Public health leaders were slow to act on repeated warnings over Christmas 2020 that contact tracing and isolation should be triggered immediately after a positive lateral flow test result, leaked evidence to the Covid inquiry shows.
A scathing “lessons learned” document written by Dr Achim Wolf, a senior test and trace official, and submitted to the inquiry, gives his account of a trail of missed opportunities to improve the NHS test-and-trace regime in the first winter and spring of the pandemic – before vaccines were available.
It suggests that people will have unnecessarily spread the virus to friends and relatives in the first Christmas of the pandemic and subsequent January lockdown period because they were not legally required to isolate and have their contacts traced as soon as they got a positive lateral flow test.
Instead, for around two months, those eligible for rapid testing were told to get a confirmatory PCR test after a positive lateral flow. About a third of those who subsequently got a negative PCR result were likely to have had Covid anyway.
The policy was eventually changed on 27 January 2021 so that some people were required to contact trace and isolate immediately after receiving a positive lateral flow result – after about 6m lateral flow tests had been carried out.
However, for NHS workers, adult social care workers, primary school teachers and hauliers there was still a requirement for a confirmatory PCR test and therefore no immediate contact tracing. This carried on until a new contact-tracing regime from the point of a positive lateral flow test at the end of March 2021 – months after the issued was first raised.
Daily deaths from Covid were running at about 400 a day in the week before Christmas 2020, when limited household mixing was allowed as part of the tier and bubble system. Johnson announced a third lockdown in early January 2021, with confirmed cases at about 70,000 a day. Daily deaths in the pandemic reached their peak at more than 1,000 a day during the last two weeks of the month.
In the “lessons learned” document seen by the Guardian, Wolf says: “Over the winter months, the prevalence in individuals who had 1) a positive lateral flow; followed by 2) a negative PCR; may have been upwards of 30%. These individuals were then allowed to return to their high-risk workplaces.”
The former head of policy at NHS test and trace highlights how it took too long to get clear advice from Public Health England about policy on contact tracing and isolation rules in the face of changing scientific evidence on the accuracy of lateral flows.
He also drew attention to a “lack of appropriate expertise” in the science of testing at Public Health England and NHS test and trace, which led to a failure to evaluate the evidence.
In the document, Wolf outlines how he first tried to raise the issue of a lack of modelling in relation to Innova lateral flows and how many false positives they would produce in September and October 2020 and again in November.
The document says the official then became increasingly concerned in December 2020 that a positive lateral flow result had a higher chance of being correct than existing studies suggested, and also at times of high prevalence of Covid – regardless of the confirmatory PCR result.
At the time, rapid testing was increasingly available to NHS workers, care workers, those in care homes, staff in prisons, food manufacturing workers, those delivering and administering Covid vaccines, teachers, some pupils and university students, as well as pilots.
This meant those people who had tested positive by lateral flow were still allowed to go about their business, and no contact tracing was taking place until the confirmatory PCR had been returned.
According to the “lessons learned” document, Wolf conducted his own analysis and repeatedly attempted to raise the issue of low rates of false positives on lateral flow tests with senior public health officials on 21 and 22 December 2020.
Susan Hopkins, the then incident director of Public Health England’s Covid response, said on 22 December, that this was against the consensus, although she agreed to commission a “further opinion”. Wolf repeated his concerns the next day by email. By 24 December, Public Health England reversed its position and said it agreed it was right to suspend confirmatory PCR tests.
However, it took another month for the decision to be enacted on 27 January – weeks too late to stop people with positive lateral flow results but negative PCR results from mingling with friends and relatives over the Christmas period.
Furthermore, NHS and adult social care settings, primary teachers and hauliers were exempt from the policy – believed to be due to concerns that too many people would be forced to isolate and cause staff shortages as a result.
From January 2021, Wolf made 13 attempts to get official updated advice from Public Health England on whether contract tracing should be triggered for everyone as soon as they received a positive lateral flow result.
He eventually conducted his own analysis again and submitted it to senior public health leaders at the beginning of March. This was later turned into a scientific paper by Wolf, Jack Hulmes and Dr Susan Hopkins, now chief medical adviser, published on the Gov.uk website, questioning previous assumptions about how likely a positive LFD result was to be correct versus a negative PCR result.
A decision was finally made by Hopkins to trigger contact tracing from the point of all positive lateral flows on 15 March 2021, overruling previous advice from other Public Health England and test and trace public health experts. By this point, the technology was available to rescind contact tracing if a confirmatory negative PCR was received – and confirmatory PCR was reinstated as a policy at the end of March, even though about a third of the original LFD results were likely to be correct.
Subsequent analysis by Dr David Spiegelhalter suggested there was little value in a confirmatory PCR at times of high prevalence, as about 40% of those testing positive by lateral flow and negative by PCR would still have the virus and be falsely reassured.
However, the issue of suspending confirmatory PCR remained controversial, with some experts arguing following the publication of the government’s paper that there was still too high a risk of false positives and unnecessary isolation, especially among schoolchildren.
Wolf’s attempts to sound the alarm about the issue of testing, isolation and contact tracing are documented in evidence to the Covid inquiry, which has been collected on a central Whitehall database.
The inquiry, led by Heather Hallett, will seek to investigate the response to the pandemic and identify lessons learned for future public health crises. The “lessons learned” document details concern that there was insufficient expertise within Public Health England, later the UKHSA, in relation to the science of testing and diagnostic epidemiology, as well as an over-reliance on consultants without the relevant knowledge in these areas.
Safiah Ngah, who lost her 68-year-old father, Zahari Ngah, to Covid in February, and is a spokesperson for the Covid-19 Bereaved Families for Justice campaign, said: “These revelations are incredibly hard to hear even if they are not surprising. Just a few weeks after this advice was ignored, cases had spread so rapidly that one in 20 people in my borough had Covid-19, and my family were left desperately trying to do everything we could to keep my Dad safe. Unfortunately it wasn’t enough.”
She said: “It was clear before the second wave that the test-and-trace system was a complete disaster, so why was advice that would have saved lives ignored? If the advice had been heeded, thousands of lives might have been saved, months of lockdowns might have been avoided and I might be spending today with my Dad. The inquiry must now get to the bottom of how and why this happened, so that disasters like this are never repeated again in the future.”
Wolf declined to comment. Prof Hopkins, now the chief medical adviser at UKHSA, said: “The advice given in this time period was clear; if someone had a positive lateral flow test they should self-isolate.”
