2. Group Discussion on:
SURVEILLANCE
Prepared By

3. WHAT IS
THE DEFINITION
OF SURVEILLANCE …?

4. DEFINITIONS OF SURVEILLANCE
• “The continued watchfulness over
the distribution and trends of
incidence through the systematic
collection, consolidation, and
evaluation of morbidity and
mortality reports and other
relevant data, together with
dissemination to those who need to
know.”
LANGMUIR, 1963

5. DEFINITIONS OF SURVEILLANCE
• “Surveillance serves as the
brain and nervous system
for programs to prevent
and control disease.”
D.A. HENDERSON, 1976

6. DEFINITIONS OF SURVEILLANCE
“Systematic ongoing
collection, collation and analysis
of data and the timely
dissemination of information to
those who need to know so that
the action
can be taken”
WHO 2001

7. KEY ELEMENTS
1. Collection of health data expressly for
use in health planning, disease control/
prevention, and/or health promotion.
2. Ongoing collection of data.
3. Timely analysis.
4. Easily understood.
5. Dissemination of results.
6. Action based on results.
7. Periodic evaluation of the system.
(Detels, 1989)

8. What Are
THE TYPES
OF SURVEILLANCE…?

11. Uses of Surveillance
Outbreaks
Detection
Human Diseases
Zoonotic Diseases
Food Safety
Drug resistance
Organisms
Monitor Changes or
trends in heath
factors
Disease burden
Emerging
diseases
Geographic
distribution
Risk group
distribution
Health information
for intervention
programs
Evaluate effectiveness
of intervention
strategies.

14. 10Stepsoutbreak
investigation
1.Prepare to investigate.
2. Verify the diagnosis and confirm outbreak.
3. Case definition.
4. Case finding.
5. Perform descriptive epidemiology.

15. 6. Hypothesis generation—the how and the
why.
7. Evaluate hypothesis thorough statistics.
8. Additional environmental studies.
9. Implement control/prevention measure.
10. Communicate findings.
10Stepsoutbreak
investigation

16. EVALUATION …. Of
SURVEILLANCE SYSTEM

17. SURVEILLANCE SYSTEM
EVALUATION
Sensitivity
Timeliness
Representativen
essPredictive value
positive
Acceptability
Flexibility
Simplicity
Cost/benefit
Dissemination
of results
Appropriate
action taken

18. SURVEILLANCE SYSTEM
EVALUATION
• What proportion of
“cases” are
identified?
• Does the system give
an accurate picture of
trends and
magnitudes?
• Sensitivity

19. SURVEILLANCE SYSTEM
EVALUATION
• Timeliness
Is information disseminated
rapidly enough to permit timely
action based on the surveillance
system?

20. SURVEILLANCE SYSTEM
EVALUATION
• Representativeness
• Do reported cases
differ from unreported
cases?

21. SURVEILLANCE SYSTEM
EVALUATION
• Positive predictive
value
• What proportion of
those identified
actually have the
disease or factor?

22. SURVEILLANCE SYSTEM
EVALUATION
• Acceptability
• Does the system stimulate
the cooperation of
respondents?
• Does the process
discourage participation?

23. SURVEILLANCE SYSTEM
EVALUATION
• Flexibility
• Can changes be easily made in
the system to reflect changes
in trends, magnitude and
other relevant factors?

24. SURVEILLANCE SYSTEM
EVALUATION
• Simplicity
• Can the system be simplified
and still obtain the necessary
information?

25. SURVEILLANCE SYSTEM
EVALUATION
• Cost/benefit
• Is the system worth the cost?
• Can costs be reduced without
sacrificing the essential quality
of the system ?

26. SURVEILLANCE SYSTEM
EVALUATION
• Dissemination of
results
• To decision-makers
• To data collectors
• To the general public

27. SURVEILLANCE SYSTEM
EVALUATION
• Appropriate
action taken
• Are appropriate actions
taken in response to the
surveillance data?
• Does surveillance lead to
effective intervention?

28. Comparison With
International Standards
• Use of electronic notification system.
• Category of reported cases.
• Using of disease specific indicators.
• Wide use of active surveillance.
• Monitoring of diagnostic efforts.

29. Comparison With International
Standards
• Monitoring circulation of organisms.
• Awareness about the surveillance.
• Giving frequent and relevant feedback.
• Dissemination.
• Risk Communication.
• Evaluation of surveillance system.