What will it take for Americans to emerge from our shelter-in-place existence and ween ourselves from routine social distancing?

The Centers for Disease Control and Prevention is crafting a two-fold plan to do just that. CDC Director Robert Redfield told National Public Radio in an April 10 story that his plan involves ramping up coronavirus testing and “very aggressive” contact tracing of those who test positive for the virus.

Contact tracing is part of the detective work of infectious disease control. It involves identifying, assessing, and then managing people who have been exposed to a contagious disease to prevent further transmission. Physicians in the U.S. used contact tracing during the 1980s to track the spread of HIV during the AIDS epidemic.

The Winnebago County Health Department has employed contact tracing since the virus was identified here a month ago, Administrator Sandra Martell said.

“Every time we get a positive case, we then will go through a detailed interview,” Martell said during a recent news conference. “So, for instance, in a long-term care facility or assisted living facility, we will interview the staff about who was involved in the care of that individual and if they had outside services provided. Who may have been with that individual? Was it a visitor? Were they in a congregate room together?”

As much information as possible is gathered, Martell said. Anyone who came in contact with the infected person is told they may have been exposed and that they should monitor their health “and if they show signs and symptoms of the virus, we test them,” she said.

Contact tracing is as labor intensive as it sounds. For example, to contain the outbreak in Wuhan, China, “1,800 teams of epidemiologists, with a minimum of five people per team, are tracing thousands of contacts a day,” the World Health Organization reported in February.

China, Singapore and other countries with more centralized governments than ours are leveraging technology to contain the virus by tracking the movement of millions of people through location data associated with mobile phone apps. Private companies are in on it, too, including Unacast, a Norwegian company that gathers and analyzes location data from cellphone apps for retailers and advertisers. Unacast has used its technology to measure the social distancing behavior of U.S. cities since the outbreak began.

The company has given Winnebago County's social distancing grades ranging from B to D- during the last couple of weeks. Unacast's data is somewhat useful, “but if this type of data is all that you're relying on, it's not really useful for deciding things about a city's response to an outbreak,” said David Gunkel, a communications professor at Northern Illinois University.

“You need to consider that your population is much larger than cellphone owners and users,” Gunkel said. “There's got to be a way to capture the whole population and not just those with phones because not everybody has a cellphone. You also have to realize that people leave home without their phone. That happens a lot when you're out in the street, taking a walk or when you're at the park. Sometimes, people just forget and leave their phone at home."

Israel's Health Ministry partnered with developers to create a mobile phone app called HaMagen, which uses location data to alert users who have crossed paths with a coronavirus patient. About 1.5 million Israelis have downloaded the app, according to an April 1 Reuters story.

Google and Apple have announced plans to develop technology that would allow phones to use Bluetooth data to track when they’re near each other. A person who has tested positive for COVID-19 could tell the app, which would then notify anyone nearby whose phone also has the app.

Gunkel said the U.S. may, eventually, embrace a digital upgrade for contact tracing. The federal government would need to play a role, he said, and the technology would need to be secure enough to cast aside doubts about privacy.

“We're not there yet,” Gunkel said. “I think part of the reason is, at the federal level, we're not on a unified front about how to respond to the virus. Right now, the federal government is leaving it up to states to respond on their own. Of course, the coronavirus doesn't stay within borders. It doesn't know the border limits of Illinois or Indiana. A state could oversee a statewide app, but it's not as effective unless all states are doing the same thing.”

And Americans aren't likely to use such apps, he said, “if they smell any problem with privacy.”

Isaac Guerrero: iguerrero@rrstar.com; @isaac_rrs