New daily cases have hit records in 12 states, and the White House acknowledges preparing for a fall wave.

Peter Navarro, the White House director of trade and manufacturing policy, said in an interview on Sunday that the White House was working to prepare for the possibility of a second wave of the coronavirus in the fall, though he said it wouldn’t necessarily come.

“We are filling the stockpile in anticipation of a possible problem in the fall,” Mr. Navarro told Jake Tapper on the CNN program “State of the Union.” “We’re doing everything we can.”

The comments come in contrast to President Trump’s repeated assertions that the virus will “go away” and his questioning of its ability to last into the fall and winter.

But if anything, the virus is gaining ground. Nationwide, cases have risen 15 percent over the last two weeks. Cases are rising in 18 states across the South, West and Midwest. Seven states hit single-day case records yesterday, and five others hit a record earlier in the week.

Florida and South Carolina had their third straight day breaking single-day records, and Missouri and Nevada both hit their records on Saturday — increases that came as the United States reported more than 30,000 new infections on both Friday and Saturday, its highest totals since May 1.

Florida reported 4,049 new cases on Saturday, bringing the state’s total to about 94,000 cases and more than 3,000 deaths; South Carolina reported 1,155 new cases; Missouri 375; and Nevada 452. Arizona, Utah and Montana also hit records.

California, Texas, Alabama, Oklahoma and Oregon hit records last week as well.

At the same time, overall deaths have dropped dramatically. The 14-day average was down 42 percent as of Saturday.

Strikingly, the new infections have skewed younger, with more people in their 20s and 30s testing positive, Gov. Ron DeSantis of Florida said. These clusters may be especially worrying to colleges and universities that plan to bring students back to campus in the fall, when the coronavirus and the flu virus are expected to be circulating simultaneously.

In Florida — which “has all the makings of the next large epicenter,” according to model projections by the PolicyLab at Children’s Hospital of Philadelphia — an advisory from the state’s Department of Health this weekend recommended that people avoid crowds larger than 50 people. It also encouraged social distancing and mask wearing at smaller gatherings.

Mr. Trump is set to deliver his national convention speech on Aug. 27 in Jacksonville, Fla., inside an arena that holds 15,000 people.

A top epidemiologist warns of a new U.S. trajectory: not waves, but a ‘forest fire.’

A prominent epidemiologist who initially predicted a first and second wave of the coronavirus in the United States, with a decline in between, warned on Sunday that the country was likely instead to experience one long stretch of cases, hospitalizations and deaths.

“I’m actually of the mind right now: I think this is more like a forest fire,” said Dr. Michael Osterholm, the director for the Center of Infectious Disease Research and Policy at the University of Minnesota, on NBC’s “Meet the Press.”

“I don’t think this is going to slow down. I’m not sure the influenza analogy applies anymore,” he said, referring to a report he and colleagues authored in April using influenza pandemics as a model for understanding the virus. “I think that wherever there’s wood to burn, this fire is going to burn it.”

He added, “I don’t think we’re going to see one, two and three waves — I think we’re just going to see one very very difficult forest fire of cases.”

He also called for a more unified national structure for dealing with the virus, rather than a patchwork of states using various strategies and reopening plans. “We have not really gotten the message across to the public yet, that this is a very serious issue,” he said. “We can’t shut down the economy, but we can’t suddenly say we’re done with it.”

Alarm is building over an explosion of cases in Houston.

As cases and deaths rose earlier this spring in New York, Los Angeles and Chicago, the country’s three largest cities, the outlook seemed much better in Houston, the fourth largest.

But this month, as new case reports plummeted around New York City and Chicago, they exploded around Houston. More than 1,100 new infections were reported both Friday and Saturday in Harris County, which includes most of Houston, by far the two highest daily totals there. Public health experts in Texas warned of a dire outlook. Houston’s mayor, Sylvester Turner, pleaded with residents to wear masks.

“The numbers are only getting worse,” said Lina Hidalgo, Harris County’s top elected official, who spoke of “significant, uncontrolled spread” of the virus and “very disturbing trends” in hospitalizations. “It is so crucial that all of us modify our behaviors, because that is the only thing that is going to keep us from going into a crisis.”

For now, at least, Houston is faring better than its three larger peers. Its per capita infection rate is far lower than that of New York City; Los Angeles County, Calif.;and Cook County, Ill., which includes Chicago. Cook County, which is slightly larger than Harris County, has four times as many cases and 13 times as many deaths.

Still, the trends are alarming across most of Texas, where the economy began to reopen in early May. The state’s testing positivity rate is now approaching 9 percent, up about four percentage points from a month ago. More than 3,200 coronavirus patients are hospitalized statewide, the highest number yet, though many more hospital beds remain available. And in the Dallas area, one of several places seeing huge case growth, residents will soon be required to wear masks at businesses.

“When you see an increase in hospitalizations, you know that there is an exponential number below the water of people who are sick and spreading the disease in our community,” Clay Jenkins, the top official in Dallas County, said. “That’s why we’ve moved to masking.”

China temporarily halts some imports of Tyson Foods poultry.

As Beijing struggles to stop a coronavirus outbreak that appears to have started at a vast wholesale food market in the city this month, China’s customs agency is taking aim at a U.S. company in a politically contentious industry: Tyson Foods.

China’s General Administration of Customs said on Sunday that effective immediately, it was temporarily suspending poultry imports from a Tyson Foods slaughterhouse that has had coronavirus cases among its workers. Shipments from the slaughterhouse that have already arrived in China will also be seized, the customs agency said in a public notice.

Scientists have said that the coronavirus appears to spread mostly through the air, not contaminated meat. But China has already curbed almost all transmission of the virus within its own borders and is looking to stamp out even low-probability risks.

The Chinese agency’s notice did not identify the location of the slaughterhouse, providing instead a registration number: P5842. Over the course of this spring, Tyson Foods has disclosed cases among its workers in several U.S. states.

On Friday, the company said that 13 percent of the 3,748 employees at its facilities in northwestern Arkansas had tested positive for the coronavirus. Almost all were asymptomatic. Arkansas is one of 18 U.S. states where daily new cases have been increasing. Tyson is one of the only large U.S. meat producers that is voluntarily disclosing the number of workers who have tested positive for the virus in its plants.

Safety limits on food imports from the United States could make it even harder for China to meet its promise to buy more U.S. goods as part of its Phase 1 trade agreement with the Trump administration that was signed in January. But American critics of food processing giants, particularly pork producers, contend that the companies have risked the health of their workers by keeping operations running, in part to supply China.

Tyson released a statement saying that it was “looking into” China’s action, noting that it operated in compliance with all government safety requirements and adding, “It is important to note that the World Health Organization, the Centers for Disease Control & Prevention, U.S.D.A. and the U.S. Food & Drug Administration agree that there is no evidence to support transmission of Covid-19 associated with food.”

At a rally in Tulsa, Trump blamed China for ‘the plague’ and claimed he wanted to ‘slow the testing down.’

In his first rally in months, President Trump bragged about his response to the pandemic, despite widespread criticism of his administration’s faltering management of the crisis.

Addressing a mostly maskless crowd on Saturday night in a sparsely filled 19,000-seat indoor arena in Tulsa, Okla., Mr. Trump mocked the coronavirus, which has killed 121,000 Americans, and claimed that he wanted to slow down testing.

“Here’s the bad part,” Mr. Trump said, after boasting that the United States had tested millions more people than any other country. “When you do testing to that extent, you will find more cases. So I said to my people, slow the testing down, please.” He also insisted that schools needed to open in the fall.

On Sunday, Peter Navarro, the White House director of trade and manufacturing policy, said in an interview with Jake Tapper on the CNN program “State of the Union” that the president’s comment about slowing testing was “tongue in cheek.” But the House speaker, Nancy Pelosi, took the comment at face value, tweeting on Sunday: “The President’s efforts to slow down testing to hide the true extent of the virus means more Americans will lose their lives.”

At the rally, Mr. Trump also blamed China for the pandemic’s economic damage in the United States, saying the country “sent us the plague.”

Mr. Navarro picked up that theme, a favorite among Republicans, alleging without evidence that China’s leaders may have done it on purpose and revisiting the claim that the virus was a Chinese bioweapon. Most American intelligence agencies remain skeptical of such a claim.

“China created this pandemic,” he told Mr. Tapper. “They hid the virus. They created the virus. They sent over hundreds of thousands of Chinese citizens here to spread that around and around the world. Whether they did that on purpose, that’s an open question.”

“They are guilty until proven innocent,” Mr. Navarro said, saying that China should be “responsible for the trillions of dollars of damage that they’ve inflicted on us.”

Mr. Trump told the rally that the low turnout had resulted from news media reports on local officials’ health concerns about the indoor rally, and campaign advisers claimed that their supporters had trouble entering the arena because of protesters.

In reality, there were few protests across the city, and black leaders in Tulsa had made calls earlier for people to stay away. TikTok users and fans of Korean pop music groups claimed to have registered potentially hundreds of thousands of tickets for Mr. Trump’s campaign rally as a prank.

Concerns that the event could spread the virus were amplified hours before Mr. Trump took the stage, when his campaign acknowledged that six staff members working on the rally had tested positive.

On Sunday, Tulsa County reported 143 new cases of people infected with the virus, its highest one-day increase since the pandemic began. The number of infections has been sharply increasing since the second week of June.

Downing St. seeks new powers against foreign takeovers of vaccine firms and other health-related businesses.

The British government will seek greater powers to intercede in foreign business takeovers to make sure that “they do not threaten” Britain’s ability to deal with a public health crisis like the pandemic, according to a government statement published on Sunday.

The law in question is the Enterprise Act 2002, which gave the government the oversight of mergers and takeovers on three public interest considerations: national security, media plurality and financial stability.

The proposed changes, to be presented to Parliament on Monday, would allow the government to intervene on a fourth: the country’s ability to combat a public health emergency.

“The economic disruption caused by the pandemic may mean that some businesses with critical capabilities are more susceptible to takeovers — either from outwardly hostile approaches, or financially distressed companies being sold to malicious parties,” it said, naming as examples “a vaccine research company or personal protective equipment manufacturer.”

India, Germany, Italy, Spain and other countries have also moved to protect businesses from unwanted takeovers since the start of the pandemic.

“These measures will strike the right balance between the U.K.’s national security and resilience while maintaining our world-leading position as an attractive place to invest — the U.K. is open for investment, but not for exploitation,” Alok Sharma, Britain’s business secretary, said in a statement on Sunday.

Bullfighting, already in decline in Spain, is battered by the lockdown.

Extremeño, an imposing black bull who weighs more than half a ton, was set to fight to the death next month in Valencia, Spain. Instead, the coronavirus gave him an unexpected lease on life: The event was canceled.

Spain ended its state of emergency on Sunday, allowing European visitors to fly in for the first time in months and relaxing lockdown measures across the country. But most of the bullfighting season, which runs from March to October, had already been called off.

Bull breeders and matadors have locked horns with a left-wing Spanish government that they accuse of wanting to use the epidemic as an accelerator for bullfighting’s permanent removal, in line with the wishes of animal rights activists, who say it amounts to torture.

“I find it deplorable that the fiesta of the Spanish people has become so politicized,” said Aurora Algarra, who owns Extremeño. “We now find ourselves under tremendous attack from Spain’s government, but at least this crisis has united us in the face of adversity in a way that I had not seen before.”

Since the lockdown, some animal rights associations have asked the government to disburse funds to help those working in bullfighting find alternative jobs. Many workers are contractually tied to a specific matador, making it hard for them to get jobs elsewhere. Even so, most of the support staff earn money only when there is a fight.

Ana Belén Martín, a politician from Pacma, a party that defends animal rights, said that bullfighting had been declining for over a decade and that it was heading for a natural death. She argued that the coronavirus crisis should not become a reason to extend a lifeline to a cruel pastime.

Contact tracing in New York City is off to a rough start.

New York City hired 3,000 disease detectives and case monitors for its contact-tracing program, but the effort has gotten off to a troubling start.

The tracers are expected to identify anyone who has come into contact with the hundreds of people in the city who are still testing positive for the coronavirus every day. But the first statistics from the program, which began June 1, indicate that tracers are often failing to find infected people or are unable to get information from them.

Of the 5,347 people whose contacts needed to be traced in the first two weeks of the program, only 35 percent provided information about close contacts, the city said in releasing the first statistics.

In lieu of a vaccine, contact tracing is one of the few tools that public health officials have to fight Covid-19, along with widespread testing and isolation of those exposed to the coronavirus. The stumbles in New York’s program raise fresh concerns about the difficulties in preventing a second surge of the outbreak in the city, which is to enter a new phase of its reopening on Monday.

China, South Korea and Germany and other countries have set up extensive tracking programs that have helped officials make major strides in reducing outbreaks. But in Britain, the program has struggled to show results with a low-paid, inexperienced work force.

In Massachusetts, which has one of the United States’ most established tracing programs, health officials said in May that only about 60 percent of infected patients were picking up the phone. In Louisiana, less than half were answering.

With Stonehenge closed to the public, millions watch its solstice sunset and sunrise online.

More than 3.6 million people tuned in this weekend to watch a live-streamed summer solstice sunset and sunrise at Stonehenge, the prehistoric monument in southwestern England, after the site’s annual gathering was canceled because of the pandemic.

“The sun might have been elusive, but over 3.6 million of you managed to watch sunset and sunrise with us from Stonehenge,” English Heritage, a charity that manages hundreds of English monuments including Stonehenge, said in a tweet on Sunday.

The summer solstice — when the Northern Hemisphere takes a maximum tilt toward the sun, bathing in direct sunlight for longer than any other day of the year — took place on Saturday, marking the scientific start to summer for half of the world.

Although it remains unclear exactly what kind of events occurred at Stonehenge when it was first erected around 2500 B.C., “marking the movements of the sun” was important to the farmers, herders and pastoralists who built it, and its layout is “positioned in relation to the solstices,” according to English Heritage.

Thousands typically gather at the Neolithic monument each year to celebrate the beginning of summer. Some still made their way close to the site on Saturday, according to local news outlets, despite the rain and the coronavirus restrictions that prevented the site from opening to the public.

Nursing homes are forcing vulnerable residents into homeless shelters and rundown motels.

Amid the coronavirus outbreak, a resident of a Connecticut nursing home was told that he had less than a week to pack his things and move to a homeless shelter, his lawyer said. In April, Los Angeles police officers found an 88-year-old man with dementia crumpled on a city sidewalk. His nursing home had recently deposited him at an unregulated boardinghouse.

And in New York City, nursing homes tried to discharge at least 27 residents to homeless shelters from February through May, according to data from the city’s Department of Homeless Services.

More than any other institution in America, nursing homes have come to symbolize the deadly destruction of the coronavirus. Residents and employees of nursing homes and long-term care facilities represent more than 40 percent of the death toll in the United States.

At the same time, nursing homes across the country have been forcing out older and disabled residents — among the people most susceptible to the coronavirus — and often shunting them into unsafe facilities, according to 22 watchdogs in 16 states.

Critics suggest that such ousters create room for a class of customers who can generate more revenue: patients with Covid-19. Aside from sheltering older people, nursing homes gain much of their business by caring for patients of all ages and income levels who are recovering from surgery or acute illnesses like strokes.

Because of a change in federal reimbursement rates last fall, Covid-19 patients can bring in at least $600 more a day from Medicare than people with relatively mild health issues, according to nursing home executives and state officials.

Many of the evictions, known as involuntary discharges, appear to violate federal rules, and at least four states have restricted nursing homes from evicting patients during the pandemic. But 26 ombudsmen from 18 states provided figures to The Times: a total of more than 6,400 discharges, many to homeless shelters.

“We’re dealing with unsafe discharges, whether it be to a homeless shelter or to unlicensed facilities, on a daily basis,” said Molly Davies, the Los Angeles ombudsman. “And Covid-19 has made this all more urgent.”

Making difficult pandemic conversations easier.

When it’s time to invite people over or arrange a play date, would-be hosts face tough conversations with friends, neighbors and family on their standards for avoiding coronavirus infection. Here are some strategies to help.

Reporting was contributed by Anne Barnard, Keith Bradsher, Aurelien Breeden, Benedict Carey, Emily Cochrane, Melina Delkic, Ben Dooley, Amy Julia Harris, Iliana Magra, Raphael Minder, Aimee Ortiz, Sharon Otterman, Jessica Silver-Greenberg, Liam Stack, Ana Swanson, Hisako Ueno, Neil Vigdor, Mark Walker and Karen Zraick.