Outbreak Investigation

Question 1

Outbreak

Answer 1

the occurrence of disease in an area at a level exceeding the normally expected number of cases

Question 2

Steps to an outbreak investigation (8)

Answer 2

1. Establish that an outbreak exists
2. Determine the key questions
3. Define cases and noncases
4. Record all events
5. Collect data on epidemiologic factors
6. Look for patterns and associations between risk factors and disease
7. Form and test hypotheses about disease control
8. Plan and implement control methids

Question 3

How do you determine an outbreak is present?

Answer 3

• calculate prevalence or incidence
• explore concurrent changes

Question 3

Considerations when establishing that an outbreak exists

Answer 3

• misdiagnosis/false report (false positive, lab errors, change in case defintion, false report)
• changes in awareness, record keeping/review, observation, population composition
• evaluate economics

Question 3

What are the key questions during an outbreak investigation?

Answer 3

• who?
• where?
• when?
• how are cases connected?
• what caused this?
• what is the magnitude of the problem?
• why did this occur and what can we do?

Question 4

Defining the cases and non-cases (2)

Answer 4

• CDC has defined definitions for cases for many disease
• should include clinical criteria and/or lab test

Question 5

Recording Events and Non-Events

Answer 5

• list each case with a column for each characteristic of interest
• include all cases and all or sample or noncases for comparison