Compared with the previous five influenza seasons, the 2014-2015 season was moderately severe, with overall high levels of outpatient illness, high levels of hospitalization and a relatively high percentage of deaths attributed to pneumonia and influenza. The season was a severe one for people 65 years and older. The season was a relatively early in terms of timing, with influenza activity increasing through November and December, and peaking in late December. The frequency of outpatient visits to doctors for influenza like illness (ILI) went above the national baseline the week ending November 22, 2014 and remained elevated for 20 consecutive weeks, making the season longer than average and the longest in more than a decade. Over the previous 13 seasons, ILI was at or above baseline for 13 weeks on average, with a range of one week to 19 weeks.
