Why is finding "patient zero" in an epidemic so important?

Answer 1

When you find patient zero you find the source of the outbreak! This means you can better understand how the disease spread, make sure all cases are getting the healthcare they need, and figure out why disease reporting, case detection, and disease prevention failed to happen earlier. It may also help pinpoint an environmental point source of a disease. For example, if you find patient zero for a Legionella outbreak you can better pinpoint the contaminated water source. If you find patient zero for a swine flu case, you can find the implicated pig and isolate it so the disease does not spread to other animals.