URMC / Center for Community Health & Prevention / Surveillance & Prevention / Emerging Infections Program / Influenza Surveillance

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.

flu surveillance graph

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

2023-2024 Monroe County Flu Season Report

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

2023

White EB, O'Halloran A, Sundaresan D, Gilmer M, Threlkel R, Colón A, Tastad K, Chai SJ, Alden NB, Yousey-Hindes K, Openo KP, Ryan PA, Kim S, Lynfield R, Spina N, Tesini BL, Martinez M, Schmidt Z, Sutton M, Talbot HK, Hill M, Biggerstaff M, Budd A, Garg S, Reed C, Iuliano AD, Bozio CH. High Influenza Incidence and Disease Severity Among Children and Adolescents Aged <18 Years - United States, 2022-23 Season. MMWR Morb Mortal Wkly Rep. 2023 Oct 13;72(41):1108-1114. doi: 10.15585/mmwr.mm7241a2. PMID: 37824430; PMCID: PMC10578954.
Doyle JD, Garg S, O'Halloran AC, Grant L, Anderson EJ, Openo KP, Alden NB, Herlihy R, Meek J, Yousey-Hindes K, Monroe ML, Kim S, Lynfield R, McMahon M, Muse A, Spina N, Irizarry L, Torres S, Bennett NM, Gaitan MA, Hill M, Cummings CN, Reed C, Schaffner W, Talbot HK, Self WH, Williams D. Performance of established disease severity scores in predicting severe outcomes among adults hospitalized with influenza-FluSurv-NET, 2017-2018. Influenza Other Respir Viruses. 2023 Dec 17;17(12):e13228. doi: 10.1111/irv.13228. PMID: 38111901; PMCID: PMC10725795.
Famati EA, Ujamaa D, O'Halloran A, Kirley PD, Chai SJ, Armistead I, Alden NB, Yousey-Hindes K, Openo KP, Ryan PA, Monroe ML, Falkowski A, Kim S, Lynfield R, McMahon M, Angeles KM, Khanlian SA, Spina NL, Bennett NM, Gaitán MA, Shiltz E, Lung K, Thomas A, Talbot HK, Schaffner W, George A, Staten H, Bozio CH, Garg S. Association of Chronic Medical Conditions With Severe Outcomes Among Nonpregnant Adults 18-49 Years Old Hospitalized With Influenza, FluSurv-NET, 2011-2019. Open Forum Infect Dis. 2023 Nov 29;10(12):ofad599. doi: 10.1093/ofid/ofad599. PMID: 38130595; PMCID: PMC10733180.
Sumner KM, Masalovich S, O'Halloran A, Holstein R, Reingold A, Kirley PD, Alden NB, Herlihy RK, Meek J, Yousey-Hindes K, Anderson EJ, Openo KP, Monroe ML, Leegwater L, Henderson J, Lynfield R, McMahon M, McMullen C, Angeles KM, Spina NL, Engesser K, Bennett NM, Felsen CB, Lung K, Shiltz E, Thomas A, Talbot HK, Schaffner W, Swain A, George A, Rolfes MA, Reed C, Garg S. Severity of influenza-associated hospitalisations by influenza virus type and subtype in the USA, 2010-19: a repeated cross-sectional study. Lancet Microbe. 2023 Sep 25:S2666-5247(23)00187-8. doi: 10.1016/S2666-5247(23)00187-8. Epub ahead of print. PMID: 37769676.

2022

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.

2021

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

2020

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]

2019

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