Public health surveillance involves the continuous collection and analysis of health data to support public health practices. It can be used for immediate detection of epidemics or long-term monitoring of disease trends. Active surveillance employs staff to directly collect data while passive surveillance relies on voluntary reporting from healthcare providers. Syndromic surveillance monitors clinical symptoms before confirmation of diagnoses. Integrated disease surveillance at national and global levels aims to strengthen communicable disease monitoring through standardized guidelines and collaboration across networks.

1. Public health
surveillance
Dr. Manisha Mandal
Junior Resident
CCM, A.I.I.M.S.
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2. Bubonic plaque
Public health authorities boarded the ships from port to prevent
people with bubonic plaque like illness from disembarking
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3. Definition
• Public health surveillance is the
continuous, systematic collection, analysis
and interpretation of health-related data
needed for the planning, implementation,
and evaluation of public health practice.
WHO | Public health surveillance [Internet]. WHO. [cited 2016 Nov 4]. Available
from: http://www.who.int/topics/public_health_surveillance/en/
Adapted from: Thacker SB, Birkhead GS. Surveillance. In: Gregg, MB, ed. Field
epidemiology. Oxford, England: Oxford University Press; 2008.
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4. Public health core sciences
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5. Uses
Immediate detection
of:
• Epidemics
• New health
problems
• Changes in health
practices
• Changes in
distribution of
population at risk
Periodic
dissemination
for
• Estimating health
problem magnitude
• Assessing control
activities
• Setting research
priorities
• Determining risk factors
• Facilitating planning
• Monitoring changes in
health practices
Stored
information for
• Describing natural
history of diseases
• Validating use of
preliminary data
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9. SURVEILLANCE TYPES AND
DEFINITION
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10. Definitions
1. Indicator: a measurable factor that allows decision makers
to estimate objectively the size of a health problem and
monitor the processes, the products, or the effects of an
intervention on the population
• immunization indicators
2. Active surveillance: a system employing staff members to
regularly contact heath care providers or the population to
seek information about health conditions.
• most accurate and timely information
• expensive
• eg: Measles , Tetanus , Poliomyelitis
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11. Definitions
3. Passive surveillance: a system by which a health jurisdiction
receives reports submitted from hospitals, clinics, public health
units, or other sources.
• relatively inexpensive strategy to cover large areas
• depends on people in different institutions to provide data
• data quality and timeliness are difficult to control.
• eg : Diptheria , Hepatitis B , Mumps
4. Routine health information system: a passive system in which
regular reports about diseases and programs are completed by
public health staff members, hospitals, and clinics.
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12. Definitions
5. Health information and management system: a passive
system by which routine reports about financial, logistic, and
other processes involved in the administration of the public
health and clinical systems can be used for surveillance.
6. Categorical surveillance: an active or passive system that
focuses on one or more diseases or behaviors of interest to an
intervention program.
• useful for program managers
• inefficient at the district or local level
• eg. HIV, T.b., S.T.D.
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13. Definitions
7. Integrated surveillance:
a combination of active and passive systems using a single
infrastructure that gathers information about multiple diseases
or behaviors of interest to several intervention programs
• Eg: a health facility–based system may gather information on
multiple infectious diseases and injuries
 duplication and inefficiency
8. Sentinel surveillance:
• missing data
• When data about disease cannot be completed with help of passive
surveillance
• eg: Hib, HIV 13

14. Sentinel surveillance
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15. Definitions
9. Syndromic surveillance: an active or passive system that uses
case definitions that are based entirely on clinical features
without any clinical or laboratory diagnosis
• number of cases of diarrhea rather than cases of cholera
• "rash illness" rather than measles
Inexpensive
Fast
Often the first kind of surveillance begun in a developing country
 lack of specificity
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16. 16

17. Syndromic surveillance
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Overview of Syndromic Surveillance What is Syndromic Surveillance? [Internet]. [cited 2016 Nov 7]. Available from:
http://www.cdc.gov/Mmwr/preview/mmwrhtml/su5301a3.htm
Overview | NSSP | CDC [Internet]. [cited 2016 Nov 7]. Available from: http://www.cdc.gov/nssp/overview.html

18. Syndromic surveillance
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19. Definitions
10. Behavioral risk factor surveillance system (BRFSS):
an active system of repeated surveys that measure behaviors
that are known to cause disease or injury
• Eg: tobacco or alcohol use, unprotected sex, or lack of physical
exercise
• provide a direct measure of their effect in the population
before the anticipated health effects are expected
• provide timely measures of program effectiveness for both
communicable and non-communicable disease interventions.
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20. BRFSS
• Premier system of health-related telephone surveys that
collect state data about U.S. residents
• regarding their health-related risk behaviors, chronic health
conditions, and use of preventive services
20CDC - BRFSS - Survey Data & Documentation [Internet]. [cited 2016 Nov 7].
Available from: http://www.cdc.gov/brfss/data_documentation/index.htm

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22. BRFSS
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23. Other Surveillance types
• Environmental public health surveillance
• Injury surveillance
• Surveillance for biologic terrorism
• Chronic disease surveillance system
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24. Objectives and action plan
Objective Action Data System
-Detect
epidemics
Epidemic
response
Early warning
information
Active
surveillance
-Monitor
intervention
programs
Program
monitoring
Program
indicators
Health
information
-Monitor impact
of policy change
Health policy Health
indicators
Health
information
-Monitor health
system
Resource
allocation
Administrative
data
Health
information and
management
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25. ATTRIBUTES OF SURVEILLANCE
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26. Attributes
1. Completeness :
• Essential in highly transmissible and severe infectious
disease
• To interrupt transmission
2. Representativeness :
• To know the target intervention
• Affected by variation in reporting
3. Predictive value :
• affected by criteria used
• laboratory services
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27. Attributes
4. Timeliness :
• to detect outbreaks, monitoring within hours or days
• for chronic diseases, long term over period of years
5. Acceptability
6. Simplicity
7. Flexibility
• change in criteria
8. Stability
9. Interoperability : ability to compare or share information
across multiple surveillance systems
10. Cost 27

28. ELEMENTS OF SURVEILLANCE
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29. Develop case definitions
Establish goals
Acquire tools and clearance for collection,
analysis, and dissemination
Select personnel, data collection
Data analysis
Evaluate surveillance activities
Elements in establishing and maintaining a
surveillance system
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30. Case definitions
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31. Case definitions
• Objective definition for
• Time period
• Place
• Person
• Categorizing into “susceptible” or “ confirmed “
• Sensitivity V/s Specificity
 Outbreaks
 Self reported, syndromic
approach
 Non epidemic periods
 Laboratory confirmed
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32. Data collection
• Reported diseases or syndromes
• Electronic health records (e.g., hospital discharge data)
• Vital records (e.g., birth and death certificates)
• Registries (e.g., cancer, immunization)
• Surveys (e.g., National Health and Nutrition Examination
Survey [NHANES])
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33. Global infectious disease surveillance
framework
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34. Integrated Disease Surveillance
(IDS) Programme
• Ensures availability of guidelines for integrated disease
surveillance and response
• provides necessary technical support for strengthening
national communicable disease surveillance systems
• through implementation of the Regional Strategy for
Integrated Disease Surveillance and the International health
Regulations.
Integrated Disease Surveillance - WHO | Regional Office for Africa [Internet]. [cited
2016 Nov 6]. Available from: http://www.afro.who.int/en/integrated-disease-
surveillance/
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35. Integrated Disease Surveillance
(IDS) Programme
• establishes links with –
National Centres of Excellence (CoE)
Regional and global networks for disease surveillance
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36. International health
regulations
Binding international legal
agreement involving 196 countries
across the globe, including all the
Member States of WHO
AIM: prevent, protect against, control and provide a public health response to the
international spread of disease in ways that are commensurate with and restricted
to public health risks, and which avoid unnecessary interference with international
traffic and trade.
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37. IDSP
• Launched by Hon’ble Union Minister of Health & Family
Welfare November 2004 for a period upto March 2010
• The project was restructured and extended up to March 2012
• The project continues in the 12th Five year plan as
Programme
• A Central Surveillance Unit (CSU) at Delhi
• State Surveillance Units (SSU) at all State/UT head quarters
and District Surveillance Units (DSU) at all Districts in the
country
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38. IDSP
• Data is collected on epidemic prone diseases on weekly basis
(Monday–Sunday)
• The information is collected on three specified reporting
formats, namely “S” (suspected cases), “P” (presumptive
cases) and “L” (laboratory confirmed cases)
• filled by Health Workers, Clinicians and Laboratory staff
• weekly data gives information on the disease trends and
seasonality of diseases.
• Whenever there is a rising trend of illnesses in any area, it is
investigated by the Rapid Response Teams (RRT) to diagnose
and control the outbreak
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39. National notifiable diseases
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40. Analysis and evaluation
Source: Centers for Disease Control and Prevention (CDC). National Notifiable Diseases Surveillance System and
Supplemental Pertussis Surveillance System and 1922-1949, passive reports to the US Public Health Service. Atlanta, GA:
US Department of Health and Human Services, CDC. Available at: http://www.cdc.gov/pertussis/images/incidence-
graph.jpg.
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42. References
• Oxford textbook of public health surveillance
• WHO | Public health surveillance [Internet]. WHO. [cited 2016 Nov
4]. Available from:
http://www.who.int/topics/public_health_surveillance/en/
• Integrated Disease Surveillance - WHO | Regional Office for Africa
[Internet]. [cited 2016 Nov 6]. Available from:
http://www.afro.who.int/en/integrated-disease-surveillance/
• Nsubuga P, White ME, Thacker SB, Anderson MA, Blount SB, Broome
CV, et al. Public Health Surveillance: A Tool for Targeting and
Monitoring Interventions. In: Jamison DT, Breman JG, Measham AR,
Alleyne G, Claeson M, Evans DB, et al., editors. Disease Control
Priorities in Developing Countries [Internet]. 2nd ed. Washington
(DC): World Bank; 2006 [cited 2016 Nov 4]. Available from:
http://www.ncbi.nlm.nih.gov/books/NBK11770/ 42

43. References
• Introduction to Public Health Surveillance|Public Health 101
Series|CDC [Internet]. [cited 2016 Nov 6]. Available from:
http://www.cdc.gov/publichealth101/surveillance.html
• CDC - BRFSS - Survey Data & Documentation [Internet]. [cited 2016
Nov 7]. Available from:
http://www.cdc.gov/brfss/data_documentation/index.htm
• Overview of Syndromic Surveillance What is Syndromic
Surveillance? [Internet]. [cited 2016 Nov 7]. Available from:
http://www.cdc.gov/Mmwr/preview/mmwrhtml/su5301a3.htm
• Overview | NSSP | CDC [Internet]. [cited 2016 Nov 7]. Available
from: http://www.cdc.gov/nssp/overview.html
• WHO | Sentinel Surveillance [Internet]. WHO. [cited 2016 Oct 19].
Available from:
http://www.who.int/immunization/monitoring_surveillance/burden
/vpd/surveillance_type/sentinel/en/ 43