Can a smartphone app help us turn the coronavirus corner and go outside again?

When will be able to leave our homes? When will the grim news about coronavirus cases and deaths begin to wane? When will the pandemic subside in the United States and life return to something with at least a passing resemblance to normal? US government officials and experts are increasingly now saying such a reopening may not be possible for weeks or months. And any opening may entail some reduction in social distancing efforts that is followed by future rounds of restrictions. At the least, a reopening of public American life will almost certainly require widespread testing, so health authorities can tamp down on any future outbreaks as they emerge.

Once states meet some key milestones, like boosting hospital capacity, they may be able to move out of what former Food and Drug Administration commissioner Scott Gottlieb and other authors of a recent plan to lessen social distancing efforts call Phase I. In that current phase, the COVID-19 outbreak is worsening and shutdowns and social distancing are the main tools states have to combat it. Eventually, US governments may be able to move to Phase II, a comparatively permissive stage during which, as Gottlieb and his colleagues put it, a “majority of schools, universities, and businesses can reopen. Teleworking would continue where convenient; social gatherings would continue to be limited to fewer than 50 people wherever possible.”

To get to Phase II, one thing officials will need to roll out is a significant ability to do contact tracing, the technique public health departments use to map out whom an infected person may have been in contact with. In the United States, some less populated and infected states are still trying to do this. But in other cases, the COVID-19 outbreak has outpaced health authorities’ ability to map its contours. In New York City, for instance, the US epicenter for COVID-19, health officials are limiting the tracing of contacts to just a subset of cases, such those in nursing homes.

But other countries have tamed their COVID-19 outbreaks better than the United States has, in part by a broad use of contact tracing. Even in the United States, new technology may eventually help authorities to return to that epidemic fighting tool. In fact, for COVID-19, the use of digital location tracking may be by necessity.

The authors of a new Science article conclude that when it comes to the new coronavirus, the “viral spread is too fast to be contained by manual contact tracing.” An app may be the answer to achieve “epidemic control if used by enough people,” the Oxford University researchers write.

“By targeting recommendations to only those at risk, epidemics could be contained without need for mass quarantines (‘lock-downs’) that are harmful to society,” the authors write; they  go on to detail an algorithm that uses smartphone functionality to conduct a week’s worth of manual contact-tracing labor instantaneously.

“Coronavirus diagnoses are communicated to the server, enabling recommendation of risk-stratified quarantine and physical distancing measures in those now known to be possible contacts, while preserving the anonymity of the infected individual,” Luca Ferretti, a senior researcher at Oxford University’s Big Data Institute, and his colleagues write. “The [COVID-19] tests can be requested by symptomatic individuals through the App.”

Madhav V. Marathe, a computer scientists and expert in computational epidemiology at the University of Virginia, says that if contact-tracing apps can overcome privacy concerns, they would certainly help contain the coronavirus outbreak. “I think they would have a significant impact on controlling the disease,” he said. “In a perfect world, I think those are excellent ideas.”

A group at MIT has designed software that can share anonymized location data among phones to let people know if they’ve come in contact with an infected person who also uses an app called Private Kit: Safe Paths. Users can also push this information to public health officials to help contact-tracing efforts. A group of health professionals and technologists have proposed digital contact tracing in the United States, as well. While privacy will be a key concern, apps could be designed to circumvent that problem, Marathe says.

One might not know exactly who is sick, Marathe says, “but I can get a fairly good sense that [in a] square kilometer block, so many people are sick,” he said. “You want to get a general sense of incidents. That’s useful for the government and for you … but you never want to sort of release it at the level of detail that it’s a problem.”

In Singapore, a country that’s turned to cellphone contact tracing, an app called TraceTogether uses Bluetooth to log when a user’s phone encounters another phone that has the app. If someone tests positive for COVID-19, he or she can easily submit a log of all the other people (and their phones) that he or she came in contact with in the last 21 days. Without the app, manual contact tracing for COVID-19 cases would be difficult. “It is a complex and arduous process of interviewing the patient, listing down everything they did in the past 14 days, and identifying every person they had come into close contact with,” a Singaporean government website says. “Yet, it is a crucial step to detect further cases and preventing further possible spread of the virus.

That country of about six million people has so far had under 1,000 cases of COVID-19 and just three deaths, according to an April 1 tally by the World Health Organization. Singapore is being held up as an example when it comes to contact tracing and isolating potential cases. Schools and businesses remain open, while certain other aspects of life face restrictions, like a requirement that people remain about 3 feet (1 meter) apart from one another in public.

South Korea is also aggressively testing for COVID-19 and tracing the contacts of infected people. After a 2015 outbreak of Middle East Respiratory Syndrome, another coronavirus-caused disease, the government implemented reforms that have led to greater transparency around where infected people have been. “The disclosure of epidemic information is very significant for disease prevention and control, because we experienced the failure of disease control and prevention during the MERS of 2015,” HyunJung Kim, a PhD student in biodefense at George Mason University who has written about Korea’s public health system, says.

“Information … makes people more comfortable because they can avoid and detour the areas/hospitals where infected people visited.”

App developers in South Korea have also been using public information about patients to map out where they’ve been, although some services appear more geared toward the public rather than health officials. Nonetheless, widespread COVID-19 testing and contact tracing has helped South Korea remain relatively open compared to much of the United States.

“The US disease prevention and control efforts based on shelter-in-place orders are much more stringent than what South Korea did. Social distancing in Korea is recommendation, not [an] order,” Kim says. “The Korean government encourages people to conduct social distancing, but if they have to go to essential places such as markets or work, the government encourages people wearing masks.”

The Trump administration is now saying that even with social distancing, COVID-19 could claim 240,000 lives in the United States. Staying inside for weeks longer will be a small price to pay to keep that number as low as possible. Still social distancing and shutdowns are not strategies that Gottleib and other experts think are sustainable forever. The ability to do contact tracing—digitally or otherwise—could be key to beating back the coronavirus’s full assault.

“We have also seen a rapid escalation in social distancing measures, like closing schools and cancelling sporting events and other gatherings,” Tedros Adhanom Ghebreyesus, the director general of the World Health Organization told reporters recently.

“But we have not seen an urgent enough escalation in testing, isolation and contact tracing— which is the backbone of the response.”