Hospitalizations associated with COVID-19 have risen about 30 percent in Massachusetts since hitting a low point on July 13, marking the end of a long downward trend that began in January.
The pattern matches a national increase. From June 24 through July 22, COVID hospitalizations increased by 11 percent, according to data from the Centers for Disease Control and Prevention.
The growing number of hospitalizations in the state, paired with the highest levels of coronavirus in waste water since March, raise the question of whether we are seeing the start of a late summer surge.
Experts say it is too soon to know.
Both measures are lower than they were at this time last year and far below those seen during the 2021-2022 Omicron surge, when hospitalizations in the state soared above 3,000. Last week, Massachusetts reported 130 people were hospitalized with COVID-19.
“We look back to when Omicron came in, it happened overnight,” said Dr. David Hamer, a professor of global health and medicine at Boston University and an attending physician at Boston Medical Center. ”In a two- to four-week period we went from very few cases to nearly all being related to Omicron.”
Although experts continue to remain cautious of COVID-19 transmission, many highlight the importance of understanding these increases relative to the low number of cases right now.
“We have to be very careful about interpreting the increases in smaller numbers and comparing that to what’s happened in the past with large surges,” said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. “Ten percent of 5,000 is very different than 10 percent of 125,000.”
Osterholm believes we are past the major part of the pandemic. However, he said the lack of surveillance infrastructure could pose a challenge in the future.
Since the end of the federal COVID-19 public health emergency on May 11, the ability of the CDC and of state agencies to collect data has changed.
Experts say coronavirus surveillance is no longer as accurate as it was earlier this year, making it harder to track surges.
“The state has switched to reporting cases only once a week, and a lot more people are doing at-home rapid tests,” said Hamer.
“From a surveillance standpoint, waste water surveillance is going to continue to be very important,” said Osterholm.
A late-summer surge could still happen.
Over the previous summers, COVID has surged at different times, said Hamer.
“There’s not been a real consistent pattern at least in terms of summer,” he said, “but midsummer, generally, there’s been lower transmission, and it’s been very low, although the virus is still there.”
Seasonality, however, is not a factor of the virus, said Osterholm.
It does not follow a typical seasonal pattern associated with other respiratory viruses, like influenza, Hamer said.
“If you look at what happened in the Southern Hemisphere for their winter, our summer, they had a major increase in influenza, but very little COVID activity,” Osterholm said.
The current increases are most likely related to changes in behavior over the past few months, including summer travel and the abandonment of preventive measures such as masking.
Despite this summer being better than last year’s, the number of deaths remains steady, and seniors remain among the highest risk groups.
According to the Department of Public Health, in the last two weeks, the average age of patients who died from COVID-19 was 84.
Therefore, experts recommend people in high-risk groups pay attention to the uptick and continue to take precautions.
“If they’re going to be in public places with inadequate ventilation, in buses, trains, or in other public places like supermarkets, bars, restaurants, [wearing masks] is crucial,” Hamer said, “People should also consider getting a booster, especially if this small wave increases.”
Despite the slight uptick in hospitalizations, experts are not worried about any particular variant right now.
In general, said Hamer, it is getting harder to track variants, since there are fewer cases, fewer samples being submitted, and less sequencing being done.
“The only variant that jumped out to me was EG.5,” he said. A subvariant of Omicron, EG.5 accounted for an estimated 11 percent of cases nationwide between July 9 and July 22, according to the CDC. In New England, it accounted for a slightly higher share of cases: around 19 percent.
“It seems to have increased in the last month, but it certainly has not risen quickly enough to be a problem,” said Hamer.
Neither EG.5 nor other strains have been shown to be more infectious, said Osterholm.
“I don’t think, at this point, we can attribute what’s happening to any one variant type,” he said.