If you’ve been meaning to get a flu shot but haven’t gotten around to it yet, don’t wait any longer.

That’s the advice coming from the region’s three local hospitals, which have all been hit in recent weeks by an influx of patients with flu symptoms. Flu season is peaking a few weeks earlier than normal across Connecticut and in 30 other states, according to the Centers for Disease Control, and may have caught many people off guard because it comes after last year’s unusually mild flu season.

On Wednesday, Lawrence & Memorial Hospital in New London imposed visitor restrictions in response to the uptick in flu cases, joining The William W. Backus Hospital in Norwich and The Westerly Hospital, which imposed the restrictions last month.

“We’re seeing a lot of cases for this early in the season,” said Russell Melmed, epidemiologist with the Ledge Light Health District, which provides public health services to New London, Groton, Ledyard, Waterford and East Lyme. “It’s never too late to be vaccinated, and this year’s vaccine is a good match for the main flu strain circulating.”

Statewide, there have been 606 confirmed flu cases this season, the state Department of Public Health said, but many more people are likely to have been sickened with the virus but not tested. About 8 percent of emergency room visits over the past six weeks were attributed to the flu, and about 6 percent of hospitalizations, the health department said.

Dr. Laura Rau, assistant director of L&M’s emergency department, said that all of the 56 confirmed flu cases treated at the hospital have been the predominant H3N2 strain, and none have been the H1N1 “swine flu” strain that caused the 2009 epidemic. According to the CDC, 37 percent of the cases reported nationwide thus far this year are H1N1.

Rau said flu patients coming to the hospital are showing typical symptoms including respiratory complaints, fever, cough, sore throat, sweats and body aches, and most of those experiencing the worst symptoms are elderly. She also noted there has been an influx of patients with other illnesses also causing respiratory or gastrointestinal problems. Thus far, 17 people have been hospitalized at L&M because of the flu, 12 of whom are still there, hospital spokesman Mike O’Farrell said.

Most people who become ill with the flu do not need to seek care at the hospital, Dr. Rau said, but can recover at home with a few days of rest. She advised anyone who feels the need to be seen by a doctor to first try their primary care physician before coming to the emergency room.

People should go to their doctor or the emergency room, she said, if their symptoms worsen after a few days or if they have difficulty breathing or underlying health conditions.

According to the CDC, the antiviral medications Tamiflu and Relenza are effective against the H3N2 strain.

At Backus, 19 people have been hospitalized for the flu over the last few weeks, and there have been 148 confirmed cases, spokesman Shawn Mawhiney said.

“Our ERs are very busy,” he said, referring to the both the main hospital and the Plainfield emergency departments.

Visitor restrictions, which were imposed on Dec. 14, remain in effect, he added. Restrictions include a ban on visits by anyone age 18 and younger, and a request that anyone with cough, sore throat or other symptoms refrain from visiting.

“We’re trying to be proactive,” Mawhiney said.

Westerly Hospital has had 16 confirmed flu cases and four hospitalizations for flu in the last four days, said spokesman Nick Stahl. Like Backus, it is asking people with any flu-like symptoms not to visit patients.

At L&M, the restrictions include no visitors 18 and younger; no one with fever, cough or other flu-like symptoms; and no visitors other than immediate family or caregivers. No more than two adult visitors will be allowed at once.

“Our focus is on patient safety,” Dr. Joseph Gadbaw, chairman of the department of medicine, said in a news release. “These restrictions are part of our infection prevention plan to prevent the spread of influenza at L&M.”

Visitors are also urged to wash hands when entering and leaving the hospital and outpatient facilities.

To prevent getting and spreading the flu, Melmed also advised frequent hand washing, keeping hands away from the face, and staying home from work or school when feeling sick.

“This year’s flu could cause a more severe type of illness, and the early start could mean a longer flu season this year,” he said.

j.benson@theday.com