A team of researchers at the University of Oxford’s Big Data Institute provided evidence for the potential efficacy of a mobile app for instant contact tracing of COVID-19. The team is supporting several European countries in exploring the feasibility of such an app. The infectious disease experts believe that such an app could significantly help contain the spread of coronavirus, if quickly and widely deployed.

The scientists working on the project have expertise in epidemiology, medicine, virology, immunology, mathematical modelling, phylogenetics, behavioural economics and ethics. They have suspended their usual research on the spread of viruses to direct efforts toward modelling and halting COVID-19. They researched whether it is mathematically possible to stop the outbreak – and determined that if contact tracing is sufficiently fast, effective and widespread, the pandemic can be stopped. 

Professor Christophe Fraser from the Big Data Institute, Nuffield Department of Medicine, explains why a contact tracing app could be deployed with urgency: “Coronavirus is unlike previous epidemics and requires multiple inter-dependent containment strategies. Our analysis suggests that almost half of coronavirus transmissions occur in the very early phase of infection, before symptoms appear, so we need a fast and effective mobile app for alerting people who have been exposed. Our mathematical modelling suggests that traditional public health contact tracing methods are too slow to keep up with this virus.”

Fraser continues: “The instant mobile app concept is very simple. If you are diagnosed with coronavirus, the people you’ve recently come into contact with will be messaged advising them to isolate. If this mobile app is developed and deployed rapidly, and enough people opt-in to use such an approach, we can slow the spread of coronavirus and mitigate against devastating human, economic and social impacts.”

Dr. David Bonsall, a researcher at Oxford’s Nuffield Department of Medicine and clinician at Oxford’s John Radcliffe Hospital, said: “Our findings confirm that not everybody has to use the mobile app for it to work. If with the help of the app the majority of individuals self-isolate on showing symptoms, and the majority of their contacts can be traced, we stand a chance of stopping the epidemic. To work, this approach needs to be integrated into a national programme, not taken on by independent app developers. If we can securely deploy this technology, the more people that opt-in, the faster the epidemic will stop, and the more lives can be saved.

“At the current stage of the epidemic, contact tracing can no longer be performed effectively by public health officials in the UK, and many countries across Europe, as coronavirus is spreading too rapidly. Our research of early data from other countries shows that patient histories are incomplete – we don’t know the details of the person we sat next to on the bus. We need an instantaneous and anonymous digital solution to confirm our person-to-person contact history.”  

The pandemic requires an expedient and urgent response. Fraser explains, “There are currently more daily cases in many small European countries than the whole of China. Our team is now preparing simulations for this mobile contact-tracing approach that could stop the epidemic with far less disruption than national or Europe-wide isolation. Our hope is to support communities with life-saving information as the pandemic worsens, or alternatively it could be used to release communities from large-scale isolation.”

The researchers are aware of and addressing the ethical implications of their work. Professor Michael Parker, Director of the Wellcome Centre for Ethics & Humanities and Ethox Centre, in Oxford’s Nuffield Department of Population Health recommends: “The use of any coronavirus mobile application requires high ethical standards throughout the intervention, including: guaranteeing equal access and treatment; addressing privacy and data usage concerns; adopting a transparent and auditable algorithm; considering digital deployment strategies to support specific groups, such as health care workers, the elderly and the young; and, proceeding on the basis of individual consent.”

The researchers emphasize the need for the app to be a part of an integrated approach to combat the spread of the virus.

Bonsall continues: “We need a variety of measures to slow the spread of infection before vaccines and antiviral treatments become available. A significant number of infections are being transmitted before symptoms start, so we need a fast and efficient system for alerting people when they have been exposed. Regular handwashing and hygiene remain important; in addition, people should follow any recommendations to reduce close contact with others, especially in densely populated areas. Combining these measures will help to reduce onward transmissions, which in epidemiological terms, reduces the reproductive number R; the average number of transmissions from infected individuals. If a country reduces R to less than one, the epidemic will decline and eventually stop.”

Fraser concludes, “Current strategies are not working fast enough to intercept transmission of coronavirus. To effectively tackle this pandemic we need to harness 21st century technology. Our research makes the case for a mobile application that accelerates our ability to trace infected people and provides vital information that keeps communities safe from this pandemic.”

More information on the research can be found at https://045.medsci.ox.ac.uk/.