the contacts with whom an infected person has been is key in any
pandemic to stop the spread of the pathogen. This can be done
manually, by asking the sick person, however it is an extremely slow
and complex process that requires a lot of resources. Automating this
process is the main objective of the smartphone applications that
have emerged during the covid-19 pandemic.
An international research collaboration, involving scientists from the UK, US and Spain, including as corresponding author Lucas Lacasa, Research Associate at IFISC (UIB-CSIC) and Reader in Applied Mathematics at Queen Mary University of London, has shed new light on the usefulness of these digital contact tracing (DCT) apps to control the spread of Covid-19. The study, published in Nature Communications, analyzes the effectiveness of the Spanish SES app, Radar COVID, following a four-week experiment conducted in the Canary Islands between June and July 2020.
the experiment, funded by the Spanish government's Secretary of State of Digitalisation
and Artificial Intelligence (SEDIA), the researchers simulated a
series of Covid infections in the capital of La Gomera, San Sebastián
de la Gomera, to understand whether the Radar COVID app technology
could work in a real-world environment to contain a Covid-19
outbreak. They found that over 30 per cent of the population adopted
the technology and it was able to detect around 6.3 close-contacts
per infected individual, which was over two times higher than the
national average detected using manual contact tracing alone. However
the researchers suggest that the app’s success is dependent on
effective communications campaigns to encourage people to download
and use the app in the first place.
Dr Lucas Lacasa said: “Whilst digital contact tracing has been suggested as a valuable complement to manual tracing programmes, and even already been adopted in several countries, until now we haven’t had any real experimental evidence to prove the effectiveness of this technology.”
DCT relies on the use of mobile phone apps to trace contacts and notify individuals of recent contact with others who have recently tested positive for Covid-19. It has already been introduced in countries worldwide to support manual contract tracing efforts but until now their usefulness in real-world outbreak settings has not been tested. Aside from the effectiveness of these approaches several other concerns have been raised regarding their use such as the potential detection of a high number of false close-contacts, low adoption and adherence, and privacy issues.
A population-based controlled experiment assessing the epidemiological impact of digital contact tracing, P. Rodríguez et al. Nature Communications, DOI: https://www.nature.com/articles/s41467-020-20817-6