5 August 2020

The UK’s Covid testing is not good enough to stop a second wave


With the ONS announcing a probable uptick in new cases of coronavirus in the UK last week, the big fear now is of a resurgence in the virus sweeping across the country – as it is already doing in the US and is threatening to do across much of Europe.

Just as with the rest of the coronavirus pandemic, there is simply too much uncertainty to know what is going to happen. It is not clear that we will get a second wave – after all, the evidence for an uptick is based on extrapolating from five extra individuals testing positive this week compared to last week, out of a sample of almost 30,000.

But as the saying goes: hope for the best, prepare for the worst. Unfortunately, based on my own recent experience of using the UK’s testing system, it’s still not up to scratch. Should the virus come back strongly again in the autumn or winter, when conditions will make transmission easier, then it’s unlikely that the system will be good enough to stop another flare-up.

Waking up the Saturday before last with a sore throat and feeling ever so slightly feverish, the valetudinarian in me went into hyperdrive and I immediately began worrying about whether I’d somehow picked up the virus, despite having seen hardly anyone and been stuck in my flat working for most of the past fortnight. When I still had a sore throat the next day, I ordered a home test. It was a simple enough process, but then the waiting began.

I had hoped, given that I’d placed the order at midday on the Sunday that it would arrive early on Monday so I could take the test and have it in the post before the last collection of the day at 5:30pm. Sadly, this was not to be. Despite being out for delivery in the London area from mid-morning on the Monday, the estimated delivery time wasn’t until 8pm, meaning I’d have to wait until the Tuesday to send it back. In the end the first delivery failed and I had to wait until just before 8pm on the Tuesday before I finally got my hands on the test kit.

These delays meant I didn’t manage to post my sample back to the lab until Wednesday, meaning it likely wouldn’t have arrived until late Wednesday night or Thursday morning. When you apply for a test, they say they aim to get test results back in 2-4 days after the lab receives the sample. However, in the end I ended up as one of the lucky half who get their results back within 24 hours, because on the Friday morning I woke up to a text saying my result had come back as negative, which obviously pleased me, even if the overall performance of the testing system did not.

In total it took five days from ordering the test to getting my result back – nowhere near fast enough. Given the evidence that transmission occurs before the onset of symptoms – and indeed that carriers are most infectious just before symptoms show – we can’t have a testing system which takes several days to determine whether or not you have the virus. So the recent announcement that new tests will be rolled out in hospitals and care homes which don’t need samples to be assessed by a laboratory – and get results back in 90 minutes – is very good news.

But it’s not just about speed, it’s also about who we test. As the Nobel prize winning economist Paul Romer has been calling for throughout this crisis, what we need is regular testing of everyone –  so that way you pick up more asymptomatic and pre-symptomatic carriers of the virus before they can spread it widely. And you wouldn’t need highly accurate tests for this strategy to be effective either. For one thing doing more tests will mean that you’ll reduce the inaccuracy simply by testing the same person more often. And the current PCR tests are estimated to be only 70% accurate, so many cases are already being missed anyway.

The costs of such a testing system would undoubtedly be very high. By way of comparison, the Rockefeller Foundation recently called for $100bn to be spent in the US to set up a similar system. However, this has to be weighed against the enormous cost that the pandemic and the legal restrictions are already imposing, which one estimate put as high as £2.4bn a day during lockdown – costs which will only get larger if the test and trace system can’t cope with another surge and we are forced into another lockdown.

As the Chief Medical Officer for England Chris Whitty’s comments the other day show, under the current system we are at the limit of how far restrictions can be eased while still keeping the virus under control. Ultimately, even if the Government had to spend billions on building and speeding up testing capacity enough to screen the population regularly, it would be worth it if it meant avoiding the economic catastrophe of another lockdown.

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Jethro Elsden is a Data Analyst at the Centre for Policy Studies.

Columns are the author's own opinion and do not necessarily reflect the views of CapX.