Overview of Uses for Public Health Surveillance

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Overview of Uses for Public Health Surveillance

• Daniel M. Sosin, M.D., M.P.H.
• Division of Public Health Surveillance and
  Informatics
• Epidemiology Program Office

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Public Health Surveillance

• Ongoing, systematic collection, analysis, and
  interpretation of health-related data and
  dissemination for use in the planning,
  implementation, and evaluation of public health
  practice.

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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control and prevention measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Shigellosis1968-1998
Source CDC. Summary of notifiable diseases.
1998.
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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• TOXIC SHOCK SYNDROME (TSS)
• United States, 1983-1998

160
National Center for Infectious Diseases (NCID)
data
National Electronic Telecommunications System for
Surveillance (NETSS) data
140
120
Reported cases
100
80
60
40
20
0
1992
1989
Year (Quarter)
1983
1984
1986
1987
1988
1990
1991
1993
1994
1995
1996
1997
1998
Includes cases meeting the CDC definition for
confirmed and probable cases for staphylococcal
TSS.
1985
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Rate of Hepatitis A United States, 1998
NYC
DC
PR
NA
VI
GUAM
AM SAMOA
NA
NA
CNMI
gt20.0
lt 5.0
5.09.9
10.019.9
Source CDC. Summary of notifiable diseases.
1998.
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Botulism (Foodborne) United States, 1978-1998
Laboratory-confirmed cases
NETSS data
Outbreak caused by potato salad, NM
Outbreak caused by sautéed onions, IL
Outbreak caused bybaked potatoes, TX
Outbreak caused by fermented fish/sea products, AK

Reported cases
Year
1978
1983
1988
1993
1998
Source CDC. Summary of notifiable diseases.
1998.
Data from survey of state epidemiologists and
directors of state public health laboratories.
Not yet available for 1998.
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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MEASLES (Rubeola) United States, 1963-1998
Vaccine licensed
Reported cases (thousands)
Year
Source CDC. Summary of notifiable diseases.
1998.
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Poliomyelitis (Paralytic)
United States, 1968-1998
Inactivated Vaccine
Oral Vaccine
Rate/100,000 Population
Reported cases
Year
NOTE Inactivated vaccine was licensed in 1955.
Oral vaccine was licensed in 1961.
Year
Source CDC. Summary of notifiable diseases.
1998.
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Trends in Plasmid-Mediated Resistance to
Penicillin and Tetracycline United States,
1988-1997
Source Gonococcal Isolate Surveillance Project
(GISP)
Percent
Year
Note "PPNG" (penicillinase-producing ) and
"TRNG" (tetracycline-resistant) N. gonorrhoeae
refer to plasmid-mediated resistance to
penicillin and tetracycline, respectively.
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Breast Cancer Screening
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Tuberculosis United States, 1986-1998 (U.S.-
and foreign-born persons)
Foreign-born
Source CDC. Summary of notifiable diseases.
1998.
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Uses of Public Health Surveillance

• Estimate magnitude of the problem
• Portray the natural history of a disease
• Determine distribution and spread of illness
• Detect outbreaks
• Generate hypotheses, stimulate research
• Evaluate control and prevention measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

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Surveillance for Outbreak Detection

• Convergence of technology, volumes of electronic
  data, and new priority for early detection
• Increase timeliness and completeness of routine
  data
• Capture nontraditional data that signify a
  condition before a diagnosis is made
• Analytic methods to detect smaller signals

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Surveillance for Outbreak Detection Experience

• Laboratory specificity to detect clusters
• Sentinel systems with resources to monitor and
  investigate
• Syndrome surveillance where outbreaks are
  substantial and predictable
• Case reports trigger outbreak investigation

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Surveillance for Outbreak Detection Exploration

• Enhanced reporting from clinical sites (ED, EMS,
  911, offices)
• Health care transaction warehouses (pharmacy,
  patient encounters, lab orders)
• Novel data sources (retail sales, veterinary
  encounters, environmental indicators,
  absenteeism)
• Signal detection methods

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Surveillance for Outbreak Detection Reality

• Human technology is key
• Single case detection depends on clinical acumen
  and reporting relationships
• Epidemiologic judgment in evaluating volumes of
  data
• Follow-up of system signals
• Tolerance for false alarms will vary

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Surveillance Research Needs

• Achieving the National Electronic Disease
  Surveillance System (NEDSS) architecture
• Data fusion (linkage)
• New data sources
• Case definitions (automation/validation)
• Geographic Information System (GIS) indices
• Forecasting
• Evaluation and quality control

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Resources

• www.cdc.gov/cic
• www.cdc.gov/epo/dphsi/phs.htm
• www.cdc.gov/epo/dphsi/phs/syndromic.htm
• dsosin_at_cdc.gov