Download 5.1.1: Contagious

Activity 5.1.1: Contagious
Introduction
The medical examiner who performed Anna Garcia’s autopsy pulled copies of
Anna’s medical records before proceeding with the autopsy. Interestingly, the
medical examiner discovered that Anna had been hospitalized just ten days prior to
her death for a sickle cell crisis and subsequently was treated for an infection that
was most likely acquired during her hospital stay. The medical examiner then noted
that pieces of the medical history are incomplete. Throughout this lesson, you will
play the role of medical detectives in order to investigate Anna’s mystery infection.
Ultimately, you will need to identify the exact pathogen, or infectious agent,
responsible for Anna’s illness.
An infection results when a pathogen invades and begins growing within a host.
Disease occurs if and when the invasion and growth of a pathogen impair bodily
functions. In order to cause disease, pathogens must enter the host body, adhere to
specific host cells, invade and colonize host tissues, and inflict damage on those
tissues. Entrance to the host typically occurs through openings to the body such as
the mouth, eyes, nose, genital openings, or through breaks in the skin. Infectious
agents that are easily transmitted are considered highly contagious. Those agents
that that are very likely to cause disease once transmitted are considered highly
virulent. The most troublesome infectious agents are those that are both highly
contagious and virulent.
In this activity you will demonstrate the transmission of an unknown infectious agent
from person to person as well as use deductive reasoning to determine “patient
zero,” the initial patient in the population to develop the infection.
Equipment
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Laboratory journal
PBS Course File
Activity 5.1.1 Medical History Resource Sheet
Test tube containing simulated bodily fluid
Transfer pipette
Phenolphthalein indicator
Safety goggles
Gloves
Highlighter
Procedure
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PBS Activity 5.1.1 Contagious – Page 1
1. Obtain and read through the Activity 5.1.1 Medical History Resource Sheet. Note
that the Tests section is incomplete and the Results and Diagnosis sections are
not filled out.
2. Use the Internet to look up any terms that are new or unfamiliar to you and
highlight any important information.
3. As a class brainstorm possible causes of Anna’s illness.
4. Put on the appropriate personal protective equipment.
5. Obtain a test tube containing 2 mL of “bodily fluid” and a transfer pipette.
6. Note that one student in the class is Patient Zero and is infected with the
unknown pathogen. Everyone else is healthy.
7. When directed to do so by your teacher, walk around the classroom. When your
teacher gives the signal, find one person in class to “come into contact” with. This
contact represents shaking hands with someone, coughing, or sneezing near
someone. Both you and this other student should transfer 3 or 4 drops of your
“bodily fluid” to each other. Record their first name in the chart below as “Round
One.”
Round
Student Name
1
2
3
4
5
8. Perform four more rounds of “contact,” making sure to record the student’s name
for each round in the above chart.
9. Return to your seat. Your teacher will add a couple of drops of indicator solution
to your test tube. Your bodily fluid will turn pink if you were “infected” during the
process of coming into contact with other students. If you are uninfected, your
bodily fluid will remain colorless.
10. Work with a partner to devise a way to determine Patient Zero.
11. Determine Patient Zero and show all of your work in your laboratory journal.
12. Compare your findings to your classmates.
13. File the Activity 5.1.1 Medical History Resource Sheet in the appropriate tab of
your course file. Use the PBS Course File – Table of Contents as a guide.
14. Answer the Conclusion questions.
Conclusion
1. How can the spread of an infectious disease be reduced?
© 2013 Project Lead The Way, Inc
PBS Activity 5.1.1 Contagious – Page 2
2. Why would it be important for epidemiologists, scientists who study the spread of
disease, to determine patient zero?
© 2013 Project Lead The Way, Inc
PBS Activity 5.1.1 Contagious – Page 3