Researchers in Maine have detected the first cases of a new omicron variant that is being monitored around the world and appears to be more contagious than the version that swept through the state and the rest of the country during the past three months.

Based on experience in other parts of the world, however, the new version of the virus is not expected to drive another surge of cases in Maine.

Testing wastewater finds “people who are symptomatic as well as asymptomatic, people who are tested and not tested,” says Dr. Yolanda Brooks, assistant professor of biology at St. Joseph’s College in Standish. Shawn Patrick Ouellette/Staff Photographer

And data being collected in Maine from wastewater testing continues to show a dramatic decline in coronavirus levels.

Two cases of the omicron BA.2 variant were detected by Jackson Laboratory researchers who monitor for virus mutations in Maine, Dr. Nirav Shah, director of the Maine Center for Disease Control and Prevention, said in a Twitter post Monday.

“It is one of the ‘sub-lineages’ of the Omicron family of #COVID19 viruses. Early data suggest that BA.2 is more contagious than the current #Omicron lineage in the US, BA.1,” Shah posted.

Scientists are still studying the new variant, but immunity – whether through previous infection or vaccination – still appears to protect against the virus, based on preliminary data.

Even though the new version is spreading in many parts of the world, Shah posted, “there is a reported decline in overall cases globally.”

“What does this mean for you? First, getting #vaccinated and boosted remains among the best strategies to stay safe,” Shah wrote. “If you test positive, the same guidance applies: stay home, and reach out to a health care provider about possible treatments.”

Meanwhile, wastewater testing data released Monday shows levels of the coronavirus that causes COVID-19 continuing to decline in most cities and towns participating in the testing, according to data published by the state.

Some cities are showing a steep dropoff in virus prevalence since the omicron wave hit in December. At Portland Water District’s Westbrook plant, for instance, virus levels have plummeted by more than 98 percent since late December and early January, and at the East End plant in Portland, levels have declined by 97 percent. Bangor, Augusta and Lewiston-Auburn have also experienced sharp declines since early February, when those cities and several others in Maine began wastewater testing for the virus.

Wastewater testing gives real-time, accurate data, scientists say, and is not subject to issues that arise in counting cases, such as the proliferation of at-home tests, and in Maine’s case a substantial backlog that is skewing results. The backlog at one point had reached nearly 60,000 cases, and as Maine worked through it, case counts often included illnesses that occurred weeks or even months beforehand.

The Maine CDC does not report new case counts on Mondays because it does not process tests over the weekend, so the next release of case count data will be Tuesday.

COVID hospitalizations remained unchanged Monday, with 168 patients, the same as Sunday. The number of COVID-19 patients in ICU ticked down from 40 on Sunday to 39 on Monday.

The U.S. CDC changed its indoor mask recommendations Friday. Under the new guidelines, indoor masking is recommended to be optional for 70 percent of the country, including in schools. Most of Maine is still designated high risk, and masks are still recommended indoors in 13 of the state’s 16 counties.

The new federal formula behind the updated mask recommendations is partly based on the number of new cases. And Maine’s case counts have been artificially high since Feb. 15 because of the backlog of tests.

As a result, the Maine case count data that the Maine CDC sends to the U.S. CDC – which is then used to inform decisions on school masking in individual counties – does not accurately reflect current trends that show pandemic conditions improving. Other metrics used by the U.S. CDC, such as new hospital admissions and number of staffed inpatient beds available, are up-to-date in Maine.

The Maine CDC did not answer questions Friday or Monday about whether the case backlog and inflated case numbers are why most of Maine is still considered high risk.

The backlog is still at about 5,000 positive tests, Robert Long, Maine CDC spokesman, said in an email response to questions Monday. He said the Maine CDC “is reviewing the revised federal guidelines,” especially as they relate to masking recommendations for schools.

“As has been the case with previous revisions to the (standard operating procedures) for Maine schools, input from school leaders and public health best practices will factor into any upcoming revisions,” Long said.

Long has said that deaths, hospitalizations and wastewater data are the best ways to measure current pandemic trends.