Published: 06:00, 03 December 2020
A fed-up family have been told to self-isolate for a second time after their neighbour tested positive for Covid-19 - despite not leaving home for three weeks.
Tasha Heeney believes the Test and Trace app picked up the alert through the walls of their terraced house.
On November 14, the 48-year-old's grandson tested positive, which meant Tasha, her two daughters and son-in-law had to stay indoors for two weeks as per government guidance.
Their isolation period was due to finish on Saturday, but last Wednesday, the app told them they had been in contact with a virus carrier and they would have to isolate until December 6.
Tasha, of Darnley Road, Strood, said: "We are furious about it – it's a few weeks till Christmas, we've already isolated for two weeks and my daughter is losing a lot of money.
"She works for a nursery and was put on statutory sick pay the first time, and during the first two weeks of isolation she lost over £600 in wages.
"Doing this again is detrimental, as there is no need for us to isolate. We haven't seen a single person. None of us have left the house or been near anybody.
"We messaged my neighbour to try and work out where the notification had come from, she said her son had tested positive, and that's how we worked it out.
"I spoke to test and trace and explained what had happened, but they said we have to self-isolate regardless.
"We are furious, no one seems to have the answer, no one seems to think this has happened to anyone else.
"Nobody seems to have a clue – everyone is saying it is ridiculous we need to self-isolate but no one seems to have the authority to say we don't have to.
"I'm a full-time carer for my other daughter, who lives down the road from me, as she has mental health issues, but obviously I can't go and care for her because I can't leave.
"It clearly shows that the system has errors which causes hardship to families."
The app uses an algorithm to work out who gets an alert when someone they've been near tests positive.
According to the Department of Health and Social Care, it uses data based on Bluetooth signal strength to make calculations about risk.
This is then cross-checked with the physical distance between app users and how much time they have spent near each other.
A spokesman would not be drawn on the family's case, but said: "The NHS Covid-19 app is a key tool in our pandemic response, working to break the chain of transmission as quickly as possible to stop the spread of the virus and protect our loved ones.
"The app continues to run efficiently and the vast majority of users do not experience any issues. Over 20 million people have downloaded it so far and the more people who download it, the better it works."
NHS doctors and scientists are continuously updating it to make it as accurate as possible.