Session VI

2. Session VI Writing an Outbreak Report

3. Session Overview • Outbreak report function and critical components • Case studies • E. coli 0157:H7 at the NC State Fair, 2004 • Multistate Outbreak of Monkeypox, 2003

4. Learning Objectives • Understand the role of outbreak investigation reports • Recognize the different types of reports • Recognize elements to include in outbreak investigation reports

5. Basic Steps of an Outbreak Investigation • Verify the diagnosis and confirm the outbreak • Define a case and conduct case finding • Tabulate and orient data: time, place, person • Take immediate control measures • Formulate and test hypothesis • Plan and execute additional studies • Implement and evaluate control measures • Communicate findings

6. Why Communicate the Findings? • Document for action • Share new insights • Record of performance • Substantiate recommendations In order to… • Prevent future outbreaks • Assist in investigation and control of similar incidents • Provide a document for potential legal issues

7. Why are Outbreak Reports Crucial to Public Health? Example : Foodborne outbreak • Hepatitis A contamination of green onions in TN, NC, GA, and PA, Sept-Nov 2003 • Food and Drug Administration (FDA) advisory report and MMWR alerted the public and assisted with traceback

8. Why are Outbreak Reports Crucial to Public Health? Example: Respiratory disease outbreak • Legionnaire’s Disease (LD) Associated with a Whirlpool Spa Display – Virginia, Sept-Oct 1996 • Case-patients were likely exposed by walking by or spending time near the spa • The Virginia Department of Health issued recommendations for the inspection and maintenance of display spas

9. Why are Outbreak Reports Crucial to Public Health? Example: Respiratory disease outbreak • Legionnaire’s Disease (LD) outbreak at a flower show in the Netherlands, 1999 • Source: whirlpool spa on display • Lawsuit raised against Dutch government for negligence • Failure to act on available knowledge (MMWR 1996)

10. Some Reports are a Part of History John Snow

11. Some Reports are a Part of History Morbidity and Mortality Weekly Report (CDC), June 5, 1981

12. When is the Report Written? • When the investigation is ‘complete’ • When the investigation is ‘ongoing’ • “Further analysis of data collected in this investigation may require revision of these findings and recommendations.” • “Because of the preliminary nature of this investigation, future correspondence, MMWR articles, or other published reports might present results, interpretations, and recommendations that are different.”

13. Who Writes the Report? • The field epidemiology / outbreak team • Visiting EIS officer • Other authors as assigned All participating agencies must agree with what is in the report.

14. What are the Types of Reports? • Complaint form • Internal report • Record that outbreak occurred and investigation was conducted • State publication • Newsletter, Website, statewide alert • MMWR http://www.cdc.gov/mmwr/ • Peer-Reviewed Journals • Epidemiology and Infection, Emerging Infectious Diseases, Journal of Hospital Infection

15. Peer-Reviewed Articles http://www.ncbi.nlm.nih.gov

16. Research Outbreak Updates • MMWR mailing list www.cdc.gov/mmwr/mmwrsubscribe • FoodNet www.cdc.gov/foodnet/ • ProMED-mail listserve www.promedmail.org

17. Basic Report Structure • Summary • Introduction and Background • Outbreak Description • Methods and Results • Discussion • Lessons Learned • Recommendations • Acknowledgements *Supporting Documentation ~ 2 - 3pages

18. Summary • 1 - 2 paragraphs • Overview of the investigation • WHO, WHAT, WHERE, WHEN, WHY/HOW • What caused the outbreak or the causal hypothesis based on the evidence • Key recommendations • Ongoing actions • Pending / required actions

19. Introduction and Background • Surveillance trends and similar outbreaks • Include specific events that led to the investigation • How the outbreak was first reported • Steps taken to confirm the outbreak • Those who became involved in the outbreak investigation • Description of the area / site / facility

20. Methods • Epidemiologic • Case definition and ascertainment • Study design • Microbiological / Toxicological • Clinical and environmental specimen collection • Where specimens sent • Types of analyses performed • Environmental • Site visit & risk assessment • Traceback of food products or other items

21. Results • Epidemiological • No. of questionnaires sent / returned • No. of cases and descriptive & clinical data on cases • Geographic distribution of cases • Epidemic curve • Risk factor analysis • Attack rates by age, sex, exposure

22. Results • Microbiological / Toxicological • Laboratory findings, e.g. genotyping, DNA fingerprinting via PFGE, culture results • Environmental • Results of any risk assessments • Results of any traceback investigation

23. Discussion • Discuss main hypotheses • Justify conclusions and actions • Explain action to protect public health

24. Discussion • Highlight any lessons learned • Problems encountered • Mistakes made • Limitations of the study • Useful lessons for planning future investigations

25. Recommendations • Control Measures • To control this outbreak • To prevent future outbreaks • To improve management of future outbreaks • Be specific about problems • Investigation obstacles and shortcomings • Outbreak causes • Aim to educate fellow public health professionals and inform policy makers

26. Supporting Documentation Also include the following: Graphs and tables Inspection reports Blank samples of surveys Letters to management Menus Copies of posted notices Testing results Press releases Maps

27. Case Studies

28. Case Study 1 Outbreak of E. coli O157:H7 at the North Carolina State Fair, 2004Epi Notes, December 2004-February 2005http://www.epi.state.nc.us/epi/pdf/en2004-4.pdf

29. Case Study 1 • Condensed version of a more detailed report • Includes all important components • Outbreak description • Methods and results • Discussion • Lessons learned • Recommendations

30. Case Study 1 • October 2004: E. coli O157:H7 infection associated with state fair attendance. • Case-control study design with 45 confirmed cases and 188 controls. • Data analysis and public health laboratory results (PFGE) revealed petting zoo activities at the fair as the source of infection.

31. E. coli O157:H7 at the NC State Fair:Epidemic Curve

32. E. coli O157:H7 at the NC State Fair:Resulting Legislation • “Aedin’s Law” - July 2005 • Permitting process and rules for animal exhibitions at state-sanctioned fairs • Educational campaign about diseases associated with contact with animals

33. Case Study 2 Multistate Outbreak of Monkeypox – Illinois, Indiana, Kansas, Missouri, Ohio, and Wisconsin, 2003MMWR June 13, 2003http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5223a1.htm

34. Multistate Monkeypox Outbreak Background and Outbreak Description • CDC received reports of patients with a febrile rash illness in Illinois, Indiana and Wisconsin • As of June 10, a total of 53 cases identified • Many reported close contact with pet prairie dogs and other animals • Laboratory tests indicated the causative agent was a poxvirus

35. Multi-state Monkeypox OutbreakMethods • MMWR write-up includes combined data from multiple states • Methods are not detailed • Laboratory investigation to identify the virus • Case-patient interviews to determine exposures, symptoms, and obtain clinical specimens • Traceback investigation to identify original source of illness

36. Multistate Monkeypox OutbreakLaboratory Results • CDC tests concluded the virus was monkeypox

37. Multistate Monkeypox OutbreakEpidemiologic Results Demographic information included in report: • 29 cases (49%) male • Median age 26 years (range: 4 - 53 years) • 14 cases (26%) hospitalized • Earliest onset of illness was May 15

38. Multistate Monkeypox OutbreakEpidemiologic Results

39. Multistate Monkeypox Outbreak Epidemiologic Results

40. Multistate Monkeypox OutbreakResults

41. Multistate Monkeypox Outbreak Results • All patients had contact with animals • 51 of 53 cases reported direct or close contact with prairie dogs • One patient reported contact with a Gambian giant rat • One patient had contact with a rabbit that became ill after exposure to an ill prairie dog at a veterinary clinic

42. Multistate Monkeypox OutbreakTraceback Results • Common distributor - prairie dogs and Gambian giant rats housed together • Imported animal records - Gambian giant rats shipped from Ghana to a wildlife importer in TX and sold to the distributor • The shipment contained ~800 small mammals of 9 different species

43. Traceback Investigation

44. Multistate Monkeypox OutbreakDiscussion and Recommendations • Preliminary findings suggested that the primary route of transmission is from close contact with infected mammalian pets • However, the possibility of human-to-human transmission cannot be excluded • Interim guidelines for infection control in the community and in health care settings were issued

45. Control Measure Guidelines

46. Comparison of Case Study Reports • Both outbreak reports included the major elements: • Introduction and Background • Outbreak Description • Methods and Results • Lessons Learned • Recommendations • Complexity of the report depends on the type of investigation, the extent of the outbreak, and the audience of the report

47. Summary • Outbreak reports are the final step in completing your investigation. • Outbreak reports serve many purposes, both internally and externally. • Though outbreak reports may differ in purpose and audience, reports generally follow a basic structure.

48. References and Resources • Ashford DA, Kaiser RM, Bates ME, Schutt K, Patrawalla A, McShan A, Tappero JW, Perkins BA, Dannenberg AL. Planning against biological terrorism: Lessons from Outbreak Investigations. Emerg Infect Dis 2003;9:515-9. • Conducting an Outbreak Investigation. The North Carolina Communicable Disease Control Manual, North Carolina Division of Public Health. Accessed at http://www.epi.state.nc.us/epi/gcdc/manual/outbreakinvest.pdf • Consumers Advised That Recent Hepatitis A Outbreaks Have Been Associated With Green Onions. FDA Talk Paper. November 15, 2003. Assessed 10/13/2004 http://www.fda.gov/bbs/topics/ANSWERS/2003/ANS01262.html • Den Boer JW, Yzerman PF, Schellekens J, et al. A large outbreak of Legionnaires’ disease at a flower show, the Netherlands, 1999. Emerg Infect Dis 2002;8:37-43.

49. References and Resources • Fontham ETH, Correa P, Wu-Williams A, Reynolds P, Greenberg RS, Buffler PA, et al. Lung cancer in nonsmoking women: a multicenter case-control study. Cancer Epidemiol Biomarkers Prev 1991;1:35-43. • Gaudet, M. (2003). Suggestions for Critically Evaluating an Epidemiologic Study Report. Handout developed for the UNC Chapel Hill School of Public Health EPID 160 course “Principles of Epidemiology.” • Goode B. Outbreak of E. coli 0157:H7 at the North Carolina State Fair – 2004. EpiNotes, North Carolina Department of Health and Human Services, Division of Public Health. Accessed at http://www.epi.state.nc.us/epi/pdf/en2004-4.pdf • Gordis, L. Epidemiology. 2nd ed. Philadelphia: WB Saunders Company; 2000.

50. References and Resources • Greenberg RS, Daniels SR, Flanders WD, Eley JW, Boring JR. Medical epidemiology. 3rd ed. New York: McGraw-Hill; 2001. • Guidelines for EPI-AID Investigations. Division of Applied Public Health Training, Epidemiology Program Office, CDC. • Hepatitis A Outbreak Associated with Green Onions at a Restaurant --- Monaca, Pennsylvania. MMWR 2003;52(47);1155-1157 • International Committee of Medical Journal Editors. Uniform requirements for manuscripts submitted to biomedical journals: writing and editing for biomedical publication. Updated November 2003. http://www.icmje.org/ Accessed August 19, 2004. • Last JM, editor. A dictionary of epidemiology. 4th ed. Oxford University Press; 2001.