Mobile Devices Could Be Key Tool in COVID-19 Contact Tracing

As health care workers and public health agencies rush to contain the spread of coronavirus disease 2019 (COVID-19), new research suggests officials might be able to leverage mobile technology to more precisely trace the contacts of infected people.

In a new article, published in the journal Science, investigators from Oxford University suggest contact tracing based on mobile device data could substantially out-perform manual contact tracing, and thereby boost the effectiveness of containment strategies.

The mobile-app hypothesis is underpinned by new transmission data included in the article. By analyzing key parameters of SARS-CoV-2’s spread, the team calculates that transmission is happening too quickly to be stopped through the process of asking infected persons to list contacts, and then notifying those contacts individually. Part of the problem is that, according to the analysis, as much as half of transmission occurs before the person transmitting the virus is symptomatic.

“Transmission occurring rapidly and before symptoms, as we have found, implies that the epidemic is highly unlikely to be contained by solely isolating symptomatic individuals,” wrote David Bonsall, PhD, a senior researcher at Oxford University’s Nuffield Department of Medicine.

What Bonsall and colleagues propose is a mobile app that would help quickly identify and alert all of an infected person’s contacts. However, it’s not what you might think.

The app would not need to track user’s movements using location services. Instead, the app would use a low-energy version of Bluetooth to make a note anytime the app user comes into close contact with another app user. If neither the user nor their contacts get infected, nothing would happen. However, if a user were to test positive for COVID-19, the app could automatically alert all of the app users with whom the patient had come into contact in recent days.

“If you then become infected, these people are alerted instantly and anonymously, and advised to go home and self-isolate,” Bonsall explained, in a press release. “If app users decide to share additional data, they could support health services to identify trends and target interventions to reach those most in need.”

While an app alone might not be enough to stop the virus, Bonsall and colleagues believe it could make a major difference, particularly in low- and middle-income countries, where containment and public health resources tend to be less available.

"If the mobile app is widely adopted in any country, and combined with other critical interventions such as physical distancing and widespread testing, our models suggest the epidemic could be brought under control,” Bonsall said.

Furthermore, Bonsall and colleagues argue that successful implementation of the app strategy could make it possible for governments to lessen social distancing restrictions, since it would be easier for a person to know if they had or had not been in contact with an infected person.

The app is still in development. Bonsall and colleagues are currently working with researchers from Britain’s National Health Service and the Norwegian Institute of Public Health to investigate the feasibility of quickly deploying an app. However, Bonsall and colleagues also urged the public to be judicious when installing COVID-19-related apps on their phones. They said members of the public should stick with scientifically verified apps approved by public health agencies.