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

2. 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

3. Outbreak reports First: What are they? Why write them? Who writes them? Who reads them? Then: Structure Frequent problems Confidentiality Legal issues

4. 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

5. 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

6. Who writes them? The outbreak control team (OCT) Named authors Each participating agency must agree with what is said Who owns the report?

7. Who reads them? All agencies represented on the OCT Policy making bodies Professional colleagues The public The lawyers

8. Structure of the report 1.Summary 2.Introduction and Background 3.Outbreak description 4.Methods 5.Results 6.Discussion 7.Lessons learned 8.Recommendations 9.References 10.Appendices

9. 1. Summary Key –Features, setting of the outbreak: Who – What – Where – When? –Lessons learned –Recommendations Ongoing action Further action required

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 9. References Vancouver referencing system http://www.soton.ac.uk/library/subjects/references/ vancouver.html

18. 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

19. Problems Confidentiality –What should not be included? Legal issues Delay in writing the report Not writing the report at all..

20. Confidentiality To individual patients To commercial businesses Details may remain in meeting minutes Media disclosure Legal disclosure

21. 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

22. Report published Jan. 1997: outbreak report on MMWR: –Legionaires 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)

23. Conclusion Duty to –document the outbreak –inform the colleagues –prevent and control future outbreaks Good report = half publication –Write article, case study

24. Some reports stay alive John Snow, 1843, Broad Street Pump Outbreak - Cholera