As Governor Cuomo announced on May 19, the Capital Region has finally reached its benchmark for contact tracers and can now begin its phased reopening on May 20. What had been holding the region up? The number of contact tracers, or people who remotely contact others who have tested positive for the COVID-19 virus antibody (or who been infected and since recovered) to “trace” how many people they’ve come into contact with. (The virus has already taken 90,000 lives in the US alone.) As Dr. Lisa Vande Vusse told Saratoga Living, “As social distancing continues and businesses start to open, we can’t predict what’s going to happen in terms of the transmission of the virus, and there’s a lot of interest in building infrastructure to be able to try to continue controlling the virus through understanding transmission from direct contact to direct contact.” In the last couple of weeks, Governor Cuomo has been preparing an “army” of thousands of contact tracers to assist in the piecemeal reopening of the state’s economy.
But how exactly does contact tracing work from a technological standpoint, and what does it mean to your everyday New Yorker? Saratoga Living reached out to Skidmore College’s Assistant Professor of Computer Science Aarathi Prasad, an expert on contact tracing and privacy-preserving protocols for it, to get some answers.
What does contact tracing technology look like to the average New Yorker? Would it be as simple as downloading an app?
For a smartphone user, yes: You’d need to download an app. At some point, you might then receive a notification saying that you’ve been near someone who’s tested positive [for COVID-19], and you would need to follow the instructions given to you, presumably, by public health officials.
If someone doesn’t have a smartphone, would there still be an effective way to trace him or her?
One could imagine providing web tools for personal computers that would allow people without smartphones to upload their location history. [This] is similar to what’s done currently with contact tracing without smartphones. Of course, without smartphones to record location history this could be more time-consuming—and potentially less accurate.
What about concerns over privacy? Would this be any different than many other apps that already track our location?
I developed privacy-preserving protocols for contact tracing as part of my PhD dissertation several years ago. Most location-based apps collect movements for a certain purpose. For example, to find something or someone close to you like a restaurant or a gas station. Additionally, your phone is also capable of knowing your location at any moment—for example, if you misplace your phone, you can use the Find the Phone feature on iPhone and Android phones.
Are there ways for these apps to protect our privacy or mask our identity?
Exposure notification apps that help with contact tracing will need to collect your location or proximity to other phones at all times. But this doesn’t necessarily mean that the app needs to record the specific locations or phone numbers of the smartphones you’ve come in contact with. Instead, it could be a list of numbers that represent locations or phones. There are several privacy-preserving techniques that allow apps to store a representation of your location and list of phones that you’ve been near as random numbers. Additionally, all this information never has to leave your phone unless you test positive.
And how does contact-tracing technology complement the work of public health workers? How does it keep us safer?
The technology should make it easier for a public health worker to find contacts of an infected person. Instead of depending solely upon the infected individual to accurately recall where they’ve been in a set period of time, contact tracers could use information from the infected person’s app.
As I said earlier, this information needn’t be the actual location history of the person or a list of smartphones they’ve come in contact with, but instead, it could be a list of numbers that represent [those things]. The health workers can perform contact tracing by sending these numbers out to other apps that understand these numbers; it might not necessarily be the same app, but apps that are built using the same protocol. If there’s a match, the user would get an alert. As soon as an alert’s received, the app user can take the necessary steps to self-isolate or, if they experience symptoms, to get tested.
Do you think that national implementation of contact tracing is feasible in the US?
Widespread adoption is possible if the technology is easily accessible (one-click download and install) and transparent, so experts can confirm that it meets privacy standards and individuals feel they can trust it. My prior research suggests that people are willing to share information when they see a value in how the information can be used. I expect people will be willing to share once they better understand how their data will be used and how it can benefit not just them but their friends, neighbors and their community. I refer to this as “altruistic sharing.”
Do you believe that “altruistic sharing” and contact tracing apps will become the new normal?
Yes, I hope privacy-preserving contact tracing technologies will be successfully leveraged to help in this public health emergency. There is great potential for them to play a role in reducing the spread of illness.
