BOSTON: Surging influenza infections has led Boston to declare a public health emergency Wednesday. Massachusetts has reported 18 flu-related deaths so far.
The city is working with health care centers to offer free flu vaccines and also hopes to set up places where people can get vaccinated. The city said there had been four flu-related deaths, all elderly residents, since the unofficial start of the flu season on Oct. 1.
Boston Mayor Thomas Menino said there had been about 700 confirmed cases of the flu in Boston so far this season, compared with 70 all of last season.
Massachusetts was one of 29 states reporting high levels of "influenza-like illness," according to the most recent weekly flu advisory issued by the Centers for Disease Control and Prevention that counted infections from the week of December 23 through 29.
The CDC said the proportion of people visiting health care providers with flu-like symptoms climbed from 2.8 percent to 5.6 percent in four weeks. By contrast, the rate peaked at only 2.2 percent during the relatively mild 2011-2012 flu season.
The estimated rate of flu-related hospitalizations in the U.S. was 8.1 per 100,000 people, which is high for this time of year, according to Dr. Joe Bresee, chief of the epidemiology and prevention branch of the CDC's influenza division. The agency's next advisory will be issued Friday.
"This is the worst flu season we've seen since 2009, and people should take the threat of flu seriously," Menino said in a statement. "This is not only a health concern, but also an economic concern for families, and I'm urging residents to get vaccinated if they haven't already."
Menino also urged people to stay home from work or school if they are sick.
Frederica Williams, president of the Whittier Street Health Center in Boston's inner-city Roxbury neighborhood, said her facility had opened a special flu clinic and was using social media and sending letters to residents urging them to come in and get flu shots.
"We serve a vulnerable population that is at risk for all kinds of health issues, so we put out a broadcast to our patients even before the mayor made the (emergency) announcement because we saw an increase in the number of people coming to our clinic for services."
Williams estimates that the number of patients who have come to the clinic seeking treatment for flu-like symptoms is triple that of the same time a year later.
Hospitals around the state were also taking precautions to protect patients and staff from exposure to the flu.
Baystate Health, which operates Baystate Medical Center in Springfield and two other hospitals in western Massachusetts, announced Wednesday that 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 one time.
"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.
Nationally, health officials have been urging people to get flu shots while cautioning that vaccines will not guarantee prevention of all illnesses. But 91 percent of the flu viruses that have been analyzed by the CDC were include in the 2012-2013 influenza vaccine.
"I hate needles, and I got (a shot)," Gov. Deval Patrick said Wednesday, adding that he was not 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.
Flu influx causes Chicago hospitals to turn away patients
Scientists use weather to forecast flu season
As of last Friday's report, the CDC said 18 children had died from the flu so far this season. While the CDC does not keep a tab of deaths overall from the flu, it estimates that 24,000 Americans die each year.
Raging flu rates have also caused other cities to turn to extreme measures. CBS Chicago reported about eight Chicago-area hospitals have had to divert ambulances and people going to emergency rooms to deal with the influx of sick patients.
Doctors are recommending patients who have the flu for two days or less to stay home and avoid coming to the emergency room. Instead they should stay at home and get plenty of fluids and rest.
© 2013 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.