Influenza cases in Maine declined last week for the first time since the 2022-23 flu season began in mid-October, according to data posted Tuesday by the Maine Center for Disease Control and Prevention.

The number of patients hospitalized with flu also has dropped, and hospitals are reporting that another respiratory virus – RSV – is also on the decline after a prolonged surge.

“It may be we are starting to head into a downward swing,” said Dr. Dora Anne Mills, chief health improvement officer for MaineHealth, the parent organization of Maine Medical Center in Portland and seven other Maine hospitals.

The rise of influenza and RSV, or respiratory syncytial virus, combined with a potential resurgence of  COVID-19, have for weeks fueled concern in Maine and nationally that hospitals could be stretched to capacity or beyond this winter.

There were 139 COVID patients hospitalized in Maine on Tuesday and that number has been relatively flat for several weeks. Flu-related hospitalizations fell to 87 statewide for the week ending Dec. 24, down from 133 the previous week.

Maine reported 2,881 new cases of influenza for the week ending Dec. 24, down from 3,275 the previous week, a 12% decrease.

However, last week’s case count in Maine was much higher than a month ago – there were 1,720 cases reported the week ending Dec. 3. The U.S. CDC still lists Maine in the “very high” category for flu activity, and large numbers of cases are being reported nationally.

Flu season typically extends beyond February and Mills warned that case counts could still fluctuate for the next few weeks. Indoor holiday gatherings typically increase the spread of respiratory viruses, leading to spikes in new infections afterward.

But flu cases have also started to decline in other states, a pattern that often occurs during the flu season as more people gain immunity from infection, vaccination or both. Cases have started to decline in New York, Delaware, Georgia, Alabama and other states.

Confirmed flu and COVID-19 cases don’t include other seasonal viruses that cause illness but aren’t officially diagnosed.

Hospital officials said RSV hospitalizations also appear to have dropped in recent weeks, although there is no official tracking system for RSV. RSV primarily affects infants and Maine hospitals were straining with pediatric cases in November and early this month before conditions eased.

“RSV comes in waves, and this time it came through in a big wave like a brush fire, and now it’s burning out,” Mills said. There is no vaccine for RSV, although scientists hope one will become available in a few years.

Patricia Patterson King, spokeswoman for Northern Light Health, the parent of Eastern Maine Medical Center in Bangor and Mercy Hospital in Portland, said hospital “admission rates for both RSV and flu are down, but positivity rates continue to be relatively high for both.” A high positivity rate – the percentage of tests that come back positive – indicates a virus is still actively spreading.

With COVID-19 restrictions in place the past two winters, viruses that cause influenza, RSV and other illnesses did not circulate as easily and case counts were much lower. But with people no longer wearing masks and back to gathering indoors in large numbers, respiratory disease cases spiked early this season.

Public health experts say the flu surge could have been worse. This year’s flu vaccine appears to be a good match for influenza A H3N2, the predominant strain circulating, public health experts say.

Public health advocates are recommending flu vaccinations as well as all available vaccines against COVID-19, including a booster shot that protects against the omicron strain circulating now. Like this year’s flu shot, the COVID-19 vaccines also are considered very effective.

Mills also recommends maintaining good hygiene, including frequent hand-washing, staying home when not feeling well, and she said people should consider masking, especially in crowded, indoor spaces.