Basic Epidemiology (77 mins)
Scroll down to "Chapter 7: Communicable Diseases: Epidemiology surveillance and response" and read pages 117 to 130. Answer 'Study questions' 7.2, 7.3, and 7.4.
Click http://apps.who.int/iris/bitstream/handle/10665/43541/9241547073_eng.pdf link to open resource.