Britain has got itself into a terrible mess on mass testing. A recent study led by Oxford academics, which found that up to a third of people found positive on a PCR test were not contagious, should give the Government cause to reconsider the wisdom of this approach.
At an individual level, knowing your own infection status can be extremely helpful, for example if you are planning to visit a vulnerable relative or friend. However, as we all know, a positive test result can have significant negative impacts, particularly if it entails loss of income and opportunity. If the tests are too sensitive, the problem is even worse.
Furthermore, the truth is that we are permanently crawling with germs. Expecting the individual to bear responsibility for any infection that he or she might pass on risks leaving us all living in a state of permanent guilt. Normally, this guilt is dispersed within the community.
This is not to say that, during a pandemic, we should not exercise care to protect the vulnerable by limiting contact with them while we are infectious (in fact, I would highly recommend this) but it is also important to remember that once a disease has become endemic, there is little else we can do other than not visit granny when we have a fulminant cold.
But to what extent should we self-isolate upon testing positive or being told that we may have been in contact with someone who tested positive? As we have witnessed over the past few months, these actions do little to stop the spread of infection and create enormous problems for the delivery of healthcare and education. Sanctioning the use of tests that suggest people are contagious even when they are not magnifies the problem.
It is, however, important to recognise that things would not have been much different if we had a perfect test, as in some sense we now have with the new generation of LFDs. We would still have vast numbers of key workers unable to function and children being deprived of the safety and intellectual and emotional stimulation that our educational system seeks to provide. We would still have to endure life being endlessly disrupted – all having scant impact on the prevalence of an infection in its endemic state.
Testing could have been profitably used at the population scale. Even imperfect measurements of the incidence of infection done randomly could have allowed us to make intelligent assessments regarding the progression of the pandemic and the effects of the restrictions, allowing greater flexibility and better tailoring advice to the vulnerable and the NHS.
Some deficiencies in the rigour of testing early in the pandemic, given that we were dealing with an emergency, could be tolerated on the basis that it was important to garner information on the development of the situation. What cannot be forgiven is that, instead, we used a faulty testing scheme to transfer societal responsibilities to the individual, sentencing many to loss of livelihood, education, social contact and hope – and we still are.
Continuing with a mass testing, mass isolation strategy in response to a disease that has become endemic is merely piling up the misery. The Government must change course.
Sunetra Gupta is professor of theoretical epidemiology at the Department of Zoology, University of Oxford