EVERETT — As the curve of the COVID-19 pandemic begins to bend, health workers will need to return to what Dr. Geoff Baird calls “the bread and butter of epidemiology.”

Test many people for the virus.

Isolate those who test positive.

Find out who they’ve had contact with.

Quarantine them, too, until they can be tested.

And repeat, over and over and over again, until the virus has been stamped out for good.

“That’s the mode we’re getting into right now,” said Baird, the acting laboratory medicine chair at the University of Washington. “As the acuity lessens, we’re going to need to start doing the more traditional approaches of managing diseases, so that we don’t have another large outbreak.”

Experts agree this is the path forward. Traditional testing will need to be paired with tests to determine whether people have immunity, they say, for the world to see the end of the pandemic anytime soon.

But public health systems — local and national — face a host of obstacles to achieve this vision for the future. Local health departments need more resources for widespread contact tracing. Critical scientific questions still need answers.

“I’m very concerned that, as a country, we’ve got a lot to do before we can be ready,” said Dr. Jared Baeten, vice dean of the UW School of Public Health. “What needs to be done has been laid out really clearly now by lots of people. So what we have to do is put all effort into checking those boxes.”

Hurdles ahead

Gov. Jay Inslee mapped out a plan Wednesday for bringing the state economy back online. He will only begin to relax social distancing restrictions when the number of people infected falls and health workers can rapidly test, isolate and treat those with COVID-19, he said.

Washington is under a stay-home order through May 4. For Inslee to lift it, he said, the state needs to increase testing to track potential cases; bolster efforts to protect the must vulnerable from infection; ensure hospitals can handle any future surges; and guarantee social distancing at schools, businesses and other gathering spots.

Public health professionals and others are “scrambling” to get these pieces in place, said Baeten, a professor of global health, medicine and epidemiology.

“The testing still has to be better — still has to be faster with faster turnaround and easier access,” he said. “We’re not there yet. But we really do have to be there in May.”

As the governor and public health experts have underscored in recent weeks, though, testing woes that have plagued the country from the start of the outbreak continue today.

Test kit shortages have delayed research efforts, and some people have gone into isolation for much longer than necessary because there’s a lag in testing time, said Dr. George Diaz, an infectious disease expert at the helm of the coronavirus response at Providence Regional Medical Center Everett.

More broadly, those issues have made it impossible to “know the true burden of disease in the community,” said Diaz, who oversaw the successful treatment of the nation’s first COVID-19 patient.

A series of testing snags — a dearth of protective gear needed to conduct the tests, for example — raises questions about what problems might lie down the road as the pandemic evolves.

There will be supply line limitations for testing materials, such as the swabs and the liquid that workers put the swabs in, said Dr. Nariman Heshmati, secretary-treasurer of the Washington State Medical Association and a surgeon at The Everett Clinic.

“And you are going to have limitations in each region for who’s able … to test,” Heshmati said. “We’re not where we need to be yet, statewide, for testing. I’m optimistic that we’re getting there, though.”

Magic numbers

More than 128,000 tests have been done since the beginning of the outbreak in Washington, according to the state Department of Health.

Recently, there have been roughly 150,000 new tests a day in the United States, according to the COVID Tracking Project, which aggregates testing data from across the country.

Experts do not agree, however, on how many more tests will be needed nationwide.

A report by former Food and Drug Administration Commissioner Dr. Scott Gottlieb pegged that number at 750,000 per week. Other experts have suggested millions more will be needed on a regular basis.

In a white paper released this week, U.S. Sen. Patty Murray said that at least 500,000 tests a day will be necessary. She called on Congress to allot $30 billion in emergency funding to expand testing efforts.

“Testing may be the first step in our path forward, but we need to bolster it with the public health capacity needed to follow testing with tools like a massive increase in contact tracing, which will require a major investment in public health workers,” Murray, a Democrat, told reporters in a Wednesday conference call.

Each week, Snohomish County completes about 2,500 tests, said Dr. Chris Spitters, health officer for the Snohomish Health District.

“And that may be adequate,” Spitters said. “We’re in consultation with the state health department going forward about all the branches of the transition, containment and mitigation efforts.”

President Donald Trump on Thursday released a broad set of recommendations for a phased reopening of businesses, schools and other institutions; however, the plan does not include an implementation date or national testing strategy, reported The Washington Post.

UW’s Medicine Clinical Virology Laboratory is able to process more than 7,000 tests a day, Baird said. But on the average weekday, the lab usually fields some 2,000 or so, Baird said.

“We’re not getting nearly as many tests as we could do,” Baird said. “I largely think that that has to do with upstream shortages of materials and testing kits.”

The lab is consistently processing tests in under 12 hours, Baird said. Some commercial labs take days to return results.

“We have adequate supplies for now. But we’re not adequately supplied for months to years on this,” he said. “This could take a while.”

Timeline to reopen

Exactly how long will it take for the COVID-19 pandemic to wind down is unclear.

“This is something that may unfold (in) May, June, and then probably have a tail that goes on through the summer,” Spitters told the Snohomish Health District on Wednesday. “Beyond that, I don’t think we can say.”

COVID-19 hospitalizations peaked in the state on April 5, according to the UW’s Institute for Health Metrics and Evaluation (IHME).

But a modeling study released this week by Harvard’s T.H. Chan School of Public Health suggests bouts of social distancing will likely be needed into 2022 to ensure hospitals aren’t overwhelmed by future influxes of COVID-19 patients. The study took into account questions that researchers are now grappling with — such as whether the virus will reemerge in the winter, similar to the seasonal flu.

“There are a number of epidemiological unknowns here that we need to race to find out so that we can really make sense of what to expect for the coming months and this possibility of resurgence in the fall,” said Dr. Caroline Buckee, an epidemiologist and associate director of Harvard’s Center for Communicable Disease Dynamics.

A lack of testing has also left researchers without an answer to another critical question: How many people had the virus but only mild symptoms, or no symptoms at all?

“We’ve missed a lot of people — partly because testing capacity hasn’t ramped up fast enough,” Buckee told reporters at a Wednesday press conference held via video chat. “Until we start looking for evidence of past infection through the immune response, we won’t know how far along we are. And if we don’t know how far along we are, we won’t be able to say when it’s safe to reopen.”

Thus another type of testing is paramount, public health officials agree.

Serology tests are used to identify antibodies, or proteins, that show the person had an immune response to COVID-19.

The Centers for Disease Control and Prevention has accelerated research on serology testing, with a goal of determining how much of the population has already been infected and how much remains vulnerable to coronavirus. This month, it’s also working with other agencies to evaluate commercially manufactured serology tests.

Scientists still don’t know if antibodies grant protection against COVID-19 reinfection — and, if they do, how long that immunity will last.

Plus, it’s still unclear whether someone can carry and transmit the virus, even if they aren’t symptomatic, said Michael Mina, an assistant professor of epidemiology at Harvard.

“I think it’s going to be at least a few months before we have a lot of that information,” Mina said during a Friday news briefing. “We’re really entering into this area of antibody testing, and we’re not anywhere close to where we need to be.”

The quest to trace

Nationwide, you would need 100,000 people to trace all contacts, isolate the sick and quarantine the exposed, according to a study from Johns Hopkins Bloomberg School of Public Health.

To do this, Congress would need to provide an estimated $3.6 billion in emergency funding to local and state public health agencies, the study suggests.

“The health department — what they’re going to need moving forward with this is going to be a lot more than what they needed a couple of months ago,” said Heshmati, the doctor from The Everett Clinic. “They’re going to need more people. They’re going to need more funding.”

The Snohomish Health District is working with the state Department of Health on a plan that will outline the technology and human resources needed for widespread contact tracing, said Spitters, the health officer.

“That’s a plan in process that needs to be in place before there’s any significant lightening up of social distancing,” Spitters said.

Tech firms have pitched smartphone apps that would help public health officials with the mammoth endeavor. The government of Iceland is using such a program. In the United States, Google and Apple recently announced a partnership that will harness Bluetooth technology to help governments and health agencies slow the spread of coronavirus.

But as civil liberties advocates have pointed out, these solutions come with a host of privacy concerns.

“People will only trust these systems if they protect privacy, remain voluntary, and store data on an individual’s device, not a centralized repository,” Jennifer Granick, surveillance and cybersecurity counsel for the American Civil Liberties Union, said in a recent statement.

Other issues will arise, too, as public health officials begin to quell the new coronavirus pandemic. And some might not be ones that doctors and epidemiologists have banked on — or even thought of.

“It’s all going to change day-by-day,” Heshmati said. “We’re going to have barriers that we don’t even know about right now as we expand this, and we see how do things evolve.”

Herald writer Phillip O’Connor contributed to this story.

Rachel Riley: 425-339-3465; rriley@heraldnet.com. Twitter: @rachel_m_riley.