Airport testing could identify up to six in ten coronavirus cases, experts claim.
Public Health England has said testing travellers on arrival would only detect seven per cent of people carrying the virus.
It has been used time and time again by ministers to justify a lack of screening at airports, given the UK is an outlier compared to other countries.
But research by Oxera and Edge Health has claimed the PHE figure is ‘significantly understated’. The experts pointed out numerous holes in the government agency’s research.
This included that PHE assumed in its modelling that people who have symptoms of the coronavirus would not get on a plane to the UK because they would be too sick or stopped before boarding.
It also assumes that ‘silent carriers’ who do not have symptoms test positive before boarding, and there is no chance of a person becoming infected during their flight, which could be several hours.
Oxera and Edge Health say that this ‘evidently is not the case’ in real life.
Had all those passengers been on the flight, the firms estimate that 63 per cent of infected passengers attempting to enter the UK could be detected by testing in the arrivals lounge.
Airport testing could identify up to six in ten coronavirus cases, experts claim, nine times higher than the seven per cent figure given by the Government. Pictured: A nurse swabbing the throat of a traveller at Heathrow Airport, which recently began using rapid testing for passengers
Oxera and Edge Health estimate that up to 63 per cent of infected passengers attempting to enter the UK could be detected. Pictured: Heathrow’s rapid testing centre inside the arrivals hall of Terminal 5
Oxera, a firm which advise policymakers and regulators on economic issues connected with competition, and Edge Health, a healthcare consultancy, were commissioned by a consortium of airlines, airports and industry organisations to undertake the independent review.
They looked at a PHE paper, which was given to scientists advising the Government (SAGE) in June, and two other prominent studies from the London School of Hygiene & Tropical Medicine (LSHTM), published in July, and the Animal and Plant Health Agency (APHA), published in September.
Dr Kit Yates, a senior lecturer in mathematical biology at the University of Bath, was involved with the research.
The aviation sector is desperate for flights to pick up again, with industry leaders including chief executives of airlines arguing the UK’s 14-day quarantine rule is putting travellers off.
The travel sector has made repeated calls for testing at airports in order to reduce quarantine periods.
PHE PAPER ARGUED FOR DOUBLE TESTING TO REDUCE QUARANTINE RULES
Quarantine guidelines, which came into effect only in June, was ministers attempt to protect the UK from imported cases of the coronavirus.
Anyone arriving from a country with high cases, such as Turkey or Poland at the moment, must self-isolate for 14 days.
Current rules requiring holidaymakers to quarantine for 14 days could be slashed by repeat testing, SAGE was told in their 42nd meeting on June 18.
The group reviewed several papers that analysed how useful repeat testing was. It would require testing someone on their arrival to the airport and several days later.
A paper from Public Health England in June for SAGE modelled how ‘double testing’ could work.
It showed that testing people seven to ten days after arrival was 14 times better at detecting cases of Covid-19 than just once on arrival.
The best day to take a Covid-19 test was between five and eight days after exposure, SAGE said.
That means if someone catches the virus on the last day of their holiday in Spain, it would likely show up on a test eight days after they come home. Therefore, if it is negative, they are free to leave quarantine.
And, if travellers are tested twice a few days apart, it significantly rules out the possibility of an initial false negative result at the airport, SAGE said.
That is, it makes sure that those who have the virus are definitely spotted and the test was not incorrect.
It could shave off three to seven days, according to experts commenting on the papers.
Linda Bauld, a professor of public health at the University of Edinburgh, said if someone was tested a second time on day five, and it came back negative two days later, they may only have to quarantine for seven days, instead of 14.
If the second test was on day ten, it may only save three days off granted the result came back within 24 hours.
Keith Neal, an emeritus professor of the epidemiology of infectious diseases at University of Nottingham, said double testing is not likely to be ‘cost effective’.
He said: ‘Testing at one week will only find asymptomatic cases assuming those with symptoms get themselves tested.
‘As most cases do produce symptoms then testing will only identify the minority of cases that would otherwise be missed.’
The Transport Secretary Grant Shapps told a virtual ABTA travel industry conference in September that the self isolation period may be cut to seven day, according to the Telegraph.
Travellers will begin to self-isolate at home before taking a coronavirus test a week after landing. If travellers test negative, they could stop quarantining.
The scheme could be in place by December 1, the paper reported last week, after plans are overseen by the new global task force Shapps chairs jointly with Health Secretary Matt Hancock.
Quarantine guidelines, which came into effect only in June, was Number 10’s attempt to protect the UK from imported cases of the coronavirus.
In contrast, more than 30 other countries, including Germany and Italy, have gone ahead with a testing scheme, some with the addition of quarantine rules.
‘This policy is driven in part by evidence from PHE that testing on arrival at an airport would identify only “7 per cent” of virus cases,’ the report from Oxera and Edge Health said.
It broke down the flaws of the PHE paper in its report, revealing PHE bizarrely excluded travellers who actually had the virus.
Its research assumed that 100 per cent of people with the coronavirus would be tested before they board, and be stopped from flying, or become too sick to fly.
‘We consider that this may actually be an overestimation,’ the Oxera report said, noting that obviously only a very small proportion of Covid-19 carriers would be picked up (seven per cent) if none were actually on board, as PHE claims would be the case.
LSHTM researchers said that at least 30 per cent of symptomatic passengers would travel because either testing was not sensitive enough, or because the person is not tested and they choose to fly because symptoms don’t develop until later on in their journey.
The Oxera team said if it is assumed a proportion of symptomatic passengers board a plane to the UK, which they believe is realistic, detection rates on arrival would be higher and therefore testing would be recommended.
PHE also assumed that those without symptoms would be detected through PCR testing at the departure lounge, right before boarding.
In reality, Oxera said, they would be tested several hours before, in which time it is possible for them to pick the virus up at their gate, in the airport or on the flight, which may be long-haul.
The paper said: ‘If detectable asymptomatic passengers are included in estimating the effectiveness of a testing scheme, the seven per cent figure becomes approximately 33 per cent.
‘If all infected passengers (including detectable symptomatic passengers) who attempted to enter the UK population but were prevented from doing so were to be included in the estimate, this estimate would be 63 per cent.’
The researchers also claimed the PHE and the two other papers supporting it cannot be relied upon because they are based on theoretical modelling, and not real data.
For example, benchmarking against real testing schemes in places like Jersey could give a better indication of if it works, rather than using modelling.
The LSHTM paper used the same assumptions as PHE but concluded that testing on arrival reduces the number of infectious travellers into the community by about 45 per cent.
And the APHA paper said testing on arrival could catch 39.6 per cent of cases using the same scenario as PHE. It was not explained in the report why the estimates are so vastly different, but using different modelling can produce varied results.
LSHTM said at most, 48 per cent of asymptomatic infected travellers can be detected by a single PCR test, and 77 per cent of symptomatic cases.
‘This is significantly lower than the maximum sensitivity found in recent studies,’ the Oxera report said.
It also noted that LSHTM’s and APHA’s modelling use infection rates the country a person is travelling from, calculated based on reported deaths and cases.
The papers do not account for countries perhaps having a high number of high-risk people, due to age demographics or prevalence of underlying health conditions, and so cannot be applied to a group of people getting on a plane.
London School of Hygiene & Tropical Medicine (LSHTM) said at most, 48 per cent of asymptomatic infected travellers can be detected by a single PCR test, and 77 per cent of symptomatic cases. ‘This is significantly lower than the maximum sensitivity found in recent studies,’ the Oxera report said. Pictured: A test at Heathrow Airport this week
The report said: ‘All three papers assume that the risk of travellers spreading the virus is reduced to close to zero with a mandatory 14-day quarantine requirement.
‘However, this is unlikely to be the case given that returning travellers are currently permitted to quarantine with other individuals (who do not have to quarantine) and there is evidence to show that compliance with quarantine may be as low as 20 per cent.’
A study published in September by King’s College London found that 70 per cent of people would self-isolate if they developed Covid-19 symptoms, such as a cough or high temperature.
However, only 18.2 per cent of respondents who did report Covid-19 symptoms over the past week reported that they had in fact self-isolated.
More recently SAGE has cited that only ‘around 20 per cent of those reporting symptoms of Covid-19 in England report fully self-isolating by staying at home’.
Oxera said low levels of compliance would be expected for travellers who have entered the UK if they have not been tested, and there is limited enforcement of quarantine restrictions.
From 8 June to 7 September, only 34 fixed penalty notices for breaches of international travel measures were issued in the UK.
Oxera’s work will be given to the Government’s Global Travel Taskforce, which is considering how a testing regime for international arrivals could be implemented to boost safe travel to and from the UK.
The group was unveiled earlier this month to help find a potential way of easing quarantine restrictions for arriving passengers.
It comes after a pre-departure rapid Covid-19 testing facility was launched at Heathrow Airport on Tuesday.
The facilities in Terminals 2 and 5 will initially offer tests to passengers travelling to Hong Kong before they fly, with hopes to test passengers to Italy in the coming weeks.
The facilities will offer LAMP testing which, unlike PCR tests, can be processed without being sent to a laboratory.
The paid for-tests, costing around £80 per passenger, aim to boost demand for holidays decimated by the pandemic and quarantine rules.
Virgin Atlantic’s chief executive Shai Weiss said: ‘As long as the 14-day quarantine remains in place, demand for travel will not return and the UK’s economic recovery, which relies on free-flowing trade and tourism, cannot take off.
‘Half a million UK jobs depend on open skies and a fully functioning UK aviation industry.
‘The Government’s global travel task force must act swiftly to replace quarantine with passenger testing in November.’
A government spokesperson said: ‘The scientific evidence on testing international arrivals was reviewed and approved by SAGE. Scientific modelling groups and the London School of Hygiene & Tropical Medicine independently generated similar results.
‘International arrivals from non-exempt countries must quarantine for the full 14 days as the incubation period for the virus means passengers who do not follow this advice may pose a risk to others.
‘Work is ongoing with clinicians, the devolved administrations and the travel industry to consider if and how testing could be used to reduce the self-isolation period.’
The spokesperson noted that the PHE study said the seven per cent figure comes from testing people on ‘day zero’ – when they arrive. But it improves to 88 per cent on day five and 94 per cent on day eight.