Other Cape communities, including Barnstable, Falmouth, and Truro, are also reporting a recent rise in cases, prompting a flurry of actions from state health officials, including the deployment of hundreds of rapid COVID test kits to health care providers and stricter staff COVID testing rules for Cape nursing homes. State health officials also are closely tracking the new cases, many of them tourists who live in other parts of Massachusetts and beyond.
Fueling anxieties is the rapid rise of the Delta variant, a mutated strain of the coronavirus that spreads more easily than other versions and now accounts for the vast majority of US COVID cases. Cape health officials say they don’t yet know what percentage of the new infections are attributed to the Delta strain, but suspect it is playing a large role.
The Delta variant “is virulent and not to be trifled with,” said Vaira Harik, deputy director of Barnstable County’s Department of Human Services.
Local officials have little doubt the flood of summer visitors is one driver of the COVID surge, with the Cape’s population easily doubling during the summer season, and Provincetown swelling from 3,000 to 60,000.
“We have an influx of tourists, as well as people from the July Fourth weekend, which has put people in closer proximity with each other and these factors are contributing to the cases in several towns in Barnstable County,” she said.
Reverberations from the Provincetown outbreak are already reaching Boston. The city’s Public Health Commission reported at least 35 COVID-19 cases in Boston residents have been traced back to Provincetown and the “overwhelming majority of those have been fully vaccinated,” officials said in a statement Tuesday.
The commission urged Boston residents who have traveled to Provincetown since July 1, and until further notice, to get tested at least five days after they return, even if they were vaccinated and are showing no symptoms. The commission also called on Provincetown visitors to self-isolate until they receive a negative COVID test.
So-called breakthrough infections among vaccinated people are rare. The state health department reports 4,814 such cases as of July 17, accounting for just 0.1 percent of all those vaccinated in Massachusetts. Instances of hospitalization or deaths among such cases are even more rare.
Yet, while most cases are mild, at least one fully vaccinated 35-year-old Boston resident infected in Provincetown over the July 4 holiday said he was hit hard by the illness.
“For two days, I was the sickest I’ve ever been in my life,” said Travis Dagenais, describing days of muscle aches, fever, and chills so bad he couldn’t sleep. And after two weeks, he still is fatigued.
Dagenais said he had been cautious about socializing until the July 4 holiday, even though he has been fully vaccinated since April.
“I started feeling safer and more comfortable, and so when friends and I wanted to go to a crowded nightclub in Provincetown, with hundreds of other people, it didn’t feel like a risk to me, frankly,” he said.
Dagenais was encouraged by the fact that Provincetown was “open for business,” and the busiest he’d seen it in over a decade of regular trips. “I interpreted the town of Provincetown allowing these nightclubs and spaces to operate as a signal of safety,” he said.
Now, he said, he would like to see more mask mandates return, as well as checks to see whether people are vaccinated in public places.
Provincetown leaders issued an advisory Monday for people to mask up indoors, regardless of COVID vaccination status “where social distancing cannot be achieved.” The advisory also urges businesses to require customers to show proof of vaccination when social distancing is not possible.
Harik, with Barnstable County’s human services department, said there has not been talk yet of expanding that advisory beyond Provincetown, or issuing mandates.
However, other officials fear that the Provincetown surge could soon come to their towns.
“I’m concerned about it spreading from Provincetown,” said Bruce Murphy, the health director in Yarmouth, about 40 miles away, mid-Cape. “It’s a mobile population and workforce on the Cape. Obviously it goes to other towns.”
At the Maplewood at Mayflower Place in West Yarmouth, a senior living facility, officials have recorded 33 people testing positive for COVID since July 10; 24 residents are residents and nine are staff.
The majority of residents who tested positive were vaccinated and are either asymptomatic or have mild symptoms, the state health department said. All staff who tested positive are in stable condition.
Murphy said Yarmouth has also recorded five new infections outside the nursing home in the past week, including some vaccinated people. He said the town is now working with the state to determine whether the cases are linked to the nursing home infections.
The state health department said the majority of nursing homes in Massachusetts continue to report no new cases in residents or staff. Statewide, 88 percent of nursing home residents are fully vaccinated, as are 73 percent of staff.
The department has deployed a team from the state’s Partners in Health-led initiative to assist Cape communities in contacting those who have been infected and analyzing emerging clusters. It also is providing health information in multiple languages to inform visitors and staff of the risk of COVID-19. And it has offered to send a large quantity of masks and hand sanitizer from its emergency preparedness warehouse for local officials to distribute.
State Senator Julian Cyr, a spokesman for the Cape Cod COVID-19 Task Force, said his panel is now working with the state, trying to reach seasonal workers who may not be vaccinated, including immigrants who come to the Cape for the summer on special work visas.
He said officials are also monitoring hospitalizations, as they tend to be a good barometer of the severity of illness in a COVID outbreak. Right now, he said, five people with COVID are hospitalized on the Cape.
“Hospitalizations may increase slightly, so long as they stay below a threshold and not overwhelm the system,” he said.
“I tend to think we are seeing the future,” Cyr said. “I think we are entering a new endemic phase of COVID-19 in that we are learning to live with this virus.”
Kay Lazar can be reached at kay.lazar@globe.com Follow her on Twitter @GlobeKayLazar. Camille Caldera can be reached at camille.caldera@globe.com.