Health officials in Maine are bracing for a bad flu season, after a relatively mild one last year.

“We’ve seen a fair number of cases already,” said Dr. Stephen Sears, the state epidemiologist, with about 30 to 40 confirmed statewide.

Sears said it’s not unusual for a severe flu season to follow a mild one, largely because any immunity that people have from previous exposure to a particular strain of the virus fades if the strain doesn’t circulate widely for a few years.

“Influenza acts like this – we have a year when it’s not so active and then it comes back with more or less a roar,” he said.

The flu has already shown up this season in four or five counties in Maine, including Aroostook County in far northern Maine and Cumberland County in the south, so the geographic spread is wide, Sears said.

Although most flu cases are confirmed by rapid tests in doctor’s offices or clinics – and don’t have to be reported to the Maine Center for Disease Control and Prevention – state health officials have confirmed cases this year by taking cultures, Sears said.

The CDC already has taken as many cultures as it did all of last winter, he said.

Caroline Teschke, program manager for clinic services at Portland’s India Street clinic, said the early arrival of the flu in Maine is worrisome because the flu usually shows up much later in the winter, often not peaking before March.

Sears and Teschke said this year’s predominant flu strain, known as H3N2, is not particularly deadly, like the bird flu that many officials feared might become a pandemic about five years ago.

But Teschke noted that the flu and related complications kill an average of 24,000 Americans every year, so every season carries risks.

The flu can be particularly hard on the very young and the very old, and people whose health is otherwise compromised, she said. Even people who are healthy can expect to be out of action for at least a week if they get the flu.

“The disease is not trivial,” she said.

Typical symptoms are high fever, chills, nausea, vomiting and diarrhea, as well as “this complete lack of energy” that often lasts days after other symptoms have faded, Teschke said.

“You feel like you can’t lift your head off the pillow,” she said.

Sears and Teschke said people should take precautions, such as making sure they cover their coughs and sneezes and wash their hands frequently. The most important step, they said, is getting a flu shot.

“Anyone who’s really had influenza can’t wait to get the vaccine,” Teschke said. “It’s preventable and it’s something not just for your own health, but it affects the common good, too.”

Any time is a good time to get a flu shot, Sears said, and it might be even more important to get one now because the vaccine takes 10 days to two weeks to become fully effective.

That means a shot now can guard against the flu during the holiday season, when large numbers of people gather, including some who may have picked up the virus.

He said it’s also a good precaution for people who plan to travel during the holidays and might be going someplace where influenza is widespread.

Teschke said federal experts appear to have targeted the right strain of flu virus this year, and vaccine is now plentiful.

In past years, she said, strains that scientists didn’t anticipate have appeared, forcing manufacturers to quickly produce different vaccines and causing occasional shortages.

Most doctor’s offices and many drugstores offer flu shots, Sears said. Teschke said the India Street clinic will offer shots by appointment and, if staffing levels can be increased, on a walk-in basis after Jan. 1.

The clinic charges $10 for a shot, she said, but won’t turn away anyone because of an inability to pay.

Staff Writer Edward D. Murphy can be contacted at 791-6465 or at:

emurphy@pressherald.com