(CNN) Ten states saw a record number of new Covid-19 cases this week, and one of them could be the next epicenter of the national health crisis.
Florida reported 3,207 additional coronavirus cases on Thursday -- the largest single-day count in the state since the pandemic, according to the state health department. Florida's total reported cases climbed to nearly 86,000, according to data.
The Sunshine State has "all the markings of the next large epicenter of coronavirus transmission," and risks being the "worst it has ever been," according to projections from a model by scientists at Children's Hospital of Philadelphia and the University of Pennsylvania.
"That makes me very worried because, at the numbers they're now seeing, it's very easy to start doubling and lose control of the epidemic," Dr. David Rubin, director of PolicyLab at Children's Hospital of Philadelphia, told CNN on Thursday.
Rubin said model predictions are matched by actual cases in Florida and confirmed by increasing hospitalizations from Tampa to Orlando to Miami-Dade County and up the east and west coasts of the state.
"The potential for the virus to take off there is very, very nerve-racking and could have catastrophic consequences" because of the state's aging population and the prevalence of nursing homes and retirement communities, said Dr. Jeanne Marrazzo, director of the division of infectious diseases at the University of Alabama at Birmingham.
Florida joins nine other states -- Alabama, Arizona, California, Nevada, North Carolina, Oklahoma, Oregon, South Carolina and Texas -- that are seeing record-high seven-day averages of new coronavirus cases per day, according to a CNN analysis of data from Johns Hopkins University.
The governors of Florida and Texas are among state and national leaders who attribute the increase in cases to more testing and other factors. Epidemiologists argue case numbers should go down with greater testing, because theoretically health officials should be able to trace the cases and slow the spread of the virus.
Health experts, such as Dr. Aileen Marty, often respond that hospitalizations are a sign of a "real increase in cases."
"The reality remains that there are more hospitalizations happening here right now, so we know this is a real increase in cases," Marty, an adviser to the Miami-Dade County mayor and an infectious diseases professor at Florida International University, told CNN's Erin Burnett.
Florida Gov. Ron DeSantis blamed the surge in cases, in part, on crowded living conditions in migrant families.
More than three quarters of Florida's adult intensive care unit beds are occupied, according to data from the Florida Agency for Health Care Administration. General hospital beds were at nearly 75% capacity across the state.
People in Miami are "extremely concerned" about the increase in cases and hospitalizations, Miami Mayor Francis Suarez told CNN's Wolf Blitzer on Thursday night.
"We're going to do everything we can to keep Miami from becoming an epicenter," Suarez said.
St. Petersburg Mayor Rick Kriseman is requiring all workers at businesses who come face-to-face with customers to wear masks. "Certainly as we reopened, we did expect to see an increase but not like this," he told CNN on Thursday.
"There are all kinds of alarm bells that are going off for me. I'm not comfortable with what I see happening in my community and that's really the reason I took the actions I took. I think you're going to see mayors across the state of Florida that are going to take actions in response to these numbers because we're just not seeing that from our leadership in Tallahassee."
Police officers in Miami-Dade County, for instance, were being dispatched to stores, beaches and parks to enforce social distancing and mask wearing.
In a video message, Miami-Dade Mayor Carlos Gimenez vowed enforcement actions against business and vacation rentals used as "party homes."
"We're going to get tough," said Gimenez, adding that violating business and rental properties would be shuttered. "People are getting way too comfortable."
Miami will be stepping up enforcement of protective measures for businesses to try to slow the spread, Suarez said, and stricter measures could be brought back if the virus is out of control.
"Everything has to be on the table," if hospitalizations increase further, Suarez said.
North Carolina Gov. Roy Cooper, a Democrat, said 1,333 new cases were identified Thursday, raising the state total to 48,188. There were 857 people in hospitals -- a record high -- and 1,170 reported deaths from the virus.
"These numbers continue to concern us," Cooper said.
In Arkansas, which reported 322 new cases on Thursday, Gov. Asa Hutchinson extended a state public health emergency set to expire Friday by another 45 days.
Louisiana Gov. John Bel Edwards said the state added 4,200 Covid-19 cases -- the majority resulting from community spread -- in the past seven days. Coronavirus hasn't left," he told reporters. "It is still very much here with us, and it is present in every community across the state of Louisiana."
In Arizona, health officials on Thursday reported a new single-day high for coronavirus cases for the second time in this week, with 2,519 new cases.
"What we're looking at is the reality that we're going to have rolling outbreaks," Dr. Scott Gottlieb, former commissioner of the US Food and Drug Administration, said on MSNBC's "Morning Joe" on Thursday. "There's going to be parts of the country that get hot where there's a lot of infection."
Gottlieb said "more complacency" in Southern and Southwestern states not initially hit hard by the virus has led to "full-blown outbreaks."
California on Thursday issued updated guidance requiring all residents to wear face coverings in most public settings, with limited exceptions.
"Simply put, we are seeing too many people with faces uncovered -- putting at risk the real progress we have made in fighting the disease," Gov. Gavin Newsom, a Democrat, said in a statement.
Twenty-three states are seeing an upward trend in new coronavirus cases. Health experts continue to stress the importance of taking precautions to reduce the virus's spread.
Despite the rising number of cases, the White House has downplayed the risks, with President Donald Trump saying Wednesday in an interview with Gray TV that the virus is "dying out."
With the White House at odds with the data, health experts including Dr. Deborah Birx and Dr. Anthony Fauci have been absent from many public updates. Dr. Jonathan Reiner, a professor of medicine at George Washington University, told CNN it's because "they tell the truth."
"And the truth is that the pandemic is still very, very active in the United States and that we're not getting back to normal and there are difficult things that the public has to do," Reiner said.
Fauci warned about an "anti-science bias" contributing to case spikes.
"One of the problems we face in the United States is that unfortunately, there is a combination of an anti-science bias that people are -- for reasons that sometimes are, you know, inconceivable and not understandable -- they just don't believe science and they don't believe authority," Fauci said in an episode of the US Department of Health and Human Services' podcast "Learning Curve" on Wednesday.
"So when they see someone up in the White House, which has an air of authority to it, who's talking about science, that there are some people who just don't believe that -- and that's unfortunate because, you know, science is truth."
States reporting increases in new cases will have to re-implement "significant levels of social distancing," Dr. Peter Hotez, a professor of pediatrics and molecular virology and microbiology at Baylor College of Medicine, told CNN.
"We've never finished the first wave," Hotez, dean of the National School of Tropical Medicine, said of spikes in new cases in Florida, Texas and Arizona. "We didn't complete that social distancing period that we needed to do."
Models showed states needed to extend stay-at-home orders through May, according to Hotez.
"Things opened up prematurely," he said.
According to data from Johns Hopkins University:
• 23 states are seeing upward trends in newly reported cases from one week to the next: Alabama, Alaska, Arizona, Arkansas, California, Delaware, Florida, Georgia, Hawaii, Idaho, Kansas, Oregon, Louisiana, Montana, Nevada, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Washington, West Virginia and Wyoming.
• Eight states are seeing steady numbers of newly reported cases: Indiana, Maine, Mississippi, Missouri, Nebraska, Ohio, South Dakota and Utah.
• 18 states are seeing a downward trend: Colorado, Connecticut, Illinois, Iowa, Kentucky, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Mexico, New Jersey, New York, North Dakota, Pennsylvania, Rhode Island, Virginia and Wisconsin.
• One state, Vermont, has seen a decrease of at least 50%.
Nationwide, more than 2.1 million people have been infected and at least 118,386 people have died of the virus.
Local officials are hoping to manage the spread by mandating mask usage.
A day after the city council failed to pass an ordinance, Montgomery, Alabama, Mayor Steven Reed implemented an executive order Wednesday requiring those in the city to wear face masks and coverings in public, according to a post from the city's official Twitter account.
Arizona physicians have called upon Gov. Doug Ducey to implement a similar executive order statewide. While the governor announced Wednesday that he would be calling up 300 National Guard soldiers to help with contact tracing, he said he would leave mask requirement decisions to mayors.
Some local leaders are unlikely to follow the mandate, rendering it "a self-defeating executive order," he said.
Scottsdale Mayor Jim Lane, a Republican, was consulting the municipal legal team to develop a mandatory public mask ordinance, according to the city. Scottsdale is in Maricopa County, which represents more than half the state total of confirmed cases.
Earlier this week, nine Texas mayors, including those in Houston, Dallas, Austin and San Antonio, urged Gov. Greg Abbott to give them the authority to require masks be worn in public "where physical distancing cannot be practiced."
The mayors and physicians have reason to believe the requirements could be effective. A study reported Tuesday found that an estimated 230,000 to 450,000 cases of the virus were prevented in states that required mask use between April 8 and May 15.
Loosening precautions and restrictions means more people are gathering in larger groups, which has, in some cases, swiftly resulted in positive coronavirus tests.
Pinal County, Arizona, Sheriff Mark Lamb announced Wednesday that he tested positive for Covid-19 and is self-quarantining for at least 14 days. He likely encountered an infected person at a campaign event he held Saturday, he said.
The county Public Health Department is working to track everyone he came into contact with, he said on Facebook.
Fauci told the "Learning Curve" podcast that shutdown policies across the country saved "millions of lives" during the pandemic. He predicted the National Football League season may not start this year, particularly if there is a second coronavirus wave.
"Unless players are essentially in a bubble -- insulated from the community and they are tested nearly every day -- it would be very hard to see how football is able to be played this fall," he told CNN.
Dr. Colleen Kraft, associate chief medical officer at Emory University Hospital, said states needed to figure how to protect people while continuing to reopen economically.
"There's not going to be a post-Covid world for a long time," she told CNN.
Earlier this week, a group of 16 friends in Florida said they all became infected with coronavirus after a night out at a recently reopened bar.
Still, Oklahoma, one of the states reporting a record-setting number of new cases, is scheduled later this week to host a campaign rally for Trump. When questioned, Trump said he is not worried about attendees getting sick, though attendees must agree not to sue the campaign if they contract the coronavirus.
"Actually, Oklahoma has had a very low rate relatively speaking. It is a little spike, a small spike for a specific reason," he said. "We'll go there, everyone is going to be safe."
Republican Sen. James Lankford of Oklahoma acknowledged to CNN the rise in rates, but said the rally should not be postponed and "we are pushing people to be attentive on this."