Massachusetts must revert to stricter shutdown rules to ward off a resurgence of COVID-19 in the state, according to some epidemiologists and doctors who have watched the small but unmistakable increase in cases with growing alarm in recent days.
Though new cases on Monday totaled a relatively low 165, the state reported 643 new cases over the weekend, up from 483 last weekend and 395 the weekend before that. For nine of the past 14 days, new cases exceeded 200.
In addition to the bump in daily case counts, the state’s seven-day average test positivity rate has also risen slightly in past weeks, averaging around 2 percent for the first time since June.
The state should seize on the numbers as evidence that it’s time to roll back reopening, said Samuel Scarpino, a Northeastern University epidemiologist.
“We’re not seeing a major surge in cases. What we’re seeing are the indicators that a surge is coming,” Scarpino said in an interview. “Given how challenging it can be to intervene and slow the spread of COVID-19, the actions we take now are what’s going to determine whether we’re risking a situation like heading back to April or a situation that’s far more manageable.”
Scarpino advocated for returning to “at least” the second stage of Phase 2 of the state’s reopening plan, which would mean once again shuttering venues including gyms, casinos, and movie theaters. Phase 2 occurred in two steps: one step that reopened outdoor dining, some retail, and child care and another that added indoor dining and close-contact, personal services such as nail salons to the list. Phase 3, which began on July 6 in most of the state, allowed for more indoor entertainment.
Reflecting concern over the uptick, a key doctor at Massachusetts General Hospital, which has one of the largest emergency departments in the region, is now expecting to see a second surge starting later this month rather than in September or October as he initially anticipated.
“The rising positivity rate is one of the first indicators,” Dr. Ali Raja, vice chair for emergency medicine, said Monday. “I would expect that to translate to more hospitalizations in about a week or two.‘‘
Already, he said, their number of COVID-19 patients has stopped declining in the past two weeks and is holding steady.
Raja said that if the positivity rates keep rising this week, he would advocate for the state to move back to Phase 2.
In a statement Monday, the governor’s office did not specify its threshold for rolling back parts of the reopening but highlighted steps the state has taken to contain the virus.
“The Baker-Polito administration instituted one of the most stringent out-of-state travel policies in the nation and thousands of travelers are submitting the required information,‘' the statement said. “As with all COVID-19 measures, a combination of personal responsibility and enforcement at the local and state level is necessary. The administration will augment the order if public health and travel data warrants it.”
The Department of Public Health did not respond to requests for comment.
The increase in cases and other closely watched indicators after the state entered the first step of Phase 3 has led some officials and public health experts to worry about continuing to reopen safely. The state has not set a date for step two of Phase 3, which would reopen small indoor theaters and allow closer contact, indoor recreation including laser tag and roller skating.
Massachusetts began to see increasing infections about two weeks after Phase 3 began, suggesting that rising numbers are in part linked to reopening, said Dr. Robert Horsburgh, a professor of epidemiology, biostatistics, and global health and medicine at Boston University’s School of Public Health.
“I would back up to the last level the governor had, and we know that worked,” Horsburgh said. “Somewhere between that and now is the sweet spot. Level 2 worked. Level 3 didn’t work.”
Dr. David Rosman, president of the Massachusetts Medical Society, said the group is in regular communication with Baker and his staff and has expressed concern about the rising numbers. Rosman called last week for the state to seriously reconsider whether gyms, indoor dining, and casinos should be allowed to remain open.
“It hasn’t skipped anyone’s observation that it’s a worrisome trend, and unless we get a handle on it, we are in for a long fall and winter,” said Rosman, who is associate chair of radiology at Massachusetts General Hospital.
The city of Somerville broke with the rest of the state and decided to delay Phase 3, in part to “give ourselves a fighting chance of getting our kids back into schools,” according to a tweet last week from Mayor Joseph A. Curtatone. The city announced on Friday there is “no fixed date for reopenings,” though it will continuously review relevant data.
In settling on its more cautious approach, Somerville considered its uniquely high population density alongside testing delays and upticks in local and national cases, said Doug Kress, head of the city’s Health and Human Services Department.
“I am not ready to say that there’s a distinct trend that things are getting out of control,” said Dr. Barry Bloom, a professor and former dean of Harvard T.H. Chan School of Public Health.
Bloom is especially focused on the percentage of COVID-19 tests that have come back positive, averaged over a period of seven days — which has reached above 2 percent in recent days.
“I would say the absolute limit, which means we really have lost the ability to track things, would be 5 percent, and I would start shutting things down at 2.5 or 3,” he said.
Daily positivity rates reached 33 percent in April, though it is difficult to compare to present figures since test access has expanded significantly to include people without symptoms or known exposure to a sick person.
When the state released its reopening plan in May, some epidemiologists voiced concern that it did not include specific standards for what would trigger new lockdowns. Experts agreed that data on where new outbreaks are coming from is also important to guiding more targeted closures.
“I would encourage the governor to be more specific around where cases are coming from and be more specific about the indicators they’re tracking,” Scarpino said. “Are [new cases] coming from the house parties we’re reading about, or are they coming from the casino floors, the gyms, indoor dining?”
As for the cause behind increasing COVID-19 cases, Baker said in multiple press conferences last week that large gatherings were to blame for several clusters and called parties without enforced social distancing a “recipe for disaster.” The state has not specified what number of new cases have been traced back to gatherings or listed other explanations for the increasing number of cases.
Based on state data by age group, people in their 20s account for 24 percent of new cases since July 1, despite making up 14 percent of the state’s population. People in their 30s, who make up 13 percent of the population, account for 17 percent of recent cases.
But experts said the uneven age distribution is not enough on its own to support theories about young people carelessly spreading infections. Younger adults’ return to work and school or patronage of allowed indoor businesses could also be to blame. Transparency about the exact sources of new infections, experts said, will be key to preventing a dramatic resurgence in the fall.
“The trajectory that COVID takes, it takes awhile to get it turned around,” said Rosman of the Massachusetts Medical Society. “Problems we’re seeing in August will resonate in September and October.”
Dasia Moore is the Globe Magazine's staff writer. E-mail her at email@example.com. Follow her on Twitter @daijmoore. Kay Lazar can be reached at firstname.lastname@example.org Follow her on Twitter @GlobeKayLazar.