• within a few days / weeks of index case
• limited data available
• no or limited intervention
• no depletion of susceptibles
• urgent assessment needed to inform response

• dates of symptom onset

• contact data: exposure (who infected you?) and contact tracing (who could you have infected?)

• dates of exposure / infection

• dates of outcome: death / recovery

• metadata on patients: age, gender, location, occupation, etc.

• data from past outbreaks

Disease-dependent, but generally includes:

• How fast is it growing?
• What is driving the epidemic growth?
• What is the case fatality ratio?
• Who is most severely affected?
• How many cases should we expect in the next days / weeks?
• …

• population: set of all possible observations of a given process/entity
  example: all possible cases of cholera in location xxx

• sample: subset of the population
  example: all cases of cholera in xxx reported last week

• a statistic: quantity used to describe sample / population
  example: % of fatalities in cholera cases in xxx last week

• inference: statement about population(s) from sample(s)
  example: % of fatalities in cholera cases in xxx is greater than in yyy

• when presenting estimates, show the associated uncertainty

• always show the data when possible (not just a model)

• account for the variability in the data