Test and Trace app ‘pinging’ people whose neighbours have Covid through walls, report claims

Fears millions could be told to self-isolate as source admits app signal can travel through walls

The NHS Test and Trace app can “ping” people through walls and ask them to self-isolate if their phone is close enough to their neighbours, a report has claimed.

The app occasionally forces people to quarantine, despite them not coming into contact with a positive case of Covid-19, because the bluetooth signal used for it is strong enough to penetrate walls, sources told The Telegraph.

The report follows growing concerns about the number of people who could be asked to self-isolate if Covid cases soar as expected following the lifting of restrictions next week.

The Unite union warned on Thursday that factories were on the verge of shutting due to staff shortages as hundreds of employees are off work at some sites, especially in the automotive sector.

A source for the Telegraph said that officials were aware of “anecdotal cases” of the app tracking people through walls.

“We are hearing of anecdotal cases and we do know that it is possible for the signal to travel through walls, although it is weakened,” they said.

In response to the report, a Department of Health and Social Care spokesperson said there was “no issue with the app tracing close contacts through walls”.

“The NHS Covid-19 app has been downloaded more than 26 million times, saved thousands of lives and stopped hundreds of thousands of cases by doing exactly what it is designed to do - informing close contacts of someone who has tested positive for COVID-19 they are at risk and advising them to isolate,” the spokesperson said.

“In the context of rising cases it is vital people are aware of their personal risk so they can make informed decisions on their behaviour to protect those around them.”

On Friday, Downing Street said that it was “highly unlikely” that the app was leading to “large numbers” of people being tracked through the walls of their house.

"We're confident that that is not contributing to large numbers of individuals being asked to self-isolate,” Boris Johnson’s spokesperson told reporters.

“The app uses low-energy bluetooth and its signal strength is significantly reduced through things like brick walls, so therefore it is highly unlikely that through brick walls would lead to an alert.”

According to analysis by the BBC, more than 4.5 million people could be asked to self-isolate between July and 16 August - when rules will be changed to allow close contacts in England who are double-vaccinated to avoid quarantine.

Sir Jonathan Montgomery, former chair of the ethics advisory board for the app, said on Friday that officials should look at changing the requirements after getting “pinged” by the system rather than changing the bluetooth signal.

“We need to think about the consequences of being pinged,” Sir Jonathan, a professor of healthcare law at University College London, told LBC.

“When the app was designed, we didn't have the ability to do a reliable home test, we didn't have very many people jabbed, and the big worrying thing about this virus is that you can pass it on before you know you have it.

“So, I wouldn't be changing the pinging but I would be changing the consequences of being pinged.”

The latest official figures showed that more than half a million alerts were sent to users of the NHS app in England and Wales in the seven days to 7 July, asking them to self-isolate due to close contact with a positive Covid case.

This was up 46 per cent on the previous week and the highest seven-day total since data was first published in January.

Ministers are understood to be examining whether to make the app’s bluetooth signal less sensitive, in order to prevent a surge in workers and medics being forced into self-isolation in the coming weeks.

The Royal College of Anaesthetists and the Faculty of Intensive Care Medicine issued a joint call this week to exempt double-jabbed NHS staff from isolation over close contacts.

“The risk of patients contracting Covid from vaccinated healthcare staff is minimal compared to the damage that patients could suffer by having their treatment delayed,” they said in a statement.

“Without this exemption in place, the NHS will not be able to address the waiting lists. We encourage the government to not wait until August to free vaccinated healthcare workers from the isolation rules - we need this to happen now.”

Meanwhile, transport unions have said there will be “dire consequences” next week when staff are "pinged" with instructions to self-isolate over close contacts.

Additional reporting by PA