Using Surveillance Indicators for Vaccine-Preventable Diseases: National Notifiable Diseases Surveillance System Sandra W. Roush, MT, MPH National Immunization Conference April 2010

Vaccine-Preventable Diseases (VPDs) Surveillance Indicators Team National Center for Immunization and Respiratory Diseases Centers for Disease Control and Prevention Linda M. Baldy, MPH Albert Barskey, MPH Susan B. Redd Sandra W. Roush, MT, MPH

Purpose of Surveillance Indicators Assess national surveillance and data quality for measles, mumps, rubella, pertussis, and Haemophilus influenzae, in terms of: surveillance infrastructure timeliness of reporting adequacy of case investigation appropriateness of laboratory testing and diagnostic effort

National Surveillance Background Diseases/conditions under national public health surveillance o determined by the Council of State and Territorial Epidemiologists (CSTE) o reported by health care providers and laboratories to local/state public health officials o included in the National Notifiable Diseases Surveillance System (NNDSS) National Notifiable Diseases Surveillance System o passive system o monitor epidemiologic trends and assess programmatic impact o electronic data to CDC through the National Electronic Telecommunications System for Surveillance(NETSS) or the National Electronic Disease Surveillance System (NEDSS) – –

Factors Related to Reporting Variations for Vaccine-Preventable Diseases Disease/condition Jurisdiction (laws, regulations) Patient and provider awareness o symptoms o incidence Clinical severity Transmission setting Availability of laboratory diagnostics Capacity for electronic data transmission

General Methods NNDSS data o weekly (provisional) o annual (provisional and final) o published in CDC's MMWR MMWR surveillance data o final, 2009 provisional o analyzed to assess surveillance indicators for - measles - mumps - rubella - pertussis - Haemophilus influenzae

Measles, Mumps, and Rubella Shared Surveillance Indicators Measles, mumps, and rubella have four indicators in common: The proportion of confirmed cases reported to NNDSS with complete information The median interval between symptom onset and notification of a public health authority The proportion of confirmed cases that is laboratory- confirmed The proportion of cases that has an imported source

Measles and Rubella Disease- Specific Surveillance Indicators Measles: o the proportion of cases for which at least one clinical specimen for virus isolation was collected and submitted to CDC o the number of discarded measles-like illness (MLI) reports (discontinued 1/1/2006) Rubella: o the proportion of confirmed cases among women of child-bearing age with known pregnancy status

Pertussis Surveillance Indicators The proportion of cases reported to NNDSS with complete information The mean interval between date of symptom onset and date of public health notification The proportion of cases meeting clinical case definition that is laboratory tested The proportion of cases with complete vaccine history

Haemophilus influenzae Surveillance Indicators The proportion of cases reported to NNDSS with complete information The proportion of cases among children < 5 years of age with complete vaccine history The proportion of cases among children < 5 years of age with isolate serotyping

Assessment of Measles, Mumps, and Rubella Surveillance Indicators Analyses included: ▲ cases reported with confirmed or unknown case status (measles, rubella) or ▲ confirmed, probable, and unknown (mumps) case status Reporting interval: median number of days from date of onset to notification Reporting completeness assessment: ▲ clinical case definition ▲ hospitalization ▲ lab testing ▲ vaccine history ▲ date reported to health department ▲ transmission setting ▲ outbreak related ▲ epidemiologic linkage ▲ date of birth ▲ onset date Missing values were considered invalid Unknown values were considered valid

Assessment of Pertussis Surveillance Indicators Analyses included cases reported with: ▲ confirmed ▲ probable or ▲ unknown case status Reporting interval: median number of days from date of onset to notification Reporting completeness assessment: ▲ clinical case definition ▲ complications ▲ antibiotic treatment ▲ lab testing ▲ vaccine history ▲ epidemiologic data (outbreak, epidemiologic linkage) Complete vaccination history: vaccine date and type for all reported doses Missing and unknown values were considered invalid

Assessment of Haemophilus influenzae Surveillance Indicators Analyses included cases reported with: ▲ confirmed ▲ probable or ▲ unknown case status Reporting completeness assessment: ▲ clinical case definition (species, specimen type) ▲ vaccine history ▲ serotype Missing values were considered invalid Unknown values were considered valid

Results: Disease Epidemiology and Surveillance Indicators

Reported Pertussis Cases* U.S., † All Ages <7 yrs old *National Notifiable Diseases Surveillance System (NNDSS) † 2009 data provisional DTP (1949) DTaP for doses 4 & 5 (1992) DTaP for all doses (1997) Tdap (2005)

Haemophilus influenzae Incidence* Per 100,000 Children <5 years, By Year and Serotype, *From CDC’s Active Bacterial Core surveillance (ABCs)

Measles – United States,* † Vaccine Licensed 1963 Measles cases – rd Goal Set (1993) 2 Doses EndemicEliminationDeclared (2000) 1 st Elimination Goal Set (1966) 2 nd Goal Set (1978) *National Notifiable Diseases Surveillance System (NNDSS) † 2009 data provisional

Rubella - United States,* † Vaccine First Licensed 1969 Current Vaccine Licensed 1979 Endemic Elimination Declared (2004) Reduction Goal Set (1989) Elimination Goal Set (2000) Rubella cases CRS: Year *National Notifiable Diseases Surveillance System (NNDSS) † Provisional 2009 data

Mumps – United States,* † Mumps Vaccine licensed 1967 Routine childhood recommendation dose MMR (1989) *National Notifiable Diseases Surveillance System (NNDSS) † Provisional 2009 data Year

U.S. Pertussis Surveillance Indicators for NNDSS: Completeness *, Lab Testing, Vaccination History, Reporting Interval,** 2000 – 2009*** * Clinical case definition, complications (pneumonia, seizures, hospitalized, encephalopathy, death), antibiotic treatment, laboratory testing, ever received pertussis vaccine, epidemiologic data (epi-link, outbreaks); unknown and missing=“incomplete” response ** Reporting interval (onset to report) range days (mean) percent ***Annual number of cases ranged from 7,580 (2001) to 25,827 (2004); 2009 data are provisional

U.S. Measles Surveillance Indicators for NNDSS: Completeness*, Lab Confirmation, Importation Status, Reporting Interval**, and CDC Specimens, *** * Clinical case definition, hospitalization, any lab test done, ever received measles vaccine, date reported, transmission setting, outbreak related, epi linked, date of birth, onset date: yes, no, unknown = “valid” ** Reporting interval (median days rash onset to report) range 1-6 days percent ***Total cases ranged from 140 (2008) to 37 (2004); 2009 data are provisional

U.S. Rubella Surveillance Indicators for NNDSS: Completeness*, Lab Confirmation, Importation Status, Reporting Interval,** and CDC Specimens, *** * Clinical case definition, hospitalization, any lab test done, ever received rubella vaccine, date reported, transmission setting, outbreak related, epi linked, date of birth, onset date: yes, no, unknown = “valid” ** Reporting interval (median days rash onset to report) range 1-16 days percent *** Total cases ranged from 176 (2000) to 4 (2009); 2009 data are provisional

U.S. Haemophilus influenzae Surveillance Indicators for NNDSS: Completeness*, Vaccination History, Serotype, 2000 – 2009** * Clinical case definition (e.g., specimen, invasive infection, species=Hi), serotype, ever received H. influenzae vaccine: unknown and missing=“incomplete” response percent **Annual number of cases (all ages) ranged from 1,398 (2000) to 2,895 (2009); annual number of cases (<5 yrs) ranged from 294 (2000) to 446 (2009); 2009 data are provisional

U.S. Mumps Surveillance Indicators for NNDSS: Completeness*, Lab Confirmation, Importation Status, Reporting Interval**, and CDC Specimens, *** * Clinical case definition, hospitalization, any lab test done, ever received mumps vaccine, date reported, transmission setting, outbreak related, epi linked, date of birth, onset date: yes, no, unknown = “valid” **Median reporting interval (symptom onset to report) range 4-11 days percent *** Total cases ranged from 6,582 (2006) to 231 (2003); 2009 data are provisional

Conclusions Surveillance indicators: can be monitored using passive surveillance data collected electronically. H. influenzae: data completeness is very low, especially the percent of cases <5 years with serotype and with complete vaccine history. Measles: effort must be maintained to ensure data completeness, determination of importation status, and laboratory testing at CDC. Pertussis: strategies must be implemented to enhance documentation of (adult and child) case vaccination history, while building laboratory testing infrastructure. Rubella: effort must be enhanced to achieve data completeness, focusing on pregnancy status for females and importation status for all cases. Mumps: effort must be enhanced to achieve data completeness, including specimen collection, laboratory testing, clinical description, vaccination history, and epi linkage.

Recommendations Continue annual assessment of VPD surveillance indicators Communicate results to partners Apply results in setting surveillance goals and strategies Explore application of surveillance indicators to other VPDs

Limitations of Analyses Phased implementation of data systems (NETSS mid-1990’s, NEDSS/NBS/PHIN ongoing) Published data possibly different from electronic data set prior to mid-1990’s Incomplete data possibly due to data system (transmission errors, coding errors) in addition to investigative effort Few external standards are available to monitor completeness of case reporting