Proportion of Emergency Department Visits For
Influenza-Like Illness (ILI) per Week
Region 1: waydownRegion 2: waydownRegion 3: waydownRegion 4: waydownRegion 5: downRegion 6: waydownRegion 7: waydownRegion 8: downRegion 9: waydownRegion 10: waydown
% above or
below 2009-2010
seasonal mean:
  • above > 20%
  • above < 20%
  • mean (-5% - 5%)
  • below < 20%
  • below > 20%

Society for

Distribute Program FAQ

General | Participants | Data Use Policy


  1. What is the Distribute Project?

    In its proof-of-concept phase, Distribute stood for Distributed Surveillance Taskforce for Real-time Influenza Burden Tracking and Evaluation. This initial stage was made possible through an award from the National Association of County and City Health Officials (NACCHO) to the International Society for Disease Surveillance (ISDS), through its cooperative agreement with the Centers for Disease Control and Prevention (CDC). In order to ensure that the work corresponded with the views and needs of local, state, and federal public health entities, ISDS partnered with the CDC, NACCHO, the Council of State and Territorial Epidemiologists (CSTE), and the Association of State and Territorial Health Officers (ASTHO). The ISDS Distribute project demonstrated the ability to provide rapid and meaningful surveillance information from a variety of local health department Emergency Department (ED) surveillance systems. Particularly valuable features of Distribute were the ability for participating public health authorities to access accurate and rapid age-specific morbidity trends and collaborate with peers to better understand the data.

  2. What is the current Distribute initiative, related to influenza?

    This project is a partnership of the CDC, ISDS, and the Task Force for Global Health/Public Health Informatics Institute (PHII) to leverage and enhance the Distribute system, merging summary-level information from Distribute participants with other existing surveillance systems to provide a more comprehensive and detailed situational awareness of geographic and age-specific patterns of influenza-like illness.

  3. What is the overall goal of this initiative?

    The project seeks to inform influenza response by enhancing and supporting ED surveillance with aggregate level data in order to effectively analyze patterns of healthcare seeking behavior, infection spread, and severity of illness, for a more timely response and investigation.

  4. What new or different opportunities for response does this initiative offer?

    The current influenza-related initiative directs summary level data from separate local health department ED surveillance systems from across the U.S. to the Distribute system. By providing local, state and CDC epidemiologists with access to statistical visualizations in a single view on the Distribute website, the initiative enhances communication across jurisdictions, supports critical public health decision-making, and facilitates scientific advancement and practice for the public’s health.

  5. How did the current influenza-related Distribute initiative come about?

    In the spring of 2009, the United States declared a public health emergency due to the novel H1N1 influenza outbreak. With the possibility of the virus becoming more virulent in the upcoming flu season, timely, nation-wide data on the presentation of influenza-like illnesses would be critical for preparing the country to respond quickly and appropriately to the crisis. Arising from that need, this initiative brings together the CDC, ISDS and PHII to expand and facilitate the participation of state and local public health jurisdictions in providing ED syndromic surveillance data to the Distribute system. This participation provides public health authorities with timely, accurate access to widespread geographic and age-specific morbidity trends, and enables them to collaborate with peers to better understand the data and respond to the current H1N1 influenza outbreak.

  6. What are the roles of the partner organizations?

    As the host of the Distribute system, ISDS’ role in the partnership is focused on growing the participant network, facilitating the collection of data, and putting it into context of a national picture of the H1N1 outbreak. ISDS is engaging state and local health departments, providing a safe environment for sharing their aggregated ED data, and supplying expertise and guidance on the visualization and analysis of contributed data to support the public health system’s response to the pandemic. CDC provides executive sponsorship, influenza expertise and technical assistance, helping to recruit and equip new states and local jurisdictions to participate in the project, sending data collected from the state and local jurisdictions to Distribute, and coordinating the data collection and validation efforts of the CDC flu division and ISDS. PHII facilitates communication between the project partners, and with federal, state and local public health practitioners who are participating in the project, and assists in the development of a communications strategy, messages and materials for the project. Further, the Institute assists ISDS in nurturing a community of practice with participating jurisdictions.

  7. What data are collected, stored and presented for public view?

    Only aggregated data are collected and presented for public view, protecting the anonymity of reporting jurisdictions and their residents, while still supporting effective analysis of trends in infection spread and severity of illness. To this end, five data variables are considered:
    1. Date of encounter
    2. First three digits of patient zip code (or facility, if patient information is not available)
    3. Age group of patient
    4. Indicator (syndrome or measure)
    5. Count (representing number of visits for indicator for age group, three-digit zip code and date; this variable can be worked around if there are significant concerns about the anonymity of aggregate data based on this information)
    There are two additional data variables that are collected if they are available, to serve as indicators of severity of illness:
    1. Disposition of ED visit
    2. Temperature

  8. Who provides the data?

    The participating health jurisdiction, in most cases the state or local health department that has jurisdiction over the area being covered, collects and submits the aggregate ED data. In some cases, arrangements have been made with the health jurisdiction for Distribute to accept data directly from participating providers.

  9. How are the data being used?

    The data are visualized and analyzed to improve the monitoring of, preparation for, and response to the novel H1N1 outbreak. They will be used to develop analytic methods to identify possible events or concerns that may warrant further follow-up investigation, or immediate public health intervention actions.

  10. How are health jurisdictions being recruited to participate?

    At the outset of the project, in August 2009, a letter from CDC Director Dr. Thomas R. Frieden was sent to public health agencies across the nation, announcing the partnership and encouraging the agencies to contribute by joining the growing community of participants reporting data from their respective jurisdictions. This was followed by a letter to the Regional Collaborative partners with the National Center for Public Health Informatics/CDC, wherein the division director provided additional detail about the project, and similarly encouraged them to get involved. Representatives from both CDC and ISDS then began a calling campaign, reaching out to all potential participants, in order to answer any remaining questions, get them enrolled, and begin the data collection process.

  11. How can the public see the results of the initiative?

    Official visualized data from the project, updated daily, can be viewed at ISDSdistribute.org.

  12. Does my local or state health department participate?

    A list of participating jurisdictions is also available at ISDSdistribute.org.

  13. What is the Community Forum?

    The Forum is an on-line tool for information exchange, collaboration and learning among Distribute contributors and project partners. It is a secured, by invitation only space administered by the International Society for Disease Surveillance (ISDS). Within the Forum, you can connect with other surveillance professionals, learn, solve problems and exchange ideas and innovative tools.

  14. Who do I contact to learn more? Who do I contact for press interviews?

    You may contact any of the following for general inquiries, media requests, information about participation, and technical or project information:

    CDC: Taha Kass-Hout, tik2@cdc.gov 404.498.2014

    ISDS: Emily Cain, ecain@syndromic.org 617-461-3436

    PHII: Debby Robic, drobic@phii.org 404-592-1404

  15. How are the percent changes (blue, red, gray color gradients) on the map calculated?

    The Distribute project displays a color gradient map that shows whether ILI emergency visit activity for the current week in each region is increasing or decreasing. The map shows the percent change (up or down) of the current week of ILI activity compared to the annual weekly average during the 2009-2010 influenza season (2009-2010 baseline). Due to the early emergence of the A/H1N1 pandemic, the 2009-2010 baseline period is measured from August 1, 2009 through July 31, 2010.


  1. What data are you asking for?

    We are asking for daily, aggregate counts of ILI syndrome ED visits and total ED visits by age group and three-digit zip code.

  2. Are HIPAA rules and regulations followed?

    The data being requested for the Distribute project are aggregate counts only, and would qualify as de-identified according to Health Insurance Portability and Accountability Act (HIPAA) standards.

  3. How often must the data be sent?

    Daily data transmission is preferred but weekly transmission of daily counts can be arranged.

  4. Will individual patients be identifiable?

    No, individual information is not being collected by the Distribute project. The project is asking for aggregate syndrome counts by three-digit zip code only.

  5. Will specific hospitals be identifiable?

    Health facility identifiers are not being collected by ISDS for the Distribute project. Although it is possible that some facilities provide nearly all care for certain three digit zip-codes, only the proportion of febrile visits for this hospital could be inferred, and is unlikely to be considered sensitive information.

  6. What syndrome definition are you using?

    We are asking that each jurisdiction provide data using whatever syndrome definition they have found most useful for monitoring influenza-like-illness visits to their hospital emergency departments. In instances where a jurisdiction uses more than one definition to capture that data, we are asking for the higher count, less specific, index of febrile illness in the community in order to detect earlier indications of influenza.

  7. Who can view the raw data?

    Only authorized ISDS personnel working on the Distribute project can view the raw data.

  8. How will the data be used?

    The data will be visualized and used to provide public health practitioners with useful and timely influenza morbidity benchmarking trends allowing them to compare the relative timing, severity and age distribution mix of influenza season.

  9. Who can view the data visualizations?

    Every participating health agency can view the data visualizations.

  10. Can participants share the data visualizations with others?

    No. As part of the data sharing agreement, we are asking that all agencies respect other jurisdiction’s privacy and authority and refrain from discussing ANY other health jurisdiction’s data without explicit written permission from that health agency. However, jurisdictions are free to share their own and regional visualizations.

  11. What about data from health jurisdictions not participating with the project?

    If the data includes visits from areas outside of a jurisdiction, that data will not be made available as a separate, jurisdiction-specific visualization. However, the data may be integrated into a participating jurisdiction’s visualizations, or may be used as part of a regional visualization.

  12. Will Distribute include national data only, or are there plans to make this an international system?

    The Distribute system is able to accept data from any jurisdiction. The initial focus is on national health jurisdictions but we are in conversations with international health agencies discussing how to incorporate their data into the Distribute system.

  13. How can my agency participate?

    If you are interested in participating, please contact the ISDS Research Director, Don Olson, at drolson at syndromic.org

Data Sharing and Research Use Policy

The Distribute project collects and presents city, county, state and regional emergency department (ED) syndromic surveillance trends. The public website (i.e., ISDSdistribute.org) displays ratios of febrile, respiratory and influenza-like-illness (ILI) syndrome visits over total emergency visits within each jurisdiction. ILI visit and total ED counts are not presented on the public website.

Distribute visualizations are intended to provide timely representation of influenza-like syndrome visit trends (syndrome over total visits) by jurisdiction. Up to a year of data can be visualized on the public website. Distribute does not provide historical trends on the public website.

Currently, Distribute data are not available for research and ISDS does not condone the use of publicly visualized Distribute data for research or analysis. Data contributing health authorities retain control over the detailed age- and geography-specific syndrome and total count data.

If you have specific questions or comments regarding potential changes to the current data sharing policy, please submit them to .