Fifty-two passengers on one flight from Delhi to Hong Kong test positive for Covid-19 after landing

Authored by dailymail.co.uk and submitted by ahm713
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All of the passengers who tested positive flew into Hong Kong on a flight from Delhi, run by Indian airline Vistara on April 4

At least 52 people from a single flight from Delhi to Hong Kong have tested positive for Covid-19, despite all passengers presenting a negative coronavirus test before boarding.

All of the passengers who tested positive flew into Hong Kong on a flight from India's capital, run by Indian airline Vistara on April 4.

Hong Kong as a whole has been recording fewer daily new infections than the total number detected on the flight, since it brought a fourth wave of infections under control in January.

Meanwhile in India, the country's healthcare system is collapsing under a devastating second wave of coronavirus that is killing more than 2,800 people a day in the nation that is home to 1.3 billion people.

A total of 188 passengers could have been on-board the flight, but Hong Kong authorities did not disclose how many people were on the plane.

Health experts have insisted that advanced plane ventilation systems make the risk of catching the virus from a fellow passenger is extremely low, and there are a number of theories to explain the Hong Kong flight cluster apart from transmission on the plane.

Professionals have outlined four reasons why such a high number of people could have tested positive after the flight.

First, they say the passengers could have been infected in India after their pre-flight Covid-19 test which had to be taken within 72 hours of the flight.

Second, India's overloaded health system could have been unable to accurately detect the cases before they boarded the flight, or some passengers presented fraudulent test certificates,

A third possibility is that the passengers could have picked it up in one of the quarantine hotels in Hong Kong.

Or they say that there could have been passengers infected with a particularly severe strain of Covid-19 that which could have passed between the passengers despite the filters on the plane ventilation systems.

At least 52 people from a single flight from Delhi to Hong Kong have tested positive for Covid-19, despite all passengers presenting a negative coronavirus test before boarding. Pictured: An earlier graphic showing the seating plan of 49 passengers who tested positive for Covid-19 - the figure has since increased to 52

Meanwhile in India, the country's healthcare system is collapsing under a devastating second wave of coronavirus that is killing more than 2,800 people a day in the nation that is home to 1.3 billion people

Workers prepare to bury a person who died of Covid-19 in Gauhati, India, on Sunday

STUDIES SUGGEST RISK OF CATCHING COVID ON A PLANE IS LOW Experts and studies suggest that the risk of catching coronavirus on a plane, despite potentially hundreds of people being cooped up in the same room, is not particularly high. Advanced ventilation systems and mask-wearing do a good job of minimising the risk of spread even if there is someone on board with the virus. A study by the US Department of Defense suggested that if a plane was full, everyone was wearing masks, and one person on board was infected, only around 0.003 per cent of air particles would have the virus in them. This is equal to one part coronavirus per 33,000 parts uninfected air. As a result it would take, they predicted, a 54 hour flight for someone to breathe in enough of the virus to get sick, Sky News reported. The current longest direct flight in the world is just short of 19 hours, from Singapore to New York. The study found that 99.99 per cent of infectious particles were filtered out of plane air by the ventilation system. Passenger aircraft have fans and vents that replace the air in the cabin every five minutes, pumping it in from above and sucking it out from the footwells. This air is then either vented out of the plane or filtered – a process that would remove viruses – and pumped back in. This, combined with the fact that people do not come into close contact with many others, means the risk of transmission is quite low. Although people in the seats immediately next to, and in the rows in front of and behind the person with the virus, might be at risk of catching it, people in other parts of the plane probably wouldn't get close enough to them to inhale an infectious dose. On land, 2m is generally the safe social distancing guide, and even 1m is accepted in some countries if people are wearing masks. The International Air Transport Association (IATA), an airlines union, said in its own research that the risk was 'extremely low'. It claimed to have detected only 44 confirmed or possible cases of Covid linked to a flight out of 1.2billion passenger journeys in 2020 – one case per 27m journeys. The IATA said in its press release: 'Air is exchanged 20-30 times per hour on board most aircraft, which compares very favorably with the average office space (average 2-3 times per hour) or schools (average 10-15 times per hour).' A separate study by the Massachusetts Institute of Technology suggested that leaving the middle seat empty in plane rows could halve the risk of the virus spreading. Professor Arnold Barnett estimated the risk of transmission on an Airbus 320 or Boeing 737 – two of the most commonly used planes – was one in 7,000 for a passenger in a window seat on a packed aircraft. But the odds dropped to just one in 14,000 under the 'middle seat empty' policy. Even if the risk of catching coronavirus on a plane is relatively low, however, there are still risks associated with the process of boarding and disembarking, as well as travelling through the airport. Advertisement

The positive results have surfaced during the mandatory three-week quarantine period enforced by Hong Kong. It is one of the strictest entry measures in the world.

Rashida Fathima, who boarded the flight with her husband and two children, is one of the 52 people who have tested positive at their quarantine hotel since.

Speaking from hospital, Fathima told the Wall Street Journal that she believes she was infected on the flight, despite her family wearing masks for most of the flight and avoiding the bathroom on board.

She revealed that some passengers were coughing repeatedly during the flight while others removed their masks to eat and families walked their crying children through the aisles.

All passengers flying into Hong Kong must present a negative test that was taken within 72 hours before departing - and all of the passengers on the Hong Kong flight did so.

All travellers entering Hong Kong must also take a mandatory Covid-19 on arrival to the country before entering the three-week quarantine.

Several cases have also been detected on flights arriving into Hong Kong from Mumbai, according to authorities.

'We’re shocked by this,' said Poonam Nanda, the director of Nanda Travel. 'This one flight appears to be an astonishing outlier and we are all confounded by these numbers.'

Eric Feigl-Ding, an epidemiologist at the Federation of American Scientists, said on Twitter that only eight cases from the flight were detected before hotel quarantine began. The remaining cases were identified during the time in quarantine.

'If it weren’t for hotel quarantine – [Hong Kong] would have completely allowed these [positive cases] to begin spreading in the community.' he said. 'This is why border quarantines are critical.'

India recorded 2,812 Covid deaths overnight and infections in the last 24 hours rose to 352,991 on Monday - a record peak and a new global high for a fifth day running.

Health experts, including Feigl-Ding, say there is a chance that some of the 52 passengers who have tested positive on the flight from Delhi were infected in India after their pre-flight Covid-19 test.

'Some may have occurred after the initial 72 hour pre departure time window after they got tested,' Feigl-Ding said. 'India cases increased 60% each week for the last 2 weeks. But this is why our border testing is leaky.'

Scientists also pose the notion that the passengers could have picked it up in one of the quarantine hotels in Hong Kong.

'It could also be hotel transmission to some degree too,' said Fiegl-Ding. 'Hotel room cross infections have been observed in Australia’s hotel quarantine system too.'

Health experts also said India's overloaded health system could have been unable to accurately detect the cases before they boarded the flight.

Health experts also said there could have been those with a particularly severe strain of Covid-19 which could have easily passed around the plane in such a compact space with people taking off their masks to eat.

Scientists from the University of Hong Kong are now working with the city's health department to sequence genomes from the passengers who tested positive to try and understand whether they were infected while on board.

It is not known how many - if any - of the passengers on the flight had received a Covid-19 vaccine. At the time of the flight, less then five per cent of India's population had received at least one dose of the jab.

Indian airline Vistara said they did everything they could to minimise transmission of Covid-19.

Coronavirus infections in India over the last 24 hours rose to 352,991 on Monday - a record peak for a fifth day running

India, with a population of 1.3 billion, has a tally of 17.31 million infections and 195,123 deaths, after 2,812 deaths overnight, health ministry data showed, although health experts say the death count is probably far higher. Pictured: A graph showing new Covid-19 deaths per-day

Health experts, including Feigl-Ding, say there is a chance that some of the 52 passengers who have tested positive on the flight from Delhi were infected in India after their pre-flight Covid-19 test

Relatives and municipal workers prepare to bury the body of a person who died of COVID-19 in Gauhati, India, Sunday, April 25, 2021. vital life-saving oxygen is in short supply and countries including Britain, Germany and the United States pledged to send urgent medical aid to help battle crisis collapsing India's tattered healthcare system

'The risks of air travel are generally quite manageable with staggered seating and consistent mask usage, especially when using toilet facilities,' said Siddharth Sridhar, a clinical virologist at the University of Hong Kong’s Department of Microbiology.

Hong Kong has since banned all flights from India, Pakistan and Philippines from April 20 to May 3 following detection of a mutant Covid strain called N501Y.

Dr Leung Chi-Chiu, a specialist in respiratory medicine, argued that the two-week ban was not enough, reports RTHK.

He said the ban should last until the situation in the three countries improves.

'We will have to keep this ban unless the situation there improves or unless we have devised other measures to reduce the chance of importation of these dangerous variants into Hong Kong,' he said.

Hong Kong was one of the first areas hit by the pandemic but strict border controls and lockdown measures have kept infections to just over 11,000 with 209 deaths.

But in contrast, India is on its knees.

Daily Covid-19 deaths hit a record peak of 2,812 on Monday as morgues ran out of stretchers forcing medical workers to use blankets to transport corpses - and relatives of coronavirus patients are wandering the streets of the capital in search of a hospital with open beds.

The percentage change in daily Covid infections by Indian state today compared to at their peak, most of which were recorded last year

Trees from parks in the worst-hit areas are set to be chopped down and used to burn bodies because crematoriums are unable to keep up with demand.

And Indian social media videos have depicted other hellish scenes including a body falling from an overloaded ambulance and a son abandoning his Covid-stricken mother on the street.

Meanwhile, oxygen is in short supply as countries including Britain, Germany and the United States have pledged to send urgent medical aid to help battle the the second deadly wave that is collapsing India's tattered healthcare system.

India recorded 2,812 Covid deaths overnight and infections in the last 24 hours rose to 352,991 on Monday - a record peak and a new global high for a fifth day running. Experts say the second wave will peak in May at up to 500,000 deaths a day, meaning around 5,000 people could die every day at the current case fatality ratio of 1.14%

On Sunday, Prime Minister Narendra Modi urged all citizens to get vaccinated and exercise caution, while hospitals and doctors have put out urgent notices saying they were unable to cope with the rush of patients.

Nearly all intensive care unit (ICU) beds used to treat Covid patients in three of India's most populated regions - Delhi, Mumbai and Ahmedabad - are full, meaning they are being forced to run away patients, leaving families to ferry people sick with coronavirus from hospital to hospital in search for treatment and patients dying on pavements outside.

neutrinome on April 27th, 2021 at 15:04 UTC »

I flew in Jan from India to Dubai. I was surprised they were doing a second round of Covid test at the Dubai airport, after we presented negative certificates. But now I know why.

soulsurfa on April 27th, 2021 at 12:37 UTC »

My friend got herself and mum home to Australia on a repatriation flight a few months ago. and they could buy the negative covid test result from the ticket agent.

sephstorm on April 27th, 2021 at 12:05 UTC »

If they had to present documentation, chances are at least one person presented fake documentation. I doubt the airline is going to make an effort to validate any of the information.