How Contact Tracing Works
As New York begins a regional re-opening strategy, the state has released guidelines for contact tracing to follow the spread of COVID-19.
As per Governor Andrew Cuomo's office, each designated region in New York would require at least 30 contact tracers per 100,000 people.
To learn more about what contact tracing entails and how mobile technology can assist tracers to determine a person’s whereabouts, WAMC’s Southern Adirondack Bureau Chief Lucas Willard spoke with Aarathi Prasad, an Assistant Professor of Computer Science at Skidmore College.
It's up to the health workers to actually figure out who you may have been in contact with. Right? So then they would try to talk to you and figure out where have you been in this period called incubation period. So that's the time between when you might have been infected to when you were showing the first symptoms. So they will try to figure out during the infectious period where all did you go, and based on that they reach out to people who you may have been in contact with.
I'm imagining that that doesn't always go over as smoothly as it is on paper.
Exactly. Yeah. Yeah. And imagine if I asked you in the past two weeks, where have you gone? I mean, now it's easy because you know, I don't leave the house. So it's easy for me to remember where all I have been. But imagine if there was no lockdown. It would be really difficult to come up with that.
Is there an actual software that's used in contact tracing?
So one popular way to do this is using wireless technology. So we mean most people have a smartphone. And our smartphones already have patient based apps. So for example, your Google Maps, when you tell Google Maps you want to go somewhere Google Maps can actually record your location. Right? There could be other location apps like Yelp, for example, when you want to look at restaurants. So these assets are location-based apps, because they are able to connect to some WiFi signal, or the GPS to identify your actual location.
If all this information about you know where you've been is being collected over your smartphone app, is there a lot of concern about privacy? Are people being reluctant to share that information and saying, ‘Yeah, you don't, you can't take a look at my phone and where I've been?’
So there are privacy preserving techniques that are available. It is complicated to get into it, but it is straightforward to actually figure out a way where you don't have to release the exact location history of a person. So you can sort of hide the actual location history, there's also a way that your location information never has to leave the phone. So this is something I did as part of my PhD dissertation. So the technology that we came up with, you would, unless you're infected, your location information, pretty much stays on your phone. And so that way, you can even protect your own identity as well as your location history. So there are several privacy preserving techniques that are known and available to actually handle the situation.
One other issue is people trust, you know, for example, there might be people who mistrust the government. They might not be comfortable with companies such as Apple and Google. But I'm part of an initiative that's through MIT Media Lab, where they're designing an open-source app. What this means is the content data source code at the app, right, all the code that's about the app is available online. So that provides some sort of transparency and hopefully trust in the app, because experts can actually look at the code and know what exactly it's collecting and what it's sharing.
But on the other hand, you know, the solutions that are provided by Apple and Google is easir, because you don't already have to download an app. Right? It's already part of your phone. So if you have your phone, you don't really have to do anything, except just carry a phone wherever you go.
When it comes to government saying ‘We need to step up contact tracing,’ what is needed in terms of human capital in terms of actual people to make phone calls to assist in gathering data? Where are we now and what's needed?
There are of course, many challenges like there are lot of unknowns. We don't really understand COVID-19. So, you know, apart from the human aspect, I mean, there are other aspects. Even apart from the technology aspects, there are a lot of things that we still don't understand. But from the technology aspect, it is important right now to start thinking about how would we help with memorability? Right. So once the lockdown ends, is that do we have some sort of solution that will help public health workers reach out to people who may have been in contact with an infected person? So that's what I think we need to come up with a way to encourage people. Like, I would download this app and I will try to encourage everyone I know to also download the app, because no technology solution is going to work if everyone doesn't contribute in some way. And what you are ultimately trying to do is help you know your friends and your community to keep everyone safe. And that's why we are trying to download this app to find the people who may be infected.