Preliminary Estimated Flu Disease Burden 2023–2024 Flu Season

What to know

This web page provides estimates of the burden of influenza (flu) in the United States for the 2023-2024 flu season. The overall burden of influenza (flu) for the 2023-2024 flu season was an estimated 40 million flu-related illnesses, 18 million flu-related medical visits, 470,000 flu-related hospitalizations, and 28,000 flu-related deaths.
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Background

For the past several years, CDC has used a mathematical model to estimate the numbers of influenza illnesses, medical visits, hospitalizations, and deaths every year 123. The methods used to calculate the estimates have been described previously 12. CDC uses the estimates of the burden of flu in the population to inform policy and communications related to influenza prevention and control.

Table 1: Estimated influenza disease burden, by age group — United States, 2023-2024 influenza season*
Symptomatic Illnesses Medical Visits Hospitalizations Deaths
Age group Estimate 95% UI† Estimate 95% UI† Estimate 95% UI† Estimate 95% UI†
0-4 yrs 2,903,633 (2,316,504, 4,721,510) 1,945,434 (1,423,698, 3,205,975) 20,243 (16,150, 32,916) 268 (66, 484)
5-17 yrs 9,287,627 (7,118,757, 19,577,782) 4,829,566 (3,383,771, 10,156,811) 25,466 (19,519, 53,680) 253 (95, 621)
18-49 yrs 16,351,383 (12,094,473, 28,147,985) 6,050,012 (3,940,361, 10,858,107) 91,780 (67,886, 157,995) 2,705 (1,565, 4,465)
50-64 yrs 9,042,884 (6,536,493, 19,011,230) 3,888,440 (2,457,484, 8,502,440) 95,897 (69,318, 201,609) 5,701 (3,001, 7,973)
65+ yrs 2,610,181 (1,804,377, 5,682,833) 1,461,701 (915,510, 3,288,184) 237,289 (164,034, 516,621) 19,038 (14,814, 45,757)
All ages 40,195,708 (33,905,386, 59,655,120) 18,175,153 (14,952,464, 27,496,515) 470,676 (381,564, 780,401) 27,965 (21,640, 53,527)
Table 2: Estimated rates of influenza-associated disease outcomes, per 100,000, by age group — United States, 2023-2024 influenza season*
Illness rate Medical visit rate Hospitalization rate Mortality rate
Age group Estimate 95% UI† Estimate 95% UI† Estimate 95% UI† Estimate 95% UI†
0-4 yrs 15685.90 (12,514.1, 25,506.3) 10509.50 (7,691.0, 17,319.1) 109.4 (87.2, 177.8) 1.4 (0.4, 2.6)
5-17 yrs 17097.80 (13,105.1, 36,041.1) 8890.80 (6,229.2, 18,697.9) 46.9 (35.9, 98.8) 0.5 (0.2, 1.1)
18-49 yrs 11654.30 ( 8,620.2, 20,062.2) 4312.10 (2,808.5, 7,739.0) 65.4 (48.4, 112.6) 1.9 (1.1, 3.2)
50-64 yrs 14461.40 (10,453.2, 30,402.8) 6218.40 (3,930.0, 13,597.1) 153.4 (110.9, 322.4) 9.1 (4.8, 12.7)
65+ yrs 4405.50 ( 3,045.4, 9,591.5) 2467.10 (1,545.2, 5,549.8) 400.5 (276.9, 872.0) 32.1 (25.0, 77.2)
All Ages 12,001.77 (10,123.6, 17,812.0) 5,426.80 (4,464.6, 8210.0) 140.536 (113.9, 233.0) 8.34 (6.5, 16.0)

†95% Uncertainty intervals

*Some of the data used to calculate burden estimates are incomplete or not yet available. These estimates will change as those data become available and the estimates are updated.

More Information

Additional information on How CDC Estimates the Burden of Seasonal Flu in the United States and about influenza disease burden, influenza disease burden prevented by vaccination and influenza severity assessment for the 2023-2024 season can be found on the CDC website.

Keep Reading: 2024-2025 United States Flu Season: Preliminary In-Season Severity Assessment
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Content Source:
  1. Reed C, Chaves SS, Daily Kirley P, Emerson R, Aragon D, Hancock EB, et al. Estimating influenza disease burden from population-based surveillance data in the United States. PLoS One. 2015;10(3):e0118369.
  2. Rolfes MA, Foppa IM, Garg S, et al. Annual estimates of the burden of seasonal influenza in the United States: A tool for strengthening influenza surveillance and preparedness. Influenza Other Respir Viruses 2018; 12(1): 132–7.
  3. Centers for Disease Control and Prevention. Estimated influenza illnesses and hospitalizations averted by influenza vaccination – United States, 2012-13 influenza season. MMWR Morb Mortal Wkly Rep. 2013 Dec 13;62(49):997-1000.