passengers using test dummies and simulated coughs.
Which to believe…
Seth: Are there more details (or a link) to explain: “…proposed EU digitalised public health passenger locator form…” ? Web searches only bring up comments dated June 2020, but your information indicates that there is something currently being worked upon…any further leads, please
None that I’m aware of, unfortunately.
I do know that some tech companies were working to help implement a fuzzy matching protocol for names that might be slightly misspelled or differ from hotel registrations, but not where any of that process has ended up.
[…] Researchers link 59 Irish COVID cases to inbound long-haul flight by Wandering Aramean. […]
There are serious issues with the conclusions from this study.
“The incubation period for COVID-19 may be as short as 2 days, so the potential
for in-flight/airport transmission exists in this outbreak
In-flight transmission is a plausible exposure for cases in Group 1
and Group 2 given seating arrangements and onset dates.”
The potential exists but the probability of an incubation period of 48 hours is extremely low,
as can be seen from the distribution data from the Wuhan study referenced.
Secondly, why are the seating arrangements between Groups 1 and 2 considered close?
Group 1 and 2 do not appear close from seating plan.
Is it much more probable that the transmission from group 1 to Group 2 occurred during the social contact pre flight?
Transmission pre flight would provide an incubation period much more aligned with the statistical data.