ByBy

DR: NAJEEB DR: NAJEEB MEMONMEMON

MPHMPHAssist: ProfessorAssist: Professor

F.C.M & P.H.SF.C.M & P.H.S

LUMHS, Jamshoro PakistanLUMHS, Jamshoro Pakistane mail e mail mnajeeb80@gmail.commnajeeb80@gmail.com

SurveillanceSurveillance

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

• “The continuous scrutiny of the factors that determine the

occurrence & distribution of disease & other conditions of ill health.”

• Objective: Prevention

Surveillance ProgrammesSurveillance Programmes

• Epidemiological Surveillance

• Demographic Surveillance

• Nutritional Surveillance

• Serological Surveillance

Main Objectives of SurveillanceMain 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.

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.

Monitoring

• Careful planning

• Use of standarized procedures & Methods of Data collection

• & can then be carried out over extended periods of time by technicians & automated instrumentation.

Surveillance

• In contrast, requires professional analysis & sophisticated judgment of data.

• Leading to recommendations for control activities.

Sentinel surveillanceSentinel 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.

Types of SurveillanceTypes of Surveillance

•Active

•Passive

Active SurveillanceActive 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

Active SurveillanceActive Surveillance

Health Dept.

Designated medical personnel are called at regular intervals to collect information on the new cases of disease.

Passive SurveillancePassive Surveillance

• data generated without contact by the agency carrying out the surveillance.

• Reportable diseases fall under this type of surveillance.

Passive Passive SurveillanceSurveillance

Health Dept.

Reportable diseases fall under this type of surveillance

Communicable disease Communicable disease surveillancesurveillance

• 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.

Why do we undertake surveillance?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

• 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.

Methods:Methods:• Collection of Data

• Morbidity Mortality source of infection Mode of transmission

• Evaluation / Analysis

• Inference

• Dissemination of Information

to concerned Authorities for implementation

EradicationEradication• “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

EliminationElimination• 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.