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
Public Health Surveillance

Ongoing, systematic collection,
analysis, and interpretation of healthrelated data and dissemination for use
in the planning, implementation, and
evaluation of public health practice.
Uses of Public Health
Surveillance
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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
Uses of Public Health
Surveillance
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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
Shigellosis
15
Reported cases per 100,000
population
1968-1998
10
5
0
1968
1973
1978
1983
1988
1993
Year
Source: CDC. Summary of notifiable diseases. 1998.
1998
Uses of Public Health
Surveillance
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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
TOXIC SHOCK SYNDROME (TSS)
United States, 1983-1998
16
0
National Center for Infectious Diseases (NCID) data*
National Electronic Telecommunications System for
Surveillance (NETSS) data
Reported cases
14
0
12
0
10
0
8
0
6
0
4
0
2
0
0
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
Year (Quarter)
1993
1994
1995
1996
1997
1998
*Includes cases meeting the CDC definition for confirmed and probable cases for staphylococcal TSS.
Uses of Public Health
Surveillance
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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
Rate of Hepatitis A
United States, 1998
NYC
DC
PR
NA VI
GUAM
NA AM SAMOA
NA CNMI
< 5.0
5.0–9.9
10.0–19.9
>20.0
Source: CDC. Summary of notifiable diseases. 1998.
Uses of Public Health
Surveillance
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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
Botulism (Foodborne)
United States, 1978-1998
110
100
Reported cases
90
80
Outbreak caused by
potato salad, NM
Outbreak caused by
sautéed onions, IL
Outbreak caused by
fermented fish/sea
products, AK
70
Laboratory-confirmed
cases*
NETSS data
Outbreak caused by
baked potatoes, TX
60
50
40
30
20
10
0
1978
1983
1988
1993
Year
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.
Uses of Public Health
Surveillance
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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
MEASLES (Rubeola)
United States, 1963-1998
500
MEASLES — by year, United States, 1983–
1998
Vaccine licensed
30
450
25
400
Reported Cases
(Thousands)
20
15
350
10
Reported cases
(thousands)
300
250
5
0
1983
1988
1993
1998
Year
200
150
100
50
0
1963
1968
1973
1978
1983
Year
1988
1993
1998
Source: CDC. Summary of notifiable diseases. 1998.
Uses of Public Health
Surveillance
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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
Poliomyelitis (Paralytic)
United States, 1968-1998
60
Rate/100,000 Population
55
50
Reported cases
45
40
35
30
25
1000
100
10
Inactivated
Vaccine
Oral
Vaccine
1
0.1
0.01
0.001
1951 1956 1961 1966 1971 1976 1981 1986 1991 1996
Year
20
15
10
5
0
1968
Year
1973
1978
1983
1988
1993
1998
NOTE: Inactivated vaccine was licensed in 1955. Oral vaccine was licensed in 1961.
Source: CDC. Summary of notifiable diseases. 1998.
Uses of Public Health
Surveillance
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

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
Trends in Plasmid-Mediated Resistance to
Penicillin and Tetracycline
United States, 1988-1997
12
PPNG
TRNG
10
PPNG & TRNG
Percent
8
Source:
Gonococcal Isolate
Surveillance Project
(GISP)
6
4
2
0
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
Year
Note: "PPNG" (penicillinase-producing ) and "TRNG" (tetracycline-resistant) N. gonorrhoeae refer to plasmidmediated resistance to penicillin and tetracycline, respectively.
Uses of Public Health
Surveillance
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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
Breast Cancer Screening
Uses of Public Health
Surveillance
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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
Tuberculosis
United States, 1986-1998
(U.S.- and foreign-born persons)
20,000
Reported cases
U.S.-born
Foreign-born
16,000
12,000
8,000
4,000
Year
0
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
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
Surveillance for Outbreak
Detection
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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
Surveillance for Outbreak
Detection: Experience
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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
Surveillance for Outbreak
Detection: Exploration
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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
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
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Tolerance for false alarms will vary
Surveillance Research Needs
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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
Resources

www.cdc.gov/cic

www.cdc.gov/epo/dphsi/phs.htm

www.cdc.gov/epo/dphsi/phs/syndromic.htm

dsosin@cdc.gov