Surveillance involves the continuous monitoring of disease trends in a population to achieve several main objectives: (1) provide information on changing health status, (2) provide feedback to modify health policies and systems, and (3) provide timely warnings of public health issues. There are two main types of surveillance - active surveillance involves regular outreach to collect data, while passive surveillance uses data generated without contact by the monitoring agency, such as reports of certain diseases. Communicable disease surveillance monitors the frequency, distribution, and risk factors of infectious diseases that can spread between humans or from animals/environments to humans. The goals are to estimate disease burden, detect outbreaks, evaluate control programs, and facilitate planning.

2. By
DR: NAJEEB MEMON
MPH
Assist: Professor
F.C.M & P.H.S
LUMHS, Jamshoro Pakistan
e mail mnajeeb80@gmail.com

4. Surveillance
• Watch over with great attention,
authority & often with suspicion.

5. • “The continuous scrutiny of the factors
that determine the
occurrence & distribution of disease
& other conditions of ill health.”
• Objective: Prevention

6. Surveillance Programmes
• Epidemiological Surveillance
• Demographic Surveillance
• Nutritional Surveillance
• Serological Surveillance

7. Main Objectives of Surveillance
• 1. To provide information about new &
changing trends in the health status of a
population. E.g:-
• Morbidity
• Mortality
• Nutritional status
• Or other indicators
• & environmental hazards
• Health practices
• & other factors that may affect the health.

8. 2. To provide feed-back
Which may be expected to modify the
policy & the system itself to redefinition of
objectives.
• 3. provide timely warning of public health
disasters so that intervention can be
mobilized.

9. Monitoring Surveillance
• Careful planning • In contrast, requires
professional analysis &
• Use of standarized sophisticated judgment of
data.
procedures & Methods of
Data collection • Leading to
• & can then be carried out recommendations for
control activities.
over extended periods of
time by technicians &
automated instrumentation.

10. Sentinel surveillance
• A method for identifying the missing cases & thereby
supplementing the notified cases is required.
• The sentinel data is extrapolated to entire population to
estimate the disease prevalence in total population.
• ( Reporting bias are minimized)
• Competent physicians ( or institutions ) in selected areas
to report the cases of disease in their areas.
• More valuable than traditional notification system.
Routine Surveillance / Traditional Notification system
• No routine notification system can identify all cases of
infection or disease.

11. Types of Surveillance
• Active
• Passive

12. Active Surveillance
• the collection of data on a disease by regular
outreach.
• Designated medical personnel are
called at regular intervals to collect
information on the new cases of
disease.
monitoring domestic violence in
emergency departments

13. Active Surveillance
Health Dept.
Designated medical personnel are
called at regular intervals to collect
information on the new cases of disease.

14. Passive Surveillance
• data generated without contact by
the agency carrying out the
surveillance.
• Reportable diseases fall under
this type of surveillance.

15. Passive
Surveillance
Health Dept.
Reportable diseases fall under
this type of surveillance

16. Communicable disease
surveillance
• Communicable disease surveillance is the
continuous monitoring of the frequency and the
distribution of disease, and death, due to
infections that can be transmitted from human to
human or from animals, food, water or the
environment to humans, and the monitoring of
risk factors for those infections.
Public health surveillance also encompasses
non-communicable conditions including injury,
for example poisonings.

17. Why do we undertake surveillance?
• Estimate magnitude of the problem
• 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 changes in infectious agents
• Detect changes in health practices
• Facilitate planning

18. • Surveillance may comprise:
• (a) Individual surveillance: This is surveillance of
infected persons until they are no longer a significant risk
to other individuals,
• (b) Local population surveillance: e.g., surveillance of
malaria,
• (c) National population surveillance: e.g., surveillance
of smallpox after the disease has been eradicated, and
• (d) International surveillance: At the international level, the WHO
maintains surveillance of important diseases (e.g., influenza,
malaria, polio, etc.) and gives timely warning to all national
governments . Surveillance, if properly pursued, can provide the
health agencies with an overall intelligence and disease- accounting
capability. Surveillance is an essential prerequisite to the rational
design and evaluation of any disease control programme.

19. Methods:
• Collection of Data
• Morbidity Mortality source of infection Mode of transmission
• Evaluation / Analysis
• Inference
• Dissemination of Information
to concerned Authorities for implementation

20. Eradication
• “Tear out by roots”
• “Cessation of infection & dis: from whole world”
• Eradication is an absolute process, an” all
or none” phenomenon, restricted to
termination of an infection from the whole
world.(through surveillance & containment)
• It implies that disease will no longer occur
in a population.
• To-date only one dis: has been eradicated
Smallpox

21. Elimination
• No case but causative agent may be there
• The term elimination is some times used
for “Eradication” of dis: (e.g Measles) from
a large geographic region or political
jurisdiction.
• In the state of our present knowledge, diseases
which are amenable to eradicate are:
Measles, Polio, Diphtheria, Guinea worm
Interruption of transmission of Disease.
Regional Elimination is seen as an important precursor of Eradication.