Content on this page was developed during the 2009-2010 H1N1 pandemic and has not been updated.
- The H1N1 virus that caused that pandemic is now a regular human flu virus and continues to circulate seasonally worldwide.
- The English language content on this website is being archived for historic and reference purposes only.
- For current, updated information on seasonal flu, including information about H1N1, see the CDC Seasonal Flu website.
Interim Guidance for State and Local Health Departments for Reporting Influenza-Associated Hospitalizations and Deaths for the 2009-2010 Season
September 8, 2009 2:30 PM ET
This interim guidance provides information for state and local health departments on how to report influenza-associated deaths and hospitalizations during the 2009-2010 season.
2009 H1N1 virus infection—referred to as “pandemic (H1N1) 2009 influenza” by the World Health Organization—was first identified in the United States in April 2009. By August 2009, more than 40,000 probable and suspect cases had been reported and more than one million infections were estimated to have occurred in the United States. Efforts to track all cases of influenza, including 2009 H1N1 influenza, are impractical because of the large number of people infected.
States and CDC implemented aggregate 2009 H1N1 hospitalization and death reporting as an alternative approach to individual case reporting in May 2009. In an effort to add additional structure to this aggregate reporting, CSTE and CDC have developed new case definitions for influenza-associated hospitalizations and deaths to be applied for the 2009-2010 influenza season. These new case definitions will be implemented at the beginning of MMWR week 35. The 2008-09 influenza season will close out on August 30, 2009 and total aggregate 2009 H1N1 hospitalizations and deaths for the 2008-09 season were reported in the September 4, 2009 FluView. The first week of reporting for the 2009-2010 season (MMWR week 35) will be reported in the September 11, 2009 FluView.
States are encouraged to begin reporting consistent with these new case definitions during MMWR week 35, the week including September 1, 2009. The reporting deadline for each will be Tuesday at midnight for the preceding Sunday to Saturday period (MMWR week). Aggregate case reports can be submitted via a web-based data application. Fax reports should be used only in an emergency, and CDC should be notified before any reports are faxed to (404) 248-4094. States will be able to view and download their data entered through this system. The updated web-based data reporting application will become available Tuesday, September 8, 2009. Access to this system has been granted to each jurisdiction’s Influenza-Associated Pediatric Mortality System reporter and each state epidemiologist. Instructions for accessing this system have been communicated in a separate email for those who have access. If access for alternate staff is needed, an email may be submitted to H1N1flu@cdc.gov.
The goal of state-level reporting of hospitalizations is to track the progression of the pandemic within each state (increasing or decreasing trend).
- Laboratory -confirmed Influenza Hospitalizations
- Report weekly the number of laboratory-confirmed influenza hospitalizations by age group (0-4, 5-18, 19-24, 25-49, 50-64, 65+) from participating hospitals that occurred or were identified during the report week.
- Laboratory confirmation includes rapid influenza tests, RT-PCR, DFA, IFA, or culture. Include all cases with a positive influenza test, whether or not typing was done. CDC is not asking for reporting by specific influenza type or subtype.
- Hospitalization for Pneumonia and Influenza Syndrome
- Report weekly the number of pneumonia and influenza hospitalizations by age group (0-4, 5-18, 19-24, 25-49, 50-64, 65+) from participating hospitals that occurred or were identified during the report week.
- Report can be based on syndromic, admission or discharge data, or a combination of data elements that could include laboratory-confirmed and ILI hospitalizations.
As the season progresses, CDC recognizes that states may shift from reporting laboratory-confirmed counts of hospitalizations to reporting hospitalization for pneumonia and influenza syndrome. Please notify CDC of any reporting change immediately.
The goal of state-level reporting of deaths is to track the progression of the epidemic within each state (increasing or decreasing trend).
- Laboratory-confirmed Influenza Deaths
- Report weekly the number of laboratory-confirmed influenza deaths by age group (0-4, 5-18, 19-24, 25-49, 50-64, 65+) that occurred or were identified during the report week.
- Laboratory confirmation cases should include all influenza positives. CDC is not asking for reporting by specific influenza type or subtype.
- Death from Pneumonia and Influenza Syndrome
- Report weekly the number of pneumonia and clinically-defined influenza deaths by age group (0-4, 5-18, 19-24, 25-49, 50-64, 65+) that occurred or were identified from electronic or other death reports during the report week.
As the season progresses, CDC recognizes that states may shift from reporting laboratory-confirmed counts of deaths to reporting death from pneumonia and influenza syndrome. Please notify CDC of any reporting change immediately.
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