Basics
What is the main purpose of epidemiology?
To monitor and improve the health of populations by preventing outbreaks and evaluating the effectiveness of prevention efforts.
Define epidemic.
An unexpectedly large number of cases of a disease or event in a particular population.
Difference between communicable and Non-communicable diseases.
Communicable are caused by infectious agents and transmitted person-to-person; non-communicable are not transmissible and have complex causes.
A “snapshot” that examines exposure or surveys an outcome at one point in time.
What is passive surveillance?
Routine reporting by physicians, clinics, and hospitals.
Who is known as the “Father of Epidemiology” and what disease did he study?
John Snow — studied cholera in London.
Define endemic.
A disease that occurs regularly in a population as a matter of course.
What are the 3 parts of the epidemiological triangle?
Host, Agent, environment
What is a prospective study?
Follows healthy people over time to see who develops a disease. focus on the future data.
What are the 3 levels of prevention?
Primary (prevent onset), Secondary (early detection), Tertiary (reduce complications/restore health).
What are the 3 main types of epidemiology?
Descriptive, Analytic, and Experimental.
Define Pandemic.
An outbreak of disease over a wide geographic area (global).
List the 6 links in the chain of infection and how to break it.
agent- Reservoir- Portal of exit-Transmission-Portal of Entry- Susceptible host
Control the agent, reservoir, portals of exit/entry, mode of transmission, and improve host resistance.
What is a retrospective study?
Looks back using past data to find links between exposure and outcome.
Give an example of primary prevention for communicable disease.
mmunization programs.
What 3 questions does descriptive epidemiology answer?
Who (person), When (time), Where (place).
Formula for calculating a rate and the Form for Years of Potential Loss of Life.
Number of occurrences ÷ population at risk) × constant (K).
Years of Potential Life Lost = Life expectancy – age at death.
Give 3 examples of direct transmission.
Kissing, bitting, and sexual intercourse
What is an experimental study?
Controlled study (e.g., randomized controlled trial) testing interventions.
Give an example of secondary prevention for non-communicable disease.
Mammography or PSA screening.
Give an example of descriptive epidemiology.
Writing a summary of a food poisoning outbreak to help prevent future outbreaks.
Difference between incidence and prevalence.
Incidence = new cases; Prevalence = all existing cases (old + new)
Give 3 examples of indirect transmission.
Airborne (measles), Vehicle borne( contaminated objects), and Vector borne (animals and insects)
what is Surveillance data?
Purposefully seeking out new cases of disease.
Give an example of tertiary prevention for communicable disease.
Returning to full health after infection.