Amid flurry of national coronavirus data, Massachusetts remains a hot spot of infection

There have been more than twice as many deaths here, and our infection rate is now triple that of Washington, which has a similar size population and has been nearly as aggressive in testing for the new coronavirus.

Nationally, day after day, Massachusetts has persistently stood out by several alarming metrics, often ranking near or in the top five among states for deaths, per capita infections, and the rate of those who have tested positive for the virus.

Public health experts warn that state-by-state comparisons can be misleading. Testing has been uneven, illness and fatalities are tallied differently in different locales, and public health experts say it is likely there is a significant undercount of infections and deaths everywhere.

But we gauge progress, or the lack of it, by the numbers in this pandemic, as each state pumps out new daily figures on hospital surges, fresh outbreaks, and the multiplying sickness. The data has become a grim box score that people trapped at home study for glimmers of hope.

And, of late, the Massachusetts numbers have offered precious few reasons for hope.

State officials Friday reported 159 new deaths, the largest single-day increase of the pandemic. Massachusetts has suffered the sixth highest death rate per capita in the country, according to a analysis of data collected by The COVID Tracking Project.

The state has significantly ramped up the number of people tested, and as of Saturday morning ranked fourth per capita in the nation, trailing only New York, Rhode Island, and Louisiana. Increased testing, however, means more confirmed cases, with Massachusetts now having the third highest number of known infections per capita in the nation.

The Globe analyzed data tracking coronavirus tests, infections, and deaths from all 50 states, calculating per capita rates and taking into account each state’s population density, racial and ethnic makeup, wealth, age, and the timing of public health directives designed to slow the outbreak. Interviews with a dozen epidemiologists and other public health experts from across the country made clear that despite caveats, there are lessons in these statistics and the shared experiences of other states.

The early evidence suggests that social distancing can help slow the spread and is especially vital in densely packed cities such as those in the Northeast where the virus has thrived. And one phenomenon seems to hold true from coast to coast: Emergency orders and shutdowns, if enacted early enough, are key.

“There’s no doubt that stay-at-home orders play a role," said Jennifer Nuzzo, a senior scholar at the Johns Hopkins Center for Health Security. "The places that have done it earlier have slowed the spread.

In Washington state, this new coronavirus struck with such initial ferocity that it compelled urgent action. Governor Jay Inslee declared a state of emergency on Feb. 29, the day the state announced the nation’s first death of a confirmed COVID-19 patient. It would be another 10 days before Massachusetts took the same step, after Governor Charlie Baker cut short a family ski trip to Utah and flew home.

In that first week of March in Washington, large tech companies such as Microsoft and Amazon, were telling their employees in that state to work from home. The University of Washington on March 6 became the first major US college to cancel in-person classes.

Schools closed. Shoppers flooded local Costcos to stock up on toilet paper and other essentials. Even so, the death toll in Washington initially climbed at a terrifying rate to more than a hundred in a few weeks, with cases radiating from that one nursing home outside Seattle.

The high-profile ravaging of the Life Care Center in suburban Kirkland drove the state’s urgent response, said Ali H. Mokdad, a professor of health metrics sciences at the Institute for Health Metrics and Evaluation at the University of Washington.

“People here realized that it was spreading faster than expected in our own backyard, and they paid attention,” Mokdad said. “We knew this was serious, and then when the mortality happened at the nursing home, everybody in Washington started staying at home, even before the government issued its orders.”

Washington’s governor initially begged residents to stay home, telling them March 20 he was “pleading with” them. Inslee followed three days later with a formal order that closed nonessential business and banned all gatherings.

In Massachusetts the next day, Baker issued a similar edict, but it was a stay-at-home advisory, not an order. While Baker urged people to limit their interactions, he also said, “I do not believe I can or should order US citizens to keep confined to their homes for days on end."

The Baker administration has said its policy has been extremely effective and that “all available data show Massachusetts residents are staying home.”

While missteps by the federal government hindered testing across the country, Washington state ramped up its efforts faster than Massachusetts and other states. In recent weeks, new infections and hospitalizations with COVID-19-like illness there have dropped. The trajectory is clear in the epidemiologic curve on Washington state’s website: Confirmed cases and deaths are trending lower like steps on the downslope of a mountain.

“They started social distancing earlier,” said epidemiologist Nadia N. Abuelezam, a professor at the Connell School of Nursing at Boston College. “They got ahead of it. They were swifter.”

The Baker administration noted Friday that Massachusetts has now tested more people per capita than Washington.

The administration also said Massachusetts appears to have more COVID-19 cases because the Commonwealth is more aggressively testing in “affected” nursing homes and Washington was focused only on testing nursing homes in the county where the outbreak began.

Washington state health officials disagree.

“It is not true that we are only testing in nursing homes in King County,” Washington health officials said in a statement. “Because King County is near the first case (Snohomish County) and is the most populous area in the state, there has been a lot of testing activity there.”

In explaining why the outbreak is more severe here, the Baker administration noted that Massachusetts has an older population with a larger proportion of people over age 80, who are especially vulnerable to the virus.

Unlike Washington, the virus infiltrated Massachusetts more gradually. The first confirmed case was announced Feb. 1, but it took almost a month for the state’s first major outbreak.

In late February, executives from Biogen, a Cambridge medical research firm, assembled for a two-day company leadership conference at the Boston Marriott Long Wharf hotel. Co-workers based around the country and the world greeted each other with hugs and handshakes and ate from the conference’s breakfast buffet spread. The Biogen meeting would become infamous in the pandemic, an early super-spreader event linked to more than 100 infections, but no immediate crush of fatalities.

It would be another three weeks until the first COVID-19 death was confirmed in Massachusetts.

Washington also had another huge advantage, according to public health experts. The population, while similar in size to Massachusetts, is spread out over a much wider area, making it easier to self isolate. Massachusetts has eight times the number of people per square mile, and its largest city, Boston, is twice as densely populated as Seattle.

In national maps of the virus, hot spots concentrate in densely packed cities where people rub shoulders on subways and buses, clutching handrails, ride in crowded elevators, and navigate narrow aisles in compact grocery stores.

A new federal report issued Friday highlighted this and other factors to explain the impact of COVID-19 in different states. Because COVID-19 is primarily transmitted by respiratory droplets, crowded cities are more likely to have higher infection rates, according to the US Centers for Disease Control and Prevention report.

It also found that timing of state shutdowns is critical and can lead to “substantial reductions in rates of infection, hospitalization, critical care, and death.”

Even the availability of tests, and different rules for testing, likely contributed to striking differences in the number of cases, per population, among the states, the report concluded. It noted that two-thirds of all coronavirus cases are concentrated in seven states: New York, New Jersey, Michigan, Louisiana, Massachusetts, Pennsylvania, and California.

California’s experience underscores the importance of early action. The state’s vast population has produced a significant number of cases, but its infections per capita and death rate are roughly just one-seventh that of Massachusetts.

Leaders in California nervously watched coronavirus gain a foothold to the north. They moved quickly, issuing an emergency declaration March 4, when the state announced its first confirmed death.

Local health officials helped lead the way. In the heart of Silicon Valley, county officials banned large gatherings, shut down businesses, and issued a strict shelter-in-place order, with penalties and fines for violators.

“Those were not popular things they did because nobody knew anyone that was sick at that time and it sounded like they were overreacting,” said Richard Jackson, the state’s former health officer and now a professor emeritus at the Fielding School of Public Health at the University of California, Los Angeles. “But now ... it doesn’t seem like overreacting,” he said.

In demographic studies, there is often an outlier and here, as is often the case, it is Florida.

The Sunshine State would have seemed particularly vulnerable to this coronavirus because of its abundance of older residents, pockets of poverty, and an ethnically and racially diverse population of the kind that has been hit disproportionately hard in other states.

Those vulnerabilities, it would seem, would be exacerbated by Governor Ron DeSantis’ reluctance to enact a statewide stay-at-home order, which did not go into effect until April 3. In Florida, professional wrestling was deemed an “essential business.”

But so far, the COVID-19 statistics released by the state of Florida have been remarkably low for a state with such a large population. The reported infection and death rates are roughly one-quarter that of Massachusetts.

“It’s more complicated than that,” said Cindy Prins, a University of Florida associate professor of epidemiology. “You’ve always got to take the behavior of the population as a factor. How afraid are they? How seriously are they taking it?"

Weeks before the stay-at-home order, there were ominous signs in Florida. Images of crowds of spring-breakers sparked outrage. Cities and counties closed beaches. And on March 15, Disney World closed for only the 11th time in its history, a step precipitated in the past only by hurricanes and the attacks of Sept. 11, 2001.

“That was a wake-up call for some people that this is serious,” Prins said. “Disney doesn’t close easily.”

Five weeks later, Disney furloughed 43,000 workers as the virus continued to spread. This pandemic operates on its own timeline, affecting different states at different times.

Tennessee is one state that has approached the virus slower than many others. The state’s first case, confirmed on March 4, was traced backed to Massachusetts and the Biogen conference in Boston. A 44-year-old executive named Chris Baumgartner flew home with the virus.

Baumgartner outed himself in a Facebook post, in which he said he had mild symptoms, but that the illness was still difficult to face.

“Imagine having to confront a virus, so feared, it now has the entire world on the brink of mass hysteria, while at the same time, being forced to deal with irrational panic, people demanding to know if you are the ‘one’” he wrote.

After Baumgartner’s diagnosis, city officials in Nashville, Memphis, and Knoxville issued guidance urging people to stay home. Then Tennessee Governor Bill Lee, after initial resistance, issued a statewide guidance effective March 31, closing nonessential business and urging residents to stay home.

Just this weekend, Tennessee announced expanded statewide testing efforts, including drive-through sites operated by the National Guard. The state Friday had 6,589 confirmed cases and 142 deaths, per capita rates roughly five and 10 times below Massachusetts. Vanderbilt University recently issued a report suggesting social distancing is slowing the rate of infection in the state. “Tennessee’s recent progress, while real and positive, is fragile,” the report noted.

Everything seems fragile at the moment, there and here. Despite the constant bombardment of new facts and figures, clarity will be elusive for some time, trends will remain speculative. And more people will get sick.

“Until this pandemic begins to wane and we have accounted for all the data and the backlog of information, we cannot be sure where Massachusetts stands relative to other states,” said Summer McGee, dean of the School of Health Sciences at the University of New Haven. “But it is essential to know eventually so we can better plan for and respond to any future outbreaks.”

Andrew Ryan can be reached at andrew.ryan@globe.com Follow him @globeandrewryan. Kay Lazar can be reached at kay.lazar@globe.com Follow her @GlobeKayLazar. Mark Arsenault can be reached at mark.arsenault@globe.com. Follow him @bostonglobemark.