Wojciech Cwik, an operator at the Waste Water Treatment Plant on Lincoln Street in Lewiston, takes a sample Feb. 11 of wastewater he collected and puts it into a container in the plant’s lab. Each morning the plant takes a sample from both Lewiston and Auburn’s wastewater and sends it to the Maine Center for Disease Control & Prevention. Russ Dillingham/Sun Journal file

LEWISTON — Levels of coronavirus found in wastewater in more than a dozen public systems in Maine — including Lewiston and Auburn — are higher than those found in 90% of public systems tested across the country over the past six weeks, according to state data.

The Maine Center for Disease Control & Prevention is reporting that levels of concentration of coronavirus found in municipal sewer systems in Maine and Vermont are higher than in any other states.

Maine CDC data shows that 13 of the 16 water/sewer districts conducting coronavirus testing in Maine are higher than the 90th percentile for the country, including larger and smaller cities and towns,  Maine Health Chief Health Improvement Office and former Maine CDC Director Dr. Dora Anne Mills said Monday.

The Lewiston/Auburn district reported in the 93rd percentile over the weekend, Mills said. Seven Maine water/sewer districts in Maine showed higher levels of concentration, she said.

Those levels are early indicators of rates of incidence of the coronavirus, Mills said. Those levels are likely to show up later in coronavirus testing data.

But so-called positivity rates gleaned from coronavirus tests (the ratio of positive tests out of all of those who are tested) conducted at medical facilities and other public venues often don’t capture the total population that tests positive for the novel coronavirus, including those who use home tests and those who are infected, but don’t test at all, she said.

Although the levels of coronavirus detected recently in wastewater are lower than they were in later January, Mills said, it’s notable that most of the 16 water/sewer districts that test for coronvirus showed a recent spike compared to the past couple of months and compared to other states in the country.

Wojciech Cwik, an operator at the Waste Water Treatment Plant on Lincoln Street in Lewiston, takes a sample Feb. 11 of wastewater he collected and puts it into a container in the plant’s lab. Each morning the plant takes a sample from both Lewiston and Auburn’s wastewater and sends it to the Maine Center for Disease Control & Prevention. Russ Dillingham/Sun Journal file

Mills said they have “skyrocketed” in the past two weeks.

The numbers of cases and test positivity rates are generally rising in New England, she said, and hospitalizations have seen a slight increase or remained steady.

Although wastewater levels in other parts of New England have seen a recent rise, including in Massachusetts and New Hampshire, they haven’t risen to the same degree as those in Maine, she said.

The reason for the rise, Mills said, is the high transmissibility of the omicron BA.2 subvariant of coronavirus, Mills said.

“With a very highly contagious virus which shows significant airborne and respiratory droplet transmission, with a significant amount of immune evasion, we can expect to see continued increases in pandemic activity,” Mills wrote in a Sunday Facebook post.

“The good news is with relatively high vaccination rates in New England and a high percentage of people who contracted omicron this winter, the hope is we have a sufficient immune wall to prevent a large surge in hospitalizations,” she wrote.

In response to the high levels of the virus found in Maine’s wastewater, Mills recommended people 50 and older and people with an immunocompromising condition get a second booster shot.

She said people should continue to wear (N95, KN95 or KF94) masks in certain situations, including crowded indoor settings where others whose vaccination status is unknown, there are poorly ventilated areas, and for long periods.

Ventilating an indoor area and socially distancing are advised.

Mills recommended keeping a ready supply of home test kits for testing when experiencing symptoms or when entertaining guests or going to someone’s home. Those who test negative at home, but suspect they have been exposed to COVID-19 or whyou are at high risk medically, you should follow up with a PCR test, she said

She also recommended that people who might be at high risk of severe COVID-19 seek early out-patient medical intervention.

“The earlier you start treatment, the more effective it is,” Mills said.