The burden of influenza disease in the United States can vary widely and is determined by a number of factors including the characteristics of circulating viruses, the timing of the season, how well the vaccine is working to protect against illness, and how many people got vaccinated. While the impact of flu varies, it places a substantial burden on the health of people in the United States each year.
CDC estimates that influenza has resulted in between 9 million – 45 million illnesses, between 140,000 – 810,000 hospitalizations and between 12,000 – 61,000 deaths annually since 2010.
| 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.
Source (September 29, 2020): https://www.cdc.gov/flu/about/burden/index.html