(Hannah Norman/KHN Photo Illustration; NIAID)

It shocked people, but health experts around the country applauded the bold step, which since has been broadly replicated.

They also say it can’t go on forever. And so Bay Area leaders, along with others around the nation, are trying to figure out how we can resume something akin to normal life without triggering a catastrophic wave of illness and death.

The shelter-in-place orders were a sledgehammer response to two colliding realities: a little-understood virus that is proving ferociously deadly in vulnerable populations and a withered public health infrastructure that has made it impossible to track and contain the spread of the virus that causes COVID-19.

For all the light the new virus has shone on vulnerabilities of the U.S. hospital system — shortfalls in hospital capacity, ventilators and protective gear — what many officials see are the cracks in the foundations of public health.

“Nothing should come as a surprise,” said Laura Biesiadecki, senior director for preparedness, recovery and response with the National Association of County and City Health Officials, which represents more than 3,000 local health departments. “What you’re seeing in COVID-19 is an exacerbation of existing fault lines that everyone in the public health community has recognized over the years.”

Still, there’s broad agreement that core public health work — the ability to find people with the virus and prevent them from passing it to others — will be essential to reopening schools and businesses. That strategy is endorsed by the director of the Centers for Disease Control and Prevention, who recently told NPR the agency was working on a plan to deploy more disease investigators.

We spoke with more than two dozen health experts to get their thoughts on what public health resources will be needed to reopen the economy.

1. What works?

It may be rare that the World Health Organization and experts on the right and left in the U.S. see the same solutions to a problem, but that’s the case when it comes to reopening the economy in the face of COVID-19. The principles are simple: Stabilize the number of people who have the virus (through the strict social distancing already in place), and ensure hospitals can handle the cases they have. Then, put tools in place to stop new infections in their tracks so there isn’t a renewed outbreak.

It all starts with testing, and several countries that revamped their public health programs in the wake of the deadly 2003 SARS epidemic seem to be reaping the benefits now. That includes Singapore, which quickly ramped up testing for both active infections of COVID-19 and an antibody test to show previous infection, and South Korea, which tested tens of thousands of people in the weeks after it detected its first cases.

South Korea, like many other Asian countries, is also relying on hundreds of workers armed with phone location data, credit card information and security footage to try to reach everyone who has come into contact with an infected person. Authorities release detailed information to the public whenever someone infected has been in their area. Though South Korea and Singapore report a recent surge in cases imported from abroad, both countries have seen far more moderate economic and health fallouts than has the U.S.

Politically and culturally, European nations make for an easier comparison with the U.S. Germany not only deployed widespread testing early on, but it also has sent health teams to people’s homes to check for symptoms and initiate aggressive interventions if symptoms arise.

Italy, which has had more than double the deaths of China despite having less than 5% of its population, has lessons for the U.S. as well — and not all grim.

The scenes from Lombardy, where doctors have rationed care for weeks, making decisions about who lives and who dies, are bleak. But neighboring Veneto, which found its first case of the virus on the same day as Lombardy, is faring much better, said Dr. Nancy Binkin, a professor at the University of California-San Diego who spent 12 of her 20 years at the CDC embedded in Italy’s public health system.

Binkin and colleagues suspect the difference lies in the extensive use of public health tools to contain the initial outbreak in Veneto. That included testing nearly everyone in the town of Vò where the first cases were found, quarantining that city, and making heavy use of assistenti sanitari, or health assistants, to track down people with the virus and make sure they stay isolated.

There have been far fewer infected health workers in Veneto, and deaths overall, than in Lombardy, which is renowned for the quality of its hospitals and health care.

What the places with fewer cases have in common is not just social distancing, said Binkin, but also aggressive tactics to identify and isolate people with the virus.

2. How does the U.S. compare?

U.S. public health budgets and staff have hemorrhaged over the years, accompanied by a steady stream of warning calls that the U.S. was not ready to face a pandemic.

When COVID-19 arrived, identifying and tracking everyone with the virus was all but impossible for local health departments because of flawed tests and narrow guidelines for who should get tested. Compounding the problem was a beleaguered public health infrastructure.

The stay-at-home orders are largely about slowing the spread of the virus — to keep hospitals from being overwhelmed — not necessarily about preventing cases, said Adia Benton, an anthropologist at Northwestern University who studies inequalities in global health. Mobilizing a massive workforce to isolate everyone with the virus could prevent infections, Benton said. “The interventions we see reflect what we value,” she said.

Public health is run locally, and health departments have different resources and organization. They are also confronting different degrees of outbreak.

In Tennessee, front-line health workers still are contact tracing everyone who gets the virus. To do so, many employees are working seven days a week, 12 hours a day, said Dr. Mary-Margaret Fill, a physician and epidemiologist with the state who is helping coordinate its emergency response. “They are the internal cog in this response; without them we fall apart,” she said.

In California, public health is the responsibility of counties, and resources vary wildly. Many, including Sacramento and Orange counties, moved away from contact tracing weeks ago, citing minimal access to testing and a surge in cases. (A lack of testing is one thing nearly all health departments have in common.)

Even San Francisco, with its abundant wealth and renowned expertise in HIV, was relying on a skeleton staff to track routine communicable diseases like measles, tuberculosis and sexually transmitted diseases, according to the city’s health officer, Dr. Tomás Aragón.

Los Angeles County, with its 4,000 public health employees, is still doing some contact tracing for every person who tests positive, said Dr. Barbara Ferrer, director of the Los Angeles County Department of Public Health. Rural Tulare County is trying to do the same, but has pinpointed the need for more people to trace cases as its greatest hurdle.

Those techniques matter everywhere. “Social distancing, contact tracing, identification, quarantine and isolation. We need all of those tools,” said Ferrer.

3. How do we ramp up?

Experts say the situation necessitates, at least temporarily, adding thousands of people to the ranks of public health. Three former Obama administration officials called for a “public health firefighting force” via a program like AmeriCorps or the Peace Corps.

Others suggest we make use of programs already in place. The Medical Reserve Corps program, a national network of volunteer medical and public health professionals, has 175,000 volunteers, some of whom have already been deployed to state health departments, said Biesiadecki. That program could be expanded.

“We need a Marshall Plan. We need a New Deal. We need a WPA for public health,” said Gregg Gonsalves, a Yale epidemiologist who won a MacArthur Fellowship for his work on global health and justice.

And it doesn’t necessarily require M.D.s, Ph.D.s or even public health degrees. In many countries, governments have trained community health workers in situations like these.

But in the absence of a federal program, some local departments in the U.S. are already taking up the cause. San Francisco, for example, is planning to recruit around 160 people to keep tabs on people diagnosed with the virus. Aragón said he hopes to repurpose staff from within the county where possible, and hire where necessary.

“We started off with a scarcity mentality,” Aragón said. “We have to have an abundance mentality. The amount of money that’s being lost economically, if we put just a fraction of that into our public health workforce, we could get the economy back up and running.”

Massachusetts asked the global health nonprofit Partners in Health to help it hire 1,000 people to carry out mass contact tracing.

In Connecticut, Yale University faculty said they realized the state had the capacity to contact trace only in Fairfield County, a wealthy bedroom community of New York, leaving few resources for much poorer New Haven, where the university is located. So they recruited more than 100 public health, nursing and medical students, said Dr. Sten Vermund, dean of Yale School of Public Health. The volunteers were trained online by the state and, working alongside university staff, have been doing contact tracing for the local hospital.

But he doesn’t think these volunteer efforts are the solution. Vermund called it “the definition of insanity” if the U.S. didn’t take this moment to reinvest in public health. “There is no greater threat to the economic well-being of planet Earth,” he said, “than pandemic respiratory viral illness.”