The analysis affirms broad national tallies by the Centers for Disease Control and Prevention, which show Latinos making up 34 percent of cases nationwide, a much higher proportion than the group’s 18 percent share of the population.

It also underscores a shift from early in the outbreak, especially in areas outside cities, like Tulare County, Calif., which initially had largely avoided the debilitating spikes in infections seen in New York, New Orleans, Chicago and other major metropolitan areas.

The disparity is particularly stark in populous states like California, Florida and Texas. But it also has sprung up elsewhere. In North Carolina, Latinos make up 10 percent of the population, but 46 percent of infections. In Wisconsin, they are 7 percent of the population and 33 percent of cases. In Yakima County, Wash., the site of the state’s worst outbreak, half the residents are Latino. In Santa Cruz County, which has Arizona’s highest rate of cases, the Hispanic share of the population is 84 percent.

Detailed coronavirus data broken down by ethnicity is incomplete in many places, making it difficult to know why Latinos have been infected at higher rates. Counties with a high proportion of Latinos also tend to have attributes that have made counties vulnerable to the recent surge: crowded households, younger populations and hotter weather that drives people indoors, said Jed Kolko, a researcher and chief economist at Indeed.com, a job search website. Contact tracers in some areas also have associated spikes in infection with large family gatherings.

But the inexorable rise since Easter in infections among Latinos — both here and in Latin American countries — has alarmed health officials and Latino organizations, who are calling for more targeted testing, more comprehensive data collection and better workplace protections as the economy reopens.

And it has become a political flash point in red states, where infections are also rising. Latino Democratic and civil rights leaders demanded an apology this week from Florida’s Republican governor, Ron DeSantis, who attributed the steep increase in positive coronavirus tests in his state to “overwhelmingly Hispanic farmworkers.” Mr. DeSantis’s critics say his administration is scapegoating immigrant workers after ignoring pleas on their behalf for more testing and protection.

In California, where Latinos make up 39 percent of the population and nearly 57 percent of new cases, the spikes have been particularly confounding. The state was the nation’s first to shelter in place, and cellphone data indicated that its residents were among the most committed to limiting their movement, and with it the spread of the disease.

Infection rates have remained relatively low in affluent neighborhoods, including those occupied by the state’s wealthy Latinos. But sheltering in place never happened for many Latino families with members who work in industries that never shut down, making them especially vulnerable to the virus.

During the lockdown, millions of Latino workers kept a bare-bones economy running: at the cutting tables of food-processing plants, as farmhands, as hospital orderlies, food preparers, supermarket workers and in many other jobs deemed essential. And they brought the virus home to often cramped living quarters, compounding the spread.

“This was totally a blind spot,” said Dr. Alicia Fernandez, a professor of medicine at the University of California, San Francisco, who specializes in Latino and immigrant health. “Much, much more needs to be done in workplace protection.”

Now the virus is stalking Latinos from the south to the north in California. Imperial County, a predominantly Latino farming region east of San Diego, has the state’s highest infection rate — twice the rate of Los Angeles, and higher than that of hard-hit New York State. In San Francisco, Latinos make up 15 percent of the population but account for half of the coronavirus cases.

Many San Francisco streets were all but deserted during the lockdown. But it was a different picture among the Bay Area’s Latino households, where the daily routine of commutes to far-flung workplaces continued.

“Sheltering is a luxury,” said Dr. Kirsten Bibbins-Domingo, the vice dean for population health and health equity at the University of California, San Francisco School of Medicine. “In wealthier parts of town, people sheltered earlier and longer, because it takes resources. Not every community has the luxury to do that.”

Hot spots developed in areas with large Latino populations, like the Fruitvale neighborhood in Oakland.

The virus spread through Kings County, an agricultural area in the Central Valley with numerous meatpacking plants; it now has the second highest rate of infection in the state. Tulare County, whose population is 64 percent Hispanic, rose to fourth place among counties.

“We’re seeing a concentration of impacts from Covid-19 in industries that are majority Latino — indoor food processing, packaging, meatpacking,” said Phoebe Seaton, co-executive director and co-founder of Leadership Counsel for Justice and Accountability, a civil rights organization based in Fresno, Calif., that is advocating for more workplace protections against the virus.

Rachel P. Cullen, the company’s chief executive, said that as with many companies, Ruiz’s initial response was to give employees the option to work at home, and to take vacation days or unpaid time off if their jobs could not be done remotely.

After Easter, however, the case count in Tulare County shot up, and the company moved aggressively to address the virus. Testing was mandated for all employees, Ms. Cullen said in a statement, and “increased physical distancing, mandatory mask wearing, flexible barriers, symptom monitoring and temperature screening, limiting visitors and travel restrictions” were quickly put into place.

No employees have died from Covid-19, Ms. Cullen said, but the Dinuba plant became a hot spot, and two workers were hospitalized. She said 331 employees have recovered from Covid-19 since April, and about 15 have active infections.

Ms. Ramirez suspects that she caught the virus in the company lunchroom, where tables are now cordoned off to enforce social distancing. On the production line where she works with hundreds of other people, she said, sheets of plastic separate employees and bottles of hand sanitizer have been placed at every walkway. That was not the case before April, she said.

Still, she doesn’t blame her employer. “A lot of us didn’t believe in Covid at the beginning,” she said in Spanish. “I didn’t, because I didn’t know anyone who had it until I got it myself.”

A week after her test results came back, her 20-year-old daughter, Cynthia Orozco, also tested positive. Because her daughter also watches Ms. Ramirez’s two youngest children, ages 2 and 10, the doctor told Ms. Ramirez to assume that they, too, had the virus.

No one in the family has required hospitalization, but as word circulated among friends and relatives in California, Nevada and Mexico, she learned that her plight was not as unusual as she had thought.

A co-worker of her husband’s at a dairy in Visalia was infected. So was a cousin in Bakersfield who clerked in a Dollar Store. In Modesto, a cousin in the construction business had Covid-19 and was worried about his crew in San Francisco.

“We’re the ones who are out in the work force,” said Ms. Orozco, a civil engineering major at California State University, Fresno, who added that the virus had cost her several weeks of work as well.

Ms. Orozco said she and her mother have not yet had follow-up tests. But last weekend, after heart-wrenching months of keeping their distance from loved ones, they put on masks and went to a big outdoor family party anyway.

“Everybody used hand sanitizer, and put their names on their cups so no one accidentally picked up anyone’s drink,” she said. “And we all just kind of did a fist pump in the air instead of hugging each other.”

Shawn Hubler reported from Dinuba, Thomas Fuller from Moraga, Calif., and Anjali Singhvi and Juliette Love from New York.

Shawn Hubler is a California correspondent based in Sacramento. Before joining The Times in 2020 she spent nearly two decades covering the state for The Los Angeles Times as a roving reporter, columnist and magazine writer, and shared three Pulitzer Prizes won by the paper’s Metro staff.  @ShawnHubler

Thomas Fuller is the San Francisco bureau chief. He has spent the past two decades in postings abroad for The Times and the International Herald Tribune in Europe and, most recently, in Southeast Asia. @thomasfullerNYT • Facebook

Anjali Singhvi is a graphics editor. She is a trained architect and holds a master’s degree in urban planning/urban analytics from Columbia University. @singhvianjali