• Texas on Wednesday reported 2,504 new coronavirus cases, the highest one-day total since the pandemic emerged.
• A month into its reopening, Florida this week reported 8,553 new cases — the most of any seven-day period.
• California’s hospitalizations are at their highest since May 13 and have risen in nine of the past 10 days.

A fresh onslaught of the novel coronavirus is bringing challenges for residents and the economy in pockets across the U.S. The localized surges have raised alarms among experts even as they’re masked by the nation’s overall case count, which early this week rose just under 1%, the smallest increase since March.

“There is a new wave coming in parts of the country,” said Eric Toner, a senior scholar at the Johns Hopkins Center for Health Security. “It’s small and it’s distant so far, but it’s coming.”

Though the outbreaks come weeks into state reopenings, it’s not clear that they’re linked to increased economic activity. In Georgia, where hair salons, tattoo parlors and gyms have been operating for a month and a half, case numbers have plateaued, flummoxing experts.

Puzzling differences show up even within states. In California, which imposed a stay-at-home order in late March, San Francisco saw zero cases for three consecutive days this week, while Los Angeles County reported well over half of the state’s new cases. The White House Coronavirus Task Force has yet to see any relationship between reopening and increased cases of COVID-19, Food and Drug Administration Commissioner Stephen Hahn said on a podcast.

But in some states, rising numbers outpace increases in testing, raising concerns about whether the virus can be controlled and whether it could overwhelm hospitals. It will take a couple of weeks to know, but by then “it’s going to be pretty late” to respond, Toner said.

Since the pandemic initially swept the U.S. starting early this year, almost 2 million people have been confirmed infected and more than 110,000 have died.

After a national shutdown that helped arrest the spread, rising illness had been expected as restrictions loosened. The trend has been observed across 22 states in recent weeks, though for many the increases are steady but slow. Because overall levels are low, outbreaks in settings where the virus spreads easily, like nursing homes or meatpacking plants, could be influencing the numbers in an outsize way.

But experts see evidence of a second wave building in Arizona, Texas, Florida and California. Arizona “sticks out like a sore thumb in terms of a major problem,” said Jeffrey Morris, director of the division of biostatistics at University of Pennsylvania’s Perelman School of Medicine.

Arizona’s daily tally of new cases has abruptly spiked in the last two weeks, hitting an all-time high of 1,187 on June 2.

This week, its Department of Health Services sent hospitals a letter urging them to activate emergency plans and prepare to staff beds. The department’s director, Cara Christ, told a Phoenix television station that she was concerned about the rising case count and percentage of people tested who are found to be positive. The state, she said, has no current plans to shut down businesses a second time, but she didn’t rule it out.

“That’s not part of our discussion—that’s not on the table for what we’re looking at—but we know that we have a whole range of options,” she said in an interview Tuesday with Fox 10 news.

Mobile Texans

In Texas, Governor Greg Abbott was criticized for an aggressive reopening last month. Mobile-phone data show activity by residents is rebounding toward pre-COVID levels, according to Morris’s collaborators at the Children’s Hospital of Philadelphia’s PolicyLab.

That could reflect a perception that the virus wasn’t “ever a big threat,” said Morris, who recently moved to Philadelphia after 20 years in Houston. Brazoria County, near Galveston on the Gulf Coast, has seen just a 6% reduction in visits to nonessential businesses, compared with a roughly 50% reduction in New York City and Los Angeles County, according to the PolicyLab.

Bucking the trend is Georgia, which was the first U.S. state to reopen. COVID cases there have plateaued.

Despite some local outbreaks, “their sea levels did not rise,” said David Rubin, director of the PolicyLab, which has been modeling the virus’s spread in local areas around the country. “They’ve kind of held this fragile equilibrium.”

Creeping in

California was the first state to shut down its economy over the coronavirus, after one of the nation’s earliest outbreaks in the San Francisco Bay Area. It has been slower than most to reopen.

Even so, the state has also seen the number of people hospitalized with COVID-19 rebound in the past two weeks, as more commerce picks up. Case counts are climbing too, although state officials attribute that more to increased testing and say it’s a sign of their preparation.

In part, rising numbers represent the virus spreading into places that largely avoided the first round of infections, including rural Imperial County in California’s southeastern desert. Yet the contagion also remains present in some places that bore the brunt of the first wave, including Los Angeles County. Hospitalizations there are lower than at the start of May, but deaths remain stubbornly high, with 500 dying in the past week alone.

Barbara Ferrer, Los Angeles County public health director, said in an interview that the region has likely not seen the end of the first wave. And despite concerns about infections coming out of mass demonstrations that have gripped the sprawling city, she thinks the reopening of the economy will have a bigger impact.

“We’re not at the tail end of anything,” she said. “We never had a huge peak. We’ve kind of been within this band. We’re not in decline, we’re kind of holding our own in ways that protect the health-care system.” But, she added, “go to Venice and see the crowds, and you’ll understand why I have concerns.”

Another onslaught

The U.S. has long been bracing for another wave of the coronavirus, but future outbreaks are likely to take a different shape. Precautions like social distancing and mask-wearing, as well as careful behavior by individuals, are likely to have staying power in many parts of the country even as economies reopen.

But experts are also steeling for autumn, when changes in weather and back-to-school plans could have damaging repercussions.

“The second wave isn’t going to mirror the first wave exactly,” said Lance Waller, a professor at Emory University’s Rollins School of Public Health in Atlanta. “The distancing works to dampen things at the beginning, and it’s not snapping back to exactly the same thing as before, because we’re not exactly the way we were before.”

Daniel Lucey, a fellow at the Infectious Diseases Society of America, compared the virus’ new paradigm to a day at the beach: The U.S. has been bracing for another “high tide” like what engulfed New York City. But today is a low tide and “the waves are always coming in.”