FAQs: Case Surveillance Modernization
This page provides answers to common questions about implementing enhancements to case surveillance. CDC will continue updating this page with new information about this ongoing effort.
If your jurisdiction has questions that are not answered on this page, please contact CDC using this form.

Q: How was the case surveillance sprint conducted?
A: In mid-July 2022, a team led by the United States Digital Service (USDS) and in collaboration with CDC completed its discovery sprint to help identify opportunities to modernize the flow of case surveillance data. The team provided findings and recommendations to CDC, many of which are challenges previously identified, and CDC is implementing these recommendations.
The sprint examined the flow of case reporting and notification for both infectious and non-infectious conditions. The team conducted 65 interviews with 148 individuals representing 8 state and 11 local health departments at all levels of performance.
The sprint specifically looked at the lifecycle of the data, starting at the point of care and ending in public health action. Its goal was to deepen understanding of the current technologies, processes, and policies around disease surveillance data that will contribute to informing what a modernized, sustainable system could look like.
Q: How will the sprint findings be used?
A: The findings from the sprint will be used to determine how to better support state, local, tribal, and territorial (STLT) partners and CDC programs in data collection and notification, with an emphasis on minimizing the burden on state and local health departments.
In addition, the sprint findings will help move toward greater flexibility in how CDC receives data from jurisdictions. Sprint findings also will help to ensure greater bidirectionality of data so that jurisdictions can both see the data they submitted and access analytic and visualization tools that will help them better understand how their data fit into the national picture.
Finally, the sprint findings will help develop ways to build up the public health informatics and data science workforce capacity at the local and state levels, including through technical support, training, and innovative approaches to surveillance and staffing.
Q: Is this work connected to the CDC Data Modernization Initiative (DMI)?
A: Yes. Case surveillance data are a core data source used across the public health ecosystem and are prioritized within DMI.
The USDS discovery sprint and the implementation of these recommendations support the vision outlined in DMI for CDC to create a flexible, efficient, and scalable data pipeline of core data sources for both routine and emergency public health needs. This vision is centered on providing valuable data to the jurisdictions, CDC, and the public while also reducing burden on reporting partners.
To support this vision, CDC and partners have defined a “reference architecture” (North Star Architecture) for the public health ecosystem. This reference architecture is built upon modular “building blocks,” or functionality that will be used across diseases and conditions.
Currently, CDC is focused on the data exchange building block, which supports the concept of a single “CDC front door.” In this approach, all data from STLT partners, including case surveillance data, would enter and leave CDC through a single point that can manage standardized data in multiple message formats, such as Health Level 7 V2 (HL7 V2), comma-separated values (CSV), Fast Healthcare Interoperability Resources (FHIR), and application programing interface (API).
The CDC front door eliminates the need for jurisdictions to send the same data in multiple formats to multiple places at CDC.
The intent of the pause in Message Mapping Guide (MMG) development and onboarding efforts is to allow partners and CDC to focus our efforts and resources to make significant progress on data standardization and create the “CDC front door.”
Q: How will previous work implementing disease-specific MMGs inform how CDC implements the sprint recommendations?
A: CDC will continue using data elements that were defined in collaboration with CDC programs and jurisdictions for disease-specific MMGs to develop standardized data dictionaries going forward. The data dictionaries will provide a larger set of core data elements that have been harmonized across conditions in addition to disease-specific data elements.
CDC also will use disease-specific MMGs to inform our efforts to expand the range of available data formats beyond HL7 V2, including options for jurisdictions to send additional, disease-specific data gathered from their ongoing case investigations.
Q: What is your strategy for developing the flexible data pipeline?
A: CDC, including the Division of Health Informatics and Surveillance (DHIS) and the Office of the Chief Information Officer (OCIO, and USDS will identify flexible approaches to receive case data from jurisdictions. CDC will lead collaborative efforts across partners to develop these approaches. Approaches include:
- Enable generic core case data elements and other standardized data elements to be submitted through multiple file formats, including HL7 V2, CSV, and FHIR.
- Identify flexible mechanisms to receive additional data elements using existing data pipelines to support emergent and evolving public health goals.
In addition, CDC (DHIS) will ensure that the capabilities developed align with existing healthcare standards, electronic case reporting, and a modernized CDC-supported surveillance system such as NBS. CDC (DHIS) also will bolster existing customer service-oriented teams to include a primary point of contact for each jurisdiction and CDC program to receive technical assistance and support across all data pipeline-related needs.
CDC (DHIS, DDPHSS, OCIO) and USDS also will:
- Develop a plan for how case data flowing into CDC from jurisdictions will undergo quality control measures and make the steps and code available for review by stakeholders.
- Develop a plan for how data will land in an environment that is accessible to CDC programs and jurisdictions and identify the strategy to grant jurisdictions access to data for bidirectional data flow and information sharing.
- Develop innovative tools that can be accessed in a shared environment by jurisdictions and CDC programs and used to generate national or regional data views for all partners to better place reported data into the appropriate context.
- Identify a surveillance team that uses these tools in a central, program-agnostic organizational unit to routinely review the data for quality control measures and for public health purposes such as anomaly detection and concerning trends.
- Work closely with CDC programs and jurisdictions to share findings and improve communication and collaboration across partners.
Q: How will CDC support jurisdictions to be able to send case notifications using generic version 2 (GenV2)?
A: In collaboration with MITRE, DHIS has undertaken a landscape analysis to understand where gaps in GenV2 onboarding currently exist and to help us understand what barriers and challenges jurisdictions face in being able to send data through new message formats. We expect to complete this activity within the second quarter of 2023. CDC will use the findings to strategize how to expedite onboarding for jurisdictions who have not implemented GenV2.
Q: Does this mean that jurisdictions will use only GenV2 to send their data to CDC?
A: No. CDC is not requiring nor requesting that jurisdictions send all conditions through the GenV2 MMG. Disease-specific data are vitally important to jurisdictions and CDC and an important part of the National Notifiable Diseases Surveillance System (NNDSS) data flow. Jurisdictions who have onboarded disease-specific MMGs and can send HL7 v2 messages will continue to do so at this time.
In addition, CDC will continue to support legacy messages (NETSS, NBS, Master Message, GenV1). The intent is to maintain current data flow for condition-specific data while CDC further develops the “CDC Front Door” data exchange. Jurisdictions sending legacy case notifications that include disease-specific data important to CDC programs should continue to send those messages.
Q: Does this mean that only jurisdictions that have already onboarded HL7 messaging can send notifiable data to CDC?
A: No. Jurisdictions should continue to send case notification in their current formats until they successfully transition to a new format. We plan to expand the range of data formats that jurisdictions can use to send case surveillance data to CDC beyond HL7 V2, such as CSV, FHIR, and other formats, as one method to help ease the burden on jurisdictions.
Q: How are you making decisions about whether and when to pause work on disease-specific MMGs currently in progress?
A: CDC (DHIS; Center for Surveillance, Epidemiology, and Surveillance [CSELS]; Deputy Director Public Health Science and Surveillance [DDPHSS]) will identify disease-specific MMGs currently in development by CDC programs and work with those programs to outline their objectives and a plan for data collection.
Also, in collaboration with our internal and external partners, CDC will use data elements and established standards to inform different approaches for receiving those data that extend beyond the core data elements in GenV2, including
- developing additional blocks of standardized data elements that capture the most relevant information for case surveillance needs,
- more flexible solutions to receive related data that jurisdictions already have available, and
targeted, flexible approaches to gather additional risk factor-related data from a selected sampling scheme for cases or using other data sources
Q: What disease-specific MMG development is being paused?
A: At this time, development of new disease-specific MMGs is paused. In addition, most disease-specific MMGs in draft or with current development efforts will be paused; there may be a few exceptions, and CDC is working to provide those details as soon as possible.
Q: How will you pause disease-specific MMG onboarding?
A: CDC (DHIS, CSELS, and DDPHSS) will identify disease-specific MMGs in the middle of the onboarding process and the CDC programs and jurisdictions involved to develop an appropriate strategy that considers closeness to completion and outbreak surveillance needs, among other factors.
CDC (DHIS) will work with programs to understand how this strategy affects their needs and capabilities and develop action plans that include a clear definition of purpose, aims, and objectives of the data collection.
Q: What will the MMG pause mean for jurisdiction onboarding?
A: For onboarding MMGs, our current guidance is:
- Jurisdictional work on mapping or prepping for published MMGs is paused.
- Jurisdictions who have initiated onboarding for published MMGs can continue.
- Jurisdictions who are in the final stages of pre-onboarding for published MMGs (made system changes or created or validated test messages) can choose whether to continue onboarding.
- MMGs that will not be paused regardless of the jurisdiction implementation status are
- GenV2 (for the 72 GenV2-only conditions)
- Tuberculosis (TB)/latent TB infection (LTBI).
Q: If disease-specific MMG onboarding is paused, how will this affect jurisdictions’ ability to comply with the Epidemiology and Laboratory Capacity Health Information Systems (ELC HIS) Cooperative Agreement (CoAg) and, if applicable, the Emerging Infections Program (EIP)?
A: Due to recent adjustments in CDC surveillance efforts related to the adoption of MMGs, jurisdictions do not need to complete the ELC HIS MMG performance measure as you originally described in your application. CDC will provide further guidance on where efforts should focus for the remainder of the CoAg period.
For EIP, discussion will continue around methods for transmitting data to CDC.
Q: How will jurisdictions that use NBS meet the requirement to report tuberculosis (TB) using the MMG by 2023?
A: CDC will support any jurisdiction, including those that use NBS, that wants to onboard the TB MMG no matter where they are in the MMG implementation process (just starting, engaged in pre-onboarding technical assistance, or actively onboarding).
Q: Do these pauses mean that you are asking CDC programs to stop their surveillance?
A: No. Existing surveillance efforts with finalized MMGs and onboarded jurisdictions, as well as other existing mechanisms for receiving case notification data, will continue while CDC pauses MMG development and onboarding of disease-specific MMGs.
This pause aims to ease the burden on jurisdictions posed by implementing current guides, as well as free up CDC resources to work on harmonizing data standards and create streamlined, resource-appropriate, and effective enhanced surveillance methods to support jurisdictions and CDC programs.
During the pause, CDC (DHIS, CDC programs) will work together with jurisdictions to do the following:
- Define data elements based on disease-specific MMGs, which will inform a future enterprise-standardized data dictionary.
- Identify opportunities to harmonize data elements across conditions.
- Use previous work on disease-specific MMGs to inform our efforts to expand the range of available data formats beyond HL7.
Q: If there are disease-specific HL7 MMGs that have been developed and implemented in many jurisdictions, will CDC programs continue to receive that data?
A: Yes, for jurisdictions that have already onboarded and are sending HL7 messages for disease-specific MMGS, those data can and will continue to flow and be used. The pause is on development of new disease-specific MMGS and on onboarding new jurisdictions to HL7.
- DHIS will continue to lead work to standardize the disease-specific data beyond GenV2 needed for most programmatic activities.
- The vision is that, led by DHIS and guided by the North Star Architecture, agile, flexible solutions incorporating common data standards for supplemental case data will be implemented.
- This includes standardized data dictionaries that define supplemental sets of data elements and more flexibility at CDC to receive disease-specific data from jurisdictions, not just HL7 as currently required by the MMG approach.
Q: What is the plan and timeline for developing new and more modern, agile methods for reporting disease-specific data? Will programs simply ask for those data in a myriad of ways in the interim?
A: CDC expects to provide more details about the implementation plan and timeline for these case surveillance enhancements in the coming weeks, after we gather feedback from CDC programs and jurisdictions, which is critical to informing our work.
As part of this outreach during the next month, CDC will identify disease-specific MMGs currently in development by CDC programs and work with those programs to outline their objectives and a plan for data collection that also eases the burden on jurisdictions. Programs will be asked not to start any new data exchange work with jurisdictions as CDC needs to ensure that data exchange methods align with DMI efforts such as the North Star Architecture.
We recognize that disease-specific data are vitally important to jurisdictions and CDC and an important part of the NNDSS data flow. Disease-specific MMG content will still be used for supplemental data to CDC through a wider range of formats and to inform standardized data dictionaries that define supplemental sets of data elements that can be used across conditions.
CDC plans to expand the range of data formats that jurisdictions can use to send case surveillance data to CDC beyond HL7 V2, such as CSV, FHIR, and other formats, to help ease the burden on jurisdictions. New technology strategies are expected to reduce the need for mapping data elements to a message, further reducing the jurisdiction burden.