What is Epidemiology?
The study of the distribution and determinants of health‑related states or events in populations and the application of this study to control health problems.
Epidemiology focuses on patterns (person, place, time) to inform prevention and control.
Who are Epidemiologists?
Disease detectives who study patterns and causes of health problems in populations.
Epidemiologists apply findings to prevent disease and guide public health policy.
What is the attack rate in Epidemiology?
The proportion of people who become ill after exposure to a disease during a specific outbreak.
Attack rate = (number of new cases among exposed ÷ number exposed) × 100.
What does the incident rate measure in Epidemiology?
The rate of new cases in a population over a specified time period.
Often expressed per 1,000 or 100,000 persons per year (or as person‑time).
What is analytic epidemiology?
The branch of epidemiology that investigates the causes and risk factors of health-related events.
Analytic epidemiology uses study designs such as cohort, case-control, and cross-sectional studies to test hypotheses about associations between exposures and outcomes.
What does the mortality rate in Epidemiology detail?
The frequency of death among infected persons during a certain interval of time, including age-specific rates.
CFR = deaths among cases ÷ total cases; mortality rate is per population.
What do age-specific rates in epidemiology determine?
The rate of a health event in specific age groups within a population.
Useful for comparing disease risk across age categories.
What is co-morbidity in the context of epidemiology?
The presence of two or more diseases or medical conditions in a patient at the same time.
Co-morbidities can complicate treatment and outcomes.
What are the steps for an outbreak investigation?
What are the different types of epidemiological studies?
Case‑control (OR; retrospective)
Cross‑sectional (prevalence)
Cohort (RR; incidence, prospective/retrospective)
What occurs during descriptive epidemiology?
Characterizing the outbreak by time, place, and person, repeating until new information is reported.
What are the ten steps in the epidemiology process?
The epidemiology process contains steps similar to the scientific method.
What is an epidemic?
A higher‑than‑expected occurrence of a disease or health event in a defined area and period.
Example: The Ebola epidemic of 2014.
What is an endemic?
When a disease is regularly found within a certain population of people or in a certain area and is predictable.
Chicken pox and malaria are examples of endemics.
What are the three main patterns that epidemiologists may identify?
Epidemic, Endemic, and Pandemic.
These terms describe different patterns of disease occurrence.
What is the difference between an epidemic and an endemic?
Epidemic - The yellow fever epidemic of 1793
Endemic - chicken pox
How is chicken pox transmitted?
Through droplets in the air after an infected child sneezes or coughs.
Chicken pox was first discovered in the 1500s and mostly affects school-aged children.
What is the main mode of transmission for malaria?
Through mosquitoes that carry one of five species of Plasmodium parasites that can infect humans.
Malaria is seen regularly in most countries of Africa and other tropical regions close to the equator. Malaria has been eradicated in the United States since the 1940s.
What is the disease that is regularly seen in most countries of Africa and other tropical regions close to the equator?
Malaria
Over 180 million people contract malaria every year with over 550,000 people dying from the disease.
What is a pandemic?
An epidemic that is worldwide or over a significantly large area and affects a large portion of the population.
Example: the 1918 influenza pandemic; COVID‑19 (2019–2021+).
What was the most dangerous flu pandemic recorded in history?
Spanish flu (1918 influenza pandemic)
Caused by an H1N1 influenza A virus; infected ~500 million people worldwide.
What is another notable pandemic besides the Spanish flu?
HIV
(Human Immunodeficiency Virus)
The first cases were identified in 1984 with the peak of HIV infection in 1996. By the end of 2013, approximately 35 million people had been infected.
What is DNA forensics?
A field that uses genetic material during criminal investigations to help solve a crime or answer questions about a crime.
DNA forensics uses DNA profiling, which is basically a DNA fingerprint, in order to find a match between a potential suspect and a crime scene.
What is gene therapy?
A technique that allows doctors to prevent or treat a disease by manipulating genetic material as opposed to administering medication or performing surgery.
Several gene therapies are now approved in addition to ongoing clinical trials.