Contact tracing is the next big hurdle in the push to re-open cities

As some states take steps to partially re-open their economies, public health officials and local governments are trying to aggressively ramp up contact tracing to track the spread of COVID-19 in their communities.

Why it matters: If we are indeed in the midst of a war against an invisible enemy, a contact-tracing offensive — launched by both an army of human tracers and an arsenal of technological tools — will be a big part of the key to winning. 

• Identifying who has come in contact with people infected with the disease is critical to isolating the coronavirus while also allowing some semblance of daily life to resume.

Between the lines: State and city budgets are being hammered by the economic fallout of COVID-19, making it harder to find the resources to hire and train people to contact trace or acquire needed technologies.

• Some governments are recruiting volunteers, retirees and students to do the work. But the sheer number of people needed — at least 100,000 across the U.S., per Johns Hopkins — and the open-ended duration of the work makes that a very daunting task.
• "We haven't seen a big push coming from the federal government in either traditional contact tracing or these technology-based approaches," said Josh Michaud, associate director for Global Health Policy at the Kaiser Family Foundation. "That leaves most of the legwork and decision-making to the states and local authorities."

State and county public health officials are ramping up tracing efforts now that testing availability is improving — since tracing only works with widespread testing.

• Massachusetts Gov. Charlie Baker allotted $44 million to an ambitious contact tracing program, which is training 1,000 tracers to staff a virtual call center to track people who came in close contact with those who've tested positive for the virus, starting from 48 hours before the symptoms emerged, per the Boston Globe.
• Texas' Harris County — the nation's third-most populous county with 4.7 million people, including the city of Houston — this week approved the hire of 300 contact tracers.

"For every case, we have an average of about 20 people to contact. ... So if you have 100 cases, you've got 2,000 contacts you've got to handle for that day because you know the next day you'll have maybe another 100–150 cases."

What's happening: Other countries are relying on tech to varying degrees to augment contact tracing.

• In March, Singapore launched TraceTogether, an app that uses Bluetooth signals to help users learn whether they've been in contact with someone who tests positive. More than 1 million people have downloaded it, and Singapore has made it available to other countries.
• Australia said more than a million people downloaded its Bluetooth contact tracing app, based on Singapore's version, within hours of the government making it available.
• South Korea used phone GPS records, credit card transactions and closed-circuit television to augment patient interviews for its contact tracing effort.
• Iceland claims a 93% success rate of voluntary contact tracing through a smartphone app.

In the U.S., the most likely scenario for widespread, tech-enabled contact tracing lies with work done by Google and Apple.

• The two companies are sharing an early version of what they're calling COVID-19 exposure notification technology with certain developers working with public health authorities. Apple and Google want to release the first phase of the project, which will enable users to opt-in to Bluetooth-based contact tracing, by mid-May.

• MIT researchers, who launched a project to perform private automated contact tracing, are using their expertise with radar to help figure out how Bluetooth can show the distance between users.
• Marc Zissman, associate head of the Cyber Security and Information Sciences Division at MIT's Lincoln Laboratory, said Google and Apple's effort appears to be incorporating the privacy principles researchers have called for, including sending randomized data that is not personally identifiable.
• "Our best guess is that when Google and Apple release this, this is going to be what it is," Zissman said. "There was Betamax and VHS. Everybody was using Betamax. And then every company but Sony went with VHS, and that was it. And then Betamax just stopped being used. That's kind of like what's going to happen here I think in the United States."

The success of the effort will depend on widespread adoption of the technology so people will be notified when they come in contact with someone who tests positive.

• Yes, but: Nearly 3 in 5 Americans say they are unable or unwilling to participate in the Google-Apple initiative, according to a Washington Post-University of Maryland poll.

What to watch: Zissman said MIT researchers will reverse engineer the Google/Apple programs to ensure they are following the privacy protocols, and also expect pilot testing in limited settings like hospitals or universities before states begin implementing.

• It may also take a public service campaign featuring trusted voices to encourage Americans to opt in.
• "There’s a lot of doubts, one, that people's privacy concerns can be addressed sufficiently and, two, that enough people would download the app to make it helpful and actually provide the service it's supposed to provide," Michaud said.