epidemiology
branch of science that investigates the factors that contribute to the presence or absence of disease
incidence
number of new cases of a disease in a population over time
prevalence
number of existing cases of a disease at a given time.
Name the 3 things that epidemiologist study about health and disease.
1. agent
2. host
3. environmental factors
epidemic
- disease in a population with numbers greater than what is expected at time/place. (measles, smoking)
pandemic
- disease or condition that spreads across regions (COVID, Bubonic Plague)
endemic
- disease present all the time (common cold, flu)
Cluster
- two or more cases associated with the same location, group or event, around the same time. (Food borne illness)
Name the 4 categories of disease
1. infectious
2. hereditary
3. degenerative
4. deficiency
infectious disease
caused by a virus, bacteria, fungi or protist
ex. COVID
hereditary disease
a genetic disorder (cystic fibrosis, down syndrome)
degenerative disease
malfunctions or break down in the body
Ex. osteoporosis
deficiency disease
lacking in nutrients, minerals, etc.
Scurvy: lack of vitamin C
Anemia: not enough red blood cells, low iron
Name 4 modes of disease transmission
1. Direct contact
2. Airborne (aerosol)
3. Ingestion
4. Vector
Direct contact
disease transmission through skin to skin contact, body fluids
MRSA
Airborne disease
passed in respiratory droplets, inhalation
COVID
Ingestion Transmission
disease passed through food or water
E.coli, cholera
Vector transmission
disease passed through insect transmission
Malaria
West Nile Virus
Contagious
the ability of a disease to be passed from one person to another.
Disease
– a disruption of normal body functions.
pathogen
agent capable of causing disease
(virus, bacteria, prions, fungi, parasitic worms)
patient zero
first person to become infected with the disease before it spreads