Influenza in Maine is now considered “widespread” by the federal Centers for Disease Control and Prevention, leaving only five states – New Hampshire, Louisiana, Florida, Oklahoma and Hawaii – with less severe outbreaks.

The CDC’s “widespread” designation means outbreaks of the illness are reported and confirmed by laboratory testing in at least half the state.

As recently as last week, Maine was one of a handful of states hanging on to their “sporadic” status, with just a small number of laboratory-confirmed influenza cases or a single outbreak reported. But in recent days, flu has hit hard in at least three nursing homes and a residential job training facility for young people, and has also accounted for more visits to doctors’ offices and hospitals.

Dora Mills, the state’s chief medical officer, said the increase in reported cases was predictable. Only two Maine deaths have been linked to the disease so far, she said, but other indicators have been pointing to a spread of cases, including increased school absenteeism, reports from doctors’ offices and health clinics, hospital emergency department visits and intensive care unit admissions for flulike symptoms.

At Eastern Maine Medical Center in Bangor, the emergency department has been swamped for two or three weeks, according to spokeswoman Suzanne Spruce.

“There are just a ton of people in the ED with flulike symptoms,” she said. Likely cases are tested with a throat swab, Spruce said.

Since most people are best treated with rest and fluids, hospitalization isn’t required except in severe cases. Health officials generally recommend keeping flu victims at home to limit the spread of the germs that cause the disease.

Although reported cases are beginning to drop off in some Western states, Mills is certain the season in Maine has not peaked yet.

“We can expect to see increases over the next several weeks,” she said in a phone interview Friday.

There is still time to get vaccinated against the flu, and even though this year’s vaccine is not a perfect match, health officials say it’s likely to provide some protection. Mills said the state will continue to receive small supplies of the scarce injectible form of the vaccine for the most at-risk individuals, including children between 6 and 23 months, adults 65 and over, anyone with a chronic disease and pregnant women past the first trimester.

Healthy, nonasthmatic people between 5 and 49 years old should get the nasal form of the vaccine, which is more readily available at doctors’ offices.

More information on flu activity, treatment and vaccine clinics can be obtained on the Web page of the Maine Bureau of Health, mainepublichealth.org.