Blanket coronavirus testing is not optional

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We thought we were living in crazy times before the coronavirus outbreak – then the gods took a look and said ‘Hold my beer’ …

The British government didn’t exactly get off to the best of starts, but it is now getting many things right. It’s asking everyone to socially distance; has ordered the closure of facilities that make that impossible (like pubs and theatres); and has put in place the financial support needed to make social distancing practical for most people. We still need to make proper arrangements for the self-employed, and those on zero-hours contracts, but the 80% support for employees was a very bold and impressive move.

However, there’s one area where the UK is still massively failing: testing. Our current policy is to test only serious, hospital-presenting cases. What we need instead is blanket testing, for three reasons.

Getting accurate data

First, and most trivially, we need accurate data. You can’t address a problem effectively unless you know the extent of it. By waiting until people turn up at hospitals, we’re always behind the curve in identifying new hot-spots.

If you look at the comparative mortality rates for COVID-19, they appear to vary tremendously by country. Some of the difference is undoubtedly real. Germany, for example, has 8 hospital beds per 1,000 people; the UK has 2.5. The UK also has a relatively low number of doctors and nurses per head of population. Those are factors that will become increasingly important as the spread progresses.

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But much more of it is about testing. If you only test the most serious, hospital-presenting cases, then the mortality rate will obviously appear to be very high. Testing everyone with any symptoms, however mild, gets us closer. But it’s only by blanket-testing the entire population that we’ll know for sure, as we know many people can be completely asymptomatic.

Persuading people to take it seriously

Data is needed for resourcing purposes, but it’s also needed to persuade people to take it seriously.

At the moment, there are still people who don’t appreciate the urgency of social distancing. Look at the supermarket scrums, or those who have until recently been happily crammed into crowded tubes.

Once they see just how many people are already infected, and how quickly that number is rising, we might finally see mass respect for the two-metre rule.

A safe return to normality

But by far the most important reason for blanket testing is that we need to know when it’s safe to stop socially distancing. Many people are currently under the impression that this will last just a few weeks. The experts are saying otherwise.

We show that in the UK and US context, suppression will minimally require a combination of social distancing of the entire population […]

The major challenge of suppression is that this type of intensive intervention package – or something equivalently effective at reducing transmission – will need to be maintained until a vaccine becomes available (potentially 18 months or more) – given that we predict that transmission will quickly rebound if interventions are relaxed.

Clearly it’s not remotely feasible for people to remain socially-distanced for 18 months. But what we can’t have is random people resuming normal life at random times. We need people to do so only when they have had the virus, are recovered, no longer infectious, and have immunity. And the only way that can happen is with testing.

Right now, the NHS is only making presumptive diagnoses on people not ill enough to require hospital treatment. That’s the position Steph is in – enough symptoms match – and it’s assumed I was also infected by her as it’s hard to see how I could have escaped. But neither of us can rely on that. Millions of people are going to end up in the same position.

Swab tests for the infection itself are probably not practical. My understanding is that we are only infectious for around five days after first showing symptoms (as well as for some time before). Getting testing done during that narrow window is difficult in itself, and swab tests are not massively reliable when carried out by professionals, let alone people taking their own swabs at home.

What we really need is blanket antibody testing, so people know when they’ve had the virus. That can be done at any time. As soon as people are confirmed positive for the antibodies, give it another seven days to be sure and they can then continue life as before.

Yes, there are caveats. There is data to show that some people can get reinfected, but this appears to be a vanishingly small minority. There is the risk of mutation to the point where the original antibodies are no longer effective, but so far this appears to be a slowly-mutating virus. And antibodies don’t remain present forever, but this is about slowing transmission, not preventing it entirely. (And the biggest caveat of all: I’m not an expert. This is my layman’s understanding, having done a lot of reading.)

The British government has said it plans to buy ‘hundreds of thousands’ of these tests. That’s a start, but what we need are millions. Enough to test the entire population of the country (and more than once in the case of those who test negative – they will need another test once they subsequently believe they have been infected.)

Sure, start with NHS staff and other key-workers, which of course includes supermarket staff. Put the early resources where they are most needed. But we need to ramp up antibody testing to the whole population as quickly as production allows.

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