Using Surveillance Indicators for Vaccine-Preventable Diseases (VPDs): National Notifiable Diseases Surveillance System (NNDSS), 2000-2009

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 VPD reporting and notification may be due to disease/condition characteristics (e.g., symptoms, incidence, severity), availability of laboratory diagnostics, patient and provider awareness, jurisdiction attributes (e.g., laws, regulations), disease transmission setting, and capacity for electronic data transmission. Surveillance indicators can assess infrastructure, practices/procedures, thoroughness and appropriateness of case investigation, laboratory performance, and completeness of case reporting.

Objectives: By the end of the presentation participants will be able to: • describe surveillance indicators • understand surveillance indicator data for measles, mumps, rubella, pertussis, and Haemophilus influenzae • discuss the utility of new surveillance indicators for varicella, invasive pneumococcal disease, and meningococcal disease

Methods: Analyses used NNDSS data from MMWR (2000-2009). 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: Final national data suggest that annually, for H. influenzae, the percent of cases <5 years with serotype testing was 40-63% (range by year) and with complete vaccine history was 15-22%. For measles, overall completeness of data was 56-87%, importation status was known for 18-73% of cases, and laboratory testing was done at CDC for 21-70% of cases. For pertussis, 17-51% of children <7 years had complete vaccine history. For rubella, pregnancy status was known for 33-84% of cases and importation status was known for 0-44% of cases. For mumps, overall data completeness was 40-60%.

Conclusions: Surveillance indicators, monitored through electronic national passive surveillance data, can assess the quality of national surveillance data and identify components of surveillance that need improvement.