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Influenza Hospitalization Surveillance


InfluenzaActive 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) 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.


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:


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.

Latest 2023-2024 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.

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