Epidemiology: Study of Disease Distribution

Epidemiology Fundamentals

• The primary focus of epidemiology is to study the distribution and determinants of health-related events, diseases, or health-related characteristics among populations.

Studying Disease Causes

• The purpose of studying the cause (or etiology) of diseases in epidemiology is to understand the underlying factors that contribute to disease development and to identify risk factors.

Disease Transmission

• Dissemination in epidemiology refers to the spreading of diseases from one person to another.
• Infection refers to the entry and multiplication of an infectious agent in a host, which may or may not result in illness.
• The immediate location from which the infecting organism has been transmitted is called the source of infection.
• Carriers are hosts that harbor a pathogen without clinical symptoms and transmit the infection.
• Vectors are biological sources that aid in the transmission of infection from one host to another.
• Zoonosis is an infection where the disease is transmissible from vertebrate animals to humans.

Disease Measurement

• Prevalence represents the number of cases of the disease existing in a given population during a specific period.
• Incidence represents the number of new cases of a disease in a defined population over a specific period.

Disease Patterns

• Endemic occurrence is a regular, continuing occurrence (a constant number of cases in one geographic area).
• A highly transmissible agent is said to be contagious.
• An epidemic is a significantly increased occurrence (if the incidence of disease is greater than expected or greater than normal sporadic or endemic disease).
• A pandemic refers to the occurrence of a disease in multiple countries (the incidence of a disease is spread across continents).

This quiz covers the study of determinants, occurrence, and distribution of disease in a defined population and its application to health problem control. It includes uses of epidemiology such as determining the natural course of disease, aiding in health service planning, and providing administrative data.