While airplanes have started to take off in post covid 19, two international studies revealed the chances of Coronavirus transmission on long haul flights.
One study was conducted by the National Institute of Hygiene and Epidemiogy, Vietnam and the other was from a multi-national group of institutions, including the London School of Hygiene and Tropical Medicine, University of Hong Kong and others.
The researchers from the National Institute of Hygiene and Epidemiogy said that many international flights have claimed that the risk of transmission of the deadly virus was low. However, they raised concern over long flights, which could aid in in-flight transmission.
The scientists from the National Institute of Hygiene and Epidemiogy looked into several cases among passengers on a ten hour commercial Vietnam Airlines flight from London to Hanoi on March 2, 2020. They analysed 217 passengers, crew members and close contacts. During the quarantine period, they were checked daily for symptoms and fever. They were also given PCR tests three times.
They found that 16 people were infected. Of these people, 12 travelled in business class along with “Case 1,” the only symptomatic person on board the flight. The researchers said that the seating proximity was strongly associated with increased infection risk. Four others who were infected, who include the sister of Case 1, had personal contacts and came into close proximity with infected passengers between the flight’s arrival and the quarantine period.
The researchers maintained that the risk for on-board transmission of the virus during long flights was higher. They said that there was higher risk of Covid-19 clusters, which was quite evident from the people who contacted the disease even when travelling in business class. The Business class is spacious and seating arrangements are well beyond the established distance.
The study by multi-national group of institutions had analysed four passengers who had severe Covid-19 infection. These passengers took a 15 hour flight from Boston to Hong Kong on March 9, 2020. The Covid 19 cluster comprised these two passengers and two cabin crew members, all of whom were asymptomatic at the time of the flight. They tested positive within five to 11 days later.
The researchers sequenced viruses of the four patients and found that the near full-length viral genomes from all the four were 100 per cent identical. This was a proof that transmission occurred between the four patients. The only place where the four were in close contact was inside the airplane.