Flu season strikes U.S.

Flu season in the U.S. has struck early and, in many places, hard. From the Rocky Mountains to New England, hospitals are swamped with people with flu symptoms. Boston declared a public health emergency, with the city's hospitals

counting about 1,500 emergency room visits since December by people with

flu-like symptoms.

This Monday, Jan. 7, 2013 photo shows a tent prepared for expected flu patients outside of the Emergency Room at Lehigh Valley Hospital at Cedar Crest, in Salisbury Township, Pa. The tent was set up after cases were piling up at the Salisbury Township hospital Monday, with the hospital reporting an extremely busy flu season so far. The flu season arrived early in the U.S. this year, but health officials and experts say it's too early to say this will be a bad one. Experts say evidence so far is pointing to a moderate flu season - it just looks worse because last year's season was so mild. Flu usually doesn't blanket the country until late January or February. Now, it's already widespread in more than 40 states. That could change when the next government report comes out Friday. (AP Photo/Express-Times, www.lehighvalleylive.com, Matt Smith)

Pam Horn administers the flu vaccine to employee Michael Karolitzky at Philly Flu Shots on Thursday, Jan. 10, 2013, in Philadelphia. The flu season arrived early in the U.S. this year, but health officials and experts say it's too early to say this will be a bad one. Experts say evidence so far is pointing to a moderate flu season - it just looks worse because last year's season was so mild. Flu usually doesn't blanket the country until late January or February. Now, it's already widespread in more than 40 states. That could change when the next government report comes out Friday. (AP Photo/Matt Rourke)

Here Damien Dancy puts masks on his children Damaya, 3, left, and Damien, 7, on Wednesday, Jan. 9, 2013 at Sentara Princess Anne Hospital in Virginia Beach, Va. Hospitals in Hampton Roads are urging patients and visitors to wear a mask at their facilities to help stop the spread of the flu. The recommendation was issued Wednesday by more than two dozen medical centers. In a joint statement, the hospitals said the recommendation applies to hospitals, urgent care centers and branch clinics, among others. (AP Photo/The Virginian-Pilot, Stephen M. Katz)

Here Damien Dancy puts masks on his children Damaya, 3, left, and Damien, 7, on Wednesday, Jan. 9, 2013 at Sentara Princess Anne Hospital in Virginia Beach, Va. Hospitals in Hampton Roads are urging patients and visitors to wear a mask at their facilities to help stop the spread of the flu. The recommendation was issued Wednesday by more than two dozen medical centers. In a joint statement, the hospitals said the recommendation applies to hospitals, urgent care centers and branch clinics, among others. (AP Photo/The Virginian-Pilot, Stephen M. Katz)