Latest Technology

[ Recent Updates –original_title]

Could contact tracing bring the US out of lockdown?

Could contact tracing bring the US out of lockdown?

South Korea and the United States reported their first cases of Covid-19 on the same day. Yet while most Americans remain under stay-at-home orders, many in South Korea are doing what seems unthinkable in the US — returning to their offices.

South Korea has often been touted as rolling out one of the best national responses to the coronavirus, and the country’s approach has been comprehensive. All passengers that arrive at Incheon Airport — South Korea’s hub for international flights — receive mandatory temperature checks and must download the country’s coronavirus app, where they report any changes in their symptoms (or lack thereof) every single day.

This app is an important part of South Korea’s effort at contact tracing: the effort to find and notify every person who comes in contact with someone who tests positive for Covid-19. And a few weeks ago, Apple and Google announced that they were developing software that would enable contact tracing apps in the US. How might this technology change the trajectory of the US coronavirus crisis?

In this episode of Reset, host Arielle Duhaime-Ross talks with Stat News reporter Sharon Begley about how digital contact tracing is our best hope of emerging from lockdown, and why we didn’t start working on it sooner.

A lightly edited transcript of their conversation follows.

Subscribe to Reset wherever you get your podcasts, including Apple Podcasts, Google Podcasts, Spotify, and Stitcher. You can check out our guide to news of the coronavirus outbreak here and listen to other Vox podcasts on the topic here.


Arielle Duhaime-Ross

There are a lot of ways in which the US has been sort of playing catch-up in its response to the pandemic. Is that the case with contact tracing?

Sharon Begley

It is the case with contact tracing for the basic reason that experts in contact tracing, and also in infectious disease, have forever believed and argued that contact tracing does not work with a respiratory disease. And the reason experts told us that contact tracing would not work with respiratory diseases is that respiratory diseases spread too easily — air is a lot easier to come into contact with than someone else’s blood — and that they also spread too quickly. So from the get-go, this country has not even attempted to do serious contact tracing. We didn’t try it in the first cases in the state of Washington. We didn’t try it after cases appeared in California, [we] certainly have not tried it since cases appeared on the East Coast. And in addition, contact tracing is immensely laborious. You need an army of thousands of people to do it.

Arielle Duhaime-Ross

But right now, contact tracing is being touted as one of the ways that we’ll eventually be able to sort of reopen the country. Why are we seeing this shift in the way that people are talking about this?

Sharon Begley

Because of what happened in other countries. In South Korea, in particular, in Singapore, both of which had very, very early cases, not surprising given their proximity to China, that’s what they did. Those countries did contact tracing. It worked. And suddenly that opened the eyes of experts who said, no, no, it could never be done.

Arielle Duhaime-Ross

So wait, does that completely change the way that we look at respiratory illnesses like this?

Sharon Begley

It really does. You know, just as with the recognition that face masks actually can help, all sorts of assumptions about respiratory diseases are being rewritten and, in fact, overturned as a result of what we’re seeing in this pandemic.

Arielle Duhaime-Ross

Okay, so, in all the plans that we are seeing to reopen the country, to reopen the United States, how important is contact tracing going to be?

Sharon Begley

Everybody who has looked at this — academics, officials in other countries — say that this will be the only way that the country can be reopened, that we can have an exit from the very strict social distancing [and] physical distancing that we’ve had for the last month and a half. You know, whether it’s the governors talking about how to figure this out, testing and contact tracing is at the center of all of those plans. And the sequence is, test, in other words, you have to identify people who carry the virus, trace their contacts, you isolate people, and you hope that works.

Arielle Duhaime-Ross

I can’t help but notice that you’re not talking about antibody testing. You’re not talking about vaccines. I guess that’s sort of surprising, probably for a lot of people hearing this, that contact tracing and not these future things that we’re hoping will happen will be central to this approach.

Sharon Begley

You know, the reason I’m not emphasizing vaccines now is because there’s not going to be a vaccine in this calendar year. As far as serology testing, [that is], the blood tests that identify if somebody has antibodies to this coronavirus, that absolutely can play a role in reopening the economy. But, you know, let’s look at the numbers. … The country has some 350 million people. If you’re only going to let go back to life, back to work, people who have survived their Covid-19 infection, that’s not going to give you the numbers that you need. The reason you need testing and contact tracing is that you want a whole lot more people to be able to go back to their stores and their workplaces and their factories and be able to safely ride the subway and all of those things. So it can’t be only the blood tests for the antibodies.

Arielle Duhaime-Ross

Okay, so what do we need to do to implement a successful contact tracing program for Covid-19, and what are the obstacles?

Sharon Begley

So here’s the problem. As we were saying earlier in the experts’ objection to contact tracing for a respiratory virus, it has to be done fast. On average, to identify a person’s contacts — just to identify them, let alone to track them down — takes something like 12 hours of asking, “Where were you? What were you doing? What was it like there?” So that’s an average.

Arielle Duhaime-Ross

Twelve hours is a really long time. To be clear, that’s a long interview.

Sharon Begley

That’s a long interview. Probably not sitting in one place for all that time, but going back to the person to say, “Wait, are you sure you weren’t here or there? And what about this block of time when you forgot where you were?” So it’s very time-consuming to do that with just plain old analog human beings. The estimates are that the United States would need at least 100,000 tracers, possibly as many as 300,000. And, of course, we’re going to pay these people and value them and encourage them. So, you know, you’re probably looking at … upwards of 3.6 billion … dollars just to do that. And absolutely, it’s worth it. But that’s the order of magnitude that you’re talking about in terms of effort.

Arielle Duhaime-Ross

So it sounds like doing contact tracing with human interviewers will be expensive and time-consuming. And now we’re seeing lots of attempts to automate this process with technology. So in theory, how could technology help?

Sharon Begley

The technology that’s being discussed can be basically instantaneous. The way many of these systems would work is, again, you opt-in. And the opting in means that … you would … get an alert saying, “Yes, you came into close contact with someone. We think you should now isolate yourself for 14 days.” If you can get through those two weeks without symptoms, then that casual passing by the person did not infect you. That can be done virtually, instantaneously — certainly, you know, faster than human contact tracers. And the hope is that by doing it that quickly, you can snuff out any transmission chains that might crop up.

Arielle Duhaime-Ross

Right, because to be clear, it’s not just reducing the time of that 12-hour interview. It’s also reducing the time that it takes to contact the people that the person has been in touch with by just making it automated and automatic.

Sharon Begley

A group at Oxford university in the UK did model this. And they found that if you can accelerate how quickly you find, you diagnose cases, and trace their contacts, then you can ease up on social distancing to a degree that nothing else will enable you to do.

Arielle Duhaime-Ross

So could a tech solution for contact tracing work in the US in a widespread way?

Sharon Begley

So it’s always dicey to talk about a technological fix. But in this case, again, as with so much in Covid-19, we have other countries that have shown us the way. Singapore, South Korea, they used everything from security camera footage to smartphone tracing. Israel rolled out a system like this. What’s important to remember is that success does not mean zero cases. Success means that we do not have another instance where we overwhelm our hospitals and have the horrible situations that we’ve all seen, in especially New York hospitals. Bottom line, you can have way, way less than 100 percent opt-in and still have a really good chance of catching any incipient new infections after we’re over the current wave.


Support Vox’s explanatory journalism

Every day at Vox, we aim to answer your most important questions and provide you, and our audience around the world, with information that has the power to save lives. Our mission has never been more vital than it is in this moment: to empower you through understanding. Vox’s work is reaching more people than ever, but our distinctive brand of explanatory journalism takes resources — particularly during a pandemic and an economic downturn. Your financial contribution will not constitute a donation, but it will enable our staff to continue to offer free articles, videos, and podcasts at the quality and volume that this moment requires. Please consider making a contribution to Vox today.

Comment here