Nurses Kristy Haynes, left, and Crysta Swift on Monday look over supplies inside a temporary mobile unit set up outside Grady Memorial Hospital in Atlanta to help handle the ever-growing number of flu cases. Photo: David Goldman/Associated Press Emergency departments across the U.S. have been slammed in recent weeks by an onslaught of flu visits, forcing hospitals to devise new spaces to house patients, to restrict visitors and to postpone elective surgeries.

Visits to hospital emergency departments, urgent care centers and other outpatient clinics by people with flu symptoms have been skyrocketing for several weeks. As of mid-January, such visits had surpassed every flu season except 2009-10, when a new flu strain caused a global pandemic. The dominant strain this season, H3N2, is particularly virulent, and the vaccine isn’t very effective against it. NYC Health & Hospitals has seen a 40% increase in the number of people being tested for the flu compared with this time last year, according to Sean Studer, deputy chief medical officer of the group, which runs New York City’s public hospitals, clinics and long-term care facilities. READ MORE