Many thousands of people around the UK may have isolated unnecessarily because a British government error meant they were pinged by the NHS Covid app to say they had been in close contact with an infected person in the previous five days rather than two days, a whistleblower claims.
As UK isolation rules for double-vaccinated people were relaxed on Monday, it has emerged that users were never told the app could notify them of contact with an infected person as far back as five days before the positive test.
Official guidance for the NHS Covid app defined close contact as occurring two days before the infected person had symptoms; the official NHS test-and-trace service has also always used two days as its definition.
The civil-service whistleblower says the error was flagged in a submission to Matt Hancock, Boris Johnson's then health secretary, shortly before he resigned at the end of June but it had never been publicly admitted.
About a month later Sajid Javid, the new health secretary, said he would be updating the app so that people without symptoms would have their contacts searched for only two days prior to their positive test, rather than five days. He said this was being "updated based on public health advice to look back at contacts two days prior to a positive test".
It is understood that the UK department of health and social care’s online guidance on the Covid app has never had a reference to a lookback period of five days.
The disclosure means that many thousands of people – those who had contact with symptomless people between five and three days before the positive test – were potentially asked to isolate unnecessarily.
“The standard definition of a contact in all the scientific and public stuff from Public Health England and NHS test and trace is someone who has been in contact from two days before they have symptoms, and if they don’t have symptoms but test positive you go back two days from the test,” the Whitehall source says.
“But the app had five days in it. A submission was made to Hancock from test-and-trace people around the time of his resignation, saying, ‘It’s five days, but it should be two days: should we change it now?’ And it didn’t happen.”
The department of health and social care has not challenged the whistleblower’s account and has not been able to point to a place where the UK Covid-app guidance publicly referred to contacts being searched five days prior to a positive case.
It is understood the department is making the case that the Covid app had different definitions of a close contact from test and trace, with a five-day period chosen for the asymptomatic because it is the halfway point in a potential 10-day infectious period. A department source says the lookback period had shortened partly because of the success of the UK’s vaccine rollout and the department had wanted to find a “reasonable balance between public health and wider social and economic factors”.
Asked for a response to the allegations of an error in the app and lack of transparency about the five days in the guidance, a spokesperson for the department of health and social care says: “The NHS Covid-19 app is a key tool in our pandemic response, saving thousands of lives and breaking chains of transmission. The app prevented up to 2,000 cases of Covid-19 a day in July.
“App users will only ever be advised to isolate if they have been in close contact with an individual who goes on to test positive for Covid-19. It is important users isolate when asked to do so in order to stop the spread of the virus.
“The recent change to the app logic will result in fewer low-risk contacts being advised to isolate, while advising the same number of high-risk contacts to self-isolate.”
At the peak, in what became known as the pingdemic, about 500,000 people a week around the UK were being told to isolate by the Covid app and NHS test and trace during the third wave of the pandemic, causing disruption across society.
But, on Monday, the British government relaxed the isolation rules to say that double-vaccinated people who came into close contact with a confirmed case no longer need to stay at home for 10 days.
In Ireland, anyone who is a close contact of somebody who tests positive for Covid-19 and is not fully vaccinated needs to be tested and to stay at home for 14 days. They can stop restricting their movements once they have a negative Covid test taken 10 days after they were last in contact with the person who tested positive, as long as they have no symptoms of Covid-19.
Anybody in close contact with somebody who tests positive does not need to restrict their movements or get a test if they have no symptoms and it is more than seven days after their second Pfizer-BioNTech dose; more than 14 days after their second Moderna dose; more than 14 days after their Janssen vaccine; or more than 15 days after their second AstraZeneca dose. – Guardian
