5 Epidemiology Outbreak Investigation

Question 1

Steps of outbreak investigation

Answer 1

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis
4. Define and identify cases
5. Describe / orient data (Person, Place, Time)
6. Develop hypotheses
7. Evaluate hypotheses
8. Refine hypothesis / perform additional studies
9. Implement control and prevention measures
10. Communicate findings

Question 2

1. Prepare for field work

Answer 2

Unusual risk factors

get ready Competent resources

Who’s in charge, on the team

Question 3

1. Prepare for field work

2. Verify the existence of the outbreak

Answer 3

Confirm outbreak

Is increase unusual for area or time period?

Baseline data specific to area and time

Question 4

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis

Answer 4

Review clinical findings by talking to cases, clinical and lab tests

Be specific about causative agent

Question 5

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis
4. Define and identify cases

Answer 5

Cases divided into confirmed (lab confirmed), probable (lab results not available), possible (less strict clinical criteria)

Case definition includes: 
clinical information,
people,
place, 
time,

Question 6

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis
4. Define and identify cases
5. Describe / orient data (Person, Place, Time)

Answer 6

Epidemic curve/graph: time x. # cases y, could show a common point source outbreak

Map

Demographic, exposure (risk factor), clinical (symptom and duration), onset and identification information.

Question 7

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis
4. Define and identify cases
5. Describe / orient data (Person, Place, Time)
6. Develop hypotheses

Answer 7

perform descriptive epidemiology

what trends appear over time

Question 8

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis
4. Define and identify cases
5. Describe / orient data (Person, Place, Time)
6. Develop hypotheses
7. Evaluate hypotheses

Answer 8

Use studies to confirm hypothesis

Question 9

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis
4. Define and identify cases
5. Describe / orient data (Person, Place, Time)
6. Develop hypotheses
7. Evaluate hypotheses
8. Refine hypothesis / perform additional studies

Answer 9

If not already confirmed

Question 10

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis
4. Define and identify cases
5. Describe / orient data (Person, Place, Time)
6. Develop hypotheses
7. Evaluate hypotheses
8. Refine hypothesis / perform additional studies
9. Implement control and prevention measures

Answer 10

Measures put in place during the outbreak to minimise contamination and spread

Break links in chain of infection ASAP

Question 11

1. Prepare for field work
2. Verify the existence of the outbreak
3. Confirm the diagnosis
4. Define and identify cases
5. Describe / orient data (Person, Place, Time)
6. Develop hypotheses
7. Evaluate hypotheses
8. Refine hypothesis / perform additional studies
9. Implement control and prevention measures
10. Communicate findings

Answer 11

oral briefing to health authorities

written report + future action

Maintain surveillance to decide if outbreak is over and the effectiveness of control measures

Question 12

What are common study designs for an outbreak investigation

Answer 12

MUST BE FAST

case-control studies
cohort studies