New Home for NNDSS Weekly and Annual Tables

New locations for weekly and annual data

In January 2025, CDC's Wide-ranging ONline Data for Epidemiologic Research (WONDER) platform migrated to a new Azure cloud environment, where it previously shared weekly and annual NNDSS data. This change helps make CDC's internal data infrastructure more compatible, efficient, and responsive across the agency.

As a result of the WONDER migration, CDC has moved PDF and text versions of the weekly and annual NNDSS data tables to new locations on our website:

• Annual data tables can be found on CDC Stacks, an online repository available to public health professionals, researchers, and the public.

• Weekly tables can be found on CDC Stacks or data.cdc.gov, a publicly available data catalog of data resources

However, CDC WONDER will continue to host the interactive NNDSS annual summary data query.

Accessing the data

To help users learn how to access data in their new locations, we will follow an example of a user who wants to find weekly data for pertussis in Morbidity and Mortality Weekly Report (MMWR) week 49 in December 2024. Learn more about MMWR weeks.

To find NNDSS data on CDC Stacks:

1. Go to CDC Stacks and select National Notifiable Diseases Surveillance System (NNDSS) from the drop-down menu under "Search our Collections" near the upper left side of the page.
2. Hit Search. This will take you to the NNDSS collection landing page.
3. On the left-hand side, select Genre, Publisher Year, and Topic to filter the search results. For example, to find weekly tables of pertussis cases for December 2024 (week 49), select Weekly Tables, 2024, and Pertussis to locate the desired table.
4. Sort the results by Published Date in descending order to see the most recent tables.
5. Alternatively, type pertussis 2024 into the search bar at the very top of the NNDSS collection landing page (Look for the text labeled 'Search Stack Collections').

For help with using CDC Stacks, visit the Help Center or email publishinghd@cdc.gov.

To search weekly tables on data.cdc.gov:

1. Go to data.cdc.gov and select National Notifiable Diseases Surveillance System.
2. Scroll down and select this table to access the latest weekly data: NNDSS Weekly Data; the other tables will be kept for archival purposes.
3. In the upper right-hand corner, select Actions. A drop down will appear. Choose Query Data to filter the information of interest.
4. In the Filter section, go to the Select a column to filter menu and select Label from the drop-down list. Then, type pertussis in the box marked Search.
5. Click the + sign next to the And button. In the drop-down list, select Current MMWR year and type 2024 in the Search box.
6. Click the + sign again next to the And button. In the drop-down list, select MMWR week and type 49 in the Search box.
7. Click the Apply button at the bottom of the page. There should be 70 rows of data available at the top of the screen.
8. At the top of the page, click the Export button to download a comma-separated value CSV file or another file type.

For help using data.cdc.gov, email edavplatformdatagroup@cdc.gov.

Questions and feedback

• CDC recognizes that NNDSS users have relied on the WONDER application to get the data they need for decision-making and analysis. CDC will continue to provide PDF tables and versions of the files that are publicly accessible.

• CDC welcomes feedback and questions from users as we plan for future improvements. Please contact NNDSSWeb@cdc.gov to learn more.