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What is contact tracing and can it help in the fight against coronavirus?

Lockdowns across the world continue in an effort to help stem the spread of COVID-19, commonly referred to as coronavirus, but now Google and Apple are teaming up to try to help make it easier for us to interact again without so much health risk.

New “contact tracing” technology to be implemented through an app will allow people to see if they have been near someone infected, but the way it works brings up issues of privacy, access to technology, and whether this could really ease restrictions but still “flatten the curve” of infections.

What is contact tracing?

Contact tracing has been around since the 1930s as a way to track the spread of diseases, according to George Rutherford, a professor of epidemiology at the University of California-San Francisco. He told Digital Trends the method uses “real shoe-leather” detective work.

Someone infected gives “investigators” — who could be doctors, nurses, volunteers, or medical and nursing students — a list of people they have been in contact with over a specified amount of time, usually about an eight-day window before and after when they started exhibiting symptoms. The Centers for Disease Control and Prevention (CDC) define “contact” in this instance as occurring at a distance of six feet or less, for 10 or more minutes.

Investigators call or text the list to inform them of possible exposure, advise them to self-quarantine, and recommend follow-up medical care if they are at risk or start exhibiting symptoms.  The infected person then remains in quarantine for 14 days whether that’s at home or the hospital.

If one of the people contacted is exhibiting symptoms of coronavirus, then investigators ask them for a list of people they have been in contact with and the process continues.

In other instances, like if an infected person walks into a grocery store and spends about an hour there, the store could be contacted and would be advised to alert customers who were at the store around the same time as the infected person to contact investigators.

Normally, Dr. Rutherford said, contact tracing is used to track sexually transmitted diseases — so using contact tracing for coronavirus would not be an unfamiliar procedure for public health officials.

How could contact tracing help?

Dr. Rutherford explained that if we ever want to get back to our regular lives, contact tracing can be one of the ways to ensure we do that safely by limiting our exposure to those infected. By isolating pockets of infection, public health workers can help contain the spread of the highly infectious disease.

But the process isn’t foolproof; it requires people to follow the recommendations on self-quarantine and social distancing, Rutherford said. Still, it is one of the best options, he continued.

Contact tracing is already being conducted in parts of California and less populated states like Utah where social distancing is simply much easier to maintain. However, public health officials in the epicenter of the outbreak in New York City are not really doing any kind of contact tracing.

Apple and Google’s new technology could help with that and eliminate one of the bigger problems with manual contact tracing: investigators being able to reach people.

How will Google and Apple’s apps work?

Health authorities could use Google and Apple’s APIs, or application programming interfaces, into their agency’s apps when the companies roll them out in mid-May. Users would then have to download, for instance, the CDC app in order for it to be effective. The companies will “work on building tracing functionality into the underlying operating system” after the APIs have been released.

The technology does not operate like GPS, which tracks exact locations, but it basically shares surrounding Bluetooth signals anonymously. Both Apple and Google said the app is opt-in and that no “personally identifiable information” would be collected or stored. But, the issue of being tracked by a public health app has concerned some privacy advocates. Public health authorities would get access to some of the data.

Neither Google nor Apple has confirmed with Digital Trends which public health authorities will have access to the information or whether data shared with them would contain identifiers. The companies also have not confirmed whether a user has to enable Bluetooth for the contact tracing app to work.

Apple will enable the new tracking tools in an upcoming update, while Google will use its Google Play Services to push out its update, according to

What are the limitations of contact tracing?

In order to be effective, contact tracing requires widespread testing to be available to identify those who are infected. But the U.S. is only able to test about 8,000 people per million at the moment, half the rate of other hotspots like South Korea and Italy.

While technology-based contact tracing like Google and Apple’s APIs are helpful, Dr. Rutherford noted there is another major problem with it. Rates of infection are growing among service workers and poor, minority populations who may not have smartphones, unlimited data plans, or be able to work remotely due to their jobs or lack of broadband access, he said.

“The underlying assumption that everyone has access to technology is life and death ‘digital divide’ stuff, writ large,” he said.

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