In this Oct. 21, 2020, file photo, pedestrians wear masks while walking along Main Street in Belfast. Credit: Linda Coan O'Kresik / BDN

The Maine counties subjected to new mask recommendations could change on a near-daily basis, as the state’s relatively low case numbers and small population make it easy for counties to slip above or below the threshold set by health officials.

The U.S. Centers for Disease Control and Prevention said Tuesday that it was recommending all people wear face coverings indoors, regardless of vaccination status, in counties with significant transmission of the virus, defined as 50 weekly cases per 100,000 people. Gov. Janet Mills announced the following day that Maine would adopt that guidance.

The new recommendations come as infections and hospitalizations have continued to rise across Maine. The Maine Center for Disease Control and Prevention reported 120 new cases Thursday, the highest single-day total since May. Forty patients were hospitalized statewide as of Thursday, up from 25 a week ago.

Conditions in Maine still remain better than most of the nation. Roughly two-thirds of counties nationwide qualify as having “substantial” or “high transmission” as of Thursday, according to the U.S. CDC, compared with only one county here. But the counties fitting that label keep changing.

When the U.S. CDC announced the guidance on Tuesday, York and Piscataquis counties were over the case threshold. By Wednesday, both dropped under that rate while Waldo County had swung over, according to a chart on the agency’s website. On Thursday, virus numbers in Somerset County also exceeded the threshold, a Bangor Daily News analysis suggested.

But the U.S. CDC had not updated its map as of the late afternoon and Maine’s COVID-19 website only listed Waldo among the affected counties. That site will be updated daily to indicate in which counties masks are recommended based on U.S. CDC designations, Maine CDC spokesperson Robert Long said Thursday.

The problem of counties swinging above and below the threshold is somewhat unique to Maine given the state’s comparatively low COVID-19 case rate. Many counties in the southern and western U.S. have infection rates two or three times higher than any Maine county and are unlikely to come back down below the 50 cases per 100,000 threshold in the next few weeks.

The fluctuations are also more likely in counties with fewer people. They could be especially felt in Piscataquis County, which has a population of a bit under 17,000, according to U.S. Census data. That means the county will go over the U.S. CDC’s threshold if it sees nine or more cases in the span of seven days.

While saying he did not want to downplay the virus and encouraging people to get vaccinated like he has, Sen. Paul Davis, R-Sangerville, whose district includes all of Piscataquis County, said Mills should have stayed the course after the spring end of a mask mandate and other restrictions.

“I think it’s getting confusing and draining for people and we just need to move on,” Davis said.

Unlike earlier in the pandemic, counties over the threshold are only subject to a recommendation, not a requirement. That means businesses can do what they think is best regardless of how their county is designated, said Greg Dugal, director of government affairs for HospitalityMaine.

“If you think it’s important to mask, then you should just do it,” Dugal said. “It’s a business decision.”

Some Waldo County businesses signaled they would ask customers to use masks beginning Thursday, aligning with businesses in Piscataquis and York counties earlier this week that indicated they would follow the recommendations. The Colonial Theater in Belfast, which reopened in June after a 15-month pandemic hiatus, said patrons would now be asked to wear masks when not eating or drinking.

Health officials are still encouraging people to get vaccinated to protect themselves against the virus and slow its spread. Maine — which has the fifth-highest vaccination rate of any U.S. state — has seen an increase in the number of daily vaccinations administered over the past week, Long said.

“Vaccinations are the best and most effective path to fully emerge from the pandemic,” he said.

BDN writer Michael Shepherd contributed to this report.