BACKGROUND: The National Notifiable Diseases Surveillance System (NNDSS) supports assessment of epidemiologic trends and programmatic impact. NNDSS data are used by states/jurisdictions and are transmitted to CDC through the National Electronic Telecommunications System for Surveillance (NETSS) or the National Electronic Disease Surveillance System (NEDSS). Variations in reporting/notification may be due to disease/condition characteristics (e.g., symptoms, severity), availability of laboratory diagnostics, patient/provider awareness, jurisdiction attributes (e.g., laws, regulations), disease transmission setting, and capacity for electronic data exchange. Surveillance indicators can assess infrastructure, practices/procedures, thoroughness/appropriateness of case investigation, laboratory performance, and completeness of case reporting.
METHODS: Analyses used final NNDSS data (2006-2015) from MMWR. Specific indicators included overall completeness of epidemiologically important information, timeliness of reporting and notification, appropriateness and completeness of laboratory testing, completeness of vaccination history, and importation status.
RESULTS: Annual national data suggest that between 2006-2015, for H. influenzae, the percent of cases <5 years with serotype testing was 41-67% (range by year) and with complete vaccine history was 15-25%. For measles, overall completeness of data was 48-78%, importation status was known for 9-63% of cases, and laboratory testing was done at CDC for 14-69% of cases. For pertussis, 23-36% of children <7 years had complete vaccine history. For rubella, pregnancy status was known for 33-100% of cases and importation status was known for 17-75% of cases. For mumps, overall data completeness was 51-76%.
CONCLUSIONS: Surveillance indicators can assess the quality of the national electronic surveillance data. Although these indicators may not accurately reflect jurisdiction-based data or surveillance effort in certain situations, they can identify components of surveillance and electronic data exchange that need improvement and provide programmatic evaluation documentation.