Epidemiology Basics

Epidemiology

The branch of medicine that studies the distribution and determinants of health-related events in populations.

Population

A group defined by characteristics such as location, age, gender, or occupation, which is the focus of epidemiological studies.

Health-Related Events

Includes diseases, injuries, disabilities, and behaviors that influence health.

Distribution

The patterns of disease occurrence studied by epidemiologists, focusing on who is affected, where, and when.

Determinants

Factors influencing disease development, including biological, environmental, social, and behavioral aspects.

Descriptive Epidemiology

A type of epidemiology that describes the who, what, when, and where of health events.

Analytical Epidemiology

Investigates the why and how of health-related events, studying relationships between risk factors and health outcomes.

Experimental Epidemiology

Involves controlled experiments to test the effectiveness of interventions like vaccines and public health strategies.

Morbidity

The presence of disease or illness in a population.

Mortality

Refers to death in a population.

Incidence

The number of new cases of a disease in a population during a specific time period.

Prevalence

The total number of cases (new and existing) of a disease in a population at a specific point in time.

Modes of Transmission

Ways which diseases are spread, including direct, indirect, and vector-borne transmission.

Reservoirs

Places where infectious agents live, grow, and reproduce, such as humans, animals, or the environment.

Endemic

A disease consistently present in a population at a stable rate.

Epidemic

A sudden increase in disease cases above what is normally expected in a specific area.

Pandemic

An epidemic that spreads over multiple countries or continents, affecting a large number of people.

Epidemiologic Triad

A model explaining the interaction between the agent, host, and environment in disease spread.

Public Health Surveillance

The systematic collection and analysis of health data to monitor and prevent disease spread.

Passive Surveillance

Relies on healthcare providers to report cases to public health authorities.

Active Surveillance

Public health officials actively search for cases through various methods.

Epidemic Curves

Graphs displaying the number of cases over time to understand disease outbreak patterns.

Point Source Outbreak

All cases occur within a short time period due to a common source of infection.

Continuous Common Source Outbreak

Exposure continues over time, leading to a gradual rise in cases.

Propagated Outbreak

Spread from person to person, resulting in successive waves of cases.

Outbreak Investigation

A systematic process to confirm, define, identify, describe, hypothesize, test, implement control measures, and communicate findings during an outbreak.

Primary Prevention

Actions taken to prevent the occurrence of disease.

Secondary Prevention

Early detection and treatment of disease to prevent progression.

Tertiary Prevention

Managing disease to reduce complications and improve quality of life.

Classical epidemiology

Studies the origins of health problems related to nutrition, environment, and human behavior.

Clinical epidemiology

Studies patients in health care settings to improve diagnosis and treatment

Infectious Disease Epidemiology

Heavily dependent on laboratory support

Chronic Disease Epidemiology

Requires complex sampling and statistical methods