WHAT ARE YOU SPREADING?
Teacher Preparation:
In this experiment, students will simulate the spread of an infectious agent by using a
fluorescent gel to demonstrate how such a material can be transmitted through a
population. Students will use “shaking hands” as the basis of the horizontal spread of
an infection. A few of the students (CARRIERS) will start the infection using a
fluorescent gel while others will use a non-fluorescent gel. The challenge will be to
trace the infection to the primary source. NOTE: Choose two students from the class
to be CARRIERS and keep a record of their Code Numbers.
Prepare two bottles of “lotion”. One bottle will contain the glow-germ gel. The other
bottle will be filled with a liquid that resembles the gel in color and texture. To prevent
students from knowing what type of lotion they receive, prepare a shield as follows: use
an open box approximately 12” to 14” square; cut a hole in the box bottom large enough
for a student’s gloved hand to pass through. Place the box on its side with the lotion
bottles in the box. Prepare a 3”x5” index card with a Code Number for each student
with a space to record a Code Number for three Student Contacts. Record the students’
Code Number on the Class Data Sheet. A Class Data Sheet, a highlighter, gloves,
goggles and a copy of the STUDENT LAB GUIDE should be supplied. The completed
Class Data Sheet must be displayed in order for the students to answer the questions.
Procedure:
1. Place a glove on the hand you DO NOT use for writing.
2. Place your gloved hand through the hole in the box hiding the two bottles of lotion.
The teacher will apply a small amount of lotion to the palm of your gloved hand.
3. Remove your gloved hand from the box and use the fingers of your gloved hand to
spread the lotion on your gloved hand. Use care not to get the lotion on your skin. You
are now ready to perform the experiment.
4. Select a student to be your “Contact 1” and shake GLOVED hands with this student;
at this point you will not be aware if he or she is a carrier of the infection.
5. Record the code number for Contact 1 on your 3”x5” card.
6. Repeat steps 4 and 5 for a second time by randomly selecting a second student.
Remember to record the code number for Contact 2.
7. Repeat steps 4 and 5 for a third time by randomly selecting a third student.
Remember to record the code number for Contact 3.
8. It is possible that you or one or more of the students were the carrier of the infectious
agents. Your Instructor knows the identity of the carrier(s) and it’s up to you to
determine who it is.
9. Pass a long-wave UV fluorescent black light over your glove to determine if you have
contracted the “infectious agent”; if your glove fluoresces you have contracted the
“infectious agent.”
10. On the class DATA SHEET, next to your Code Number, record the Code Numbers
of your three Student Contacts. Highlight your Code Number if your gloved hand
fluoresced.
11. If your gloved hand fluoresces under the light, you or one or more of your contacts is
a carrier of the disease. After all the data has been collected, answer the following
questions:
a. How many students have contracted the infectious agent?
b. What percentage of the student groups does this cover?
c. Who are the suspected carriers? They would be common among the groups whose
hand fluoresced.
d. Can you determine the primary source(s), i.e., the spreading point(s), of the
infection?
The teacher will now ask the following questions, using whatever method he/she
chooses:
What percentage of Americans do not wash their hands before leaving public
restrooms? (68%)
What percentage of American men wash their hands after coughing and sneezing?
(less than 50%)
What percentage of American men wash their hands before handling food? (75%)
What percentage of adults wash their hands after using their restroom at home? (80%)
Those with (a) less education or (b) more education are more diligent about washing
their hands after petting a dog or cat, handling money, or before handling food. (a)
Research data has shown no significant change since 1996 to 2004 in the above habits.