Influenza Surveillance Systems in an International Setting

1. Influenza Surveillance Systems in an International Setting Case Study 1

2. Learning Objectives • Define the surveillance objectives, methods of hospital selection, and key data collection priorities for sentinel surveillance for seasonal influenza and severe respiratory diseases • List appropriate surveillance strategies and trigger criteria needed for the early detection of Influenza A(H5N1) in hospitals and communities • List appropriate surveillance strategies and trigger criteria needed for a broader pandemic early warning system • Describe how a sentinel site surveillance system for influenza provides an important support function for a pandemic early warning system • Identify five ways to enhance human, avian, and pandemic influenza surveillance activities in areas where there are known Influenza A(H5N1) outbreaks in poultry

3. Outline • Introduction to the scenario • Routine Surveillance for Respiratory Disease and Seasonal Influenza • Influenza A(H5N1) and Pandemic Early Warning Surveillance

4. Introduction

5. Introduction to the Republic of Pegu • Developing country • Southeast Asia • 21 provinces • Population: 50 million

6. Anawrahta Geography Monsoon climate Bordered by 5 countries • Population: • 75% rural • No highway access Migrants

7. Pegu Provincial Hospitals Pelu Jaghai Dava Ghar Anawrahta Health Care • Kinds of facilities • Teaching hospitals • Specialist hospitals • Provincial hospitals • District hospitals • Local health stations • Traditional clinics • 12 traditional medicine hospitals • Each province • 16-50 bed hospital • Each district • Medical officer, public health, and medicine

8. Influenza Laboratory Testing National Laboratory PCR Diagnosis Closest WHO Reference Laboratory is in a neighboring country • Regional Laboratories • Serological Diagnosis No laboratory testing Traditional Hospital Provincial Hospital

9. Surveillance Infrastructure • National notifiable disease surveillance system • Immediate reporting • Diphtheria • Cholera • Yellow fever • Routine reporting (3 days) • Standard reporting form

10. Part I: Routine Surveillance for Respiratory Disease and Seasonal Influenza

11. Question 1 The main goals of routine (seasonal) influenza surveillance include all of the following EXCEPT: • Describe virus circulation and provide virus isolates for vaccine development • Provide rapid response to seasonal outbreaks • Define the epidemiology and patterns of viral circulation • Provide a support mechanism for pandemic early warning and monitoring systems Answer: b.

12. Question 2 What surveillance approach might be used to achieve these goals? • Universal surveillance • Sentinel site surveillance • Influenza registry • Laboratory-based reporting Answer: b. Sentinel site surveillance for: • Hospitalizations due to respiratory disease • Outpatient visits for influenza-like illness

13. Arrival in Pegu You are to : • Evaluate the influenza and respiratory disease surveillance infrastructure • Work with the MOH to develop a protocol to implement a sustainable national influenza surveillance system

14. The Pegu Deputy Director • Situation: Due to mass poultry die-offs • Team: Chief Surveillance Officer and the Director of Epidemiology, and you • Develop guidelines for expanding their national pneumonia and influenza surveillance system • Use money from World Bank to develop pandemic early warning network

15. Current Case Identification • Clinician initiated pnuemonia and influenza surveillance among hospitalized patients • Doctors select hospitalized patients • No case definitions • Nasopharyngeal and serum specimens submitted to regional laboratories • Regional laboratories test sera • National laboratories test high-priority specimens and confirm positive influenza A results from regional laboratories

16. Current Laboratory Testing • Regional laboratories test clinical specimens • Acute and convalescent samples for serum specimens • 90% of specimens tested within 9 days • National laboratory conducts PCR for severe cases • Confirmatory tests within 24-48 hours • Detailed characterization performed at WHO reference laboratory • Number of influenza A specimens shared with WHO unknown

17. Current Surveillance Reports • Routine reports monthly • Based on total counts of patients discharged with pneumonia, ARI, or clinician-defined influenza • Data presented by • Age • Gender • 1% diagnosed with laboratory confirmed influenza • 3-4% of specimens tested at National Laboratory are influenza positive, annually

18. Current Data Collection on Pneumonia Cases • Standard patient-level data form for any patient tested for influenza • Consistent and accurate data entry • Case demographics • Date of admission • Date of data entry • Limited completeness / updating of fields • Specimen collection • Date of illness onset • Fever • Final laboratory results

19. Your Data Collection • All 21 provincial hospitals submit P & I data • 4 of 6 you visited report data monthly • Criteria for “pneumonia” discharge are unclear • National laboratory confirms influenza A, B, and subtypes Involvement with WHO FluNet unclear • Data do not suggest seasonality Two hospitals account for 70% of pneumonia cases • Feedback to physicians occurs rarely, if ever

20. Question 3 Does this system achieve the objectives for seasonal/human influenza surveillance that were discussed earlier? Why or why not? Before we answer…

21. Remember…. Does this system achieve the objectives for seasonal/human influenza surveillance that were discussed earlier? Why or why not? • Objectives of virologic surveillance • Describe the epidemiology and burden of disease of influenza, and • Provide virologic isolates for vaccine development

22. Question 3 Does this system achieve the objectives for seasonal/human influenza surveillance that were discussed earlier? Why or why not? • Consider: • Timeliness • Answer: • Not many metrics have been defined • Lag of up to 9 days for testing refrigerated specimens is long • May affect influenza confirmation rate

23. Question 3 What might be appropriate indicators for timeliness? • Data reporting, time from: • From sentinel site to the next administrative level • From administrative level to the national level • Time interval between date of onset of fever and specimen collection • Specimen testing, time from: • Collection to laboratory • Receipt of specimen to test result • Laboratory result to informing referring institution and physician

24. Question 3 Does this system achieve the objectives for seasonal/human influenza surveillance that were discussed earlier? Why or why not? • Consider: • Timeliness • Acceptability • Answer: • Lack of feedback to physicians limits acceptability to physicians

25. Question 3 Does this system achieve the objectives for seasonal/human influenza surveillance that were discussed earlier? Why or why not? • Consider: • Timeliness • Acceptability • Representativeness • Answer: • Large % of cases from only 2 hospitals • Many hospitals not reporting regularly • Need more information to determine representativeness of population

26. Question 3 Does this system achieve the objectives for seasonal/human influenza surveillance that were discussed earlier? Why or why not? • Consider: • Timeliness • Acceptability • Representativeness • Completeness • Answer: • Some sites over-represented compared to others • Laboratory data variable • Need to re-train clinicians and data-entry staff

27. Question 3 Does this system achieve the objectives for seasonal/human influenza surveillance that were discussed earlier? Why or why not? • Consider: • Timeliness • Acceptability • Representativeness • Data Validity / Data Quality • Answer: • No case definition limits ability to • Determine baseline • Interpret trends • Estimate rates of illness • Assess risk factors • Incomplete reporting by most facilities • Long refrigeration affects specimen quality

28. Question 3 Does this system achieve the objectives for seasonal/human influenza surveillance that were discussed earlier? Why or why not? • Consider: • Timeliness • Acceptability • Representativeness • Data Validity / Data Quality • Flexibility • Answer: • With appropriate laboratory facilities, the system may be flexible enough to identify respiratory pathogens in circulation • With case definitions, the system could be expanded to capture a wider range of diseases

29. Your Recommendations • Develop a standard case definition for “severe acute respiratory illness” • Formally identify sentinel sites • Training for sentinel site clinicians • Routinely send influenza isolates to WHO collaborating centers, and enter into WHO/Flu-Net • Implement a plan for regular feedback of surveillance information to clinicians • Immediate notification and response for high priority cases and clusters

30. Your Recommendations • Performance indicators for objective monitoring and evaluation • Increase laboratory PCR testing • Additional laboratory quality control

31. Your Next Task • Work with MOH of Pegu • Write a formal set of national guidelines • Outline the approach to establish sentinel surveillance • Standard case definition of SARI among hospitalized inpatients • Standard case definition if ILI among outpatients

32. Question 4 What criteria will you use to decide where sentinel hospitals should be located? Answer: • Representative of a defined population • Reasonable logistics within the hospital for • Case identification • Specimen collection • Specimen transportation • Politically acceptable • Practically Feasible • Added benefit: Location in “high risk” location Number of facilities selected will be based on local resources Each facility should have a focal point to oversee collection and reporting of data and specimens

33. CDC/WHO SARI Case Definitionfor persons > 5 years old Lower respiratory tract illness consisting of ALL of the following: • Sudden onset of fever over 38°C, AND • Cough or sore throat, AND • Shortness of breath or difficulty breathing, AND • Requiring hospital admission

34. CDC/WHO Case Definitionfor persons < 5 years old Any child 2 months to 5 years of age with cough or difficult breathing and: • breathing faster than 50 breaths / minute (2 – 12 months) • breathing faster than 40 breaths / minute ( 1 – 5 years) or,  Any child 2 months to 5 years of age with cough or difficulty breathing and any of the following general danger signs: • Unable to drink or breastfeed • Vomits everything • Convulsions • Lethargic or unconscious • Chest indrawing or stridor in a calm child AND Requiring hospitalization

35. Question 5 Which of the following are reasons why good SARI case definitions are a key data collection priority in Pegu? • The use of a SARI case definition provides some standardization of reporting across hospitals and regions. • Testing defined SARI cases will yield circulating pathogens and strains • Surveillance using a good SARI case definition will yield a better understanding of epidemiology and burden of respiratory disease • It could detect emergence of a new pathogen • All of the above Answer: e.

36. Question 6 True or False: One drawback of Pegu’s case definition is that it is not sensitive enough Answer: False. Pegu’s case definition is sensitive. This is actually a drawback because the country’s single national laboratory could become overwhelmed with cases

37. Question 7 What kinds of data should be collected from the SARI cases from which specimens are being collected and why? • Consider: • General information • Answer: • Unique identification number* • Medical record number* • Name (and parent’s name, if a minor)* • Date of Birth* • Sex* • Address* • Date of onset of symptoms* • Date of collection of epidemiologic data* • Part of an outbreak investigation • Inpatient or outpatient

38. Question 7 What kinds of data should be collected from the SARI cases from which specimens are being collected? • Consider: • General information • Specimen • Answer: • Throat swab – date of collection* • Nasal swab– date of collection • Other specimen (if collected) – date of collection

39. Question 7 What kinds of data should be collected from the SARI cases from which specimens are being collected? • Consider: • General information • Specimen • Clinical signs, symptoms • Answer: • Fever >38* • Cough* • Sore throat* • SOB/Difficulty breathing* • IMCI danger signs (per WHO protocols)* • Diarrhea

40. Question 7 What kinds of data should be collected from the SARI cases from which specimens are being collected? • Consider: • General information • Specimen • Clinical signs, symptoms • Risk factor information • Answer: • Occupation * • Contact with: • Suspected H5N1 cases • Sick or dead poultry or wild birds* • Severe respiratory illness cases • Travel • Eating raw or undercooked poultry products

41. Question 7 What kinds of data should be collected from the SARI cases from which specimens are being collected? • Consider: • General information • Specimen • Clinical signs, symptoms • Risk factor information • Pre-existing medical • Answer: • Liver disease* • Kidney disease* • Immune compromised state* • Neuromuscular dysfunction* • Diabetes* • Heart disease* • Lung disease* • Smoking history*

42. Question 7 What kinds of data should be collected from the SARI cases from which specimens are being collected? • Consider: • General information • Specimen • Clinical signs, symptoms • Risk factor information • Pre-existing medical • Treatment history • Answer: • Vaccination against influenza within the past year* • Currently taking anti viral medicine

43. Question 7: Key Points • Laboratory-Epidemiology link is critical • There must be a system in place where the same unique identifier is place on both sets of data

44. Chief Surveillance Officer Response • Concerned about having too many hospitals report too many SARI cases, overwhelming the laboratory • Random sampling at hospitals may be complicated for staff • Instead suggests sampling all SARI cases from a few hospitals

45. Surveillance for Less Severe Influenza • Chief Surveillance Officer would like to include less severe, more common, influenza cases in the system • Can be provided by outpatient surveillance • WHO criteria for influenza-like illness • Sudden onset of fever over 38C • Cough or sore throat • Absence of other diagnoses

46. Question 8 How could the sentinel site system be expanded to include some less severe influenza cases? Answer: • Implement ILI surveillance in outpatient clinics of SARI sentinel-site hospitals • Weekly counts of ILI outpatient visits testing positive for influenza • Choose small sample of cases for specimen and epidemiologic data collection

47. SARI and ILI Surveillance • Outpatient ILI surveillance at 5 SARI sentinel site hospitals • Systematically select first 2 cases each day for laboratory and epidemiologic investigation • Sentinel hospitals will provide weekly tally of total ILI cases at facilities

48. Part II: Influenza A(H5N1) and Pandemic Early Warning Surveillance

49. Media Reports • Mass deaths of flocks of chickens, geese, waterfowl • Southeastern Pegu • Ministry of Agriculture investigation 3 chicken samples ‘weakly positive’ for Influenza A (H5N1) • No systematic avian surveillance exists

50. Question 9 Are you confident that a hospitalized human case of Influenza A(H5N1) would be recognized and responded to? Why or why not? Answer: No. • There is no system of 24-hr SARI notification and prioritization for influenza A (H5N1) testing • Rapid detection is needed: Treatment is most effective if given within 48 hours, but infectiousness may occur 24 hrs prior to onset – need to quickly identify cases and contacts