Experts question benefit of covid tracker app

THE tracker app was used by 4,600 Covid-19 positive users in Ireland to alert close contacts, the HSE has confirmed.

But experts have questioned how many of the 8,500-plus people who received those alerts would not have been tracked down by other means.

The latest available figures show that the app has an active user base of 1.31million.

In total, 8,522 people were sent close contact alerts as a result of carrying the app – after the positive cases uploaded their random IDs to the software app.

This means on average fewer than two – or 1.8 – contacts per positive case were notified. The 4,674-plus cases represents around 7.5% of the over 61,000 confirmed positive cases notified to Irish health authorities.

It is not known how many of those contacts would otherwise have been identified.

Trinity College computer science professor Dr Stephen Farrell said the key to finding out whether the app is successful is the exact number who would not have been identified through manual contact tracing.

He told the MoS: ‘It seems to me that the interesting subset of those 8,500 are the ones who would not otherwise have been found by ”manual” contact tracing. The ones that would be found in any case (partners, children, parents, close work colleagues) get no benefit at all from the app and must be a very significant chunk of the 8,500.

‘I don’t know of any public health authority measuring or publishing that kind of detail. Without that it’s never going to be possible to evaluate the efficacy of these apps.’

The HSE said: ‘The Covid Tracker App does not replace the normal contact tracing process, but is a significant enhancement. Combining manual and app-based contact tracing gives us a better chance of reaching more people that have been in close contact with someone who has coronavirus.

‘One significant benefit is its ability to identify and communicate with close contacts that are unknown to each other. Manual contact tracing simply can’t do this.

‘These types of close contact might happen in a restaurant, café, out shopping or on public transport.’