2. EPIDEMIOLOGY
DEFINITION:
The study of the distribution and determinants of disease or health
related states and events in specified populations, and the application
of the knowledge for disease prevention and control.
3. EPIDEMIOLOGY
Uses of Epidemiology
Establishing the magnitude and distribution of need
Identifying high risk groups
Health Situation Analysis/Health Status Assessment
Planning provision of health care services
Evaluate the impact of current services
Identify factors, if they could be removed, would prevent the disease or modify its course
Knowing which is the most effective way of delivering a curative or preventive measure
Determine cost and expected effectiveness of a proposed strategy
4. EPIDEMIOLOGY
Components of Epidemiology
Studies of Disease frequency
Studies of the distribution.
Studies of determinants.
5. EPIDEMIOLOGY
Disease Frequency
The basic measure of disease frequency is rate or ratio.
These are essential for comparing disease frequency in different populations or subgroups of the
samepopulation in relation to suspected casual factors.
Such comparisons may yield clues to disease etiology- which in turn is a vital step in the development of
strategies for prevention or control of health problem.
6. EPIDEMIOLOGY
Distribution of Disease
The distribution patterns in various subgroups of the population should be studied by time, place and
person.
This study helps in formulation of etiological hypothesis.
7. EPIDEMIOLOGY
Determinants of disease
Identifying the underlying causes (or risk factors) of disease.
It helps in developing scientifically sound health programmes, interventions and policies
It also helps in understanding the chronic disease causation.
15. EPIDEMIOLOGY
The Role of the Public Health System
Control of Epidemics (Three Types)
First Type : Directed toward reducing eliminating the source or reservoir of infection or etc
1. Quarantine and isolation of cases and/or carriers
2. Destruction of an animal reservoir of infection
3. Treatment of sewage to reduce water contamination
4. Therapy that reduces or eliminates infectivity of the individual
16. EPIDEMIOLOGY
The second type : designed to break the connection between the source of the infection and susceptible
individuals. (general sanitation measures – Transmission)
1. Chlorination of water supplies
2. Pasteurization of milk
3. Supervision and inspection of food and food handlers
4. Destruction of vectors by spraying with insecticides
17. EPIDEMIOLOGY
The Third type : reduces the number of susceptible individuals and raises the general level of immunity by
immunization.
1. Passive immunization to give temporary a immunity following exposure to a pathogen or when a
disease threatens to take an epidemic form
2. Active immunization to protect the individual from the pathogen and the host population from the
epidemic
The most important is Surveillance – Observation, recognition and reporting of Diseases as they occur.
