Public health experts say the United States can reopen and stay open during the COVID-19 pandemic if it does three things well: testing, isolation of people who are sick with the virus and contact tracing. But there’s nothing simple about identifying and notifying everyone who might have come in contact with a sick person. The logistical challenges, not to mention the potential privacy concerns, make a full-fledged national contact tracing program daunting.
Think about the last time you got sick. Days before your illness was diagnosed, where did you go, and with whom — including strangers — did you interact? When grappling with an infectious illness, such as measles, tuberculosis or COVID-19, public health officials turn into detectives, asking these questions to map out who else may be at risk of infection.
It’s a two-step process: First, you test everyone who is believed to be ill and confirm if they have the virus. Next, you figure out where they went, and who else was there. Did they go to the grocery store? A family gathering? Their job? You alert the people with whom the infected may have come in contact, recommend that they, too, get tested and that they quarantine themselves so they do not expose others to the same virus. If done effectively, contact tracing can box in a virus, resulting in dwindling case counts as the illness plays itself out.
“If we don’t have extensive contact tracing in every community in America, it’s going to be really hard not to see this virus when we open back up,” said Dr. Ashish Jha, a physician and professor at the Harvard T.H. Chan School of Public Health. “It’s not a ‘nice to have’ — it’s an ‘absolutely fundamental to have.’”
Testing alone without extensive contact tracing is not enough to control COVID-19, Jha said. Because routine dictates the rhythm of most people’s lives, he said models suggest people generally have between six and 19 contacts. That’s how many people each of us could potentially expose to an illness if we were sick and not practicing social distancing.
But people sometimes forget where they’ve gone or who they’ve seen, especially when they are not feeling well. Or maybe they don’t want to be totally forthcoming for some reason. And those details, willfully withheld or not, matter when you’re trying to pin down a highly contagious virus with potential asymptomatic transmission.
“If you don’t identify enough of the contacts, you don’t identify enough of the people who you may have infected or may have infected you,” Jha said. “Then, those people stay in the community.”
Because human contact tracing could not be done quickly enough to contain COVID-19’s rapid, broad spread, social distancing measures were put into place, Jha said. To reopen the country, new solutions are needed.
Massachusetts launched the nation’s first coronavirus contact tracing program on April 3 with Partners in Health, a nonprofit health care organization based in Boston that put these skills to work during the Ebola outbreak in West Africa. The collaboration with the state is “designed to not just flatten the curve, but bend the curve downward to more rapidly reduce the number of cases,” according to a statement released by Partners in Health last month.
The work has been slow, said Jha, who is not involved in the program. Volunteer contact tracers call people on a list derived from an infected person’s memory of whom they saw during the time they might have been contagious. Wary of calls coming from local area codes but unfamiliar numbers, people might not pick up the phone for a human. So, he said, public service announcements have encouraged people to do so, saying unexpected calls might not be spam, but someone from the local health department calling about possible COVID-19 infection.
There are campaigns underway to build on Massachusetts’ work. On April 27, health policy leaders — including former officials from the Obama and Trump administrations — submitted to Congress a $46.5 billion proposal for a national contact tracing program to better monitor and mitigate COVID-19. Their plan would increase the number of human contact tracers to 180,000, at a cost of $12 billion, until researchers develop a vaccine to prevent COVID-19. The proposal also recommended income support for people who self-isolate when sick, and using vacant hotels for isolating patients with mild cases, among other measures.
At this point, the U.S. can only hope to contain this disease, and this is how you do it, said Andy Slavitt, who signed the letter and is a former acting administrator for the Centers for Medicaid and Medicare Services during the Obama administration and founder of the health advocacy organization United States of Care.
“If you’ve infected a friend, you want to be able to notify that friend if you find out you’ve been infected,” he said. The suggested national contact tracing program “is really only to provide the tools and resources to make that possible.” But it’s unclear how widely these efforts will be adopted.
Can technology play a role?
U.S. public health and technology experts are also working to figure out how to develop and utilize digital tools that can track a person’s health status without compromising their privacy or civil liberties, and how to scale up such a system safely.
In other countries, such as South Korea, mobile technology has been an effective and efficient tool for tracing contacts and stifling the virus. North Dakota and South Dakota are already using a contact tracing app that assigns users an anonymous ID number, does not collect any personal data beyond location and needs your consent to use your data if you test positive.
But a widespread, national app might still be a tough sell: The concept of being tracked with your cellphone by a national entity may conjure for some a “Minority Report”-style surveillance state, even if there are strict limits on what data can be gathered in the U.S.
Critics have voiced those concerns about China. The country, whose government has long surveilled its people, has deployed an app called Health Code, which lets Chinese authorities know who should be quarantined amid the coronavirus pandemic. Those tools, which could aid in contract tracing, could also be used for more nefarious reasons, according to a report from Human Rights Watch.
To make contact tracing via technology successful in the U.S., Jha said people must trust the digital components of the system. Otherwise, they’ll protest, find workarounds, or simply leave their phones at home and turn off their devices. To win the American public’s trust, Jha suggested such a system must be voluntary and supplement human-driven tracing.
“We have to be careful not to be seduced by technology,” Jha said. “I don’t think technology is going to be our savior here. It’s not personal enough.”
Criteria for digital contact tracing sketched out by the Centers for Disease Control and Prevention advocate for a system that isn’t completely automated, but combines human case managers and device-based (i.e. cellphone) proximity tracking.
Daniel Weitzner, founder of the Internet Policy Research Center at MIT who led White House initiatives for privacy and cybersecurity under the Obama administration, has helped evaluate multiple proposals on leveraging technology against this virus as part of a consortium of cybersecurity and privacy experts called Private Automated Contact Tracing. If an app were used, Weitzner stressed that smartphone technology should complement traditional human-based contact tracing efforts, and that public health departments should guide both processes. Apple and Google have been working to develop an app that relies on Bluetooth technology to help government and health agencies get a better handle on the virus’ spread. Both companies say this tool could be useful to “slow the spread of COVID‑19 and accelerate the return of everyday life.”
But aside from potential privacy issues, even the basic functioning of a digital system could face some hurdles. Broadband connectivity and cellphone ownership are not universal, meaning some people could fall between the cracks. Another tricky thing is how to make devices judge how close one needs to get to be considered exposed to someone with COVID19. That is, how long would you need to stand next to someone with the virus to qualify as someone who needs to be contacted, either by a text message or a health department official?
Bluetooth-equipped phones — carried by people with the virus or at risk — could be allowed to “talk” to each other, and measure signal strength. But that’s not as easy as it may sound. For example, if you are standing 6 feet from another person at an intersection waiting for the traffic light to change, and you both are holding your cellphones , it would be easy for your Bluetooth to swap radio signals with the other phone. But, say you then drop your phone into your backpack while standing still. The Bluetooth signal is disrupted, Weitzner said, and you may suddenly appear to be 100 feet away.
In the system Weitzner’s team is working on, he said proximity data — not location — would be collected. They are still figuring out how long to hold the data–should they destroy it after 14 days? Twenty-eight days?
“We started with a more privacy-preserving approach,” Weitzner said. “You could always expand.”
Since the virus ignores national boundaries, some people have suggested the need for a global contact tracing app. But having one system in place in the U.S. and a different one in, say, Europe, could be a good thing, said Jon Callas, a senior technology fellow at the American Civil Liberties Union and the inventor of the Pretty Good Privacy, or PGP — a system of encryption for private data communication. That little bit of diversity can help developers and public health officials learn from each other, and what works and what doesn’t. No matter what, Callas said, “privacy has to be built in from the very bottom to the very top” of any digital contact tracing system.
And there are many reasons to be skeptical of such a system, said Jennifer Granick, the ACLU’s surveillance and cybersecurity counsel. Tracking technology can be very inaccurate and discriminatory, she warned, and access to these devices can further exacerbate existing inequities in income and social status.
“Don’t believe that technology is going to swoop in and solve all our problems,” Granick said. “There’s hard work to be done.”
Sometimes, disease outbreaks have worked to ease public reservations about sharing data. After the 2015 MERS outbreak, South Korea relaxed its rigid data privacy laws, in a change “that somehow didn’t get a lot of public attention,” said Haksoo Ko, professor at Seoul National University School of Law and author of a recent piece in the journal JAMA that dissected the nation’s COVID-19 rebound.
The changes that followed MERS allowed officials to use cellphone location data, closed-circuit television footage, public transit data, credit card transactions, medical and immigration records and more to establish the whereabouts of potentially infected people and those who had been in contact with them during future outbreaks. Koreans had no choice, Ko said. Participation was mandatory.
Five years later, COVID-19 tested the updated law and the ethics of collecting people’s private data to track down and contain a deadly virus. South Korea reported its first infections in January, which then peaked by late February. In March, the Korean Centers for Disease Control and Prevention launched enhanced contact tracing, relying on the laws inspired by MERS and organized by the federal government.
When someone was sick, the government withheld the person’s name but released to local leaders the person’s sex, age, neighborhood and where they had been. That information was sometimes enough for the community to figure out the person’s identity, and in some cases, people were harassed or businesses were avoided, Ko said. Eventually, the government gave more guidance about the level of detailed data it disclosed and how local communities could use information based on contact tracing.
The country has since flattened the curve, and Ko said that the outcome likely has maintained positive public opinion about the government’s use of private data to monitor who was sick.
However, he said it is unclear how long Korean officials will hold that data or when it would be destroyed — that they have said they’ll discard the information once the pandemic ends. At other points in South Korea’s history, Ko said, people “didn’t like the feeling of being tracked wherever they go.”
In that country right now, Ko said, “because the pandemic is such a priority, people don’t care much about the feeling of being tracked.”