To a nation in the grips of coronavirus panic, Florida in mid-March looked destined to be the next hot zone.
Spring breakers partying carefree on beaches. Senior citizens fraternizing in retirement communities. International travelers leaving germs around Disney World.
Medical professionals saw a trajectory of cases that tracked alarmingly close to the early days of the outbreak in New York. They implored Gov. Ron DeSantis to swiftly shut down the state. He waited two weeks.
After the state shut down, the predicted tsunami did not arrive. Temporary hospitals sit unused. Ventilators were never in short supply. The death count, though tragically nearing 1,800 today, remains short of what many feared.
Why didn’t Florida see an explosion of cases?
To answer that question, Tampa Bay Times reporters reviewed the methodology behind several prominent models and studied data tracing the virus’ spread into every corner of the state.
Then the Times analyzed cell phone tracking data collected by three companies that paints a vivid picture of how Floridians reacted during the outbreak’s early days. Fifteen experts reviewed the work and shared their observations.
The analysis indicates that while Florida’s politicians debated beach closings and stay-at-home orders, residents took matters into their own hands.
By the time each county shut down, there had been large reductions in activity, the cell phone data shows. People in the worst-hit counties were overwhelmingly staying home weeks before DeSantis’ order went out — and even before the much-earlier orders issued by local governments.
At the time Floridians stopped venturing out, the virus most likely had spread to fewer individuals compared to the places that became national hotspots, according to epidemiologists who reviewed the Times’ analysis. But in the late days of March, this was masked by a severe lack of testing across the country, which made it impossible to tell.
The state’s sprawling cities and random strokes of good fortune may also have worked in Florida’s favor. But public health experts warned that as Florida reopens, its good luck could change with one asymptomatic disease carrier stepping into a large nursing home.
"The thing that is really easy — because this is silent and because it may not be immediately impacting you — is you get really complacent about it,” said Jeffrey Shaman, professor of environmental health sciences at Columbia University. “There is a lot of opportunity for this virus to grow exponentially, if it's given the opportunity."
Already, residents’ willingness to stay home appears to be shifting.
The latest cell phone data shows a marked uptick in movement in many counties starting in the second half of April.
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DeSantis made the call on April 1: Most residents should stay home to avoid spreading the coronavirus.
Pressure had been mounting for weeks. Local leaders demanded a uniform statewide shutdown. More than 900 medical professionals signed a letter to the governor pleading for more drastic intervention.
Floridians, it turned out, weren’t waiting.
They severely cut back on going out in public before any government forced them to, according to a Times analysis of cell phone tracking data.
The Times obtained information from Google and two other private companies that use location data from apps on millions of cell phones to determine whether people are socially isolating.
Each company’s data works differently. But it all showed the same thing: In every county in the state, significant decreases in movement began before shutdown orders were issued.
Miami-Dade has had the largest outbreak in Florida. But in the five days preceding the county’s March 26 stay-at-home order, more than half the phones tracked by one of the firms never traveled more than a mile. That represented a drop of more than 80 percent compared to data the firm, Descartes Labs, collected from mid-February to early March.
Data from another company, Unacast, showed that the average distance traveled in the county had been cut nearly in half. Visits to businesses Unacast classified as nonessential, based on guidelines issued by various state governments, dropped at least 65 percent.
Similar patterns repeated across Florida.
In the days leading up to Hillsborough’s shutdown, the median distance traveled had dropped by 70 to 80 percent, according to the data from Descartes Labs. In Pinellas, it had declined by 67 percent or more.
Residents of the biggest counties were quickest to put social distancing guidelines in place. But the trend was consistent.
The self-imposed shutdown slowed the spread of the virus considerably. Its impact on the number of cases in Florida could be seen before DeSantis’ statewide order had enough time to make a difference. Experts say it takes weeks for social distancing measures to affect the daily case count. But within six days of the statewide shutdown, the average growth in new cases had started to decline in 56 of 67 counties, including all of the largest ones.
Experts who reviewed the Times’ analysis said the trend was unmistakable and consistent with other data they’ve reviewed.
“I think the true heroes here are really the people of Florida,” said Ali Mokdad, professor of health metric science at the University of Washington. “They knew it was dangerous, they reduced their mobility and they're staying home way above what you and I expected.”
In many counties, the decline began around the time of a remarkable five-day period in mid-March.
On March 11, the World Health Organization declared the outbreak a pandemic, the NBA postponed its season and President Donald Trump addressed the nation. That same day, married actors Tom Hanks and Rita Wilson revealed they had the virus. Florida schools began to close and Trump declared a national emergency March 13. DeSantis halted nursing home visitations March 14. Walt Disney World shut its gates March 15.
Meanwhile, many businesses enacted work from home plans. Others closed for lack of customers.
By April 3, when DeSantis’ shutdown order took effect, nearly half of the state’s counties had seen 50 percent drops in median movement for at least two weeks, the Times found.
That is not what epidemiologists expected, said Thomas Hladish, a University of Florida research scientist who specializes in disease modeling and has been advising the state on the outbreak.
"What you see in Florida is that people started social distancing much earlier,” Hladish said. “Whether it’s because their schools closed or they were watching the news, they seemed to have started to act before they were explicitly told, ‘Don’t go out.’ That early action is almost certainly the biggest factor in why things weren’t worse here.”
That’s not to say DeSantis’ stay at home order wasn’t important. After reviewing the Times analysis, Dr. Marissa Levine, director of the Center for Leadership in Public Health Practice at the University of South Florida, suggested the order likely suppressed a rebound in activity.
Levine and others cautioned an easing of restrictions will lead to more transmission. How well people continue social distancing — the practice of limiting close contact and avoiding crowds — will dictate the number of new infections.
“We really came together as communities in Florida and people took it seriously,” Levine said. “We can’t let up on what we’ve each done individually. That’s the foundation to preventing a second wave.”
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Other states that had serious outbreaks also saw major decreases in movement, cell phone data shows.
But evidence and experts suggest that the virus was slower to arrive in Florida than in places like New York and New Jersey. So when Floridians started scaling back social interactions, it was early enough to choke off spread of the disease.
New York and Washington “were much further along that exponential curve than Florida was” when they started responding, said Thomas Unnasch, a distinguished professor in the University of South Florida College of Public Health.
At this stage, it’s impossible to confidently say why other states were so far ahead, although the answer may become clearer as scientists study the different strains of the virus.
Several experts theorized that more international travelers carried the virus to New York City. The New York metropolitan area is home to three busy international airports. One of them, John F. Kennedy, saw almost as many international passengers in 2018 as the airports in Miami, Fort Lauderdale, Orlando and Tampa combined, federal data shows.
Of course, Florida also welcomed millions of visitors in early 2020, many from abroad. But Mokdad said Florida may have benefited from the type of people who typically visit.
Many visitors to New York are business travelers, he said, who sometimes have to make long trips when they aren’t feeling well.
“People coming to Orlando are tourists who are not sick,” he said.
To date, New York has had nearly nine times the number of confirmed cases that Florida has.
Other key data points suggest the virus has been less prevalent in the overall population in Florida than in states that experienced more severe outbreaks.
At the end of March, for example, more than a third of the people in New York and New Jersey who had taken a COVID test got a positive result, a Times analysis shows.
In Florida, it was 10 percent.
It wasn’t that Florida had tested many more people. At that point, the number of tests done in Florida was comparable to the number done in New Jersey.
New York had conducted more than twice as many.
The share of Floridians testing positive has been consistently low. And recent antibody tests may provide further evidence that Florida was less seeded with infected people than some other places.
A random test of 3,000 New York City residents found that 1 in 5 had developed antibodies to the coronavirus, suggesting that as many as 2.7 million residents had already been exposed to the virus without knowing it, the New York Times reported.
A smaller but similar test in Miami-Dade County found that about 6 percent of people there had antibodies. That would equate to about 165,000 of Miami-Dade’s 2.75 million residents.
The takeaway is clear, said Dr. Mary Jo Trepka, an infectious disease epidemiologist and professor at Florida International University. “Not as many people were exposed,” she said.
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Over the past two months, however, the models have struggled to account for what was happening, both in Florida and elsewhere in the country.
In early March, it wasn’t clear how deeply the virus had spread. And there was no way to know how Americans would react to a health crisis of proportions not seen in the modern era.
At first, epidemiologists turned to existing models for the seasonal flu. They plugged in different values to reflect the new coronavirus’ infectiousness, incubation period and mortality rate.
Before long, more sophisticated models emerged that made predictions about how people would change their behaviors and whether governments would make them.
But even including a simple measure like a mandatory face-mask policy presented challenges, said Carl Pearson, a research fellow at the London School of Hygiene and Tropical Medicine.
Masks can be beneficial, he said. But how beneficial?
“What if we have a hodgepodge of cloth masks bought off Etsy?” he said. “We don’t know how effective they are. We don’t know how people will wear them, what compliance will look like.”
One model by a coalition of data scientists, epidemiologists and public health officials known as COVID Act Now used data from Europe and China to predict best- and worst-case scenarios for social distancing.
It was the worst-case scenario estimates that made headlines in Florida in mid-March, predicting that 465,699 people in the state would be hospitalized by April 24.
The actual number of hospitalizations by that date turned out to be 4,817 — roughly one-hundredth of the estimate, according to state data.
A month later, DeSantis pointed to the prediction as an example of the models and experts being alarmist. But in an interview, COVID Act Now founder and CEO Max Henderson said the model was correct.
“The reason those outcomes didn’t come to pass is because we took action,” he said. “Full stop.”
Henderson pointed out that if Florida were to lift all restrictions on movement and stop social distancing today, there could be hundreds of thousands of cases by the middle of June.
“If we do our job right, some people will levy criticism and it will be hard to defend,” he added. “But that means it was a success, because hundreds of thousands of people didn’t have to die.”
Another model that rose to national prominence — the one produced by the University of Washington’s Institute for Health Metrics and Evaluation — had a different strategy for incorporating how people responded.
An early version of the model looked at the number of deaths in a state, then predicted how the epidemic would grow based on data from Wuhan, China. It predicted slower growth in places that closed schools and non-essential businesses, issued stay-at-home orders and halted travel.
As time went on, the team learned that more people were staying home than anticipated. They turned to data collected from cell phones to help represent that in the model, Mokdad said.
“You could see in Florida there was a 20 percent reduction in mobility,” he said. “That was a surprise. When the schools shut down, mobility went down to 55 percent. That was even more than we expected.”
Their model, which the White House cited for a while, faced criticism from some scholars for being too simplistic. It has continued to draw skepticism from other experts for predicting a low number of deaths even as some states move toward partial or full reopenings.
Mokdad defended the work.
“We’re not optimistic,” he said. “We’re assuming the people who stayed at home early on are people who can work from home, who can afford to stay at home and who will stay home.”
Several public health experts who spoke with the Times pointed out that models often make predictions that don’t come to fruition. Sometimes, the publicity around those predictions changes how the situation plays out.
That doesn’t mean the information isn’t valuable, the experts said.
Pearson drew comparisons to hurricane models, which often start out wrong and become more precise as the storm gets closer. “The people of Florida understand that those projections mean something and they are useful,” he said.
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Some scientists wonder if the Sunshine State has other advantages even more difficult to measure.
Consider Tampa. The city hosted a convention for firefighters and paramedics in early March attended by a 70-year-old man who later tested positive for coronavirus. Other cities have traced major outbreaks back to similar events — such as Boston, where a biotech company meeting became a superspreader event. But while one death is linked to the Tampa convention, it didn’t flare into a major outbreak.
And then there’s Orlando. State leaders fully expected the theme park hub to blow up with cases. When it didn’t, they were left scratching their heads.
"Disney was going all the way to mid-March,” DeSantis recently said in the White House. “We didn’t have outbreaks tied to a lot of that stuff for whatever reason. Maybe it’s because most of our activities are outdoors."
DeSantis isn’t the first to float the climate theory. Since the coronavirus first arrived in the United States, people have wondered whether the disease would go away in the summertime, fading like the flu. The way other respiratory illnesses ease up in the heat also has raised the question of whether Floridians are already benefiting from the climate.
Florida’s highest caseloads, though, have come in some of its warmest cities. Looking abroad, places like Singapore have seen outbreaks in hot weather.
“Temperature isn’t protecting anybody,” said Dr. John Sinnott, chair of internal medicine at the University of South Florida College of Medicine.
Sunshine, which Florida enjoys in spades, does help the body create Vitamin D, which doctors say is connected to good health. And while a recent study from Northwestern University identified a link between Vitamin D deficiency and coronavirus mortality, experts caution it’s not a cure-all.
Additional research has shown ultraviolet light helps kill the coronavirus, but that analysis had not been peer reviewed when it was mentioned in a White House briefing last month. Cindy Prins, a University of Florida epidemiology professor, said experts think of light beating back viruses on surfaces, like a shopping cart left in the sun, but not within people. And it doesn’t replace handwashing.
“The sunlight helps a little, the fact that people are outdoors a lot helps a little,” Sinnott said. What might have helped the most, he believes, is Florida’s addiction to cars and suburban sprawl.
Though much is still unknown about how the virus spreads, epidemiologists say one key is the frequency with which people come into contact with other people for sufficient lengths of time.
Compared to coronavirus hot zones like New York and Italy, Florida has more limited public transportation and less density in its cities. Experts said that likely has contributed to Florida’s lower case rate.
“If people are used to taking their own car, parking and going into a store, that’s very different from walking out of an apartment building, taking a bus and walking another block to get there,” said Shaman, the Columbia professor.
There’s another factor experts pointed to: Luck.
At the end of the day, one person landing in New York instead of Miami could have made all the difference.
“It could be that the virus wasn't introduced well. It could be the car culture. It could be the weather. It could just be dumb luck,” Shaman said. “If you were going to take the world and run it back and let people run loose again, would the same things happen?”
Correction: Tom Hanks and Rita Wilson revealed they had the coronavirus on March 11. An earlier version of this story misstated the date.
Times staff writers Langston Taylor and Eli Murray contributed to this report.
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