Study: Review of case studies of effectiveness of testing schemes
November 3, 2020 • Reading time 5 minutes
- Report shows air passenger testing after five days of quarantine in Iceland is between 83% and 90% effective. Testing after seven days in Toronto and Paris is between 84% and 90% effective. Real world evidence supports a significant reduction in current UK 14-day quarantine policy.
- Single tests on arrival in Canada (Toronto-Pearson Airport), France (Paris-Charles de Gaulle Airport), Jersey and Iceland detected between 54% and 76% of infected travellers—far higher figures than claimed by a Public Health England (PHE) paper, which concluded that airport testing would identify only ‘7%’ of virus cases.
- These findings are consistent with recent analysis by Edge Health and Oxera, which found that the UK government is significantly underestimating the effectiveness of air passenger testing schemes.
The UK government, which is considering a ‘test and release’ scheme on five, seven or eight days, could opt for the shorter period, while boosting safe travel to and from the UK, new independent research from Oxera and Edge Health demonstrates.
The research also estimates that a single test on arrival detects between 54% and 76% of infected travellers, which is consistent with research published on 22 October. These findings offer further evidence that the UK government is significantly underestimating the effectiveness of air passenger testing schemes by relying on a PHE paper which suggested that testing on arrival at an airport would identify only ‘7%’ of infected travellers.
Leading health and economics consultants from Edge Health and Oxera, supported by academics including Dr Kit Yates, co-director of the Centre for Mathematical Biology at the University of Bath, used data from real-world case studies, recent empirical evidence and sensitivity analysis to reach their findings. The results are based on actual testing schemes that are currently in place in different parts of the world, rather than theoretical models.
Iceland’s testing scheme identified 69% of infected travellers after one RT-PCR test upon arrival, and a further 21% after a second RT-PCR test five days later—offering 90% effectiveness in total following five days of quarantine, taking into account test sensitivity and detectability rates.
As a part of a trial in Canada that started on 3 September, authorities at Toronto-Pearson Airport have been offering a RT-PCR test to international arrivals at Terminal 1, followed by two additional self-administered tests seven days and 14 days after arrival. Taking into account test sensitivity and detectability rates, 72% of infected travellers have been detected by the on-arrival test, 18% by the second test, and 0% by the third test—offering 90% detection effectiveness in total after seven days.
The authors examined Jersey’s Safer Travel Testing Programme from July and August. The programme required international arrivals from ‘green’ lower-risk countries to take one RT-PCR test on arrival and isolate until a negative result was received, usually on the following day. Individuals also had the option to provide an RT-PCR test conducted within the 72 hours prior to their arrival in Jersey. Oxera and Edge Health estimate the effectiveness of Jersey’s on-arrival testing to be up to 63%.
Oxera and Edge Health also considered a scheme by the French authorities to test arrivals at Paris-Charles de Gaulle Airport from French Overseas Territories (La Réunion, Guadeloupe, Martinique, St Bart and St Martin) during June and July. Their analysis of the data indicated that 76% of infected travellers were detected by an on-arrival test, and an additional 14% were detected after a seven-day quarantine.
Michele Granatstein, Partner at Oxera and Head of its Aviation practice, said:
‘These results, based on real-world testing schemes, are significantly higher than the 7% estimated by PHE. The analysis provides further evidence that the UK government is significantly understating the effectiveness of testing on arrival schemes.’
George Batchelor, Cofounder and Director of Edge Health, said:
‘The evidence from other countries suggests how beneficial a testing regime is when compared to a blanket 14-day quarantine policy, like we have in the UK. The combination of testing with a short quarantine period would also be effective, in advance of a common international standard on testing, with data from Iceland providing clear evidence that there is little to be gained by introducing a seven-day period, over a five-day one.’
To date, over 30 countries, including Portugal, Cyprus, Italy and Germany, have introduced a form of passenger testing. France and Portugal require no quarantine on arrival if individuals can show a negative test result from a period of 72 hours before boarding the plane. In other cases, travellers from high-risk countries are required to take a test a certain number of days after arrival (e.g. five days in Belgium) and can then be released from quarantine subject to a negative test result.
The new analysis has been submitted to the UK Global Travel Taskforce, which is expected to report its recommendations to the Prime Minister in early November despite the new national restrictions announced over the weekend, including a ban on outbound travel until 2 December. Later this month, Oxera and Edge Health will publish final updated modelling on passenger testing effectiveness, using the latest data aligned to real-world evidence.
Contact: George Batchelor
 The UK government also refers to a London School of Tropical Hygiene & Medicine paper which suggested that testing on arrival would reduce the number of infectious travellers released into the community by about 45%. See Clifford et al. (2020), ‘Strategies to reduce the risk of SARS-CoV-2 reintroduction from international travellers’, 25 July. The authors of this paper are affiliated with the London School of Hygiene & Tropical Medicine.
 Based on aggregate data available from 19 September. Icelandic authorities tested 29,411 individuals on arrival, among whom the prevalence of COVID-19 was estimated to be 1%.
 13,000 tests of returning international travellers were administered between 3 September and 1 October 2020, with approximately 1% testing positive.
 58,139 individuals arrived in Jersey by air or sea in the period from 1 July to 1 September 2020. 55,672 PCR tests were administered to incoming travellers from abroad during this time. This scheme has since changed and travellers from green countries now require a second test after five days; however, this does not affect the period of analysis.
 The data shows that of the 55,672 RT-PCR tests conducted, 23 individuals arriving in Jersey from a green country tested positive on arrival.
 The requirement for travellers from red zones to take a test on arrival has been suspended between 21 October and 15 November, such that only certain individuals will be required to quarantine for ten days depending on their answers to the self-assessment questionnaire on arrival and whether they have symptoms