‘We’re in trouble here’: What to make of the record coronavirus levels in Boston-area wastewater

"Our data also suggests that the level of infection now is equal to or higher than the first wave."

The MWRA's Deer Island Sewage Treatment Plant seen from Spectacle Island in Boston Harbor. Lane Turner / The Boston Globe, File

COVID-19 traces in the Boston area’s wastewater have risen to levels unseen before during the pandemic.

And unlike the recent record-high number of new infections in Massachusetts, it has nothing to do with increased testing levels.

The data released this week by the Massachusetts Water Resources Authority indicates that COVID-19 levels in Boston-area wastewater have surpassed even their peak high from the initial spring surge.

As part of a MWRA pilot study, the Boston-based wastewater epidemiology company Biobot Analytics has been collecting samples at the Deer Island  treatment plant to monitor for coronavirus RNA, which can serve as an early warning sign for the increased spread of the disease. Researchers have found that COVID-19 trends appear in wastewater samples four to 10 days earlier than reported infections.


According to Biobot data updated Friday, both the southern and northern system of the MWRA’s service area reported all-time high levels of COVID-19 in wastewater earlier this week. And while the southern system reported a slight downtick Thursday, the northern system, which includes Boston, continued to rise.

“Wake up,” Joseph Allen, a professor at Harvard’s T.H. Chan School of Public Health, tweeted Friday morning. “We’re in trouble here.”

The results come after Massachusetts set records late last week for the number of new COVID-19 infections reported in a single day. The state’s positive COVID-19 test rates, as well hospitalizations and deaths due to the disease, have also steadily increased, even if they remain well below their highest levels from the spring.

Gov. Charlie Baker has stressed that Massachusetts likely missed a significant portion of infections in the spring, due to the lack of testing available. While the state was averaging around 3,000 daily COVID-19 tests in the spring, health officials are now often conducting over 100,000 new tests a day.

Still, Newsha Ghaeli, the co-founder and president of Biobot Analytics, told that the wastewater data suggests that infection levels are now “equal to or higher than the first wave,” though she added other public health data should be taken into account.


“The MWRA wastewater data suggests that there is currently more virus circulating in the community than there was from June through October,” Ghaeli said in a statement Friday. “Our data also suggests that the level of infection now is equal to or higher than the first wave. The actual risk in the community should be evaluated in conjunction with other public health information (e.g. clinical case numbers, age structure of infected individuals, hospital capacity).”

Earlier this week, Baker announced a partial rollback of the state’s reopening process, along with several new restrictions, in response to the increase in cases and hospitalizations.


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