Few expected a major return of measles to the United States this year, a quarter-century after it was declared eliminated here.

But return it has, with more than 1,300 confirmed cases this year and three deaths. Public health officials say they have seen nothing like it since the winter of 1990 to 1991, when measles last swept the country.

For some, like Justin Johnson, who was 12 in that epidemic year, it was an eerie time. Schools closed and doctors showed up at families’ homes, including his, to examine children. He was one of 13 children in a joyful and loving Philadelphia family who ate dinner together every night around a huge table.

Mr. Johnson, now 46 and living in Lancaster, Pa., was the first in his family to get measles. Then the disease spread to his siblings. Some of them did not survive.

He was part of a major outbreak in Philadelphia that winter. The disease first spread among poor children in the inner city and then ravaged children whose families were members of a church. The death rate was so high — one in 35 as compared with the usual one in 1,000 — that the Centers for Disease Control and Prevention sent a team to see if the virus had mutated.

Mr. Johnson’s close-knit family was part of that church.

From Local to National

The epidemic today has not so far approached that of 1990 and 1991. Before that epidemic was over, there were about 55,000 cases nationwide and 132 suspected deaths. It was the worst outbreak since a vaccine was licensed 1963, breaking all records for illnesses and fatalities.

But public health experts are deeply concerned. The number of measles cases is the most since 1992, when, as the epidemic waned from its peak, there were 2,200 cases.

They fear what is to come. Even as Texas health authorities declared an end to the West Texas measles outbreak on Monday, they warned of “ongoing outbreaks of measles in North America and around the world,” and forecast additional cases in Texas.

Experts say some of the same forces seen in the early ’90s are driving the spread of this preventable disease. Case numbers have dropped but measles tends to be most active in winter and early spring, said Dr. Paul Offit, a pediatrician and the director of the Vaccine Education Center at Children’s Hospital of Pennsylvania. With the school year resuming, public health authorities will be watching for more cases.

And they fear that vaccine skeptics may cite the end of the Texas outbreak as evidence of alarmism among public health officials.

Public health officials in 1990 knew all too well how easily measles spreads. One infected person may transmit the disease, on average, to 12 to 18 susceptible people. In comparison, a person infected with the flu will spread it to 1.3 to 1.5 susceptible people.

Before a measles vaccine was licensed, measles was so common it was considered a rite of childhood. Three to four million Americans got measles each year.

Yet 400 to 500 people died each year in those pre-vaccine days. Others had brain damage from encephalitis, brain swelling that can occur during or after the infection. A smaller number have a very rare complication, subacute sclerosing panencephalitis, an often fatal condition that arises seven to 10 years after infection.

In 1967, the C.D.C. attempted to eradicate measles from the United States, with television commercials promoting the vaccine and mass immunization campaigns.

Cases plummeted but local outbreaks continued. Then came the winter of 1990.

“We were battling outbreaks throughout the country,” said Dr. William Atkinson, a retired medical epidemiologist who directed measles surveillance for the C.D.C. during the 1990 to 1991 epidemic. All were similar: They occurred among mostly poor minority children, preschool age, living in inner cities in crowded conditions.

Dr. Irwin Redlener, a Montefiore Medical Center pediatrician caring for homeless children, was stunned when he saw a child with measles in 1990.

“Then we saw case after case,” he said. “We felt overwhelmed by what seemed to be an unstoppable outbreak.”

Eventually, 4,500 people in New York got measles and 17 died. Most were preschool age Black and Hispanic children.

“What really bothered me as a pediatrician is that these kids would go back to the shelter and infect other kids,” Dr. Redlener said. “We knew we were about to see a tidal wave of children infected with measles.”

What happened was that the children were not vaccinated — vaccines were required for school, but they were too young to go to school. There were community health centers that distributed vaccines but, Dr. Redlener said, “it was very difficult for homeless and indigent families to actually get there.”

Two Sisters in Five Days

In Philadelphia, by the end of 1990, 258 children had gotten measles and an 18-month-old boy had died — the first measles death in Philadelphia in 20 years.

Dr. Robert Ross, Philadelphia’s health commissioner during the measles epidemic, said in a recent interview that the epidemic got its start in poor inner-city neighborhoods. He attributed it to lack of access to health care and, he said, the crack epidemic played a role, too.

Then, on Jan. 16, 1991, the health department got an anonymous phone call from a woman who said she believed measles was spreading in a school associated with the Faith Tabernacle Congregation (the church did not respond to a request for comment). Her adult daughter was a church member.

Soon afterward, a third grader in the school, 9-year-old Caryn Still, died of measles. None of the several hundred children in the school had been immunized. Church members spurned medical care.

At that point Dr. Ross and a colleague paid a visit to the pastor, the Rev. Charles Reinert.

“We explained that we had gotten a call from an anonymous relative, that we heard it was measles and that we were concerned,” Dr. Ross said in a recent interview. “We said we needed to do an investigation.”

Pastor Reinert, Dr. Ross said, “explained they believe in the power of prayer.”

Dr. Ross convinced the pastor to give him the addresses and phone numbers of church members — just over 100 families with more than 800 children among them.

“He said it was up to the families if they wanted to talk to us,” Dr. Ross recalled, but Pastor Reinert warned him that “you won’t get cooperation.’”

Dr. Ross and his team began calling.

“I called one family and the mom said everyone was fine. One child was sick but doing better,” Dr. Ross said. “Two or three days later, that kid showed up in the morgue.”

As the days wore on, Dr. Ross escalated the health department’s efforts. With the support of Mayor W. Wilson Goode, he got court orders that allowed doctors to compel medical treatment even when the families did not want it, and to vaccinate children even if the parents refused.

In February, a doctor and a nurse came to the home of the Johnson family. Justin Johnson’s younger sister, 9-year-old Monica, had just died from measles. Most of the other children were sick or recovering from measles.

None had seen a doctor. Mr. Johnson, today a communications and marketing director for the Lancaster Chamber of Commerce, said he and his siblings had never been to a doctor’s office, never seen a stethoscope, never taken so much as Tylenol. None were vaccinated.

When family members were sick, they would listen to tape recordings of sermons — all the church’s sermons were recorded. “You would try to find a sermon that would help you,” Mr. Johnson said.

Monica, Mr. Johnson said, did not seem any sicker than the rest of the children. And when she died, the children did not start getting scared of the illness.

“There was no fear whatsoever of dying,” Mr. Johnson said. “Our belief was, you know, they have gone to heaven.”

So when the doctor and nurse arrived at his house, “I didn’t understand the gravity of it,” he said. “I was like, ‘I don’t understand why these people are here.’ The only thing I do remember was that my parents were worried that the doctors would take the children away.”

Five days after the doctor’s visit, on the morning of Monica’s funeral, Mr. Johnson’s older sister, 13-year-old Tina Louise, died from measles.

The family accepted her death and her sister’s as God’s will.

“Nobody had any regrets, like saying, ‘Oh, if only we’d gotten vaccinated we wouldn’t have had this happen,’” Mr. Johnson said. “And when Covid came around, nobody said, ‘We have to get a Covid vaccine.’”

For the health department doctors, household visits to families with ties to the church could be an exercise in frustration.

Dr. Ross remembers a visit to a family with nine children. When he arrived, their grandmother was caring for them.

He saw eight children watching television in the house’s lower level. When he asked the grandmother about the ninth child, he was told she was fine, and that she was upstairs watching TV.

Dr. Ross mounted the stairs.

“I saw a 9-year-old on a couch. She was pale, in the early stages of cyanosis, and sweaty. She did have a pulse, but it was thready. Her breathing was shallow and at a rapid rate,” he said. “She looked like if she didn’t get an oxygen tube into her, she would crash.”

He started making his way downstairs to the kitchen to get to the phone while the grandmother lectured him about the power of prayer.

“I was fending her off with one arm and dialing with the other,” Dr. Ross said. “I said, ‘Judge, I need your permission to call an ambulance.’ The grandmother was protesting and all the kids were bawling.”

He visited the girl at the hospital the next day. She was in intensive care, being treated for measles pneumonia. Her parents were at her bedside.

“I wasn’t expecting confetti and a parade, but I was expecting a ‘Thank you, doctor,’” he said.

His reception was “icily cold,” he said. “I’d violated the integrity of their religious beliefs.”

Dr. Offit, the director of the Vaccine Education Center, said that by Feb. 15, five children from the church had died in 10 days.

“It was overwhelming,” Dr. Offit said. “There had been a vaccine in place since 1963. It was like going back in time.”

The C.D.C.’s team of epidemiologists concluded that nothing about the virus had changed to make it more deadly. Children were dying because they were not getting basic supportive medical care for complications like dehydration and pneumonia.

“They died because their parents refused to allow them to go to the hospital,” said Dr. Atkinson, the retired medical epidemiologist.

A Flipped Equation

Now, measles has returned. The outbreak so far has centered on religious communities in New Mexico and Texas that choose not to vaccinate. And from there it has spread to the broader population.

But the solution that was attempted in Philadelphia, forcing children to be vaccinated, will never happen, medical experts said.

“We would have zero chance of doing mandatory vaccinations,” Dr. Offit said.

And if the Faith Tabernacle Congregation outbreak offers any lessons, it is that some faith communities do not see measles — even measles deaths — as something to fear.

“We believed in prayer, in the power of prayer,” Mr. Johnson said. And, he said, they accepted death, when it occurred, as God’s will.

Public health officials are starting to despair.

Dr. Atkinson said that there are bills in state legislatures across the country allowing people to refuse vaccines. People, he said, who simply say they don’t believe in vaccines are increasingly allowed to decline them.

“We are chipping away at our nation’s immunity,” he added.

Dr. Redlener, the pediatrician, said that there have always been two forces driving measles outbreaks: poor access to medical care and individuals who decline to get vaccinated, for religious or other reasons.

In the previous epidemic, the disease started among those with poor access to medical care, then spread to those who refused vaccines.

“Now we’ve flipped the equation,” Dr. Redlener said: Vaccine refusers are seeding the disease’s spread.

And the flipped equation raises questions of how, and when, the current epidemic will end.

Alain Delaquérière contributed research.