Introduction to Epidemiology Flashcards
Define epidemiology.
Study of the distribution and determinants of health-related states or events in human populations, and the applications of this study to prevent and control health problems.
What is disease?
An interruption, cessation, or disorder of body functions, systems, or organs.
Disease arise from:
-infectious agents (pathogens)
-inherent weaknesses (genetic mutations)
-lifestyle (smokers)
-environmental stresses (living near an oil refinery)
Major Stages in the Disease Process
- Susceptible Host: this is before exposure
- point of exposure - - Subclinical disease stage: beginning of symptoms.
- incubation period (infectious diseases)
- latency period (for more chronic illnesses)
-where disease transmission is the highest because people dont know they are symptomatic
- onset of symptoms- - Clinical disease stage: signs of symptoms and usually seek help.
- diagnosis sought
-serious case hospitalized
signs: objective and can be observed by others (rash)
symptoms: subjective and apparent only to the patient (dizziness) - Stage of recovery, disability, or death
Communicable disease
contagious diseases and transmissible from one individual to another. (COVID, measles, tuberculosis)
Noncommunicable disease
noncontagious diseases and cannot be transmitted from one person to another. (diabetes, skin cancer, motor vehicle injury)
Infectious diseases
Diseases that spread from a disease-causing agent (or pathogen). (COVID, measles, tuberculosis)
-virus, fungi, bacteria
-all contagious diseases are infectious, but not all infectious diseases are contagious (parasites).
Noninfectious diseases
Diseases that cannot be spread from a disease-causing agent or pathogen.
-diabetes, skin cancer, motor accident
Acute disease
disorder with sudden onset, relatively severe, and short duration of symptoms.
ex: asthma, broken bone, flu, heart attack
Chronic disease
less severe, but long and continuous duration, lasting over long time periods, if not a lifetime.
ex: heart disease, high blood pressure, Alzheimer’s
Major categories of disease
-> Congenital and hereditary diseases: existing at or dating from birth.
-> Allergies and Inflammatory diseases: The body reacting to an invasion of or injury by a foreign object or substance.
-> Degenerative diseases: deterioration of body systems, tissue, and functions.
-> Metabolic diseases: Cause the dysfunction, poor function, or the malfunction of certain organs or physiological processes.
-> Cancer: Characterized by abnormal growth of cells that form a variety of tumors, both benign and malignant.
Epidemiology triangle
Model to understand disease causation or spread and what factors are needed for spread.
->if we want to stop disease spread you need to stop the triangle.
Modes of transmission
Direct: immediate transfer of pathogen from one person to another.
-involves physical (person-to-person) contact.
-also applies to droplet spread through coughing
Indirect: pathogen is transferred or carried by some intermediate source.
-involves airborne transmission, inanimate objects, or living objects
Vertical transmission
from individual to its offspring through sperm, placenta, milk, vaginal fluids.
Horizontal transmission
from an infected individual to a susceptible contemporary (between others)
