2004 Public Health Training and Information Network (PHTIN) Series

1. 2004 Public Health Training and Information Network (PHTIN) Series

2. Site Sign-in Sheethttp://www.sph.unc.edu/nccphp/ • First and Last Name • Occupation • Place of Employment • Mailing Address • Email Address

3. Site Sign-in Sheethttp://www.sph.unc.edu/nccphp/ Please mail or fax your site’s sign-in sheet to: Jennifer Horney Director of Training and Education NC Center for Public Health Preparedness CB #8165, 400 Roberson Chapel Hill, NC 27599 FAX: (919) 843 - 5563

4. Outbreak Investigation Methods From Mystery to Mastery

6. 2004 PHTIN Training Development Team Jennifer Horney, MPH - Director, Training and Education, NCCPHP Pia MacDonald, PhD, MPH - Director, NCCPHP Amy Nelson, PhD Penny Padgett, PhD, MPH Sarah Pfau, MPH Michelle Torok, MPH, Doctoral Candidate Drew Voetsch, MPH, Doctoral Candidate

7. Future PHTIN Sessions June 8th. . . . . . . . . . . . “Study Design” August 17th. . . . . . . . . .“Interviewing Techniques” September 14th. . . . . . .“Designing Questionnaires” October 12th. . . . . . . . . “Analyzing Data” December 14th. . . . . . . “Risk Communication” Each session will be on a Tuesday from 10:00 am - 12:00 pm (with time for discussion)

8. Session I – VI Slides After the airing of each session, NCCPHP will post PHTIN Outbreak Investigation Methods series slides on the following two web sites: NCCPHP Training web site: http://www.sph.unc.edu/nccphp/training/index.html North Carolina Division of Public Health, Office of Public Health Preparedness and Response http://www.epi.state.nc.us/epi/phpr/

9. Session I “Recognizing an Outbreak”

10. Today’s Presenters Drew Voetsch, MPH Research Associate and Doctoral Candidate, NCCPHP Penny Padgett, PhD, MPH Epidemiologist / Surveillance Officer, NCCPHP Ron Holdway Environmental Health Director, Orange Co. Health Dept. Sarah Pfau, MPH Moderator

11. “Recognizing an Outbreak”Learning Objectives At the end of this session, you will be able to: • Identify multiple types of food borne illness surveillance systems • Recognize uses of surveillance data • Identify CDC’s steps of an outbreak investigation

12. “Recognizing an Outbreak”Learning Objectives (cont’d.) At the end of this session, you will be able to: • Develop and use a case definition • Apply the process of case finding in an outbreak • Follow methods for generating a hypothesis

13. “Recognizing an Outbreak”Session Content • Introduction to surveillance • Steps of an outbreak investigation • Foodborne disease surveillance • Case study investigated by Epi Team professionals: a. Epidemiologists b. Public Health Laboratory specialists c. Environmental Health specialists

14. Surveillance

15. What is Public Health Surveillance? “The ongoing, systematic collection, analysis, and interpretation of health-related data essential to the planning, implementation, and evaluation of public health practice, closely integrated with the timely dissemination of these data to those responsible for prevention and control” - CDC

16. Surveillance drives the cycle of public health prevention Surveillance Epidemiologic investigation Prevention measures Applied Targeted Research

17. Purpose of Surveillance • Assess public health status • Define public health priorities • Evaluate programs • Stimulate research

18. Surveillance Priority Areas • Frequency • Severity • Cost • Preventability • Communicability • Public interest

19. Uses of Surveillance • Estimate the magnitude of the problem • Determine the geographic distribution of illness • Portray the natural history of a disease • Detect epidemics / define a problem • Generate hypotheses, stimulate research • Evaluate control measures • Monitor changes in infectious agents • Detect changes in health practice • Facilitate planning

20. Reportable Diseases in NC http://www.epi.state.nc.us/epi/gcdc/pdf/10ANCAC41A.pdf

21. Estimate the Magnitude of the Problem Cases and reported incidence (cases / 100,000) of food borne diseases in North Carolina, 2002 (http://www.epi.state.nc.us/epi/gcdcpdf/CD1991-2002.pdf)

22. Determine the Geographic Distribution of Illness

23. Portray the Natural History of a Disease Incidence (cases per 100,000) of selected food borne diseases in North Carolina, 1991-2002

24. Identify baseline for disease Compare increase with baseline Eyeball, experience CUSUM statistical methods Emerging Infect Dis. 1997; 3(3): 395-400 Detect Epidemics / Define a Problem

25. Surveillance data may represent the “tip of the iceberg” True burden of disease depends on several factors Clinical symptoms Medical care seeking behavior Diagnosis Reporting Underreporting in Surveillance

26. Types of Surveillance • Active vs. passive • Clinician vs. laboratory

27. Outbreak Surveillance Sources • Laboratory-confirmed reports of notifiable diseases • Clinician reports of notifiable disease • Concerned parent/citizen reports to health department • Media

28. Outbreak Investigation

29. Why Investigate? • Increase detected through surveillance • Characterize the problem • Prevention and control • Research and answer scientific questions • Train epidemiologists • Political/legal concerns

30. CDC Guidelines for Systematic Investigations • Verify diagnosis • Confirm epidemic • Identify and count cases (define) • Tabulate and orient data: time, place, person • Take immediate control measures

31. CDC Guidelines for Systematic Investigations (cont’d.) • Initiate surveillance • Formulate and test hypothesis • Refine hypothesis • Plan additional studies • Implement and evaluate control measures • Communicate findings

32. Exceptions to the Rule • CDC guidelines provide a model for systematic outbreak investigations. • No two outbreaks are alike! • Steps of an outbreak could… • occur in a different order • occur simultaneously • be repeated after new information is discovered

33. Question and AnswerOpportunity

34. Case Study The case study that will be used in today’s session and the June 8th session is based on an outbreak that occurred in Austin, Texas in 1998.

35. Case Study Today we will review parts of the case study that illustrate how to: • Develop and use a case definition; • Apply the process of case finding in detecting an outbreak; • Verify the diagnosis; and • Follow methods for generating a hypothesis.

36. Case Study Disease Surveillance

37. Disease Surveillance On the morning of March 11,1998, the Texas Department of Health (TDH) received a telephone call from a male student at a nearby university

38. Disease Surveillance • Student and his roommate were suffering from nausea, vomiting, and diarrhea • Both had become ill during the night • The roommate had taken medication • Neither student sought medical care • Both students believed a local pizzeria the previous night was responsible • Students asked if they should go to class/take midterm exam that afternoon

39. Disease Surveillance: Case Report What questions would you ask the student? WHO: other ill persons – age, sex, symptoms, and whether they sought care WHAT: physical condition, symptoms, medication, and medical care sought WHEN: when did the affected become ill WHERE: city/school, address, telephone number of ill persons WHY/HOW: suspected cause of illness, risk factors, modes of transmission, hints from those who did not become ill

40. Case Report:Who/Where

41. Case Report:What

42. Case Report:When/How

43. Case Report:When/How • Student refused to provide food history beyond foods eaten at local pizzeria • He and his roommate shared no other meals in the last 72 hours • They ate separately at the University cafeteria

44. Disease Surveillance: Advice to the Caller • What do you advise the student about attending classes that day? • Refer to personal clinician or student health center for evaluation • If asymptomatic, can return to normal activities • Food handler? • Work with high risk populations?

45. Disease Surveillance:What next? • File the report and stop? • Investigate further?

46. Deciding to Investigate • Ideally, all reports of possible food borne outbreaks should be investigated to: • Prevent other persons from becoming ill • Identify potentially problematic food handling practices • Add to the knowledge of food borne diseases

47. Maybe you should... • If a severe (life-threatening) illness • If there are confirmed clusters/large numbers of a similar illness • If food borne illness is in a food-handler • If association with a commercially distributed food

48. Deciding Not to Investigate • Can’t investigate everything • Often must choose the highest priority • Outside pressure to investigate (media, politicians)

49. Maybe you shouldn’t... • If signs/symptoms or confirmed diagnoses among the affected suggest they might not have the same illness • If ill persons are not able to provide adequate information for investigation, including date and time of onset of illness, symptoms, or a complete food history

50. Maybe you shouldn’t... • If confirmed diagnosis and/or clinical symptoms are not consistent with the foods eaten and the onset of illness • If there are repeated complaints made by the same individual(s) for which prior investigations revealed no significant findings