I. CDC Foodborne Illness Surveillance Data Systems and Strategies
2019 FSMA Annual Report
Overview of DFWED Foodborne Illness Surveillance in Its Current State
The mission of CDC’s Division of Foodborne, Waterborne, and Environmental Diseases (DFWED) is to improve public health nationally and internationally through the prevention and control of disease, disability, and death caused by foodborne, waterborne, and environmentally transmitted infections. DFWED supports states’ capacity to conduct surveillance through the Epidemiology and Laboratory Capacity (ELC) for Infectious Diseases Cooperative Agreement and the Emerging Infections Program (EIP). The ELC is CDC’s national funding strategy that supports state, local, and territorial health departments in combatting domestic infectious disease threats. The EIP is a network of 10 state health departments that act as a national resource for surveillance, prevention, and the control of emerging infectious diseases by providing the highest quality scientific information to monitor emerging problems, evaluate public health interventions, and inform policy.
DFWED uses the following 14 surveillance systems to track and monitor reports of foodborne and waterborne diseases in the United States:
- COVIS: Cholera and Other Vibrio Illness Surveillance
- CryptoNet: Molecular-based Cryptosporidiosis Surveillance
- FDOSS: Foodborne Disease Outbreak Surveillance System
- FoodNet: Foodborne Diseases Active Surveillance Network
- LEDS: Laboratory-based Enteric Disease Surveillance (formerly PHLIS: Public Health Laboratory Information System)
- LI: Listeria Initiative
- NAFIS: Network for Aquatic Facility Inspection Surveillance
- NARMS: National Antimicrobial Resistance Monitoring System for Enteric Bacteria
- NNDSS: National Notifiable Diseases Surveillance System
- NORS: National Outbreak Reporting System
- NTPFS: National Typhoid and Paratyphoid Fever Surveillance
- OHHABS: One Health Harmful Algal Bloom System
- PulseNet: National Molecular Subtyping for Foodborne Diseases
- SI: STEC [Shiga toxin-producing Escherichia coli] Initiative
Surveillance can be passive, when healthcare providers/laboratories send reports to a health department on the basis of a known set of rules and regulations, or active, when health department staff contact healthcare providers/laboratories to solicit reports. The surveillance systems also differ in how they survey populations. Populations under surveillance can be national or sentinel, and the systems may record every single case or use a sampling scheme.
The surveillance systems record cases and outbreaks by different methods including
- Case-based surveillance – counts diagnosis of illness in a person
- Isolate-based surveillance – counts laboratory characterization of an isolate or a specimen
- Event-based surveillance – based on an event and no individual level data are reported
In addition, diseases reported in the data systems are categorized as reportable, nationally notifiable, and standardized:
- Reportable disease cases are mandatorily reported to state, local, and/or territorial jurisdictions when identified by a healthcare provider, hospital, or laboratory. State, local and territorial jurisdictions establish their lists of reportable diseases.
- Nationally notifiable disease cases are voluntarily reported to CDC by state and territorial jurisdictions, and not all nationally notifiable conditions are reportable in every state.
- Standardized surveillance captures cases meeting agreed-upon case definitions set by the Council of State and Territorial Epidemiologists (CSTE) that can be sent to CDC.
DFWED Surveillance Going Forward (2019 and Beyond)
Some CDC surveillance systems exist in silos, but improvements in connectedness are continually being made. Culture-independent diagnostics tests (CIDTs), WGS, and ongoing, agency-wide initiatives for surveillance modernization continue to transform DFWED’s surveillance systems. It is important that CDC dovetail and improve systems for national surveillance and support improved reporting from states to the National Notifiable Disease Surveillance System (NNDSS).
DFWED began working on a new surveillance strategy in 2018 to modernize and improve connectivity among surveillance systems. This strategy includes (1) forming a working group of experts in epidemiology, laboratory methods, surveillance, outbreak investigation, and bioinformatics; (2) holding regular meetings to discuss coordination of major surveillance efforts; and (3) organizing a retreat focused on developing a strategic plan. These efforts have resulted in the following surveillance objectives and strategies:
- Optimize data collection and transmission
- Hire and retain staff with informatics skills
- Support state partners
- Change data, processes, and systems in response to what is useful
- Link data sources in a timely manner
- Define standards for surveillance data and systems
- Improve compatibility between data and systems
- Drive action-oriented analyses
- Use and develop methods to identify public health problems
- Monitor progress towards prevention efforts
- Identify data needed for prevention efforts
- Disseminate data and conclusions to catalyze action
- Discuss results and plans with partners
- Translate surveillance data to prevention actions
- Communicate successes and challenges
Currently, DFWED is supporting improved reporting from all states to NNDSS by piloting in several states the Foodborne and Diarrheal Diseases Message Mapping Guide (FDD MMG) for multiple pathogens. The FDD MMG is expected to eventually be adopted by all states and will lead to streamlined data transmission between states and CDC. The FDD MMG is a guide for all jurisdictions on how to send data via an HL7 (Health Level 7) format for multiple nationally notifiable conditions and contains a subset of data elements.
The Working Group’s discussion included the following observations:
- CDC has very rich data on enteric diseases and foodborne illness, but the current surveillance data system is at times outdated, inefficient, and in need of better integration.
- While progress is being made, it is taking a significant amount of time to move away from records in paper form and provide data to multiple systems at CDC (i.e., 1991 MMWR Editorial Note).
- Surveillance data should be disseminated regularly and include information on whether the overall goal of reducing burden of foodborne illness is being achieved. Data interpretation may be complicated because better detection and better investigation increases reported cases and outbreaks; however, it is important to monitor progress toward achieving the desired outcome.
- Data and analyses disseminated by CDC should be actionable and provide enough detail to inform the frontline public health workforce.
- Having data electronically accessible to partners and the public (e.g., FoodNet Fast, NARMS Now) is more important than focusing on integrating data into fewer reports. Outward-facing, accessible data should be the goal.
- State and local health departments are the main users of data reported by CDC, but consumers, healthcare institutions, academic institutions, and industry also use these data and should be considered audiences.
- Delays in data release make it challenging for industry to act to prevent future outbreaks. Surveillance data should be made available to industry so they can determine factors associated with outbreaks and take preventive actions. Additionally, further discussion is needed about FDA’s ability to share producer information with industry.
- In addition to improving data collection, CDC should focus on collecting the “right” data rather than more data. Utilizing information from IFSAC projects (e.g., attribution and source predictive modeling) may help investigators determine which exposures are most valuable to focus resources to collect information.
- Improvements to surveillance need to focus on what would enhance public health work. The technology that is used should be streamlined rather than trying to use all new technology that may be overwhelming and, ultimately, reduce efficiencies.
- Electronic reporting of all notifiable diseases to CDC should be required. This includes a need for more automatic/electronic data systems for organisms such as Cyclospora and Cryptosporidium, which are, currently, largely labor-intensive paper systems.
- Funding to improve state epidemiological and laboratory capacity to conduct surveillance is a key priority. States continue to face technical and information technology challenges, because modernizing their systems is expensive. Funding support for states to improve core epidemiological capacity is also needed, as it is essential that investigations occur in a timely manner.
- Outbreaks could be detected much earlier if there was better surveillance. CDC has invested millions of dollars to transition its systems to align with current technology (e.g., WGS) and provide support to states to do the same. Nevertheless, the technological landscape is ever-changing, forcing CDC to adapt to be at the forefront.
Based on these discussions, the Working Group expressed interest in updates at future meetings on data integration efforts, including specific actions to advance the objectives and strategies. The Working Group highlighted the following possible responses:
- Continued infrastructure improvements are needed to enhance
- States’ ability to send electronic reports to CDC
- CDC’s ability to receive electronic data from states
- CDC’s ability to connect data systems to reduce redundancy
- CDC’s ability to adapt current systems to new technology (e.g., WGS)
- Making data available for users (e.g., using NORS Dashboard and NARMS NOW as models)
- Better traceforward/traceback data points, as well as better exposure data, are needed.
- New electronic and standardized epidemiological tools and informatics training are essential, as CDC aims to eventually phase out paper reporting and move to 100% electronic reporting from states.
- Challenges with data sharing persist. Improved surveillance data sharing from industry to FDA and CDC and vice versa is needed. Federal agencies should work closely with industry outside of outbreaks because communication is limited due to legal issues during outbreaks.
- State and local epidemiologists should receive training on interpretation of WGS surveillance data, so they can better prioritize which clusters to investigate.
- Surveillance data should be actionable to be more helpful to regulators and decision-makers. State regulators are interested in knowing their state’s illness rates, how they compare with other states regionally and nationally, and the foods causing illness, in addition to ways to eliminate sources of contamination.