Dr Waqar Rashid

Is the Liverpool mass-testing scheme a gimmick?

Is the Liverpool mass-testing scheme a gimmick?
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The revelation that both Pfizer and Modena have created seemingly effective and safe Covid vaccines that could be here by December is surely the first bit of good news 2020 has brought us. But we are, of course, nowhere near yet out of the woods. Even if a vaccine gets regulatory approval by early December, all our resources and logistics will have to be focused on procuring, delivering, and then monitoring its roll-out.

Boris Johnson himself has urged caution about the Pfizer vaccine, saying ‘there is a long way before we have got this thing beat’. But while the PM is displaying a healthy degree of realism about the challenges of deploying a vaccine, is the government still in a make-believe world when it comes to mass-testing gimmicks?

The latest scheme is the ‘moonshot’ testing programme in Liverpool, which aims to distribute rapid tests to the entire area’s population. Johnson has said that if the pilot is a success, millions of tests could be distributed elsewhere in the country before Christmas to help local authorities drive down transmission in their areas and this could enable us to defeat the virus by spring.

‘Operation Moonshot’ certainly has many advocates, including Professor John Bell of Oxford University. Those in favour of the scheme point out that lateral flow tests could have a 99.6 per cent accuracy rate, only take 15 minutes to give results, and can be administered by non-medical staff. The idea is that people would be able to test themselves in their own homes and if they are ‘Covid-free’, live their lives as normal – allowing society to fully open up.

But one basic question remains when it comes to schemes like the Liverpool moonshot programme: apart from detecting symptomatic carriers of the disease, what is the purpose of mass testing? Whether we like it or not, Covid-19 is an endemic virus now. It has been present for many months in Europe and has fully spread through the UK population. Any hope that a testing and isolation strategy will eliminate the virus at this stage is just fanciful: it has affected far too many people. Trying to stop Covid spreading by isolating people now is like trying to stamp out the common cold – no matter how much money you throw at a testing scheme, more infections will always spring up .

Nor does testing people to find asymptomatic carriers of the disease solve the problem. A recent study estimated that only around 11 per cent of people in the UK fully follow self-isolation measures when advised to do so by the test and trace programme. You would think that all of the government’s focus would be on trying to improve this figure, but instead Matt Hancock appears to be acting as if he’s on a blue-sky away-day, producing one idea after the next with little evidence to back it up.

Portable lateral flow tests certainly sound exciting – but there are increasing concerns from some experts in the field about the Liverpool scheme. They have noted that currently there is very little validation of the tests being used, with no formal studies taking place which examine large numbers of people in the community with these kits, and comparing their accuracy to PCR tests. This means that in many cases we do not know if the Innova tests being deployed in Liverpool are correctly diagnosing people with coronavirus, or if they are picking up small amounts of the virus.

So what has happened in Liverpool? Well up to 12 November, figures quoted in the local press suggest that 44,233 tests had been completed as part of the scheme, resulting in only 249 positive tests – well below current formal PCR testing rates elsewhere.

It is not surprising that positive rates are lower in Liverpool – PCR tests are more likely to get positive results when you’re only testing those with symptoms. But what about the accuracy of the lateral flow tests? An evaluation of the Innova test by Public Health England now puts the real-world accuracy rate of these tests at 84.7 per cent, with an even lower figure of 76.8 per cent positivity rate when used on people who have already tested positive using a PCR test.

This is well below the original 99.6 per cent figure quoted.

Recent analysis funded by the National Institute for Health Research shows that where tests are taken is also important when it comes to portable antigen kits. When the tests were used in a community centre they recorded 58 per cent sensitivity (the chance of picking up a positive case), 73 per cent sensitivity in a hospital with experienced nurses performing the test and 79 per cent in a laboratory environment compared with PCR.

Therefore, depending on the location, between half and a quarter of positive cases could be missed.

The failure of mass-testing schemes to detect positive cases isn’t harmless. There is a real danger here that people are given a false sense of security after receiving a false negative result, and therefore more outbreaks occur. The lateral flow tests being rolled out by the government in Liverpool and elsewhere are clearly not fit for purpose. This would have been evident had the usual piloting approach been followed rather than the mass roll-out currently being pursued by the government. As a result, it is likely that millions, if not billions of pounds may be lost. Up to £100 billion is already being set aside for mass-testing programmes in the UK (the total NHS budget for 2018-19 was £114 billion).

On many levels the whole affair is nonsensical. The portable tests have not been trialled properly on asymptomatic people and give results which could miss many cases and therefore may promote transmission within the community by giving a false sense of security.

The WHO and SAGE have stated that testing is important to catch people who are symptomatic and to promote self-isolation in those who need it. That is all testing will be useful for. Mass testing is arguably unethical, produces valueless results, and may even be harmful. Rather than waste our resource on mad ‘Moonshot’ programmes, it is vitally that we instead focus fully on the delivery of a hopefully safe and effective vaccine.

Written byDr Waqar Rashid

Dr Waqar Rashid is a consultant neurologist at St George's University Foundation Hospital NHS Trust, London. This article is a personal view and does not necessarily represent the views of the Trust. He tweets at @DrWaqarRashid1