Boston-Area Omicron Surge Continues To Decline, Sewage Says

BOSTON — Coronavirus in the Boston-area wastewater continued its decline through Tuesday, according to the latest data published by Cambridge-based epidemiology firm Biobot Analytics.

While the amount of viral RNA in Deer Island Treatment Plant sewage remains more than double the pre-omicron maximum, it seems to have peaked from Jan. 3-5 and begun to fall as quickly as it rose. The fall continued in a new sample taken Tuesday, according to Biobot data.

The plant serves 43 communities in greater Boston. Samples of wastewater are taken three to seven times a week, according to the Massachusetts Water Resources Authority.

The samples are split between the authority's "North System" and "South System," which each contain part of Boston and surrounding communities. A map of the North and South systems is available here.

According to the Centers for Disease Control and Prevention, the wastewater metric "can provide information on changes in total SARS-CoV-2 (COVID-19) infection in the community contributing to that wastewater treatment plant." In other words, an increased presence of COVID-19 in wastewater from showers, sinks and toilets can indicate an increased infection rate in the communities where the wastewater comes from.

"Every time an infected person uses the toilet, they're flushing this information down the toilet, where it's collecting and aggregating and mixing with poop from thousands of other people," Newsha Ghaeli, a co-founder and president of Biobot Analytics, told NBC News.

The wastewater data matches with expert models, which expect coronavirus cases to peak in Massachusetts within two weeks, the Boston Globe reported. High numbers of hospitalizations and deaths are likely to continue for several more weeks.