Epidemiology and Public Health: Key
Concepts and Study Methods
Epidemiology
The study of how diseases spread, who they affect, and how to control them in populations.
Public Health
The science of protecting and improving community health through education, policy, and prevention.
Population
A group of people with a shared characteristic (location, age, exposure).
Health
A state of complete physical, mental, and social well-being.
Disease
A condition that impairs normal functioning and has specific signs and symptoms.
Outbreak
A sudden increase in disease cases in a specific area.
Epidemic
A widespread outbreak affecting many people in a region or country.
Pandemic
An epidemic that spreads across multiple countries or continents.
Endemic
A disease consistently present in a specific geographic area.
Incubation Period
Time between exposure to a pathogen and appearance of symptoms.
Vector
An organism (like a mosquito) that transmits disease.
Host
The organism (person/animal) that harbors the disease.
Agent
The cause of the disease (virus, bacteria, parasite, etc.).
Chain of Infection
, Epidemiology and Public Health: Key
Concepts and Study Methods
Agent → Reservoir → Portal of Exit → Mode of Transmission → Portal of Entry → Host.
Case Study (Descriptive Study)
In-depth investigation of a single patient or small group.
Case Report
Detailed description of symptoms, diagnosis, and treatment of one patient.
Case-Control Study
Compares people with a disease (cases) to those without (controls) to identify risk factors.
Cohort Study
Follows a group over time to see who develops a disease.
Cross-Sectional Study
Examines data at one specific point in time.
Randomized Controlled Trial (RCT)
Participants randomly assigned to treatment or control group.
Observational Study
Researcher observes without intervening.
Incidence
Number of new cases in a population during a specific time.
Prevalence
Total number of cases (new + existing) at a given time.
Mortality Rate
Number of deaths in a population over time.
Morbidity
Presence of disease or illness in a population.
Case Fatality Rate (CFR)
Percentage of people diagnosed with a disease who die from it.
Attack Rate
Proportion of people who become ill after exposure.
Concepts and Study Methods
Epidemiology
The study of how diseases spread, who they affect, and how to control them in populations.
Public Health
The science of protecting and improving community health through education, policy, and prevention.
Population
A group of people with a shared characteristic (location, age, exposure).
Health
A state of complete physical, mental, and social well-being.
Disease
A condition that impairs normal functioning and has specific signs and symptoms.
Outbreak
A sudden increase in disease cases in a specific area.
Epidemic
A widespread outbreak affecting many people in a region or country.
Pandemic
An epidemic that spreads across multiple countries or continents.
Endemic
A disease consistently present in a specific geographic area.
Incubation Period
Time between exposure to a pathogen and appearance of symptoms.
Vector
An organism (like a mosquito) that transmits disease.
Host
The organism (person/animal) that harbors the disease.
Agent
The cause of the disease (virus, bacteria, parasite, etc.).
Chain of Infection
, Epidemiology and Public Health: Key
Concepts and Study Methods
Agent → Reservoir → Portal of Exit → Mode of Transmission → Portal of Entry → Host.
Case Study (Descriptive Study)
In-depth investigation of a single patient or small group.
Case Report
Detailed description of symptoms, diagnosis, and treatment of one patient.
Case-Control Study
Compares people with a disease (cases) to those without (controls) to identify risk factors.
Cohort Study
Follows a group over time to see who develops a disease.
Cross-Sectional Study
Examines data at one specific point in time.
Randomized Controlled Trial (RCT)
Participants randomly assigned to treatment or control group.
Observational Study
Researcher observes without intervening.
Incidence
Number of new cases in a population during a specific time.
Prevalence
Total number of cases (new + existing) at a given time.
Mortality Rate
Number of deaths in a population over time.
Morbidity
Presence of disease or illness in a population.
Case Fatality Rate (CFR)
Percentage of people diagnosed with a disease who die from it.
Attack Rate
Proportion of people who become ill after exposure.
