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Testing

Mass Periodic Testing for Covid-19

We have reported recently on both the United Kingdom’s attempts to meet their stated “100,000 tests per day by the end of April” target and the subsequent setting up of the “Independent SAGE” committee by Sir David King, which we initially dubbed the “Alternative SAGE” committee, or “Alt SAGE” for short.

The first Independent SAGE committee meeting will be broadcast on YouTube at 12:00 BST today. We cannot help but wonder if they will discuss the concept of “Mass Periodic Testing”, or MPT for short.

The idea was introduced by Professor Julian Peto from the London School of Hygiene and Tropical Medicine in a letter to the British Medical Journal on March 22nd 2020. Here is an extract:

In Editor’s Choice of 19 March Godlee mentions the urgent need for increased capacity to test frontline healthcare workers serologically to verify their immunity to the covid-19 virus. Even more urgent is capacity for weekly viral detection in the whole UK population. This, together with intensive contact tracing, could enable the country to resume normal life immediately. The virus could only survive in those who are untested, and contact tracing would often lead to them. Within the tested population anyone infected would be detected within about a week (0 to 7 days plus sample transport and testing) of becoming infectious.

Prof. Peto’s suggestion involves testing the vast majority if the population of the UK for Covid-19 every week. His letter continues:

Centrally organised facilities with the capacity to test the entire UK population weekly (in 6 days at 10 million tests per day) can be made available much more quickly and cheaply than a vaccine, probably within weeks. This heroic but straightforward national effort would involve a crash programme to enlist all existing PCR (polymerase chain reaction) facilities, acquire or manufacture the PCR reagents, and agree protocols including a laptop program for barcode reading in smaller laboratories. The US Food and Drug Administration (FDA) has just authorised a test kit for detecting the Covid-19 virus that can be run on machines used in the NHS for HPV screening. Only laboratories that do PCR routinely would participate, subject to central quality control and at cost price. The Wellcome Sanger Institute, UK Biocentre, and smaller academic laboratories, together with all commercial facilities, should have enough machines or can get more immediately from the manufacturers. The 24-hour extra staffing to run their machines continuously would be bioscience students, graduates, and postgraduates familiar with PCR who already work in or near the laboratory. Processing capacity equivalent to 4000 Roche COBAS 8800 systems is needed, and the UK may already have both the machines and the trained staff in post or immediately available.

Roche cobas 8800 PCR testing system

As you may have noticed, such a “heroic effort” has not yet begun. We have not yet achieved a consistent 100,000 tests per day, let alone the 10 million tests per day envisaged by Julian Peto. Skipping to his conclusion:

By the time the first test is done there may be more than a million infected people who must be treated or remain quarantined at home or in care until all residents at the address test negative. That unavoidable crisis for the NHS would be ameliorated by earlier diagnosis and treatment, and hence reduced pressure on intensive care, and by having all staff as well as patients tested regularly. Contacts of positive people who test negative could choose continued home quarantine or, at little extra risk, choose to join a group of up to 10 test-negative contacts (usually with other family members). Subsequent weekly national testing, together with behavioural changes and efficient contact tracing, would find progressively fewer infections and might soon be extended to a month. This emergency system would only be needed for about 2 months but could be rapidly reintroduced to control any future epidemic caused by a new virus.


Five weeks have elapsed since the letter was published, and an avoidable crisis for the NHS is still ongoing. According to Boris Johnson’s Twitter feed over the weekend:

However according to today’s Daily Telegraph:

When today’s lunch time meeting has concluded will the Alt SAGE committee have recommended an “end [to] the absurd, dystopian and tyrannical lockdown”, mass periodic testing or some alternative “middle way”?

Watch this space!