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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.

FluAid Special Edition

November 30, 2009, 12:00 PM ET

FluAid Special Edition is an adaptation from the previously published FluAid 2.0 software that is available through the CDC website at This newly adapted FluAid is a spreadsheet-based software program that is designed to assist states and local level planners with estimating the state level impact of 2009 H1N1 Influenza. This special edition of FluAid provides a range of estimates of impact in terms of deaths, hospitalizations, and outpatients visits due to 2009 H1N1 Influenza.

Download FluAid Special Edition Now

Who should use FluAid Special Edition?

This special edition of the FluAid software is designed to allow national, state and local level planners estimate the lower, upper, and most likely number of cases, hospitalizations, deaths, and outpatient visits due to the occurrence of 2009 H1N1 Influenza in a specific community or population.

Using FluAid Special Edition

The user must first define the population they wish to estimate the potential impact of 2009 H1N1. This is done by selecting the type of population on page 3 of 14 in the FluAid Special Edition.

FluAid Special Edition requires the user to select a specific U.S. State, Territory or the total United States (50 states plus the District of Columbia). This selection allows FluAid Special Edition to populate the model with default population estimates, stratified into 3 age groups: 0-17 years, 18-64 years and 65+ years.

If the user would like to estimate the potential impact for other locales, such as a specific city or another country, the user can select the option "other" on page 3 of 14. Then, on page 4 of 14 of FluAid Special Edition, a user can enter the population estimates stratified into the 3 age groups for the locale they wish to study.

Other input values: The other data entry pages (Pages 5 to 9 of 14) contain inputs for the model. These are: percentages of the population with pre-existing medical conditions that place then at higher risk of adverse health outcomes should they become ill with 2009 H1N1 influenza; percentages of cases that require outpatient visits, hospitalizations and deaths; and, clinical attack rates.

For each of these data entry pages, the user can either chose to use the default values, or they can enter any value that they so wish.

Sources of Default Input Values

The population numbers for the total U.S., states and territories were obtained from the U.S. Census Bureau, using population estimates as at July 01, 2008. (Available at:

The percentages of persons, by age group, with pre-existing medical conditions that place them at higher risk of adverse health outcomes should they become ill were obtained by analyzing data from the 2007 National Health Interview survey (available at: These conditions were reported among 9% of persons <18 years old, 17% of those 18-64 years old and 48% of those >64 years old.

The percentages of those clinically ill who seek outpatient care were obtained from Meltzer et al (Emerg. Infect. Dis, 1999:5:659-672, Appendix II; Table 3 -

The default percentages of those requiring hospitalization or who die were obtained from Reed et al (1), who developed a model to estimate the impact of 2009 H1N1 influenza in the United States during the Spring of 2009 (April-July). In this model, the number of cases and hospitalizations reported during the Spring 2009 were adjusted to correct for under-reporting using multipliers derived from community surveys, outbreak investigations, and published data.

The default attack rates were selected to represent possible attack rates for 2009 H1N1. The default values for the attack rates are user-defined assumptions.

Examples of Output

The program provides a summary of your own input values, as well as the default values in the form of a chart. The software program also produces outputs based upon the data that was entered for the percent hospitalizations, percent deaths, percent outpatient visits, and case attack rates in the form of charts and graphs.

Examples of an output chart:

Image: Example of an output chart displaying the estimated number of total cases per age group and their given percentage of high risk across each age group.

Image: Example of an output chart displaying the estimated number of deaths per age group at three different attack rates, along with their distribution by age group.

A graphical representation of the output results is also presented:

Image: Example of an output graph displaying the estimated number of deaths across all age groups at three different attack rates.

Help Features

Throughout FluAid Special Edition, you will find text boxes explaining specific information and calculation that are presented throughout the software program

System Requirements

  • Windows* operating system (MS Windows 2000 or newer)
  • Microsoft Excel (MS Office 2000 or newer)
  • 486 Pentium processor and at least 1GB RAM
  • 15 MB of hard drive storage space

We have successfully loaded and run FluAid Special Edition on a variety of desktop and laptop computers using the Windows operating system, it is not designed to run on Apple* or machines that use other operating systems such as Linux*

*MS Windows and Office is a copyrighted product produced by Microsoft Corporation, WA.  Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services.

Instructions for Downloading

Before loading and starting FluAid Special Edition, you must change Excel's security level.
You must first do the following steps:

  1. Open a blank Excel spreadsheet.
  2. Click Tools and then click Macro, choose Security
  3. Set Security Level to Medium.
  4. Click OK.
  5. Double click and open FluAid Special Edition file.
  6. When asked to Disable Macros or Enable Macros, click Enable Macros.

Downloading the Files

*We recommend downloading and saving the FluAid Special Edition spreadsheet to your computer, then open the spreadsheet from your computer. This will allow the spreadsheet to open in Excel instead of your web browser.

Download FluAid Special Edition Question & Answers

Download FluAid Special Edition Download Instructions

Download FluAid Special Edition Software


Please keep in mind that this is a test version of the software. The software cannot describe when or how people will become ill, nor how H1N1 Influenza may spread through a society over a period of time.



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