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