What does it mean to have an infectious disease?
What makes contracting cholera different from getting cancer or food poisoning? What did people think caused infectious disease before they had the tools to see viruses and bacteria with their own eyes? In this unit, we put modern and historical theories to the test.
Lesson 3: How do infectious diseases spread? (pdf)
Do Online: Unit 2 Multimedia
Infectious Disease Blog: Unit 2 Further Reading