By CBSBoston.com Staff

BOSTON (CBS) – Wastewater testing in Massachusetts shows an increase in the presence of COVID, which could predict a possible surge of cases in the state.

Medical experts have been tracking wastewater data throughout the pandemic to get a better idea of how prevalent COVID really is in the community.

The latest numbers are up to levels we haven’t seen since late January, based on test results from a Massachusetts Water Resources Authority pilot study.

Samples are taken at the Deer Island Treatment Plant three times a week. The wastewater tested flows in from 43 communities around Boston. Testing detects the virus from people who have symptoms and from people who don’t.

“It begins to go up a little bit before because people start shedding the virus through their bodily secretions prior to getting symptoms and prior to getting diagnosed,” said Dr. Paul Sax, professor of medicine at Brigham and Women’s and Harvard Medical School. “So it’s a pretty good predictor of what we’re going to see in the coming days to weeks by just monitoring these wastewater concentrations.”

Though Sax wouldn’t be surprised by an increase in COVID cases in the coming weeks, he also said Massachusetts is in a much better position than it was during the previous surge.

“The vaccine is doing its job in preventing severe disease and preventing deaths. I think that’s key,” Sax said. “The other thing to remember is a lot of the cases we’re seeing now are pediatric cases. Many of the people who are getting COVID this year are children and teenagers. And the vaccination rate among even those who are eligible for the vaccine is much, much lower than adults.”

Sax recommends people don’t let their guard down, and continue to do things such as wearing masks.

“If you’re going shopping, to a concert, a place that’s public, using public transportation or flying, I know some people have stopped doing that. But I actually strongly recommend it. It protects you and protects others. People can have COVID without much symptoms at all,” Sax said.

On Saturday, a woman in her 20s from Middlesex County became the first case of the Omicron variant confirmed in Massachusetts. The variant has now been detected in 17 states.

There was increased demand for vaccines and booster shots across Massachusetts over the weekend.

In Boston, Mayor Michelle Wu plans to name the members of a new COVID advisory committee on Monday. The group will be tasked with helping guide the city’s response to any new developments in the pandemic.

CBSBoston.com Staff