Want to end state lockdowns? Send in the coronavirus detectives.

As American states mull the easing of COVID-19 social restrictions, many are turning to a trusted tool for controlling infectious diseases: contact tracing.

Known as “disease detectives,” contact tracers are people who work to halt the spread of a virus. They reach out to individuals who are confirmed cases and then trace others the person came into contact with, from family members to subway riders. It’s a hands-on containment strategy that requires speed, manpower, and public trust.

South Korea, Singapore, Taiwan, and New Zealand are held up as examples of effective contact tracing. But their use of digital surveillance may prove hard to adopt here. Efforts to apply smartphone technology are underway – most notably a joint project by Google and Apple – but states nationwide are also scrambling to stand up armies of human COVID-19 tracers.

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Massachusetts has been among the more aggressive states, and it is not starting from scratch. Even before COVID-19, it had a relatively robust contact tracing program. Now, with health experts saying scaled-up contact tracing must be a cornerstone of the United States pandemic response, Massachusetts offers a window into how that response is taking shape.

“This needs to be in place before the lockdown ends,” says George Rutherford, an epidemiologist at the University of California San Francisco. “Our mitigation strategy now is to keep everyone in their houses. That mitigation has to be replaced with something else.”

Building an army

Health experts worry that a piecemeal U.S. approach – some states doubling down on virus detection and others holding back – will mar a national restart. Most U.S. states are still dogged by a lack of rapid and accessible COVID-19 testing, which tracers rely on to find and map clusters.

Massachusetts has begun building a surge force of tracers with a $44 million initiative. In recent weeks, more than 300 people have been trained for a virtual call center to track residents who may be infected. The operation is run by Partners In Health, a global health nonprofit based in Boston, which plans to hire up to 1,000 people for paid and volunteer positions.  

Illinois Gov. J.B. Pritzker said Wednesday that he was in talks with Partners In Health to stand up a similar force.

Before COVID-19, Massachusetts’ tracing program involved around 400 state epidemiologists and local public health nurses, who tracked cases of infectious diseases such as tuberculosis and HIV/AIDS. But when coronavirus cases started to surge in February, “we knew it was going to outstrip our ability to manage it,” says Catherine Brown, state epidemiologist in the Bureau of Infectious Disease and Laboratory Sciences.

Tracing has continued in Massachusetts, prioritizing health care workers and residents at care homes, jails, and prisons. Other states hit hard early on, like Washington, set similar priorities. As the pandemic intensified, Dr. Brown joined the all-out effort to trace potential spreaders.

She recalls making a call to a woman diagnosed with the coronavirus. The woman lived with two people at high risk of a severe form of COVID-19, so Dr. Brown talked her through the risks and how to isolate herself from others.

“In that small household we didn’t stop an outbreak, but we protected vulnerable individuals. Every single case has a human side,” she says.

Today, Massachusetts has the third largest number of confirmed cases. Still, Dr. Brown says the early work of tracers – at least 21,345 people were contacted in February and March – likely helped slow the rate of infections so that hospital admissions haven’t overwhelmed capacity.

Many states spend far less on public health. Alabama previously had fewer than 10 contact tracers for its nearly 5 million residents, and now has around 50 working on COVID-19, the state’s health director told the Washington Post.

“There’s a massive gulf between where we are and where we need to be in many parts of the country,” says Joshua Michaud, associate director for global health policy at the Kaiser Family Foundation.

Nationally, the number of full-time disease investigators is 2,200, according to the Association of State and Territorial Health Officials (ASTHO). That comes after a decade of double-digit cuts in public health spending following the 2008-09 global recession.

A recent report by the Johns Hopkins Center for Health Security, together with ASTHO, called for the hiring of an additional 100,000 contact tracers to contain COVID-19 epidemics, at a cost of $3.6 billion in emergency federal funding. Others have called for higher numbers.

“What we’re doing right now is simply buying time,” says Robert Bollinger, a professor in the Johns Hopkins University School of Medicine. “We don’t as a country have a strong enough public health system to do contact tracing in the community.” 

Coronavirus sleuthing

Behind these estimates is a stubborn reality: Chasing down leads in a pandemic, as detectives do after an unsolved crime, is labor-intensive and expensive. Each confirmed case yields several new contacts to trace, contact, and isolate, which averages 4 hours of work per tracer. And time is against them, since symptoms can show up days after infection.

“It has to be a rapidfire process. We know that hours and days make the difference with coronavirus,” says Mr. Michaud.

One silver lining is that millions of Americans suddenly have time on their hands. States and cities are tapping medical students, school nurses, and librarians to support COVID-19 contact tracing. In San Francisco, which had 10 tracers before the pandemic, volunteers are lining up to help, says Dr. Rutherford, who is helping the city add 150 more.

Massachusetts and six other Northeastern states are working together to ease social restrictions and reopen businesses; California, Oregon, and Washington are doing the same. Testing and contract tracing are likely to inform when and how these reopenings happen.

“I think it’s going to be critical for every state that wants to get open and back to something like a new normal to put some kind of mechanism like this in place,” Massachusetts Gov. Charlie Baker told CBS’s “Face the Nation” Sunday, referring to contact tracing.

Other U.S. states like Texas are already starting to ease controls. This piecemeal approach could raise tensions if future outbreaks in states with robust coronavirus surveillance are traced to states that aren’t doing the same. Experts point out that South Korea and Taiwan mobilized national health systems to trace and contain their pandemics – a key element of their success. That level of federal involvement has been absent in the U.S.

But states that invest in COVID-19 testing and tracing could lead others. “If strategies are shown to be effective in certain states, other states are going to adopt that,” says Dr. Bollinger. “They want to get past this phase and start opening up their schools and businesses.”

Editor’s note: As a public service, all our coronavirus coverage is free. No paywall.