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Put to the test: use of rapid testing technologies for covid-19

BMJ 2021; 372 doi: (Published 03 February 2021) Cite this as: BMJ 2021;372:n208

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Covid-19: How the UK is using lateral flow tests in the pandemic

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  1. Alex Crozier, PhD researcher1,
  2. Selina Rajan, honorary research fellow2,
  3. Iain Buchan, professor of public health and clinical informatics3,
  4. Martin McKee, professor of European public health24
  1. 1Division of Biosciences, University College London, London, UK
  2. 2Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, London, UK
  3. 3Institute of Population Health, University of Liverpool, Liverpool, UK
  4. 4European Observatory on Health Systems and Policies, London, UK
  1. Correspondence to: A Crozier alexander.crozier.20{at}

Alex Crozier and colleagues look at how new technologies can be most appropriately used to support different testing strategies and examine the benefits and risks

Governments have invested enormous resources in scaling up testing capacity in their responses to covid-19. Real-time reverse transcription polymerase chain reaction (PCR) was the first, and still the most widely used, test. However, several days can elapse between requesting a test and getting and acting on a result, leaving a window in which infection may spread. A further problem is that people may transmit infection before recognising symptoms1—a key driver of spread. In addition, some people who remain asymptomatic have a similar viral load to those who develop symptoms and may also contribute to spread, although the extent of this is unclear.123 Given the importance of presymptomatic or paucisymptomatic transmission,1 measures that shorten the time between testing and results are essential for minimising onward transmission. It is difficult to achieve this with large scale PCR testing.

Rapid antigen lateral flow tests offer an alternative. They provide a rapid result but are less able to detect infections.4 Governments are purchasing them in large quantities, with some seeing a single test as a way to free an individual from quarantine obligations, a view not supported by the World Health Organization.4 However, repeated lateral flow testing may have value in combination with other measures. In Liverpool, UK, for example, authorities are examining test-to-protect, test-to-release (from quarantine), and test-to-enable (safer return to restricted activities) regimens, alongside outbreak response and public open access to lateral flow testing.5 Such real world evaluations are needed to understand how these models work in different populations and settings, how they influence behaviour, and the contribution of lateral flow tests to overall strategies, where they have …

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