WASHINGTON — Early on, the dozen federal officials charged with defending America against the coronavirus gathered day after day in the White House Situation Room, consumed by crises. They grappled with how to evacuate the U.S. consulate in Wuhan, China, ban Chinese travelers and extract Americans from the Diamond Princess and other cruise ships.

The members of the coronavirus task force typically devoted only five or 10 minutes, often at the end of contentious meetings, to talk about testing, several participants recalled. The Centers for Disease Control and Prevention, its leaders assured the others, had developed a diagnostic model that would be rolled out quickly as a first step.

But as the deadly virus from China spread with ferocity across the U.S. between late January and early March, large-scale testing of people who might have been infected did not happen — because of technical flaws, regulatory hurdles, business-as-usual bureaucracies and lack of leadership at multiple levels, according to interviews with more than 50 current and former public health officials, administration officials, senior scientists and company executives.

The result was a lost month, when the world’s richest country — armed with some of the most highly trained scientists and infectious disease specialists — squandered its best chance of containing the virus’ spread. Instead, Americans were left largely blind to the scale of a looming public health catastrophe.

The absence of robust screening until it was “far too late” revealed failures across government, said Dr. Thomas Frieden, a former CDC director. Jennifer Nuzzo, an epidemiologist at Johns Hopkins, said the Trump administration had “incredibly limited” views of the pathogen’s potential impact. Dr. Margaret Hamburg, a former commissioner of the Food and Drug Administration, said the lapse enabled “exponential growth of cases.”

And Dr. Anthony Fauci, a top government scientist involved in the fight against the virus, told members of Congress that the early inability to test was “a failing” of the administration’s response to a deadly, global pandemic. “Why,” he asked later in a magazine interview, “were we not able to mobilize on a broader scale?”

Across government, they said, three agencies responsible for detecting and combating threats like the coronavirus failed to prepare quickly enough. Even as scientists looked at China and sounded alarms, none of the agencies’ directors conveyed the urgency required to spur a no-holds-barred defense.

Dr. Robert Redfield, 68, a former military doctor and prominent AIDS researcher who directs the CDC, trusted his veteran scientists to create the world’s most precise test for the coronavirus and share it with state laboratories. When flaws in the test became apparent in February, he promised a quick fix, though it took weeks to settle on a solution.

The CDC also tightly restricted who could get tested and was slow to conduct “community-based surveillance,” a standard screening practice to detect the virus’ reach. Had the U.S. been able to track its earliest movements and identify hidden hot spots, local quarantines might have confined the disease.

Dr. Stephen Hahn, 60, commissioner of the Food and Drug Administration, enforced regulations that paradoxically made it tougher for hospitals, private clinics and companies to deploy diagnostic tests in an emergency. Other countries that had mobilized businesses were performing tens of thousands of tests daily, compared with fewer than 100 on average in the U.S., frustrating local health officials, lawmakers and desperate Americans.

Alex Azar, who led the Department of Health and Human Services, oversaw the two other agencies and coordinated the government’s public health response to the pandemic. While he grew frustrated as public criticism over the testing issues intensified, he was unable to push either agency to speed up or change course.

Azar, 52, who chaired the coronavirus task force until late February, when Vice President Mike Pence took charge, had been at odds for months with the White House over other issues. The task force’s chief liaison to the president was Mick Mulvaney, acting White House chief of staff, who was being forced out by President Donald Trump. Without high-level interest — or demands for action — the testing issue festered.

At the start of that crucial lost month, when his government could have rallied, the president was distracted by impeachment and dismissive of the threat to the public’s health or the nation’s economy. By the end of the month, Trump claimed the virus was about to dissipate in the U.S., saying: “It’s going to disappear. One day — it’s like a miracle — it will disappear.”

By early March, after federal officials finally announced changes to expand testing, it was too late. With the early lapses, containment was no longer an option. The tool kit of epidemiology would shift — lockdowns, social disruption, intensive medical treatment — in hopes of mitigating the harm.

Now, the U.S. has more than 100,000 coronavirus cases, the most of any country in the world. Deaths are rising, cities are shuttered, the economy is sputtering and everyday life is upended. And still, many Americans sickened by the virus cannot get tested.

In a statement, Judd Deere, a White House spokesman, said that “any suggestion that President Trump did not take the threat of COVID-19 seriously or that the United States was not prepared is false.” He added that at Trump’s direction, the administration had “expanded testing capacities.”

Dr. Bruce Aylward, a senior adviser at the World Health Organization, led an expert team to China last month to research the mysterious new virus. Testing, he said, was “absolutely vital” for understanding how to defeat a disease — what distinguishes it from others, the spectrum of illness and, most important, its path through populations.

“You want to know whether or not you have it,” Aylward said. “You want to know whether the people around you have it. Because you know what? Then you could stop it.”

“You can’t stop it,” he warned, “if you can’t see it.”

A Startling Setback

The first time Redfield heard about the severity of the virus from his Chinese counterparts was around New Year’s Day, when he was on vacation with his family. He spent so much time on the phone that they barely saw him. And what he heard rattled him; in one grim conversation about the virus days later, George Gao, the director of the Chinese Center for Disease Control and Prevention, burst into tears.

Redfield, a longtime AIDS researcher, had never run a government agency before his appointment to lead the CDC in 2018. Until then, his biggest priorities had been fighting the opioid epidemic and the spread of HIV.

At first, Redfield’s agency moved quickly.

On Jan. 7, the CDC created an “incident management system” for the coronavirus and advised travelers to Wuhan to take precautions. By Jan. 20, just two weeks after Chinese scientists shared the genetic sequence of the virus, the CDC had developed its own test, as usual, and deployed it to detect the country’s first coronavirus case.

“That’s our prime mission,” Redfield said later in an interview, “to get eyes on this thing.”

To identify the virus, the CDC test used three small genetic sequences to match up with portions of a virus’ genome extracted from a swab. A German-developed test that the WHO was distributing to other countries used just two, potentially making it less precise.

But soon after the FDA cleared the CDC to share its test kits with state health department labs, some discovered a problem. The third sequence, or “probe,” gave inconclusive results. While the CDC explored the cause — contamination or a design issue — it told those state labs to stop testing.

The startling setback stalled the CDC’s efforts to track the virus when it mattered most. By mid-February, the nation was testing only about 100 samples per day, according to the CDC’s website.

“Had we had done more testing from the very beginning and caught cases earlier,” said Nuzzo, of Johns Hopkins, “we would be in a far different place.”

The consequences became clear by the end of February. For the first time, someone with no known exposure to the virus or history of travel tested positive, in the Seattle area, where the U.S.’s first case had been detected more than a month earlier. The virus had probably been spreading there and elsewhere for weeks, researchers later concluded. Without a more complete picture of who had been infected, public health workers could not do “contact tracing” — finding all those with whom any contagious people had interacted and then quarantining them to stop further transmission.

The CDC gave little thought to adopting the test being used by the WHO. The CDC’s test was working in its own lab — still processing samples from states — which gave agency officials confidence. Dr. Anne Schuchat, the agency’s principal deputy director, would later say that the CDC did not think “we needed somebody else’s test.”

Barriers to Testing

Hahn’s first day as FDA commissioner came just six weeks before Azar declared a public health emergency on Jan. 31. A radiation oncologist and researcher who helped turn around MD Anderson in Houston, one of the nation’s leading cancer centers, Hahn had come to Washington to oversee a sprawling federal agency that regulates everything from lifesaving therapies to dog food.

But overnight, his mission — to manage 15,000 employees in a culture defined by precision and caution — was upended. A pathogen that Trump would later call the “invisible enemy” was hurtling toward the U.S. It would fall to the newly arrived Hahn to help build a huge national capacity for testing by academic and private labs.

Instead, under his leadership, the FDA became a significant roadblock, according to current and former officials as well as researchers and doctors at laboratories around the country.

Even though researchers around the country quickly began creating tests that could diagnose COVID-19, many said they were hindered by the FDA’s approval process. The new tests sat unused at labs around the country.

A Lack of Trust

Azar had sounded confident at the end of January. At a news conference in the hulking HHS headquarters in Washington, he said he had the government’s response to the new coronavirus under control, pointing out high-ranking jobs he had held in the department during the 2003 SARS outbreak and other infectious threats.

“I know this playbook well,” he told reporters.

As public attention on the virus threat intensified in January and February, Azar grew increasingly frustrated about the harsh spotlight on his department and the leaders of agencies who reported to him, according to people familiar with the response to the virus inside the agencies.

By Feb. 26, Fauci was concerned that the stalled testing had become an urgent issue that needed to be addressed. He called Brian Harrison, Azar’s chief of staff, and asked him to gather the group of officials overseeing screening efforts.

Around noon on Feb. 27, Hahn, Redfield and top aides from the FDA and HHS dialed in to a conference call. Harrison began with an ultimatum: No one leaves until we resolve the lag in testing. We don’t have answers and we need them, one senior administration official recalled him saying. Get it done.

By the end of the day, the group agreed that the FDA should loosen regulations so that hospitals and independent labs could move forward quickly with their own tests.

A Tacit Acknowledgment

Previous presidents have moved quickly to confront disease threats from inside the White House by installing a “czar” to manage the effort.

But faced with the coronavirus, Trump chose not to have the White House lead the planning until nearly two months after it began. Obama’s global health office had been disbanded a year earlier. And until Pence took charge, the task force lacked a single White House official with the power to compel action.

Since then, testing has ramped up quickly, with nearly 100 labs at hospitals and elsewhere performing it. On Friday, health care giant Abbott said it had received emergency approval for a portable a test that could detect the virus in five minutes.

Public health experts reacted positively to the increased capacity. But having the ability to diagnose the disease three months after it was first disclosed by China does little to address why the U.S. was unable to do so sooner, when it might have helped reduce the toll of the pandemic.

“Testing is the crack that split apart the rest of the response, when it should have tied everything together,” said Dr. Nahid Bhadelia,​ medical director of the Special Pathogens Unit at Boston University School of Medicine.

“It seeps into every other aspect of our response, touches all of us,” she said. “The delay of the testing has impacted the response across the board.”

© 2020 The New York Times Company