Abstract After reading this chapter you should be able to: define the terms ‘communicable disease’, ‘epidemic’, and ‘outbreak’; explain the principles of preventing communicable disease; explain the key features of different types of outbreaks or epidemics; understand the key steps in investigating an outbreak or epidemic.

Impact byBIP!

	citations This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).	3
	popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.	Average
	influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).	Average
	impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.	Average