Many thousands of people may have isolated unnecessarily because a government error meant they were “pinged” by the Covid app for a “close contact” in the prior five days rather than two days, a Whitehall whistleblower has told the Guardian.
As the isolation rules for double vaccinated people were relaxed on Monday, it has emerged that users were never told the app could notify 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, while the official NHS test-and-trace service has always used two days as its definition.
The Whitehall source said that the error had been flagged in a submission to Matt Hancock, the then health secretary, shortly before he resigned at the end of June but it had never been publicly admitted.
Around a month later, Sajid Javid, the new health secretary, said he would be updating the app so that people without symptoms would only have their contacts searched for 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 Department of Health and Social Care’s (DHSC) 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 said.
“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.’”
Justin Madders, the shadow health minister, said it was “another shambolic situation from hapless ministers”. “The Covid app has been one mess after another and a lack of clear information and guidance around the app only undermines its effectiveness,” he added.
The DHSC did not challenge the whistleblower’s account and was not able to point to a place where the Covid app guidance publicly referred to contacts being searched five days prior to a positive case.
Al Ghaff, chief operating officer of the privacy campaigning organisation the Open Rights Group, said the government’s approach to privacy risked undermining public trust.
“The disclosure means that many thousands of people have been pinged by the Covid app without their consent,” he said. “Since the outset of the pandemic, this government has displayed an extremely poor and cavalier attitude towards basic privacy and transparency safeguards. The government needs to stop turning public health tools into privacy nightmares and public health risks.”
It is understood the department is making the case that the Covid app had different definitions of a close contact to 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 DHSC source said the lookback period had shortened partly because of the success of the 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 DHSC spokesperson said: “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, about half a million people a week 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 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.
Business groups broadly welcomed the loosening of the rules but cautioned there is still likely to be significant disruption to a post-pandemic recovery.
“Many businesses will be relieved by the changes to the self-isolation rules coming into force,” said Hannah Essex, co-executive director of the British Chambers of Commerce. “It should be remembered though that some disruption will continue, as about 25% of adults are not fully vaccinated, Covid infections remain high and there are persistent labour shortages in sectors such as agriculture, retail and hospitality.”
The CBI, which represents 190,000 businesses employing nearly 7 million people, said that sectors reliant on younger workers awaiting their second jab, such as hospitality, would still have a critical part of their workforce “facing the prospect of needlessly having to self-isolate”.
Essex also warned that the government needed to put in place plans to get the country through the winter, with half of businesses in consumer-facing sectors – such as hospitality and retail – saying that future lockdowns, or restrictions, would be a significant barrier to trade returning to pre-pandemic levels.