Boston declares public health emergency over flu

Boston has declared a public health emergency as it battles a widespread flu outbreak that has killed 18 people this season across the state of Massachusetts. 

Boston Mayor Thomas Menino said there had been around 700 confirmed cases of the flu in Boston since the season began in October, compared with only 70 all of last season, reports CBS News. 

"This is the worst flu season we've seen since 2009, and people should take the threat of flu seriously," Menino said in a news release.

"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. It's the best thing you can do to protect yourself and your family. If you're sick, please stay home from work or school."

City officials are encouraging residents to get vaccinated against the flu and are working with health care centers to offer free flu shots, reports CBS.

According to AP, the Centers for Disease Control and Prevention said Massachusetts was one of 29 states reporting high levels of "influenza-like illness." 

Eighteen children have died from influenza and more than 2,200 people have been hospitalized since October. 

NBC reports that the particularly bad flu season has been blamed on an especially potent strain of the flu, the A H3N2. Another common A strain, the H1N1, is also circulating along with two strains of influenza B. 

Infectious disease experts told NBC that vaccines prepared for this year will protect against three of the viruses although not a fourth strain of influenza B, which may account for up to 10 percent of this year's flu cases.