SAN JUAN, P.R. — Throughout the pandemic, Dr. Víctor Ramos, a pediatrician, had not seen more than two Covid-19 patients hospitalized at the same time at San Jorge Children & Women’s Hospital in San Juan, the Puerto Rican capital, where he works nights. When he left after one of his shifts a few days ago, the hospital’s pediatric patient count had grown to 10.
“We had never seen that,” he said.
Some children were dehydrated after the coronavirus gave them high fevers, Dr. Ramos said, but others had the inflammatory syndrome that afflicts some children with Covid-19. One of the children hospitalized with severe Covid was just 3 months old, he said.
Puerto Rico has experienced its worst coronavirus outbreak of the pandemic over the past five weeks, with an explosive growth in cases exceeding records that had been set in December. Only this week did the numbers stop rising, giving the territory its first respite since the surge began in mid-March.
Behind the rise, experts say, was a confluence of factors, including the arrival of variants that probably made the virus more contagious right when people weary of staying home and hopeful about vaccines began to let their guard down, returning to work in person and shopping and dining indoors. Tourists poured in for Spring Break season. People gathered to celebrate Holy Week, a time when many are off work.
“The government relaxed restrictions around January and February — it opened the economy completely,” said Mayor Luis Javier Hernández Ortiz of Villalba, a town in south-central Puerto Rico. “This gave the virus opportunities to spread that it didn’t have a year ago. Now the virus has the opportunity to spread in all places.”
The results were staggering. In early April, the island went from averaging about 200 new cases a day to about 800, according to a New York Times database. In the week leading up to April 13, more than 7,100 cases were identified, a record. A two-week period this month saw cases grow by a remarkable 151 percent. At its peak, the positivity rate reached about 14 percent, according to the Puerto Rico Health Department.
In response, scientists and physicians like Dr. Ramos, who is the president of the Puerto Rico Hospitals Association, begged the public to follow masking and social distancing rules and urged elected officials to tighten pandemic restrictions. Hospitals still have bed capacity, Dr. Ramos said, but doctors and nurses are stretched thin. For years, Puerto Rico has lost many medical professionals to better-paying jobs in the states, leaving fewer of them to tend to the virus on the island.
“Everyone is exhausted,” Dr. Ramos said.
Jorge Manuel Rivera, 43, has seen it firsthand: His wife has been hospitalized in a San Juan hospital since late March. She does not have Covid-19 — she had surgery and has been in and out of intensive care — but the facility has been so full of Covid patients that there has not always been room for her in the I.C.U., he said.
“You can tell that they are very, very overwhelmed,” he said.
Mr. Rivera tested positive for the coronavirus two weeks ago and lost his sense of smell.
“There are too many people who are not aware of what is happening,” he said. “You can read the numbers and statistics, but you don’t understand it if you’re not there.”
This month, the administration of Gov. Pedro R. Pierluisi shut down in-person instruction at schools because of the virus surge. Officials pushed up the start of a nightly curfew to 10 p.m. from midnight — it is the only remaining blanket curfew in any state or territory — and reduced indoor capacity to 30 percent from 50 percent for restaurants and businesses. Some mayors have adopted additional restrictions, including closing beaches. Masks remain mandatory in public places across the island.
Starting on April 28, travelers who do not show proof of a negative Covid-19 test upon their arrival will be fined $300 unless they submit a test result within 48 hours. (The previous rules allowed travelers the option of isolating for 10 days if they could not provide a negative test result. Some have been arrested after breaking quarantine orders.)
Scenes of tourists behaving badly — flouting mask orders, crowding local hangouts and refusing to heed demands that they respect pandemic rules — have routinely made headlines. But contact tracing suggests many of the new infections have come not directly from tourists, but from Puerto Ricans going to work, restaurants and shops in person, public health experts say.
Mr. Pierluisi, who took office in January, has resisted pressure for a more stringent partial lockdown endorsed by opposition lawmakers and recommended by his own coalition of experts. The coalition said that malls and restaurants are not essential, signaling that they could be temporarily closed. The governor said in a news conference this week that the recent measures he did take are working but need more time to fully take effect.
“The situation is stabilizing,” he said. “There must be a very measured, very prudent approach to these types of decisions.”
His predecessor, Wanda Vázquez, imposed strict rules early on in the pandemic, ordering the country’s first lockdown. That helped Puerto Rico avoid a drastic increase in cases for many months but also dearly cost the economy. Long lines formed to receive unemployment benefits.
The latest outbreak can be managed with more gradual measures, Mr. Pierluisi said, citing the existence of virus treatments, a contact tracing system in Puerto Rico’s municipalities and the availability of vaccines.
About 1.65 million people — about 31 percent of the population — have received at least one vaccine dose, according to a Times database, which relies on statistics from the Centers for Disease Control and Prevention. Dr. Carlos Mellado López, the Puerto Rico health secretary, said in an interview that the Health Department estimates the number is actually higher.
But one public health message — get your shot — might have blunted another — be careful about the rapidly spreading virus — said Mónica Feliú-Mojer, the director of communications at Ciencia Puerto Rico, a nonprofit that supports scientists and their research.
“So much public attention turned to vaccination,” she said. “The moment you stop hearing about all the cases, you stop hearing about the importance of preventing contagion. The numbers have been worrying for more than a month, epidemiologists were sounding the alarm and nobody was paying attention.”
The testing rate had dropped dramatically before doubling in recent weeks, Dr. Mellado said. The health department is working to send more tests directly to primary care physicians to test people in their offices, free of charge.
Outside of public testing sites, private labs in Puerto Rico still require a doctor’s order to conduct a gold-standard polymerase chain reaction test to detect the coronavirus, creating a barrier for socially vulnerable populations to find out if they are infected, said Melissa Marzán-Rodríguez, an epidemiologist and assistant professor of public health at Ponce Health Sciences University.
“The situation has deteriorated so much over the past few weeks,” she said. “It might be the worst moment we’ve been through this past year.”
Her team is using a federal grant to train community members to help people overcome barriers to testing and vaccinations. One of them is Sister Faustina Rodríguez, a nun whose community organization has identified mostly older people living alone or in poor conditions in rural areas near Ponce, in southern Puerto Rico, who need basic aid such as masks and hand soap.
“We went to one woman’s home and all she had was the same mask she’s been wearing since last year,” Sister Faustina said.
There is also resistance to mask-wearing, testing — “Some people think it’s going to hurt, up their nose,” she said — and vaccinations.
“They don’t believe in vaccines, and the Johnson & Johnson situation has only made it worse,” Sister Faustina said, referring to the pause of that vaccine to study whether it causes blood clots. “Or they say, ‘Why should I get vaccinated if I can still catch it or have strong side effects?’” (She tells them she got the shot herself and felt fine.)
Lucía Santana Benítez, 52, who lives in a public housing complex in San Juan and runs a nonprofit to feed her neighbors, caught the coronavirus last year, as did her son and husband. She described it as “bad, bad, bad, bad — I spent a week sweating, with a fever, pain. I couldn’t even bathe.”
She initially did not want to get vaccinated, though she was promoting the vaccine in her community. But she decided to get the shot so she could visit her children and grandchildren, who live in Florida, Massachusetts and New Hampshire.
“I’m being a responsible grandmother,” Ms. Santana said.
Edmy Ayala reported from San Juan, P.R., and Patricia Mazzei from Miami.