Baystate Health, which operates Baystate Medical Center in Springfield and two other hospitals in western Massachusetts, announced it was changing its visitor policy. The hospitals will no longer allow visitors younger than 14 and are recommending no more than two people visit a patient at once.
"This is the worst in several years," said Dr. Sarah Haessler, an infectious disease specialist at Baystate. She said the flu outbreak has strained the hospital's resources and helped to fill its beds to capacity.
City, state and federal officials have all identified a Type A influenza known as H3N2 as the predominant strain reported so far this season. The strain, historically associated with more serious illnesses, is among those covered by the current vaccine.
"No vaccine is 100 percent effective," cautioned Kevin Cranston, head of the state bureau of infectious diseases. Some people, for example, might be vaccinated but get the flu in the 10 days to two weeks it takes for the immunity to take hold.
"There are any number of reasons why people could have done all the right things and still get the flu," he said.
High flu rates were being reported all over Massachusetts, Cranston said, and while he didn't have specifics on the 18 statewide deaths, he noted that the flu is most dangerous for the young, the elderly and people with other chronic health conditions.
"I hate needles, and I got (a shot)," Gov. Deval Patrick said Wednesday, adding that he wasn't aware of any shortages of vaccine in the state. He also reminded residents to use common sense, such as washing their hands and sneezing into their sleeves.
The CDC said 18 children have died from the flu so far this season. While the CDC doesn't keep a tab of deaths overall from the flu, it estimates that 24,000 Americans die each year.
Associated Press writer Rodrique Ngowi in Boston contributed to this report.