Frequently Asked Questions (FAQs) about NMI

Message mapping guides used in the National Notifiable Diseases Surveillance System program describe the data content needed for electronic HL7 case notifications for nationally notifiable infectious diseases or conditions.

These MMGs include a description of each data element in the case notification as well as the attributes associated with each data element, such as its valid values, whether the data element repeats, and HL7 instructions specific for the data element. Public health jurisdictions use the HL7 message structure specification/profile to package all the variables in a MMG into an HL7 case notification message.

MMGs are used for each condition or disease that is transmitted to CDC through NNDSS. Nationally notifiable diseases that do not have disease-specific variables use only the generic v2 MMG,  which includes the basic information needed in every case notification, while conditions with disease-specific data use both the generic v2 MMG and a disease-specific MMG.

MMGs help reporting jurisdictions map each data element in an MMG to a data element in the reporting jurisdiction’s surveillance information system. A data element defines a unit of information needed by the surveillance system.

CDC is developing new HL7 message mapping guides to improve collection, transmission, and analysis of data needed at the national level for public health surveillance. In doing so, CDC is implementing messaging standards and vocabulary standards in case notifications. For some diseases and conditions, the epidemiology of the notifiable disease has changed over time and new data are needed about risk factors or new clinical information is needed, such as laboratory tests and results, vaccination information, and treatment information. For other nationally notifiable diseases, CDC previously received only generic data but also now needs disease-specific data. (Note that NETSS uses a proprietary data and vocabulary format and is not based upon modern health information exchange standards.)

A disease-specific message mapping guide is similar to a data dictionary and indicates the data elements (generic or disease-specific) and the valid values for those data elements included in case notification messages. For example, in referring to the hepatitis MMG, we are referring only to the disease-specific data elements that are included within the hepatitis message. In contrast, when we refer to a disease-specific HL7 case notification message, we are referring to both the generic data elements that are part of all case notification messages and the data elements specific to that disease. For example, in referring to a hepatitis HL7 case notification message (or hepatitis message), we are referring to both generic and disease-specific data elements that, together, comprise the complete hepatitis HL7 case notification message. For this reason, we talk about implementing HL7 case notification messages and not about implementing MMGs.

The DHIS NMI team works with subject matter experts in CDC programs to prioritize MMGs for development. The first set of guides address the generic data elements that will be included in all messages as well as the disease-specific data elements for congenital syphilis, hepatitis, mumps, pertussis, and STD.

Final message mapping guides are now available for generic v2 and hepatitis on the NNDSS HL7 Case Notification Resource Center at https://wwwn.cdc.gov/nndss/case-notification/.

In addition, to support public health’s emergency arboviral response needs, CDC developed and published an updated arboviral MMG (v1.3), which is also available on the resource center. (Please note that aArboviral v 1.3 will not be implemented through MVPS.)

Jurisdictions are encouraged to work on implementing these messages and to contact CDC when they are ready to go through the onboarding process to be approved to send case notifications using the new generic v2, hepatitis, and arboviral disease messages.

Work also is underway on guides for babesiosis, congenital rubella syndrome, foodborne and diarrheal disease, malaria, measles, rubella, trichinellosis, and varicella. The next set of conditions will be identified at a later date.

No. The new HL7 MMGs are intended for transmitting individual case notifications. NMI expects to address an HL7-based mechanism for summary notifications in the future, but the current priority is developing guides for individual case notifications.

Any jurisdiction sending summary information for specific diseases should continue to do so using their current process.

The development of any message mapping guide and implementation of the case notification message based upon that MMG is a collaborative process that involves multiple teams, both internal and external to CDC. Internal teams include the CDC programs, NNDSS team, messaging and vocabulary team, MVPS development and testing teams, state implementation and technical assistance team. External groups include health jurisdictions, CSTE, and APHL.

CDC deliverables include the message mapping guide, business rules (BRs) for processing data by MVPS, test case scenarios, HL7 test messages, and an annotated case report form. The steps in the process of MMG development and case notification message implementation are as follows:

1. Initiation/concept.
2. Requirements analysis.
3. Message design and development.
4. Message reconciliation and finalization.
5. Pilot testing of MMG.
6. MVPS application development.
7. MVPS testing and implementation.
8. Publication of final MMG.
9. Onboarding jurisdictions to transmit data.

Due to budgetary, personnel, technical, and other resource constraints, CDC is proceeding with NMI—including the development of MMGs—in a phased, incremental manner, with due consideration at each step for how to achieve the most beneficial results in the briefest amount of time.

The NNDSS HL7 MMGs and Artifacts page at https://wwwn.cdc.gov/nndss/case-notification/message-mapping-guides.html contains a list of NNDSS HL7s MMGs that are currently in development. This section, called “MMGs in Development,” also contains any NNDSS HL7 MMGs that are currently available for a 30-day external review by public health reporting jurisdictions or other implementers. CDC responses will also be posted here after external review comments are evaluated for incorporation into the MMG.

No. MMGs in development are considered draft and may be revised until the time they are finalized.

Those jurisdictions selected for pilot testing MMGs should wait until contacted by the NMI State Implementation and Technical Assistance Team before using the MMGs, before implementing surveillance information system changes, and before submitting test messages to CDC.

All other jurisdictions should not plan to submit data to CDC or implement MMG-based updates to their surveillance information systems until final MMGs have been posted.

The National Notifiable Diseases Surveillance System Event Code List, posted under “MMG Related Documentation” on the NNDSS HL7 Case Notification Resource Center at https://wwwn.cdc.gov/nndss/case-notification/, should be used by jurisdictions implementing HL7 case notification messages to identify all the diseases or conditions (and their respective event codes) that should be sent to NNDSS by using the generic v2 MMG and other HL7 MMGs. As new disease-specific MMGs are developed, they will be added to this document.

NOTE: For simplicity in identifying those diseases and conditions that will use the generic v2

MMG only, we have filtered this information from the National Notifiable Diseases Surveillance

System Event Code List and separately posted this information on the NNDSS HL7 Case Notification Resource Center as “Annual Conditions that Only Use the Generic v2.0 Message Mapping Guide.” This list will be produced annually.

The “Event Codes” worksheet in the National Notifiable Diseases Surveillance System Event Code List has a “Preferred Mechanism” column that can be filtered by the type of MMG that jurisdictions are ready to adopt. If the “Preferred Mechanism” column is filtered by the words in the drop-down list specifying “Generic Individual Case Notification v2 (HL7),” then the conditions that use only the generic v2 MMG will be listed and should be sent by using only the generic v2 MMG. Alternatively, if the “Preferred Mechanism” column is filtered by the words in the drop-down list specifying “Generic Individual Case Notification v2 with STD Case

Notification v1 (HL7),” then STD conditions that use both the STD MMG and the generic v2 will be listed.

Not all the data elements in generic v2 are required, but jurisdictions are strongly encouraged to collect and send all of this information. The data elements designated as “required” are the minimum needed to process the record. “Preferred” data elements are expected for cases and are important information for basic disease surveillance. “Optional” data elements are recommended, and states are encouraged to supply this additional information. Whether a data element is required, preferred, or optional is indicated in the final generic v2 MMG, available on the NNDSS HL7 Case Notification Resource Center at https://wwwn.cdc.gov/nndss/casenotification/. On the “PHIN Variable IDs” worksheet of the generic v2 MMG, the column named “CDC Priority” indicates the prioritization of the data element by the CDC surveillance program. Regardless of whether a data element is considered preferred or optional, jurisdictions should map to and send all the data elements requested in the MMG that they collect in their surveillance information systems. We encourage jurisdictions to enhance their surveillance systems to capture all of the data elements requested in the MMG.

CDC encourages all jurisdictions to transition to the new guides as soon as possible after they are published as final because the new data elements are important for notifiable disease surveillance.

Eventually, the generic v2 MMG will be used with all nationally notifiable conditions. However, conditions that currently have disease-specific data being sent to CDC through NETSS cannot be sent by using the generic v2 MMG until there is a disease-specific MMG to complete the case notification.

Jurisdictions should use the National Notifiable Diseases Surveillance System Event Code List, posted under “MMG Related Documentation” on the NNDSS HL7 Case Notification Resource Center at https://wwwn.cdc.gov/nndss/case-notification/, to identify which conditions should be sent by using each of the new HL7 MMGs.

NOTE: For simplicity in identifying those diseases and conditions that will use the generic v2

MMG only, we have filtered this information from the National Notifiable Diseases Surveillance

System Event Code List and separately posted this information on the NNDSS HL7 Case Notification Resource Center as “Annual Conditions that Only Use the Generic v2.0 Message Mapping Guide.” This list will be produced annually.

The case notification messages for STD and hepatitis include the data elements from the STD and hepatitis MMGs in combination with the generic v2 MMG data elements. Jurisdictions should not send HL7 TB messages with generic v2 data elements to MVPS until the TB MMG is updated and CDC is ready for jurisdictions to send the revised TB case notifications, which include the data elements from the generic v2 MMG.

With MVPS, jurisdictions receive an acknowledgement confirming receipt and parsing of messages. A dashboard summarizes data sent by jurisdictions, including the details of messages received and processed by CDC, and it flags any warnings or errors. Jurisdictions will be able to identify problems and submit corrections to reconcile the data as needed throughout the year.

CDC is working to eliminate the duplication of data requested by CDC in various formats. NMI is one part of the CDC Surveillance Strategy, which is coordinating across the agency to consolidate systems, eliminate unnecessary redundancies in reporting, and reduce reporting burden.

The period of time where jurisdictions may need to send case notification messages in both the old format and the new HL7 format will vary by jurisdiction. Jurisdictions will need to develop plans for retiring the old format feeds, and CDC can provide technical assistance to help with the development of those plans.

The Message Validation, Processing, and Provisioning System, or MVPS, is software that validates and processes nationally notifiable disease (NND) case notification messages sent by jurisdictions in the new HL7 format and provisions the data to CDC programs.

MVPS addresses a number of data processing and distribution challenges. It allows CDC to receive NND data from jurisdictions, process them, and provision them to CDC programs more efficiently and effectively than existing systems. MVPS provides several benefits to jurisdictions and CDC programs:

• MVPS is reducing the number of systems processing data at CDC and allows for streamlined message processing from jurisdictions to CDC.
• MVPS standardizes data processed at CDC.
• MVPS allows CDC programs to receive, process, store, access, share, and analyze health-related data, including electronic health record data, to further the agency’s public health goals.
• Through the MVPS Dashboard, the system provides submitting jurisdictions the ability to view the data they have submitted and identify data quality issues.

The National Notifiable Diseases Surveillance System (NNDSS) is a nationwide collaboration that enables all levels of public health—local, state, territorial, federal, and international—to share notifiable disease-related health information. Public health uses this information to monitor, control, and prevent the occurrence and spread of state-reportable and nationally notifiable infectious and noninfectious diseases and conditions.

NNDSS is a multifaceted program that includes the surveillance system for collection, analysis, and sharing of health data. It also includes policies, laws, electronic messaging standards, people, partners, information systems, processes, and resources at the local, state, territorial, and national levels.

Integrated surveillance information systems in reporting jurisdictions that are based on the National Electronic Disease Surveillance System (NEDSS) architectural standards are primary data sources for NNDSS. Jurisdictions use these information systems to create and send standards-based case notifications to CDC for NNDSS. Currently, case notifications can be sent by using three different standards; CDC’s NNDSS Modernization Initiative will provide a single, new standard to transmit data to CDC.

The NEDSS Base System (NBS) is a CDC-developed integrated information system that helps local, state, and territorial public health departments manage reportable disease data and send notifiable disease data to CDC. NBS provides a tool to support the public health investigation workflow and to process, analyze, and share disease-related health information. NBS also provides reporting jurisdictions with a NEDSS-compatible information system to transfer epidemiologic, laboratory, and clinical data efficiently and securely over the Internet.

Through the NNDSS Modernization Initiative, CDC is replacing the existing NNDSS messaging infrastructure, but not the NNDSS program, with a message validation, processing, and provisioning system—the MVPS—that facilitates the receipt and distribution of notifiable disease data. During NMI, jurisdictions will implement HL7 case notification messages and MVPS will support collection of data through new guides and a data exchange system that will result in more comprehensive, timely, and more accurate information than ever before provided to CDC programs.

MVPS is a CDC-built and operated message validation, processing, and provisioning system. It validates and processes NND messages sent by jurisdictions, provides a data quality dashboard, and provisions NND data to CDC programs.

The MVPS technology includes

• an integration engine that parses and transforms messages and files and performs vocabulary translations and data validations,
• a business rule management system processing engine, and
• a database management system that enables provisioning of data sent in the HL7 case notification messages for use by CDC programs.

MVPS provisions data to individual CDC programs, who determine user access to those data. Various options will be available over time, but, initially, data will be provided through SQL Server views.  

Data provisioning refers to the processes by which surveillance data received through NNDSS are made available to the disease-specific programs at CDC. It ensures that the necessary data relationships and data format are preserved to allow accurate and complete use of the data. It also defines the database structures (such as tables and views) that will be used to store the data and make them available to programs for analysis and reporting.  

Because the data processing and provisioning needs are different for each condition, the MVPS team identifies and documents the requirements for each condition. The MVPS team has developed a process to extract the data from the HL7 message, perform any needed validations (including content, structural, and business rules) or transformations, and populate the data into tables that are accessible by CDC programs.

The CDC Message Evaluation and Testing Service (METS) will serve as a common message validation service to assist jurisdictions in preparing and sending messages to CDC that adhere to the applicable messaging, vocabulary, and programmatic standards. Specifically, METS allows jurisdictions to evaluate their test messages as they develop their systems to send HL7 messages to CDC, ensuring that their systems are generating messages that conform to the proper message type structure, business rules, and content. 

The MVPS Dashboard is a component of MVPS that displays data sent by jurisdictions, including the details of messages received and processed by CDC, as well as warnings and errors on messages that were submitted by jurisdictions but do not pass the structural, content, and business rules validation. As a result, jurisdictions and programs use the dashboard to verify the number of messages received by CDC and to assist with the reconciliation of data throughout the year. In the longer term, MVPS also will provide information on which cases were included in the published weekly, quarterly, and yearly totals, allowing jurisdictions to reproduce counts and track case counts included within these tables.

No, MVPS will not supersede NNDSS. NNDSS is a multifaceted program that includes the surveillance system for collection, analysis, and sharing of health data. It also includes policies, laws, electronic messaging standards, people, partners, information systems, processes, and resources at the local, state, territorial, and national levels. MVPS is a data exchange system that is replacing and modernizing the current technical infrastructure that supports NNDSS.

NETSS will be used until all the notifiable conditions have been transitioned to new HL7 message mapping guides and NETSS can be retired. NETSS retirement is an NMI priority, so, although there is not a defined time table, all conditions and jurisdictions will be required to transition to the new HL7 case notifications.

As MMGs are finalized, jurisdictions are encouraged to implement MMG-based case notification messages in their surveillance systems and work with CDC for onboarding.

NETSS retirement is an NMI priority but a defined timetable has not been established. We expect to stop accepting NETSS messages as new guides are implemented for conditions. Right now, we do not have a firm timeline for how long we will continue to accept NETSS messages once MVPS is able to accept HL7 messages for a condition, but states should expect to complete the transition within 12–18 months after MVPS is able to accept data sent by using the new MMG. Jurisdictions are encouraged to begin implementing case notifications based upon new MMGs as they are finalized. The Health Information Systems component of the Epidemiology and Laboratory Capacity (ELC) Cooperative Agreement requires demonstrated progress toward the implementation of case notifications based upon the new MMGs.

The DMB and CDS systems will be replaced by the MVPS information system. Upon successful transition from DMB and CDS to MVPS, these legacy systems will be retired.

CDC asks NMI pilot jurisdictions to assist with testing MVPS releases before they are implemented. User acceptance testing is coordinated between CDC and the pilot jurisdictions. This effort includes participation from the MVPS development and testing teams, CDC programs, and the NMI technical assistance team.

Six MMGs (generic v2, STD, congenital syphilis, hepatitis, mumps, and pertussis) have been prioritized, two have been through UAT and are now final (generic v2 and hepatitis), and each of the remaining four will have an associated UAT timeframe for testing MVPS. The MVPS team will work with CDC programs and the NMI technical assistance team to define time frames and support actual testing.

Selected jurisdictions are asked to participate in two aspects of UAT: 1) formal user acceptance testing of the software, and 2) end-to-end testing, which includes provisioning data to CDC programs.

CDC is partnering with CSTE and APHL to provide and evaluate technical assistance to state and local jurisdictions to implement the new HL7 case notification messages. Through the NMI State Implementation and Technical Assistance Team, CDC and its partners will help jurisdictions adopt the MMGs and use them to send test case notification messages to MVPS to ensure that these messages will be properly received, processed, and stored for analysis through this new system. CDC, in collaboration with CSTE and APHL, provides direct technical assistance and training in the form of webinars, online technical guides, and other training materials to support implementation for all jurisdictions.

To help ensure a smooth and translatable technical assistance approach with all jurisdictions, the NMI State Implementation and Technical Assistance Team is piloting both the MMGs and the NMI technical assistance approach. For the most up-to-date list of NMI pilot states, please see the chart at the bottom of the monthly NMI Notes newsletter at https://www.cdc.gov/nmi/news.html.

In a collaborative effort, the CDC NMI team works with CDC programs, CSTE, and APHL to identify the jurisdictions to pilot the MMGs and technical assistance process. These jurisdictions are selected by using several criteria, including a jurisdiction’s technical experience and capacity, readiness and willingness to participate, scalability of their implementation experience, ability to provide feedback on NMI TA tools and resources, and ability to participate in NMI evaluation activities.

NMI pilot sites are engaged in several activities:

• adopting and providing feedback on pilot test-ready MMGs;
• providing feedback on TA tools and resources;
• testing and providing feedback on MVPS; and
• participating in the evaluation of the overall NMI pilot.

CDC has partnered with CSTE and APHL to provide technical assistance for the following activities:

• extracting data from surveillance information systems,
• mapping codes in the data extract to vocabulary specified in the MMGs,
• creating HL7 messages based on the MMGs by using an integration engine (e.g., Rhapsody) or other tools,
• facilitating secure transport of HL7 messages, and
• transferring knowledge to enhance in-house capability on the use of integration engines and infrastructure management for case notifications to CDC based upon MMGs; and
• providing education and training to build capacity to use current and future MMGs to implement case notification messages.

Yes, all jurisdictions have the opportunity to participate. The requirement to implement HL7 case notification messages, starting with the priority guides, and the ability to request technical assistance are both in the ELC Cooperative Agreement. Jurisdictions may choose to implement available HL7 case notification messages on their own as well. Either way, CDC will work with jurisdictions to monitor progress through the quarterly ELC Health Information Systems calls.

No. All jurisdictions can receive technical assistance for HL7 case notification message implementation. Jurisdictions using NBS will receive most of their technical assistance from the NBS team. Jurisdictions that do not use NBS will receive technical assistance from APHL.

No, there is no cost to the jurisdictions for technical assistance. Funding provided in the Health Information Systems component of the ELC Cooperative Agreement is intended to help jurisdictions implement the messages. When technical assistance is requested, jurisdictions will be prioritized based on their readiness and ability to conduct HL7 case notification message implementation activities.

All jurisdictions are invited to adopt finalized MMGs, go through onboarding, and send case notification messages to CDC through MVPS.

No. MMGs in development are considered draft and may be revised until the time they are finalized.

Jurisdictions selected for pilot testing of MMGs should wait until contacted by the NMI State Implementation and Technical Assistance Team before using the MMGs, before implementing surveillance information system changes, and before submitting test messages to CDC.

All other jurisdictions should not plan to submit data to CDC or implement MMG-based updates to their surveillance information systems until final MMGs have been posted.

Once an MMG is finalized, a jurisdiction may request onsite or virtual technical assistance by sending an e-mail to EDX@cdc.gov and completing a readiness assessment. The assessment will help to determine the following information:

• type(s) of assistance needed,
• identification of the guide(s), and
• primary point of contact and contact information.

No, they are related projects. Implementing case notifications based upon the new MMGs that are developed through NMI is a required activity in the Health Information Systems section of the ELC Cooperative Agreement.

Implementation of HL7 case notification messages developed through the NMI process is a requirement for jurisdictions who are receiving health information systems funding through the ELC Cooperative Agreement that covers 2014–2018. (Note that implementing the old HL7 guides does not meet this requirement, and jurisdictions should not invest effort in implementing those guides.)

The quarterly ELC Health Information Systems Implementation Support and Monitoring calls with CDC will include updates on HL7 case notification message implementation. The NMI team also is working with CSTE to evaluate the NMI effort. Additional details regarding monitoring and lessons learned activities will be provided at a later date.

Per the NMI performance objective in the CDC Surveillance Strategy, by 2016, 90% of data reported through NNDSS will be by standard HL7 messages.  A more up-to-date objective focuses on having 40% of case notifications submitted using HL7 messages by the end of 2017.

Grantees will identify a realistic number of priority HL7 case notification messages that they will implement in 2014–2018 and, by using these messages, successfully transmit associated notifiable diseases data to CDC.

Implementation of available HL7 case notification messages developed through the NMI process is a requirement for jurisdictions who are receiving Health Information Systems funding through the ELC Cooperative Agreement that covers 2014–2018.

CDC understands that jurisdictions not participating in the ELC Cooperative Agreement may face circumstances that affect their ability to implement the new HL7 case notification messages. It is nevertheless imperative that CDC and the public health community move forward with NMI so that NNDSS can provide more comprehensive, timely, and higher quality data to all users as soon as possible.