While the majority of the country is no longer being advised to wear masks indoors, most Maine residents should keep wearing masks when they step inside businesses and public spaces, according to new guidance announced by the U.S. Centers for Disease Control and Prevention on Friday.

Thirteen of Maine’s 16 counties are considered to have high potential for health care system strain and residents of those counties are still advised to wear masks indoors, the CDC said. Those counties are home to about 84 percent of the state’s residents based on the latest available census data.

Three counties – Kennebec, Waldo and Somerset – have been reclassified as having medium potential for strain on hospitals. That means masks are now recommended for certain at-risk groups but considered a personal choice for most people, according to the U.S. CDC.

The new guidelines released Friday take into account hospitalizations and hospital capacity for the first time, in addition to transmission rates.

“As the virus continues to circulate in our communities, we must focus our metrics beyond just cases in the community and direct our efforts toward protecting people at high risk for severe illness and preventing COVID-19 from overwhelming our hospitals and our health care system,” CDC Director Rochelle Walensky said.

The CDC said the new guidelines are based on how many people are hospitalized with COVID-19, how much capacity hospitals have for more patients and the current caseloads in each county. The classifications used to be based on two measures: the rate of new COVID-19 cases and the percentage of positive test results over the previous week.

It was not clear Friday what factors caused some Maine counties to be reclassified while others were not, or why most of Maine remains in the high risk category, unlike much of the country. Hospitalizations have declined rapidly in Maine, as they have in the rest of the nation.

“I have directed the Maine CDC to review this new federal guidance in order to inform Maine’s own recommendations as we enter a brighter, more hopeful period and take additional steps towards normalcy,” Gov. Janet Mills said in a statement Friday night.

Maine has had an artificially high count of new cases in recent weeks because the Maine CDC was clearing a massive backlog of positive tests that overwhelmed the agency during the peak of the omicron wave in January. It was not clear if the backlogged cases influenced the new classifications.

The Maine CDC, which has generally updated state guidelines in response to federal recommendations, did not respond to questions about the changes Friday.

SWITCH IN CRITERIA PRAISED

Dr. Dora Anne Mills, the chief health improvement officer for the MaineHealth hospital network and a former head of the Maine CDC, said the decision by federal health officials to include COVID-related hospitalizations as part of the formula is a wise one.

Mills, the governor’s sister, said relying only on positive test results would miss a lot of data, in large part because many people are using home test kits and those results aren’t reported to public health authorities.

Now, she said, the federal CDC is also looking at COVID-19 hospitalizations and monitoring how many people are admitted to hospitals for treatment of the disease, as well as those who test positive for COVID-19 while at a hospital for other treatment.

“It makes a lot of sense,” she said.

Mills said that when a patient is admitted for COVID-19 or is determined to have it after admission, the case is connected to the county where they live. In other words, if a patient from Sagadahoc County is found to have COVID-19 while at Maine Medical Center in Cumberland County, it’s counted as a Sagadahoc County case.

She said the combination of positive test results and hospitalizations “act as a barometer” of how prevalent COVID-19 is in a given community and how much pressure that community is placing on the health care system. “It’s not perfect, but it’s pretty good.”

Mills also said the state’s COVID-19 counts are high right now because officials are catching up on a backlog of positive test results, which may be reflected in the federal guidance because case counts are still one factor.

Mills cautioned that even in places where the CDC is dropping its indoor masking recommendations, the agency is still suggesting that older people and those with underlying health conditions should wear masks indoors.

“Throughout Maine, many people are at risk and should be careful. It’s a recommendation and, obviously, people can do what they want,” she said. “I’m going to continue to mask indoors. I’m used to it, it doesn’t bother me and I don’t want to get it. I’m going to continue to wear one until the rates come down significantly.”

Meanwhile, hospitalizations continue to decline as the omicron wave subsides in Maine.

The statewide number of hospital inpatients with COVID-19 dropped to 181 on Friday, a 58 percent decline from the peak of 436 on Jan. 13. Thursday was the first day in four months that the number of inpatients statewide had dropped below 200.

The number of patients in intensive care on Friday dropped to 39, the fewest since mid-August, when the delta variant was taking hold in Maine. Statewide, 14 patients were on ventilators Friday.

GUARD DEPLOYMENT ENDS

With pressures easing on Maine hospitals, the deployment of nearly 200 Maine Army National Guard members came to an end on Friday. The Guard members had been activated in December and January to provide staff support as the omicron surge pushed the limits of hospital capacity.

The governor issued a statement thanking the Guard and its members for stepping up. “We are immensely grateful for all that you have done and for the sacrifice of your families and your employers,” she said.

Meanwhile, the death toll of the pandemic in Maine has continued to rise, partly because of deaths that occurred in past weeks and were later identified as COVID-related through periodic vital records reviews. The total number of Maine lives lost during the pandemic is now 2,042, according to Maine CDC statistics.

The state on Friday also added 1,205 confirmed or probable cases of COVID-19, bringing the pandemic total to 225,253.

Those cases do not reflect current conditions because Maine officials have been working to clear the backlog of unprocessed positive COVID-19 tests that reached nearly 60,000 at the peak of the omicron wave.

The state’s shift to a partially automated process for screening tests, together with a dramatic drop in the number of new tests submitted each day, have allowed CDC staff to catch up on several weeks’ worth of cases that had not made it into the state’s official count. State officials have said they hope to have all the old tests processed by the end of this week.

Staff Writer Edward Murphy contributed to this article.