Transcript Outbreak investigation report Agnes Hajdu EpiTrain III, 25.08.2006 Jurmala, Latvia Based on EPIET material.

Outbreak investigation report
Agnes Hajdu
EpiTrain III, 25.08.2006
Jurmala, Latvia
Based on EPIET material
Steps of an outbreak investigation
•
•
•
•
•
•
•
Confirm outbreak diagnosis
Define a case
Identify cases and obtain information
Descriptive data collection and analysis
Develop hypothesis
Analytical studies to test hypothesis
Communication – Outbreak report
Control
measures
Outbreak reports
First:
• What are they?
• Why write them?
• Who writes them?
• Who reads them?
Then:
• Structure
• Frequent problems
• Confidentiality
• Legal issues
What are outbreak reports?
• Formal outbreak reports
– Preliminary, interim, final report
• Reports to colleagues
– national bulletin, Eurosurveillance, conference/
seminars
• (Inter)national outbreak reporting systems
• Journal publications
Why write them?
• To document the outbreak
– Present investigation methods, control
measures
– Potential legal issue
• To verify recommendations
• To enhance quality of investigations
In order to prevent future outbreaks and assist
in investigation&control of similar incidents
Who writes them?
• ”The outbreak control team” (OCT)
• Named authors
• Each participating agency must agree with
what is said
• Who ”owns” the report?
Who reads them?
•
•
•
•
•
All agencies represented on the OCT
Policy making bodies
Professional colleagues
The public
The lawyers
Structure of the report
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Summary
Introduction and Background
Outbreak description
Methods
Results
Discussion
Lessons learned
Recommendations
References
Appendices
1. Summary
• Key
– Features, setting of the outbreak:
Who – What – Where – When?
– Lessons learned
– Recommendations
• Ongoing action
• Further action required
2. Introduction and Background
•
•
•
•
Population demographics
Surveillance data
Previous similar outbreaks
Description of the are/site/facility
– e.g. Healthcare system
– e.g. Industries involved
– Any unusal point
3. Outbreak description
• ”The initial story”
– How was the outbreak reported?
– Steps taken to confirm it?
– What was known to date?
• Why was an investigation undertaken?
• Management of the outbreak
– OCT members, objectives, assistance, control
measures
• Media relations
4. Methods
• Epidemiological
– Case definition, case finding, study design
(descriptive-analytical)
• Laboratory
– Clinical and environmental specimens (types,
how they were collected)
• Environmental studies
– Site visit and risk assessment, traceback
• Other studies
5. Results
• Epidemiological
–
–
–
–
–
–
Number of responses and participation rate
Number of cases
Overall attack rates and by age, sex, exposure
Symptoms, duration and outcomes of illness
Description (time, place, person)
Epidemic curve (incubation period)
• Laboratory findings
• Environmental study findings
– Inspection report
• Other studies
6. Discussion
• Main hypotheses (likely causative agent and
mode of transmission)
• Justify conclusions and actions
– Clear interpretation of results
– Explain how results confirmed/disproved hypothesis
• Limitations, possible biases
• Explain action to protect public health
• Highlight any problems
7. Lessons learned
• Lessons for participating agencies
– Problems encountered
– Mistakes made
– Suggestions for improvement
• Lessons that may be useful for others
• Key points from internal/external audit
8. Recommendations
• What should be done
– To control this outbreak
– To prevent future outbreaks
– To improve management of future outbreaks
Be specific: to whom?
Be realistic: feasible actions
9. References
Vancouver referencing system
http://www.soton.ac.uk/library/subjects/references/
vancouver.html
10. Appendices
• Chronology of events
• General background
• OCT (members,
terms of reference)
• Detailed results
• Maps
• Epidemiological
questionnaire
• Letters to
patients/physicians
• Press releases
• Costs of the outbreak
• Acknowledgements
Problems
• Confidentiality
– What should not be included?
• Legal issues
• Delay in writing the report
• Not writing the report at all..
Confidentiality
• To individual patients
• To commercial businesses
• Details may remain in meeting minutes
• Media disclosure
• Legal disclosure
Legal issues
• Who ”owns” the report / the data?
• Prosecuting agencies may deem the
information to be confidential but…
… health authorities have a duty to provide
the public with information
Report published
• Jan. 1997: outbreak report on MMWR:
– Legionaire’s disease (LD) associated with
whirlpool spa on display, USA
• Febr. 1999: major outbreak LD, Holland
– Source: whirlpool spa on display
– Lawsuit against government: failure to act on
available knowledge (MMWR)
Conclusion
• Duty to
– document the outbreak
– inform the colleagues
– prevent and control future outbreaks
• Good report = half publication
– Write article, case study
Some reports stay alive
John Snow, 1843, Broad Street Pump Outbreak - Cholera