Overview of National Surveillance for Vaccine-Preventable Diseases Sandra W. Roush, MT, MPH Surveillance Officer National Center for Immunization and Respiratory Diseases (proposed) Centers for Disease Control and Prevention phone: 404-639-8741 sroush@cdc.gov March 2007

Objectives for VPD Surveillance Estimate burden of disease, severity, complications Determine geographic distribution of illness Portray the natural history of a disease Detect epidemics/define a problem Generate hypotheses, stimulate research Evaluate control measures, monitor use of vaccine Monitor changes in infectious agents Detect changes in health practices Facilitate planning

Numbers in yellow indicate at or near record lows in 2005 Comparison of 20th Century Annual Morbidity and Current Morbidity: Vaccine-Preventable Diseases Disease 20th Century Annual Morbidity† 2005†† Percent Decrease Smallpox 48,164 100% Diphtheria 175,885 Measles 503,282 66 > 99% Mumps 152,209 314 Pertussis 147,271 25,616 83% Polio (paralytic) 16,316 1* Rubella 47,745 11 Congenital Rubella Syndrome 823 1 Tetanus 1,314 27 98% Haemophilus influenzae 20,000 226** 99% †Source: CDC. MMWR April 2, 1999. 48: 242-264 † †Source: CDC. MMWR. August 18, 2006 / 55(32);880-893 * Imported vaccine-associated paralytic polio (VAPP) ** Type b and unknown (< 5 years of age) Numbers in yellow indicate at or near record lows in 2005

Pre-Vaccine Era Estimated Annual Morbidity † Comparison of Pre-Vaccine Era Estimated Annual Morbidity and Current Estimated Morbidity: Vaccine-Preventable Diseases Disease Pre-Vaccine Era Estimated Annual Morbidity † 2005 Estimated Morbidity † Percent Decrease Hepatitis A 117,333 19,183 84% Hepatitis B (acute) 66,232 15,352 77% Pneumococcus (invasive) all ages 63,067 40,325 36% < 5 years of age 16,069 4,400 73% Varicella 4,085,120 817,024 80% † Unpublished CDC data, reported November 2006

Epic Surveillance Questions What does the data mean? Does ZERO mean ZERO? Can we describe the strengths and challenges of the surveillance system? Are there vaccine failures? Are the reported cases really cases?

Critical Elements in National Surveillance for VPDs Demographic data Clinical history Vaccination history Laboratory testing, confirmation, and molecular epidemiology Role of importation

Surveillance Indicators Developed in 1988 by PAHO for polio eradication effort surveillance infrastructure timeliness of reporting adequacy of case investigation appropriateness of laboratory testing and diagnostic effort Concept for US VPD surveillance indicators approved by CSTE in 1994 initially applied to measles currently for measles, rubella, mumps, pertussis, H. influenzae type b; adding meningococcal disease and varicella

Applied Vaccine-Preventable Disease Surveillance Indicators External standard for infrastructure: polio and acute flaccid paralysis Haemophilus influenzae type b Appropriateness of testing/diagnostic effort: proportion of cases meeting the clinical case definition that is lab confirmed Adequacy of case investigation: measles/rubella with an imported source complete vaccination history

Use of Case Definitions in VPD Surveillance Assure comparability among states and year-to-year May not be the same definitions a clinician would use Are not used to determine the need for public health action

Haemophilus influenzae type b (Hib) Invasive Disease National Surveillance

Haemphilus influenzae Incidence* Per 100,000 Children <5 years, By Year and Serotype, 1989-2005 *From CDC’s Active Bacterial Core surveillance (ABCs)

* National Notifiable Diseases Surveillance System Haemophilus influenzae Serotype Reporting, Children < 5 Years, NNDSS* Percent Year * National Notifiable Diseases Surveillance System

Enhancing Surveillance for H. influenzae Serotyping on sterile site isolates from children Obtaining vaccination history Improving case ascertainment Hospital based reporting Laboratory based reporting Tracking non-type b invasive disease

Pertussis National Surveillance

Reported Pertussis Cases, DTP

Challenges – Pertussis Vaccine effectiveness against classic pertussis ~85% among infants (lower for mild disease); inferred for adolescents and adults Immunity wanes 5-10+ years after vaccine and infection Pertussis increased activity typically occurs in 3 – 5 year cycles; challenge for research and maintaining infrastructure No well-accepted correlates of protection; role of CMI not defined Laboratory diagnostics not available for practitioners or to support surveillance

* Week 52 provisional data, NNDSS Percent Completeness of Pertussis Vaccine History National Notifiable Diseases Surveillance System (NNDSS) Percent Year * Week 52 provisional data, NNDSS

* Week 52 provisional data, NNDSS Percent of Cases with Laboratory Testing Among Those Meeting Pertussis Clinical Case Definition, NNDSS Percent Year * Week 52 provisional data, NNDSS

Pertussis Surveillance and Policy Priorities Define age-specific incidence, trends in pertussis to monitor the effectiveness of the vaccination program Determine Tdap effectiveness against pertussis and transmission Define factors contributing to severe pertussis among adults Enhance surveillance (e.g., cough duration, laboratory confirmation, vaccination history)

Streptococcus pneumoniae Surveillance

National Surveillance for Invasive S. pneumoniae 1994: DRSP under national surveillance 2000: invasive pneumococcal disease in children < 5 years under national surveillance Assess impact of PCV7 For states, raise awareness of vaccine recommendations and identify areas with sub-optimal vaccine use Complement DRSP surveillance Evaluate impact of campaigns for judicious antibiotic use 2006: Enhance national surveillance

National Reporting for Invasive S. pneumoniae < 5 Years No clear relationship between PCV7 coverage and rates of reported cases No invasive S. pneumoniae (ISP) < 5 years reported from 9 states during 2005 and 2006 State case reporting for 2005 30 states/DC reported 2,996 cases of DRSP 35 states/DC reported 1,495 cases of ISP < 5 years of age

Remaining Questions for S. pneumoniae Surveillance Will replacement disease become more of a problem? What is the effect on pneumonia? How will results in other settings compare? How can CDC and state partners assess the impact PCV7 vaccination with differential coverage both within and between states?

Measles, Rubella, and Mumps National Surveillance

Healthy People 2010 (HP 2010) Objectives 14-1. Eliminate Indigenous Cases of: Target Congenital Rubella Syndrome 0 Measles 0 Mumps 0 Rubella 0

Measles – United States, 1950-2005 2004 –37 2005 –66 Vaccine Licensed 1963 1st Elimination Goal Endemic Elimination Declared 2nd Goal 2 Doses 3rd Goal *2005 provisional data

Rubella - United States, 1966-2005 CRS: 2004 - 0 2005 – 1 Vaccine First Licensed 1969 2004 –10 2005 –11 Current Vaccine Licensed 1979 Elimination Goal Endemic Elimination Declared Reduction Goal *2005 provisional data

Number and Percent of Imported Measles Cases, United States, 1985 - 2005 * Includes Imported, imported-linked, and imported virus cases

Mumps – United States, 1968- 2006 Mumps Vaccine licensed 1967 20 40 60 80 100 120 140 160 1968 1972 1976 1980 1984 1988 1992 1996 2000 2004 Cases (thousands) Routine childhood recommendation 1977 2 dose MMR

Mumps Vaccination Program Goal and Surveillance HP 2010 – Eliminate indigenous transmission Passive surveillance: < 300 cases/year since 2001 (until 2006) (Elimination??) Surveillance indicators 1997 - 2005 Median days symptom onset to report 4-11 days 42%-57% of cases were confirmed Few viral isolates for molecular typing prior to 2006 (~ 1-2 per year since 2001-2005) Occasional clusters 2-3 epi-linked cases (until 2006)

Mumps Cases Reported by States, January 1 – September 2, 2006 (N=5,587)1 750 287 355 1956 574 880 155 8 < 25 cases 25-50 cases 51-100 cases 101-250 cases 251-500 cases 500 + cases 1 Reported through the National Notifiable Diseases Surveillance System (data provisional).

Enhancing Mumps Surveillance Obtain laboratory confirmation May include serology, viral culture, or PCR In 2004: 37 % were lab confirmed, 57 % were reported as “confirmed” Obtain vaccination history Obtain viral isolates for molecular epidemiology; molecular typing available at CDC Lab challenges: in vaccinees, can not rule out cases based on negative IgM

Varicella National Surveillance

Pre-Vaccine Annual Disease Burden 4 million cases 10,500-15,000 hospitalizations 100-150 deaths Risk factors for severe disease: extremes of age, immune deficiency Significant societal health burden

Varicella Vaccination Program Goals No program goal set at the beginning of the program Healthy People 2010 Goals, published in 1998 90% reduction in varicella (2010 - 400,000 cases) 90% vaccination coverage among 19-35 month olds 90% coverage among adolescents

Antelope Valley West Philadelphia Reported varicella cases and vaccination coverage* by year Varicella Active Surveillance Project, 1995-2005 Antelope Valley West Philadelphia Vaccination coverage Varicella cases *Coverage estimates from NIS in LA and Philadelphia, among children 19-35 months of age.

Challenges for Varicella Prevention Vaccine 80%-85% effective (1 dose) Vaccinated cases are infectious Diagnostic challenges for breakthrough disease (may be mild and atypical) Varicella outbreaks among highly vaccinated school children (coverage 96%-100%) Shift in age of cases but no increase in incidence among adults

Challenges for Varicella Surveillance Improve reporting and surveillance 25 states report varicella 31 states have case-based reporting 32,242 cases reported in 2005 Implement and improve case-based reporting with phased approach Focus: age, vaccine history, severity Sentinel sites, then statewide

Resources for Surveillance Support VPD Surveillance Manual http://www.cdc.gov/nip/publications/surv-manual/default.htm VPD Surveillance Satellite Course Web links: Pertussis outbreak guide http://www.cdc.gov/nip/publications/pertussis/guide.htm Varicella outbreak guide CSTE web site www.cste.org http://www.cdc.gov/nip/ed/resources-surv-05.htm Immunization Program Operations Manual State Immunization Program Manager, State Epidemiologist, NNDSS state coordinator NCIRD surveillance officer

THANK YOU ! Sandra W. Roush, MT, MPH Surveillance Officer National Center for Immunization and Respiratory Diseases Centers for Disease Control and Prevention phone: 404-639-8741 sroush@cdc.gov