Transcript Outbreak

Outbreak: A Study in
Epidemiology
Flinn Scientific Inc
FB1794
By: George Azar
Epidemiologists – disease detectives
 They use scientific methods to determine:
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◦ Why some people get sick and others do not
◦ How and why people are sick
◦ How to control disease
Background
Pink Eye – irritation of the inner eyelid
membrane and the membranes covering the
whites of the eyes (conjunctiva).
 Infectious conjunctivitis is easily spread!
 These activities cause the spread more readily:
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Sharing towels or washcloths
Touching eyes
Eye make up sharing
Swimming
You must have a doctors note for re-admittance
into school because of this infectious nature
Conjunctivitis
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You are an epidemiologist and you are trying
to determine the source of a pink eye
outbreak at your high school.
The population is 400 students, 100 students
in each grade level (9 – 12).
You will be provided with 25 students
information from each grade level, totaling
100 students (25 – 9th, 25, 10th, 25 11th, and
25 12th).
The other 75 students from each grade level
or 300 students are non-exposed and non-ill.
Your Task!
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Each group receives:
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100 Student Demographic Cards
Supplemental Demographic Information Sheet
Conjunctivitis Information Sheet
Outbreak Worksheet
Materials
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Look through the cards and calculate :
◦ P = cases/population x 100
◦ Population = 400
Formulate hypothesis of where the pink
eye originated in the school.
 Create a 2 x 2 table as shown below:
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Pink Eye
Investigation
No Exposure
C
Exposure
A
No Pink Eye
B
d
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Test hypothesis by collecting data
◦ Calculate risk of infection for an exposed
student
 Riexp = a/a+b x 100
◦ Calculate the risk of infection for a non –
exposed student
 Rinon = c/c+d x 100
◦ Calculate the risk of infection for any student
 Rel Ri = Riexp/ Rinon
Investigate
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What are your suggestions:
Enhancements