Flu season takes dangerous turn in Boston (CBS News) The nationwide flu outbreak has taken a dangerous turn in Boston. Boston Mayor Thomas Menino has just declared a state of emergency in his city. In recent weeks, 18 people across Massachusetts have died because of the flu. National flu outbreak widens Complete coverage: Health Center: Cold & Flu At Massachusetts General, the hospital is restricting the number of visitors to some areas of the hospital, such as the OB-GYN floors to protect some of the hospital's most vulnerable patients, and asking hospital staff to wear masks throughout the day. In the U.S., 41 states are currently seeing intense flu outbreaks, almost five weeks earlier than usual this year. The harsh flu season has hit the Boston especially hard. The city has already seen some 700 cases of the flu since October 1, and four flu-related deaths. This, compared with only 70 cases at this time last year. Dr. Barbara Ferrer, executive director of the Boston Public Health Commission, said, "In the last two weeks alone, we've doubled our number, so if we continue at this rate to see new cases, we'll have an explosion of flu in the city of Boston." Dr. Paul Biddinger, emergency medical director at Massachusetts General Hospital, said, "It's very important to get the word out that the entire health care system is under strain." The hospital is dealing with many of Boston's new cases. Biddinger says this has become the most significant surge in Boston flu in five years. "We've been seeing record-setting volume," he said. We've seen 600 more patients in the month of December as compared to last year's December. Flu victim Dora Oquendo says the illness hit her on Sunday. She said, "I can't even move. I'm so weak, tired, exhausted. I'm throwing up too from doing all the coughing. Scientists recently discovered this year's vaccine is not protecting against a strain of the virus called Influenza B, but Biddinger says vaccination is still your best defense at preventing the flu. He said, "It is absolutely not too late to get your flu shot. I would strongly encourage anyone who has not gotten their flu shot yet to get their flu shot soon. It would be a great idea. Boston's mayor has said free flu clinics will be offered all day Thursday. For Michelle Miller's full report, watch the video in the player above.