A woman is believed to have caught coronavirus in the toilet of a plane according to a study published by the US Centers for Disease Control.
The study was based on evidence collected on an evacuation flight from Milan, Italy, to Incheon, South Korea, and at the government quarantine facility passengers were taken to after landing.
A total of 310 passengers were scheduled to the board the flight on 31 March, at the height of the pandemic.
It was “conducted under strict infection control procedures by the Korea Centers for Disease Control and Prevention (KCDC), based on the guidelines of the World Health Organization (WHO)” according to the research led by Dr. Sung Hwan Bae, a physician with the Soonchunhyang University College of Medicine in Seoul, South Korea.
Pre-boarding, passengers were examined by medical staff at the airport, which involved physical examinations, medical interviews and body temperature checks out of the airport.
Eleven passengers who exhibited Covid-19 symptoms were removed from the flight, while 299 asymptomatic passengers were permitted to board the 11-hour flight to South Korea.
All passengers were given N95 respirators and kept 2m apart at the airport and on the plane.
“Most passengers wore the N95 respirators except at mealtimes and when using the toilet during the flight,” according to the study.
Upon landing, all the passengers were taken directly to a government facility to quarantine in isolation and were tested for Covid on the 1st and 14th day of quarantine.
Six of the passengers tested positive for Covid on day one – they were transferred to hospital straight away but showed zero symptoms of coronavirus for the next 14 days and have since been classed as asymptomatic.
The 28-year-old woman in question did not show symptoms when she boarded the flight in Italy, and had tested negative for Covid-19 when she began her 14-day quarantine. But on the 14th day, tests came back positive.
Given the conditions, researchers believed that she picked up Covid-19 after using the plane toilet that an asymptomatic carrier had used.
The woman is said to have worn the N95 mask throughout the flight, except when she used the toilet.
The study said: “The toilet was shared by passengers sitting nearby, including an asymptomatic patient. She was seated three rows away from the asymptomatic patient.
“Given that she did not go outside and had self-quarantined for three weeks alone at her home in Italy before the flight and did not use public transportation to get to the airport, it is highly likely that her infection was transmitted in the flight via indirect contact with an asymptomatic patient.”
The only alternative explanation, which researchers said was less likely, was that she had a longer than usual incubation period.
In light of the findings, researchers recommended that to minimise transmission on aircraft, masks should be worn during the flight, hand hygiene should be maintained and social distancing measures should be maintained before boarding and after disembarkation.