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 Influenza Disease Burden, by Season — United States, 2010-11 through 2018-19 Influenza 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 (20,000,000 – 25,000,000) 10,000,000 (9,300,000 – 12,000,000) 290,000 (270,000 – 350,000) 37,000 (32,000 – 51,000)
2011-2012 9,300,000 (8,700,000 – 12,000,000) 4,300,000 (4,000,000 – 5,600,000) 140,000 (130,000 – 190,000) 12,000 (11,000 – 23,000)
2012-2013 34,000,000 (32,000,000 – 38,000,000) 16,000,000 (15,000,000 – 18,000,000) 570,000 (530,000 – 680,000) 43,000 (37,000 – 57,000)
2013-2014 30,000,000 (28,000,000 – 33,000,000) 13,000,000 (12,000,000 – 15,000,000) 350,000 (320,000 – 390,000) 38,000 (33,000 – 50,000)
2014-2015 30,000,000 (29,000,000 – 33,000,000) 14,000,000 (13,000,000 – 16,000,000) 590,000 (540,000 – 680,000) 51,000 (44,000 – 64,000)
2015-2016 24,000,000 (20,000,000 – 33,000,000) 11,000,000 (9,000,000 – 15,000,000) 280,000 (220,000 – 480,000) 23,000 (17,000 – 35,000)
2016-2017 29,000,000 (25,000,000 – 45,000,000) 14,000,000 (11,000,000 – 23,000,000) 500,000 (380,000 – 860,000) 38,000 (29,000 – 61,000)
Preliminary estimates* Estimate 95% UI Estimate 95% UI Estimate 95% UI Estimate 95% UI
2017-2018* 45,000,000 (39,000,000 – 58,000,000) 21,000,000 (18,000,000 – 27,000,000) 810,000 (620,000 – 1,400,000) 61,000 (46,000 – 95,000)
2018-2019* 35,520,883 (31,323,881, 44,995,691) 16,520,350 (14,322,767, 21,203,231) 490,561 (387,283, 766,472) 34,157 (26,339, 52,664)

* Estimates from the 2017-2018 and 2018-2019 seasons are preliminary and may change as data are finalized.