Past Seasons Estimated Influenza Disease Burden

These pages includes information about the estimated burden of influenza from past seasons, including tables of the estimated influenza disease burden (and 95% credible interval [Cr I]) by age group. Information on how these estimates are calculated can be found on CDC’s web page How CDC Estimates the Burden of Seasonal Influenza in the U.S.

Table 1: Estimated Flu Disease Burden, by Season — United States, 2010-2011 through 2022-2023** Flu Seasons

Symptomatic Illnesses Medical Visits Hospitalizations Deaths
Season Estimate 95% U I Estimate 95% U I Estimate 95% U I Estimate 95% U I
2010-2011 21,000,000 (16,000,000 – 46,000,000) 10,000,000 (7,900,000 – 21,000,000) 280,000 (190,000 – 1,000,000) 36,000 (21,000 – 140,000)
2011-2012 9,300,000 (8,600,000 – 12,000,000) 4,300,000 (4,000,000 – 5,600,000) 130,000 (120,000 – 180,000) 12,000 (10,000 – 23,000)
2012-2013 33,000,000 (26,000,000 – 66,000,000) 15,000,000 (12,000,000 – 30,000,000) 570,000 (360,000 – 1,800,000) 42,000 (25,000 – 110,000)
2013-2014 29,000,000 (24,000,000 – 41,000,000) 13,000,000 (12,000,000 – 15,000,000) 340,000 (260,000 – 640,000) 37,000 (23,000 – 100,000)
2014-2015 30,000,000 (26,000,000 – 39,000,000) 14,000,000 (11,000,000 – 18,000,000) 590,000 (410,000 – 1,100,000) 51,000 (34,000 – 100,000)
2015-2016 23,000,000 (19,000,000 – 32,000,000) 10,000,000 (9,000,000 – 14,000,000) 270,000 (210,000 – 480,000) 22,000 (17,000 – 35,000)
2016-2017 29,000,000 (24,000,000 – 44,000,000) 13,000,000 (11,000,000 – 22,000,000) 490,000 (370,000 – 830,000) 38,000 (28,000 – 60,000)
2017-2018 41,000,000 (35,000,000 – 53,000,000) 18,000,000 (16,000,000 – 24,000,000) 710,000 (560,000 – 1,100,000) 51,000 (36,000 – 95,000)
2018-2019 28,000,000 (24,000,000 – 40,000,000) 13,000,000 (11,000,000 – 18,000,000) 370,000 (300,000 – 660,000) 27,000 (19,000 – 96,000)
2019-2020 35,000,000 (28,000,000 – 70,000,000) 16,000,000 (13,000,000 – 30,000,000) 390,000 (310,000 – 720,000) 25,000 (18,000 – 78,000)
Preliminary estimates*
2021-2022* 9,400,000 (7,800,000 –  15,000,000) 4,300,000 (3,600,000 – 7,200,000) 100,000 (83,000 – 180,000) 4,900 (4,000 – 24,000)
2022-2023* 31,000,000 (26,000,000 – 51,000,000) 14,000,000 (12,000,000 – 24,000,000) 360,000 (290,000 – 670,000) 21,000 (18,000 – 97,000)

** Estimates are not available for the 2020-2021 flu season due to minimal influenza activity.