A single flight from the Middle East to Ireland was responsible for 59 coronavirus cases, a study has found.
Researchers from scientific journal Eurosurveillance, which published the study, said the findings demonstrate how the virus is seeded in countries through air travel.
The Irish outbreak was traced back to one 7.5-hour flight that took off from the Middle East this summer.
The flight ran at 17 per cent capacity, with only 49 of the 283 seats occupied.
Researchers said 13 passengers tested positive for the coronavirus, with two passengers developing symptoms within two days of the flight.
A further 46 people, who were not on the flight, caught the disease after coming into contact with the passengers or their relatives, the study said.
Within 10 days, only people who were not on the flight – but were linked to a passenger – contracted the virus.
The infected passengers had travelled in small groups with varying waiting times at the airport.
One group spent up to 12 hours in a transit lounge while on stopover, while another two groups waited only two hours, in the departure area.
The passengers who caught the virus were aged between 1 and 65.
A mask was worn during the flight by nine of the positive cases, not worn by one – a child – and unknown for three, the researchers said.
One of the passengers involved passed the virus to three members of their household, one of whom passed it on to 25 others while staying in “shared accommodation”.
The researchers said the original source case was unknown.
They said the study shows the potential for the virus to be transmitted in a plane and “imported” to countries.
“Air travel has accelerated the global pandemic, contributing to the spread of coronavirus disease throughout the world,” they wrote
Earlier this month, the International Air Transport Association said catching the coronavirus on a plane carried the equivalent risk of "getting struck by lightning".
The industry seized on a US defence department study that found masks greatly minimised exposure to the virus on a plane.
That study found an average of 0.003 per cent of air particles around a passenger’s head were found to be infectious when a mask is worn.
An Australian study published on October 2 found passengers in window seats in the middle of economy class had the greatest risk of contracting the virus.
