Milan, May 25 (beraking latest news Salute) – It is called ‘Nhs Covid-19’ and it is the Immune of the other side of the Channel: an app for digital tracking of the contacts of Sars-CoV-2 positives, which is based on the same mechanism as the ‘cousin’ Italian. For scientists on British soil it worked, it helped to “curb the spread of the virus”. A study, the results of which are described and analyzed in an article published in ‘Nature’, concludes that overall about a new case has been avoided for each person with confirmed Covid-19 infection who has consented to the notification to their contacts.
The Oxford University researchers estimate that for every 1% increase in App users, the number of cases could be reduced by 0.8% (based on calculations on a model) or 2, 3% (based on statistical comparisons). The authors also estimated that the likelihood that someone who received a notification will test positive in the next 2 weeks is 6%. Starting from this experience, the potential of these digital tools is analyzed in the article by C. Jason Wang of Stanford University School of Medicine. The App, he says, has curbed the spread of Covid in England and Wales.
The idea behind digital contact tracking is that, when a person tests positive for an infectious disease such as Covid, an App on their smartphone can send a notification to other smartphones that have been in the immediate vicinity, for example within 2 meters. , for more than a certain period of time, for example 15 minutes. However, observes the scientist, “such Apps can be difficult for people living in a democracy to accept, due to concerns about privacy”, which is actually guaranteed by a technology that anonymizes the data exchanged. Yet the case of England and Wales shows that the tool can be successfully implemented on a large scale in these companies.
Of course, Wang reasons, the flow of data must work well, because that can affect the effectiveness of digital contact tracking. And right from the start, he points out, “the App will make a significant difference in the population only if a large enough share installs and uses it”. In England and Wales it is estimated that 33.9 million people could download it (being at least 16 years old and having a compatible smartphone). Between its launch on September 24, 2020, and the end of 2020, the App was downloaded on 21 million separate devices and, between November 1 and December 11, 2020, was regularly used by an average of around 16.5 million users, approximately 49% of the eligible population, or 28% of the total population of England and Wales.
The experience of NHS Covid-19 “shows that participation in the use of the App is sufficient for it to be useful”. The scientists (Wymant et al) who conducted the study, explains Wang, used two ways to estimate its impact on the spread of Covid-19 from October to December 2020: using the number of notifications observed and the rate of contacts identified that they ended up getting infected, they built a model to calculate the number of cases avoided with the App; and second, they performed statistical comparisons of cumulative cases in neighboring regions that had similar baseline infection rates, but different levels of App usage.
A common criticism of digital contact tracing is that it could create ‘noise’ by contacting a large number of people who have a low probability of being infected, compared to those who would be involved with contact tracer tracking in the flesh and bones. But experts showed similar percentages of contacts intercepted with the two methods which then turned positive (6% for the app and 6.9% for ‘human’ tracking). They also found that the average number of contacts reached was 4.4 for digital tracking, compared to 1.8 for manual tracking.
“This strongly supports the idea that the App is accurate and can be complementary to manual contact tracking,” concludes Wang who lists the benefits, from speed to greater accuracy than allowed with positive interviews in reaching a wider I radiate people at risk for contact with the infected. The British App has evolved and now also has extra features like the one that allows you to ‘check-in’ when you go to a place, by scanning your QR code, useful in case of a subsequent notification if the venue in question has positive cases. It then has a symptom tracker connected to a test booking system; and offers the possibility to receive results via the app. While in GB it will always be an App (the Nhs App) to also support the ‘Green Pass’ – a solution that is also evaluated in Italy – the success of Nhs Covid-19, concludes the scientist, “gives hope that other tracking may prove useful elsewhere, offering new capabilities to contain the advance of a rapidly spreading virus. ” Will Immuni be able to be among these?