Influenza Hospitalization Surveillance

Purpose

Active surveillance for hospitalized laboratory–confirmed influenza cases among residents of the seven county Rochester catchment area began in 2004 as part of the Centers for Disease Control & Prevention Emerging Infections Program (EIP) Flu-Surv.net. Laboratory-confirmed influenza is reportable to the New York State Department of Public Health. EIP staff collect data to determine underlying conditions, influenza testing patterns and markers of disease severity.

Goals and Objectives

• Determine the age-specific rates of laboratory confirmed influenza associated hospitalization.
• Determine the rate of serious influenza-associated complications, such as secondary bacterial infections, and the need for intensive care unit (ICU) admission/mechanical ventilation.
• Identify factors that are associated with severe illness or influenza-associated complications.
• Evaluate adherence to influenza vaccination recommendations.

Activities

Active surveillance for laboratory-confirmed influenza hospitalizations is conducted among residents of the seven county Rochester catchment area. A case is defined as a resident in the catchment area having a hospital admission with a laboratory confirmed influenza infection. FluSurv-Net data is used to generate national estimates of the total numbers of flu cases, medical visits, and hospitalizations. 

Comprehensive and aggregate data analyses for this project are ongoing and available at the following websites:

• NYS: Influenza Activity, Surveillance and Reports
• CDC: Weekly Flu Report
• Monroe County: RocHealthData Dashboard

Data

The incidence of influenza hospitalizations varies by season and by age group and depends on the circulating influenza strains and the influenza vaccine efficacy. 

Incidence from the 2020-2021 season was lower than expected due to the COVID-19 pandemic.

Latest 2022-2023 Monroe County Flu Season Report

Available Now!

View the latest data for Monroe County on the RocHealthData dashboard. Get an in-depth and interactive look at the details, including number of ED visits, number of cases, rates by age group, and more.

Selected Publications

• Adams K, Tastad KJ, Huang S, Ujamaa D, Kniss K, Cummings C, Reingold A, Roland J, Austin E, Kawasaki B, Meek J, Yousey-Hindes K, Bennett NM, Gaitan MA, et al. Prevalence of SARS-CoV-2 and Influenza Coinfection and Clinical Characteristics Among Children and Adolescents Aged <18 Years Who Were Hospitalized or Died with Influenza - United States, 2021-22 Influenza Season. MMWR Morb Mortal Wkly Rep. 2022 Dec 16;71(50):1589-1596. doi: 10.15585/mmwr.mm7150a4. PMID: 36520656.

• Holstein R, Dawood F, O'Halloran A, Cummings C, Ujamaa D, Kirley PD, Yousey-Hindes K, Fawcett E, Monroe M, Kim S, Lynfield R, McMullen C, Muse A, Bennett NM et al. Characteristics and Outcomes of Hospitalized Pregnant Women with Influenza, 2010 to 2019: A Repeated Cross-Sectional Study. Ann Internal Med. December 2021, https://doi.org/10.7326/M21-3668.

• Cummings CN, O'Halloran AC, Azenkot T, Reingold A, Alden NB, Meek JI, Anderson EJ, Ryan PA, Kim S, McMahon M, McMullen C, Spina NL, Bennett NM, Billing LM, Thomas A, Schaffner W, Talbot HK, George A, Reed C, Garg S. Hospital-acquired influenza in the United States, FluSurv-NET, 2011-2012 through 2018-2019. Infect Control Hosp Epidemiol. 2021 Oct 5:1-7. doi: 10.1017/ice.2021.392. Epub ahead of print. PMID: 34607624.

• O’Halloran AC, Holstein R, Cummings C, Bennett NM, et al. Rates of Influenza-Associated Hospitalization, Intensive Care Unit Admission, and In-Hospital Death by Race and Ethnicity in the United States From 2009 to 2019. JAMA Netw Open. 2021;4(8):e2121880. doi:10.1001/jamanetworkopen.2021.21880

• Chow EJ, Rolfes MA, O'Halloran A, Anderson EJ, Bennett NM, Billing L, Chai S, Dufort E, Herlihy R, Kim S, Lynfield R, McMullen C, Monroe ML, Schaffner W, Spencer M, Talbot HK, Thomas A, Yousey-Hindes K, Reed C, Garg S.; Acute Cardiovascular Events Associated With Influenza in Hospitalized Adults: A Cross-sectional Study. Ann Intern Med. 25 August 2020. Online ahead of print. doi:10.7326/M20-1509. PMID: 32833488.

• Sloan C, Chandrasekhar R, Mitchel E, Ndi D, Miller L, Thomas A, Bennett NM, Chai S, Spencer M, Eckel S, Spina N, Monroe M, Anderson EJ, Lynfield R, et al. Spatial and Temporal Clustering of Patients Hospitalized with Laboratory-Confirmed Influenza in the United States. Epidemics. 2020 June; 31, doi.org/10.1016/j.epidem.2020.100387.

• Chow EJ, Rolfes MA, O'Halloran A, Alden NB, Anderson EJ, Bennett NM, Billing L, Dufort E, Kirley PD, George A, Irizarry L, Kim S, Lynfield R, Ryan P, Schaffner W, Talbot HK, Thomas A, Yousey-Hindes K, Reed C, Garg S. Respiratory and Nonrespiratory Diagnoses Associated With Influenza in Hospitalized Adults. JAMA Netw Open. 2020 Mar 2; 3(3):e201323. doi: 10.1001/jamanetworkopen.2020.1323. PMID: 32196103 [PubMed - in process]
• Czaja CA, Miller L, Alden N, Wald HL, Cummings CN, Rolfes MA, Anderson EJ, Bennett NM, Billing LM, Chai SJ, Eckel S, Mansmann R, McMahon M, Monroe ML, Muse A, Risk I, Schaffner W, Thomas AR, Yousey-Hindes K, Garg S, Herlihy RK. Age-Related Differences in Hospitalization Rates, Clinical Presentation, and Outcomes Among Older Adults Hospitalized With Influenza-U.S. Influenza Hospitalization Surveillance Network (FluSurv-NET). Open Forum Infect Dis. 2019 Jul 1;6(7). doi: 10.1093/ofid/ofz225
• Rolfes MA, Flannery B, Chung J, O’Halloran A, Garg S, Belongia EA, Gaglani M, Zimmerman R, Jackson ML, Monto AS, Alden NB, Anderson E, Bennett NM et al. Effects of Influenza Vaccination in the United States during the 2017-2018 Influenza Season. Clinical Infectious Diseases. 2019 Feb., https://doi.org/10.1093/cid/ciz075 
• Collins JP, Campbell AP, Openo K, Farley MM, Cummings CN, Kirley PD, Herlihy R, Yousey-Hindes K, Monroe ML, Ladisky M, Lynfield R, Baumbach J, Spina N, Bennett N, Billing L, Thomas A, Schaffner W, Price A, Garg S, Anderson EJ. Clinical Features and Outcomes of Immunocompromised Children Hospitalized With Laboratory-Confirmed Influenza in the United States, 2011-2015. J Pediatric Infec Dis Soc. 2018 Oct 25. doi: 10.1093/jpids/piy101
• Chandrasekhar R, Sloan C, Mitchel E, Ndi D, Alden N, Thomas A, Bennett NM, Kirley PD, Hill M, Anderson EJ, Lynfield R, Yousey-Hindes K, Bargsten M, Zansky SM, Lung K, Schroeder M, Monroe M, Eckel S, Markus TM, Cummings CN, Garg S, Schaffner W, Lindegren ML. Social determinants of influenza hospitalization in the United States.Influenza Other Res Viruses. 2017 Nov;11(6):479-488. doi: 10.1111/irv.12483. 
• Arriola CS, Garg S, Anderson EJ, Ryan PA, George A, Zansky SM, Bennett N, Reingold A, Bargsten M, Miller L, Yousey-Hindes K, Tatham L, Bohm SR, Lynfield R, Thomas A, Lindegren ML, Schaffner W, Fry AM, Chaves SS. Influenza vaccination modifies disease severity among community-dwelling adults hospitalized with influenza. Clin Infect Dis. 2017 May 19. doi: 10.1093/cid/cix468. 
• Appiah GD, Chaves SS, Kirley PD, Miller L, Meek J, Anderson E, Oni O, Ryan P, Eckel S, Lynfield R, Bargsten M, Zansky SM, Bennett N, Lung K, McDonald-Hamm C, Thomas A, Brady D, Lindegren ML, Schaffner W, Hill M, Garg S, Fry AM, Campbell AP. Increased antiviral treatment among hospitalized children and adults with laboratory-confirmed influenza, 2010-2015. Clin Infect Dis. 2017 Feb 1;64(3):364-367.
• Havers F, Sokolow L, Shay DK, Farley MM, Monroe M, Meek J, Daily Kirley P, Bennett NM, Morin C, Aragon D, Thomas A, Schaffner W, Zansky SM, Baumbach J, Ferdinands J, Fry AM.  Case-control study of vaccine effectiveness in preventing laboratory-confirmed influenza hospitalizations in older adults, United States, 2010-2011. Clin Infect Dis. 2016 Nov 15;63(10):1304-1311.