Misuse of SARS-CoV-2 testing in symptomatic health-care staff in the UK

An initiative to screen asymptomatic health-care workers for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was timely and logical,¹ and contrasted markedly with the UK Government's testing strategy of National Health Service (NHS) staff during the epidemic. The NHS staff testing policy was only to test symptomatic staff, precisely to reduce absenteeism by encouraging staff with negative results back to work, thus intentionally reducing their time in self-isolation. The Secretary of State for Health and Social Care, Matt Hancock, himself stated that “we want to get [NHS staff absences] down, and the way to do that is to get the amount of testing up”.² This testing approach was then also applied to other groups of public sector workers.³

The UK Government's approach of using SARS-CoV-2 testing as a strategy to reduce absenteeism rather than to increase the detection of otherwise asymptomatic spreaders was surely symptomatic of flawed analysis and misunderstanding of the utility of the SARS-CoV-2 pharyngeal swab RT-PCR test. WHO expressly advises against using this test as a rule-out in the event of negative results.⁴ Sensitivity of the test might be as low as 83%,⁵ and in our practice many colleagues believe it to be lower still. Overzealous redirection of self-isolating staff back to work before they had completed sufficient self-isolation to exclude infectivity was therefore likely to increase spread of the virus to other staff and to patients or care-receivers in a substantial number of cases, especially given the high prevalence and likelihood of SARS-CoV-2 infection among exposed health-care workers during the epidemic. Surely the only defensible policy would have been national opportunistic and frequent testing of NHS and social care sector staff regardless of symptomology, and the test should be used exclusively as a rule-in and not a rule-out test as per existing WHO guidance.⁴