As States Reopen, What Is ‘Contact Tracing’ and How Does it Work?

Many U.S. states are preparing to emerge from their quarantine cocoons, hoping to get their economies back on track.

But experts are concerned that these states have not yet created the public health infrastructure needed to safely reopen without causing a second wave of COVID-19 infections.

In particular, tens of thousands of new public health workers trained in contact tracing are needed to have any hope of heading off future outbreaks in local communities, warned Crystal Watson, a senior scholar with the Johns Hopkins Center for Health Security.

Contact tracing “is the best tool we have to manage this in an ongoing way and allow our economy to open up again,” said Watson, who recently co-authored a major report on public health’s ongoing role in reopening America.

Watson estimates that the United States will need at least 100,000 workers trained in contact tracing across the nation, at a bare minimum, to keep COVID-19 at a manageable level.

There are currently around 30,000 contact tracers, Watson said. That might sound like not much, but it’s better than what it was at the start of this national emergency, when there were only 2,200 trained contact tracers in state health departments around the United States.

Last week the tri-state area of New York, New Jersey and Connecticut announced plans to build a nation-leading force of 6,400 to 17,000 contact tracers — a baseline of 30 tracers for every 100,000 that can be expanded if COVID-19 cases start to surge.

“One of the most important steps to take to reopen the economy as safely as possible is to create a system of contact tracing. When social distancing is relaxed, contact tracing is our best hope for isolating the virus when it appears — and keeping it isolated,” former New York City Mayor Michael Bloomberg, who is helping lead the effort, said in a statement.

How contact tracing works

Contact tracing is essentially detective work, experts said.

“It is used to break chains of transmission, to manage epidemics of this virus at an ongoing low level, to prevent future waves or surges of cases, and to enable us to get back to work in a much safer way,” Watson said.

The use of contact tracing is one of the oldest public health tactics, dating back centuries, said Lori Tremmel Freeman, chief executive officer for the National Association of County and City Health Officials.

“It means that as soon as you know of a person who may have a virus or have tested presumptive positive, you work immediately to first isolate that person so they do not spread it further,” Freeman said. “You keep them away from other people, and then you work with that person directly to understand who they have come in contact with.”

Contact tracers wind up tracking a “spider web of transmission,” following a pathogen like the coronavirus as it spreads from person to person. Each person who’s been infected is asked about their contacts, and then those contacts are approached.

Contact tracing hasn’t been a widely implemented strategy in the COVID-19 response because the epidemic surged quickly and there were not enough tests available to figure out exactly who carried the virus, experts say.

Because of that, states were forced to use the blunt public health instrument of social isolation and shutdowns.

“You don’t want to be at the height of that bell curve and try to implement a contact tracing system in your community,” Freeman said. “It will be overwhelming and nearly impossible to do at that point.”

But there are now parts of the country where contact tracing could be implemented as part of the effort to cut back on social isolation, experts said. These places have low levels of active COVID-19 transmission, and enough testing available to identify new cases.

“In some parts of the country that haven’t seen much infection or transmission, it is absolutely possible for them to do contact tracing now,” Freeman said.

Privacy is key

The idea of contact tracing prompts some concerns regarding medical privacy, and public health officials take those concerns seriously, said public health expert Lisa Lee.

“They are ethically and, in most states, legally bound to protect the information and use it only for public health purposes,” said Lee, director of scholarly integrity and research compliance at Virginia Tech.

Effective contact tracing does not require that the sick person’s identity be disclosed, Lee noted. Public health workers simply approach people listed as potentially infected and ask them about symptoms and testing, without saying who might have transmitted the virus to them.

It also might involve a business sending out a notice that people diagnosed with COVID-19 had been there. If someone visited the business on certain days, they would be asked to self-quarantine and reach out to either their doctor or a public health official.

As you can imagine, this takes a lot of manpower.

“Contact tracing is very time- and resource-intensive because of that spider web of information you end up discovering when you start investigating who people have come into contact with,” Freeman said.

COVID-19 complicates things further because the infectiousness of the coronavirus has not been firmly established, meaning even chance encounters have to be included in the potential spread, Lee said.

For example, some studies have shown the coronavirus can travel farther than the 6 feet generally agreed upon as the social isolation standard, if the sick person is coughing or sneezing, Lee noted.

“At this point, until we know better what kind of duration and distance is actually infectious and contagious, we’re erring on the side of saying anyone who’s been in contact is potentially exposed,” Lee said.

“Talking and coughing and sneezing and exhaling can spread the virus,” Lee added. “If you’re around a person where you’ve done that, that could be considered a contact.”

Tracers could come from jobless rolls

People potentially exposed to COVID-19 are currently asked to self-quarantine for 14 days and undergo testing for the virus, experts said.

That raises another time-consuming aspect of contact tracing — caring for the people identified as potentially infected.

People who self-isolate at home need to be supported, Freeman said. They need people bringing them groceries and supplies, and access to medical care if needed.

There should also be places available — empty hotels or college dorms, for instance — to place people who can’t quarantine at home without putting their family members at risk of infection, Freeman added.

The Johns Hopkins Bloomberg School of Public Health is currently building an online training program for new contact tracers that could help public health departments across the United States get workers into the field as quickly as possible.

Funding will be needed to pay these people, said Emily Gurley, an infectious disease epidemiologist at the Johns Hopkins Center for Global Health.

Watson’s report estimated it could cost about $3.6 billion to pay all the contact tracers needed to reopen the United States, based on a year’s worth of full-time pay at $17 an hour.

But given the current state of the nation and the economy, Gurley doesn’t think it will be hard to find the tens of thousands of people needed to mount this massive effort.

“You’ll find them in the communities that need the support,” Gurley said. “Many people are out of work right now, so I would guess there’s a pool of applicants there. We also hear every day from people who are interested in getting involved. I think during times of national crises, there are many people out there who want to help, who really want to get engaged and do something.”

More information

Johns Hopkins has more about COVID-19 contact tracing.

Source: HealthDay