Contagion Epidemiology Epi means on upon befall ex epidermis Demo means people ex demographics the study of populations ology means the study ofex biology geology ID: 590611
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Slide1
The Epidemiologic Triangle
ContagionSlide2
EpidemiologyEpi – means “on, upon, befall” (ex: epidermis)
Demo – means “people” (ex: demographics, the study of populations)-ology –
means “the study of”(ex: biology, geology)
So, epidemiology is literally defined as “the study of that which befalls people”Slide3
EpidemiologyEpidemiology –
learning how diseases are distributed in a certain place and timeYour homework this week is an epidemiological study
How?You will look at
most common diseases amongst your age
group (you)
You will look at most diseases other members of your
family
might
have
gotten
From this information, we should be able to draw conclusions as a class about why certain diseases appear in certain populations at particular timesSlide4
EpidemiologyThe Center for Disease Control (CDC) uses a model called the Epidemiologic Triangle to pinpoint outbreaks of infectious diseases
TIME
HOST
ENVIRONMENT
AGENT
The triangle has three vertices:
Agent,
or microbe that causes the disease (the “What” of the triangle
Host,
or organism harboring the disease (the “who” of the triangle)
Environment,
or those external factors that cause or allow disease transmission (the “where”)
The center of the triangle is TIME – this is what epidemiologists are working againstSlide5
Outbreaks, Epidemic vs. EndemicAn
outbreak or epidemic
exists when there are more cases of a particular disease than expected in a given area, or among a specific group of people, over a particular time.
Example: Seasonal flu
Endemic
means a population has a high level of disease all the time.
Example
:
Malaria is
endemic
in AfricaSlide6
Example Case Study:
Varicella zoster
(chickenpox)
HOST
ENVIRONMENT
AGENT
Varicella zoster,
a virus
People under 15 most at risk
Anyone who
hasn
’
t had it is susceptible
Can remain in the body and cause shingles (painful blisters) in adultsTransmitted from an infected person through coughs or sneezes, or from contact with the fluid from chickenpox blistersMost commonly transmitted in the early winter or spring, when temperatures are moderate Slide7
Mystery DiseaseWatch the following clip: Mystery Disease
While watching, look for the following epidemiological clues:How might it be spreading? (Agent
)Who/what is getting disease? (Host)
Where is it happening? (Environment)Slide8
Mystery Solved!Let’s see if you were right… Mystery SolvedSlide9
Public Service Announcement SkitsWorking in
your table groups, use the information from the
case study provided to
create
a Public Service Announcement skit
about your disease.
It can be a radio broadcast, TV commercial, talk show interview, etc… be creative!
In your skit, include…
The epidemiological triangle for
how your disease is transmitted,
including time
-What people should doavoid getting diseaseTIME
HOST
ENVIRONMENT
AGENTSlide10
Common Infectious Diseases (HW or Classroom Activity)
I’ve Had
Family Members Have Had
Heard About
Compare the diseases you’ve had, and diseases your family has had with your table. What diseases do you have in common? What diseases did your family have that you haven’t had? Why do you think this is? What are some diseases you’ve heard about, but don
’
t know anyone who has had that disease?