Middle School Outbreak! Simulated disease transmission
The purpose of today’s activity is for you to act out the spread of an infectious disease (such as
the mononucleosis virus) throughout a population. The population will be this classroom. In this
population one person will start out with the infection. The infection will spread by the exchange
of body fluids (such as salvia on a cup that you share with a friend). You will act out the
exchange of body fluids with three people in this classroom. We will be using a clear liquid in a
tube labeled BF for Body Fluid. The clear liquid does not contain body fluid; this is the
simulation part of the activity. DO NOT ingest any of the materials in this activity!
The following questions are answered in detail- they information should be adapted to the level of
your class.
Questions to think about:
 What can cause a disease?
Many things can cause disease. In the case of infectious disease (as opposed to chronic
disease), the pathogens can be bacteria, viruses, parasites, fungi or prions.
 How can disease spread?
There are many types of disease transmission:
o Airborne transmission- transmission of an infection via the inhalation of airborne droplets containing the organism, which may be present in the immediate
environment as a result of an infected person having coughed or sneezed.
o Blood-borne transmission—transmission of an infection via contact with infected
blood, such as through blood transfusions or when sharing hypodermic needles.
o Direct skin contact—transmission of an infection via contact with the skin of an
infected person.
o Insect-borne transmission—transmission of an infection via insects, such as
mosquitoes, which draw blood from an infected person and then bite a healthy
person.
o Food-borne transmission—transmission of an infection via the consumption of
contaminated food
o Water-borne transmission—transmission of an infection via contact with
contaminated water
o Sexual transmission—transmission of an infection via sexual contact, including
intercourse
o Zoonotic Transmission- diseases caused by infectious agents that can be
transmitted between (or are shared by) animals and humans.

What are some examples of diseases?
o Virus: Influenza, HIV, Herpes, mononucleosis, yellow fever, mumps, measles,
rabies, West Nile Virus, SARS, Hepatitis C, B, A, Polio, Rubella, Yellow fever,
Ebola, Marburg,
o Bacteria: TB, Staph, pneumonia, meningitis, necrotizing fasciitis, campylobacter,
chlamydia, escherichia coli, salmonella, anthrax (bascillus anthracis), bordetella
pertussis, lyme disease, botulism (clostridium botulinum), helobacter pylori,
tetanus (lock jaw). Yersinia Pestus (Plague), legionellosis (legionairres disease)
o Parasites: Giardiasis, malaria, ameobas, African Sleeping sickness, bot flies,
hookworm, round worm, pin worm, guinea worm, schistosomiasis
o Fungi: Athletes foot, valley fever, hay fever
o

Prions: Bovine Spongiform Encephalitis (BSE) more commonly known as Mad
Cow Disease, Creutzfeldt-Jakob disease, Kuru (the earliest discovered prion
disease).
How does your body fight diseases?
Your body uses your immune system to fight disease. There are 2 types of immune
defenses that your body uses: Non-specific (or Innate) Immunity and Specific (or
Adaptive) Immunity.
 Non-Specific /Innate Immunity- These consist of non-speific defenses, these
defences defend against all general pathogens. It is a very rapid and very
effective response using phagocytes, natural killer cells, and mast cells.

Specific/Adaptive Immunity- This line of defense defends against individual
pathogens. It provides long lasting protection and immunity, but it is much
slower- it takes at least 4 days to produce enough antibodies to fight a pathogen.
This line of defense relies on B-cells and T-cells.

What are antibodies? What are antigens?
Antibodies are part of the Specific or Adaptive Immune system and are produced by Bcells. Each anti-body is produced to match and bind to antigens, found on the surface of
pathogens. Each pathogen has different antigens, so antibodies are specific to particular
diseases. Antibodies prevent the pathogen from doing what it wants to do by interfering
with action and signaling bigger things, like macrophages to come destroy the pathogen.

How do vaccines work?
A vaccine is a weakened or dead form of a disease. When injected in to your body, your
body can produce a lot of antibodies to the antigens of the disease. The antibodies
circulate in your blood killing the disease (antigens). These antibodies are stockpiled and
the next time your body comes in contact with the disease, it has all the antibodies it
needs to fight the disease off very fast. Since antibodies are disease specific, the
antibodies will only fight of antigens of that specific disease and cannot protect against
other diseases.
Materials you will need for the activity:
 1.5 ml tube with 1 ml of body fluid
 transfer pipette
 marker
 infection detection solution
Sharing Body Fluids Procedure:
Be sure to choose students from all over the class, and not just in your immediate area. Wait
for the signal before each body fluid exchange.
1. With a marker write you name or initials on the lid of the tube containing body fluids.
2. Find a person that you will share body fluids with and pipette one transfer pipette full of
your liquid into their tube while they pipette one transfer pipette full of their liquid into
3.
4.
5.
6.
7.
8.
your tube. This should be approximately half of your body fluids in the tube. Close the
tube and shake a little to mix. You have successfully shared body fluids.
Go back to your table and record whose body fluids you shared.
For your second share repeat steps 2 and 3 with another individual.
Go back to your table and record whose body fluids you shared.
For your third share repeat steps 2 and 3.
Go back to your table and record whose body fluids you shared.
Go to the board and record whose body fluids you shared in the order that you shared.
Record of Sample Sharing
Your name
First student shared with
Second student shared with
Third student shared with
Analysis of body fluid: Do you have the infection?
Add the infection detection solution to your body fluid tube.

What happened when the infection detection solution was added?
It turned pink/nothing

Does this mean you have the infection? How does that make you feel?
Pink= yes, nothing= no.
Epidemiology of the disease: where did it start?
Record the results of your test on the board.

How many people in the population (the classroom) have the infection?

Who do you think gave you the infection?
 Look at the class data and determine who started the infection.
Do this by having any student who is infected circle their name on the board. Then, working
backwards, you can determine who infected who in the second round of swapping, then who
infected who in the first round of swapping. There will be 2 people who were initially
infected. Since they were the first two people infected, they were the initial cause of the
disease. You will not be able to distinguish which student was the originally infected student,
therefore it is important for the teacher to note who took the tube with the initial infection at
the beginning of the activity.
Most of the time, students are able to use logic and figure out who the initial infection(s)
came from. You might have them try to explain their logic to the class then, have everyone do
it together, as described above.
 Why is determining how a disease spreads important?
If you can determine how a disease is spread, it is much easier to control and stop
transmission of the disease. For example, if you know that a certain type of food at the
grocery store is making people sick, you can tell the grocery store to stop selling it, or the
producer to check its supplies for contamination and remedy the problem. If you know that
someone is spreading a disease by walking around and coughing without covering their
mouth, you can tell sick people to stay home until they feel better, or at least to cover their
mouth when they cough.
 How can you protect your self from an infection such as mononucleosis?
Mononucleosis is a viral disease spread from human to human via contact with infected
saliva. Infected saliva can be passed to uninfected people by hands, toys, drinks, lips
(kissing), etc. To protect yourself against mononucleosis, you should avoid people who are
infected, and minimize saliva exposure to people who you think might be infected.
 Can you protect yourself in the same way against all diseases?
No. Discuss different ways of protecting yourself given the different modes of transmission.
More information on mononucleosis can be found on the CDC or NIH websites:
http://www.cdc.gov/ncidod/diseases/ebv.htm
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001617/