From the 2010–11 through the 2022–23 seasons (excluding 2020–2021, when COVID-19 control measures resulted in almost no influenza activity), the annual influenza-related disease burden has varied from approximately 9 to 41 million illnesses, 4 to 21 million medical visits, 140,000 to 810,000 hospitalizations and 12,000 to 61,000 deaths per year, including an average of 129 pediatric deaths reported to CDC (range 37–199) each year. While the 2020–21 and 2021–22 seasons’ disease burden was substantially limited as a result of measures taken by many people to reduce the transmission of COVID-19, such as wearing face masks in public and limiting interactions with other people, influenza activity returned to pre-pandemic levels by the 2022–23 season. For additional information about disease burden from CDC, see www.cdc.gov/flu-burden/php/about/index.html.
Rates of infection from seasonal influenza are highest among children, but the risks for complications, hospitalizations, and deaths are highest among adults age 65 years and older.
Last reviewed:
August 11, 2024
While even healthy children and adults get severe influenza or die from influenza and its complications, the risk of severe influenza is higher for children younger than 5 years, adults 50 years and older, pregnant people, Alaska Natives and American Indians, and residents of nursing homes or other long-term care facilities. Medical conditions that increase a person’s risk of severe influenza include chronic pulmonary (including asthma), cardiovascular (excluding isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus); immunocompromising conditions due to any cause (including, but not limited to, immune suppression caused by medications or HIV); extreme obesity (body mass index of 40 or greater for adults); and the chronic use of aspirin- or salicylate-containing medications in children through age 18 (due to the risk of Reye syndrome after influenza infection).
More information about risk factors for severe influenza infection can be found at: www.cdc.gov/flu/highrisk/index.htm.
Last reviewed:
August 11, 2024
The timing and severity of influenza seasons are always unpredictable. Although influenza viruses circulated at very low levels while measures to prevent the spread of COVID-19 were widely adopted during the pandemic, the circulation of influenza viruses has returned to pre-pandemic patterns. Current information on influenza virus circulation can be found at www.cdc.gov/fluview/.
Last reviewed:
August 11, 2024
Information regarding influenza surveillance is available year-round from CDC. For an overview and link to CDC’s influenza surveillance systems, visit www.cdc.gov/fluview/. CDC publishes updated information weekly. In addition, periodic updates about influenza are published in MMWR. CDC also publishes respiratory virus surveillance information that integrates influenza, COVID-19 and RSV at www.cdc.gov/respiratory-viruses/data/index.html.
State and local health departments should be consulted regarding local access to public health influenza vaccination programs and information about state or local influenza activity. Contact state or local health officials to report influenza outbreaks and for guidance in outbreak response.
Last reviewed:
August 11, 2024
