The US needs an 'army' of contact tracers if there's any hope of getting back to normal

• Contact tracing is detective work conducted by public health workers to determine where and when people might've been exposed to a disease.
• In the US, there are roughly 2,200 contact tracers stationed nationwide. They typically respond to foodborne pathogen outbreaks and trace back the sexual partners of people diagnosed with STDs.
• Right now, they're tracing the contacts of just a fraction of the people who've been diagnosed with the coronavirus.
• Officials across the country are sounding the alarm that hundreds of thousands of contact tracers will be needed to get the country back to work.
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Test and trace.

These two actions, one after the other, are the backbone of public health work. Both will be vitally important to help the US re-emerge from its lockdown in the weeks and months to come.

But there's a major problem with this two-part solution to the coronavirus crisis. America does not have the capacity to test or trace for the coronavirus in adequate numbers and find out where the coronavirus may be spreading. That's putting hundreds of thousands of people at risk for disease and death.

The country doesn't have nearly enough diagnostic tests available to know who has the virus in the first place, and the number of contact tracers in the country's public health departments — the disease detectives that can stop the spread of a virus in real-time, before it's taken hold in a community — is nowhere near adequate at the local or federal level.

Some states, where coronavirus outbreaks are relatively small, are already training more tracers, and aiming to make contact with every single individual who might be at risk of infection. Other coronavirus hotspots — areas of the country with major deadly outbreaks — aren't even bothering with contact tracing right now because their infection rates are so high.

But as disease rates begin to slow in major cities across the US, thousands more tracers will soon be needed to allow people to get back to work safely. Wuhan, China, for example, had 9,000 tracers that helped the city of 11 million get out of its lockdown.

"We need an army of contact tracers in every community of the US to be ready to find every contact and warn them to care for themselves and stop spreading it to others," former Centers for Disease Control and Prevention director Tom Frieden told reporters recently on a conference call.

Contact tracers spend a lot of time rushing to the phone, figuring out where people have been

The contact tracing process is time-intensive. The goal is to chat with every single person who's contracted COVID-19, the disease caused by the coronavirus, and find out who they've been around. Then the tracers can tell those people that they might've been exposed to the virus, and that they should stay home to avoid infecting others.

The coronavirus can be transmitted before people ever show symptoms, which means there's no time to waste informing an infected person's contacts.

Public health workers have used this same type of call-and-ask system in the US before to trace the origins of foodborne illness outbreaks and sexually transmitted diseases. Contact tracing has already proved effective at curbing novel coronavirus outbreaks in China, South Korea, Singapore, Taiwan, New Zealand, and Iceland.

The country has fewer than 2,500 contact tracers, a woefully inadequate number

In a recent New York Times op-ed, Frieden suggested roughly 300,000 US contact tracers might suffice. An April 8 report from The Johns Hopkins Center for Health Security estimated "approximately 100,000" nationwide might be enough, a recommendation that experts from Harvard backed up on Monday. The US has, right now, just over 2,200 tracers.

"Our current core public health capacity is woefully insufficient to undertake such a mammoth task," the Johns Hopkins report said.

Before the coronavirus hit, the country had roughly 600 federal CDC contact tracers dispatched around the country, and an additional 1,650 at state and local health departments, according to The National Coalition of STD Directors. That's nowhere near an army's-worth of tracers for a nation of 329 million.

Some states, like Vermont, which had just 1.25 contact tracers pre-coronavirus, are already ramping up their disease detective corps.

By the time that state's very first patient with COVID-19 was identified in early March, public health workers there had been re-deployed and doing drills for weeks — since the first coronavirus patient was diagnosed in the US in January.

On March 7, when the first Vermont COVID-19 case was reported, the tracers there were ready, and immediately leapt into action.

"You can't wait until the next day," Daniel Daltry, a program chief at the Vermont Department of Public Health who does some of the state's contact tracing, told Business Insider. "You've got to move."

But while Vermont's efforts are impressive, they aren't nearly enough without more testing and tracing nationwide.

Contact tracing doesn't work well when an outbreak gets too big

Some outbreaks, like New York City's, are still too big to trace. But that could soon change.

Mark Levine, Chair of the New York City Council health committee recently suggested on Twitter that dispatching contact tracers across the city could be "feasible" once the number of new daily cases gets down to around 500. (Right now, the city is logging over 1,000 new cases every day, already a reduction from the 5,000 to 6,000 per day recorded early last week.)

Governor Andrew Cuomo recently called contact tracing a "massive undertaking that we now don't do," but he said the state could start soon.

"We test Bernadette, Bernadette turns up positive," Cuomo said during a press briefing, explaining his own version of hypothetical contact tracing. "Okay, who were you with over the past week? What family members were you with? Who do you sit next to in the office? You now have a list of 30 people. If it's Bernadette, even more, because she's highly social, has a lot of friends. Now somebody's got to run down that list of 30 people. From one positive."

In Massachussetts, a state with a moderately severe outbreak, there are already plans underway to hire an additional 1,000 people for tracing.

Contact tracing could become a welcome job opportunity for thousands more across the country who are newly out of work, but the endeavor would likely require billions in federal cash appropriations from Congress to fund state and local health department hires.

Old-fashioned tracing can help contain a virus, but tracking and warning systems also may work

Vermont is a prime example of a smaller state that doesn't yet have a severe outbreak where contact tracing works well. With fewer than 850 coronavirus cases in the state to date, and more than 50 tracers on the job, Vermont can still trace back all its COVID-19 contacts, which means it's possible to control the spread of the virus through testing, and contact tracing.

"We are still in a phase of containment," Daltry said. "Really trying to get ahead of it, before this spreads out too quickly."

Rhode Island was originally doing the same kind of extensive, old-fashioned contact tracing as Vermont, but now, with more than 4,000 confirmed cases, the state is developing an app that can automatically survey state residents, checking them for potential coronavirus symptoms a few times each day.

Governor Gina Raimundo is also asking every Rhode Islander to keep a "contact tracing notebook," that logs where they have been and who they've come in contact with, just in case they get sick.

Another tech-forward approach to contact tracing that's already being tested out in Europe uses Bluetooth data to alert people who've been in close contact with someone who has tested positive for the coronavirus, suggesting they should seek out testing, too.

These kinds of coronavirus tracking and warning systems — whether done via an app or by a tracer's phone call — become less effective as an outbreak spreads out, and moves into a phase that public health experts call "mitigation."

In the mitigation phase of an outbreak, instead of trying to control the spread of disease, all public health workers can do is tell people to stay home and away from others, watching the contagion burn itself out. That's where most of the US is at right now.

There was a time in March when Daltry worried that might happen in Vermont, as the number of sick patients in the state began skyrocketing and there weren't enough supplies to test every case.

"We went from one case every other day or every two days, to suddenly getting 12 cases a day, 20 cases a day, 30 cases a day," he said. "But then we had an influx of testing, and were able to direct the contacts to testing. That happened towards the end of March. And that just gave us a renewed sense of hope and energy with what it is we can do, in terms of our containment efforts."

The same hope and energy that's alive in Vermont is not available nationwide.

In addition to the widespread testing shortage, the US has, on average, just one tracer available for every 150,000 Americans.