Mass. case numbers, coronavirus levels in waste water tick up from low levels

Two key COVID-19 measures in Massachusetts are edging higher, as experts and officials warily eye the arrival in the United States of the more-contagious BA.2 Omicron subvariant, hoping it will cause a bump in cases — not a major surge.

Coronavirus levels detected in Eastern Massachusetts waste water are ticking up slightly after bottoming out around the beginning of the month, according to data from the Massachusetts Water Resources Authority. Confirmed reported COVID-19 cases have also been ticking up for about the past two weeks, according to Massachusetts Department of Public Health data.

Both metrics, however, are still only a tiny fraction of what they were during the peak of the Omicron surge early this year.

Experts and officials are concerned because of a recent wave of COVID-19 cases in some countries in Europe, which in the past has provided a preview of pandemic trends in America. The resurgence in Europe has been blamed on factors including the loosening of pandemic restrictions and the arrival of the more-infectious BA.2 variant.

Those two factors also apply in the United States. (BA.2 now accounts for more than 72 percent of cases in New England.) But experts have also suggested there might be key differences between the European and US situations. One difference they cite is the greater proportion of people here who have already been infected by Omicron and developed some immunity to BA.2.

Another difference: BA.2 is arriving a little bit later here, at a time of year that seems less favorable to the virus. “I think that one of the things that might help us as we’re going into this next surge is that we’re entering the spring, which seems to be sort of a low time of circulation for SARS-CoV-2 across the US,” Stephen Kissler, a research fellow in the Department of Immunology and Infectious Diseases at Harvard T.H. Chan School of Public Health, said last week in a media briefing.

A number of experts have said case increases are possible here, but they don’t expect another major surge. Dr. Anthony Fauci, the nation’s top infectious disease expert and an adviser to President Biden, told The Washington Post last week he wouldn’t be surprised if there were “somewhat of an uptick.” But, he said, “I don’t really see, unless something changes dramatically, that there would be a major surge.”

Matthew Fox, a professor of epidemiology and global health at the Boston University School of Public Health, said Tuesday he was hopeful a major surge was not ahead, noting that immunity from previous infections “should blunt this wave.”

“We should be concerned but not overly concerned,” he said in an e-mail. “If cases rise sharply, we should be prepared to mask for the duration of the wave and perhaps cut back on some higher risk events (indoor dining, large crowds) but I’m hopeful that we won’t need much more than that.”

Andrew Lover, an assistant professor of epidemiology in the School of Public Health and Health Sciences at UMass Amherst, said, “There’s a very good chance we’ll see at least a moderate wave.” He predicted “something reasonably noticeable in terms of an uptick in cases and hospitalizations” and said for the next couple of weeks he would be watching the MWRA data closely.

The surge could fizzle and “we might get lucky and we certainly hope that will be the case,” he said. But he said, “We should prepare for things and be pleasantly surprised if it doesn’t turn out that way.”

A spokeswoman for the state Executive Office of Health and Human Services said in an e-mail that the state was working with the health care community and the federal government “to monitor all of the latest developments.” She emphasized that Massachusetts is a national leader in vaccination rates and said people had “ready access to vaccines, rapid tests, and therapeutics.”

Waste water from 43 communities, including Boston, the state’s largest city, converges at MWRA’s Deer Island plant on Boston Harbor for treatment before being piped miles into the ocean. The water is tested for traces of the deadly coronavirus. The MWRA reports numbers for both the southern and northern regions of its system.

The testing determines the number of SARS-CoV-2 RNA copies per milliliter of waste water. For the southern MWRA region, the seven-day average was 147 copies/mL as of Friday. That’s up from a low of 92 copies/mL on March 1. But it’s a far cry from the high of 11,446 RNA copies/mL reached on Jan. 3.

In the northern region, the seven-day average was 173 RNA copies/mL as of Friday, up from 101 on March 9. But it also was a far cry from the peak of 8,644 on Jan. 5.

The seven-day average of confirmed reported cases in Massachusetts rose to 925 per day on Monday, according to the DPH. The number had bottomed out after the Omicron surge at 604 on March 16. By contrast, at the beginning of the year, the numbers had reached more than 22,000 per day.

State officials say residents should get fully vaccinated and boosted to protect themselves from the virus, get tested if they need it, and if they get a positive result, talk to their doctor right away about COVID-19 treatments available for individuals who have mild to moderate symptoms.