The Outbreak Game
Learning Objectives
Students will be able to:
- Demonstrate how disease spreads through a population
- Graph the spread of an "outbreak" over time
- Explain why some people spread disease to many others
- Predict how changes affect disease spread
The Big Question
"If one person gets sick, how many others might catch it?"
Materials:
- Small cups with clear liquid for each student
- One cup with "infected" liquid (water + a few drops of indicator like phenolphthalein)
- Dropper bottles with base solution (to test for infection)
- Data recording sheet
- Chart paper for class graph
How to Play:
- Setup: Give each student a cup of clear liquid. ONE student secretly gets the "infected" cup (they don't know who!)
- Round 1: Everyone finds a partner and "shakes hands" by pouring liquid into each other's cups and back. Record who you met.
- Round 2: Find a NEW partner. Repeat the exchange. Record.
- Round 3: Find another NEW partner. Repeat. Record.
- Test time: Add a drop of the testing solution to each cup. If it turns pink/purple, you're "infected"!
- Count: How many people got infected?
Teacher Note:
Alternative: Use cups of water with one cup having a tiny bit of UV-reactive substance. Use a blacklight to reveal the "infection."
Tracking the Outbreak
After the activity, work together to figure out who was "Patient Zero" (the first infected person)!
Contact Tracing:
- List everyone who is infected
- Look at who each infected person had contact with
- Find the ONE person who connects to all the chains
- That's Patient Zero!
This is exactly what disease detectives do! They trace contacts to find out where an outbreak started and how it spread.
Graphing the Spread
Create a Bar Graph:
| Time | Number Infected |
|---|---|
| Start (Round 0) | 1 person |
| After Round 1 | ? people |
| After Round 2 | ? people |
| After Round 3 | ? people |
Make a bar graph showing how many people were infected after each round. What pattern do you see?
The Power of Doubling
If each sick person infects 2 new people:
| Day 1: | 1 person sick |
| Day 2: | 1 + 2 = 3 people sick |
| Day 3: | 3 + 4 = 7 people sick |
| Day 4: | 7 + 8 = 15 people sick |
| Day 5: | 15 + 16 = 31 people sick |
| Day 10: | Over 1,000 people sick! |
This is called exponential growth! The numbers get big REALLY fast.
Discuss what would happen if:
Things That SLOW the Spread
- Fewer handshakes (less contact)
- Washing hands between rounds
- Some people stay home
- Good ventilation in the room
- Wearing masks
Things That SPEED UP the Spread
- More handshakes (more contact)
- Crowded room
- Everyone comes even if sick
- Poor ventilation
- Not washing hands
Not Everyone Spreads Equally
In our game, what if one person had contact with 5 people instead of 3? They would spread the "infection" to more people!
In real life, some people spread more disease than others because they:
- Have contact with many people (like teachers or bus drivers)
- Are sick but don't feel symptoms (so they don't stay home)
- Have jobs where they touch many surfaces
- Cough/sneeze a lot
Record and answer:
- Draw your bar graph showing how infection spread over the rounds
- How many people were infected at the end?
- Were you surprised by how fast it spread? Why?
- What could have slowed down the spread?
- Why is it important to stay home when you're sick?
Key Takeaways
- Disease can spread from one person to many very quickly
- Each infected person can infect multiple new people (exponential growth)
- Contact tracing helps us find Patient Zero and track spread
- Reducing contact and improving ventilation slows the spread
- Some people ("super spreaders") spread more than others
Outbreak
When more people than usual get sick with the same disease in an area.
Patient Zero
The first person to get sick in an outbreak.
Contact Tracing
Finding everyone a sick person had contact with to stop spread.
Exponential Growth
When something grows faster and faster, like doubling each time.