The Department of Health & Social Care announced the latest version of the contact tracing app will be tested on the Isle of Wight and with NHS volunteers from this week, and in the London Borough of Newham from next week. The app will enable you to report your symptoms and book a test directly through the app. If you test positive for COVID-19, your close proximity contacts from the last 2 weeks will be notified and advised to isolate to prevent onward spread of the virus.
Professor Christophe Fraser, scientific advisor to the NHSx and Department of Health & Social Care from Oxford University's Nuffield Department of Medicine explains, "Fast and widespread contact tracing is a vital tool to help retain control of the COVID-19 epidemic, and to avoid repeated lockdowns. Tracing needs to find contacts quickly because coronavirus spreads before symptoms occur. The more communities download the app when it rolls out nationally, the more loved ones, colleagues and people we don't know or remember we've been close to can be rapidly notified of a high-risk encounter. The app will enable us to return to more active daily lives with the reassurance that we can anonymously alert our network if we become infected and help avoid a second wave."
This latest version continues to use Bluetooth technology and records proximity contacts closer than 2 metres and lasting longer than 15 mins. It also includes a feature to pause the app, if you plan to be away from your mobile phone, or work in an environment, such as a hospital, where personal protective equipment (PPE) is worn. The app provides guidance on self-isolation and updates you on COVID-19 risk in your local area. Using QR code scanning, the app simplifies the process of checking-in to businesses, including pubs and restaurants, in order to assist local public health authorities with outbreak investigations. Contact data will be stored on your phone for 14 days, and QR code data for 21 days. The data can be deleted at any time by the user.
Oxford’s team of epidemiologists and mathematical modellers expect the app to help control the epidemic, reducing the number of COVID-19 cases, hospitalisations and deaths at relatively low levels of user uptake.
Dr Lucie Abeler-Dorner, senior programme manager at Oxford University’s Nuffield Department of Medicine and scientific advisor to the NHSx and the Department of Health and Social Care advisor explains, “Our recent studies estimate that the app will start to reduce the number of infections and hospitalisations from just 15-20% of the population downloading and following the advice. If people trust in the app’s purpose to stop transmission, the more people who chose to download it, the more lives can be saved.”
The proximity distance measurement is constantly being improved thanks to the simulation work of Professor Mark Briers at the Turing Institute. The Turing team estimate that 7 out of 10 contacts will be correctly notified if they are within 2 meters and for longer than 15 mins. Detection rates within 5 metres achieve 99.3% accuracy of all contacts recorded, with a false positive rate of 45% and a true positive rate of 69%.
Dr David Bonsall, clinician and scientific advisor to the NHSx and Department of Health & Social Care from Oxford University's Nuffield Department of Medicine says, “It's important that the app identifies and notifies people at risk of infection as accurately and quickly as possible. Fast testing turnaround times are critical to achieving this.”
Dr Bonsall adds, “Only people who have been ‘close’ to someone who tests positive for coronavirus will receive a notification from the app. If 45% of notifications are sent from ‘close' contacts with an infected person, but not within 2m for 15 mins, there is still a chance this was close enough and for long enough for a transmission to occur. Digital contact tracing apps can now provide people with more accurate risk information than earlier versions of the app, and will be more accurate than people's memory of all of their 2 meter + 15 mins contacts in the days before they develop symptoms.”
Professor Fraser concludes, “ When rolled out across the country the app will be an important addition to the UK’s test and trace programme, working alongside human tracing and combined with rapid testing. We’re all keen to enjoy some of our favourite activities again, feel safe returning to work, and play our part in controlling the epidemic and avoiding further loss of life or restrictions on our lives.”
The app is not widely available on the app store, residents in the two testing localities and NHS volunteers will receive a letter with a special code to download the app during the test period. There is no fixed date for national release of the app as yet.
