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Case Investigation of Avian Influenza Rapid Response Team Training in Southeast Asia 1 Learning Objectives • Describe and conduct pre-investigation activities • Demonstrate knowledge of key epidemiologic concepts in field investigations • Describe how to communicate epidemiologic findings • Describe how to appropriately assess and respond to potential outbreak situations 2 Case Investigation Module Format • Interactive case studies and instructional slides • Rapid response team (RRT) investigation of avian influenza cluster or case • Evaluation of an RRT avian influenza investigation • Groups of 10 to conduct investigation 3 Module Overview • Pre-Investigation – Planning the Response • Investigation – – – – – Case Definition Specimen Collection Case Finding Interviewing Contact Identification – – – – – Reporting Data Management Creating an Epidemic Curve Assessing Transmission Writing a Summary Report • After the Investigation – Evaluate Performance 4 Pre-Investigation Before you leave to investigate 5 Pre-Investigation: Gather Preliminary Information Assess the situation • Information to collect: – – – – – – Number of suspected cases Geographic location of cases Date of onset of cases Signs and symptoms Exposure history – contact with birds, travel, occupational Lab tests • Consider the security situation in the area 6 Pre-Investigation: Plan the Response • Bring RRT together – Refer to Team Composition module for roles and responsibilities of RRT members • Discuss each person’s roles and responsibilities 7 Pre-Investigation: Documentation • Information already gathered – Location of case, date of illness onset, clinical or exposure details • List of contacts • Case reporting forms • Standardized questionnaires 8 Pre-Investigation: Resources • People – Local health workers caring for case-patient – Veterinarians, clinical and laboratory experts, support personnel • Ministry of Health – Advice, guidance, additional personnel • World Health Organization (WHO) • Avian influenza references • Other – – – – Transportation Security Communication devices Money 9 Pre-Investigation: Supplies • Epidemiological – Reporting forms – Notebook (or laptop) for recording data • Medical – Antiviral medication (if available) • Laboratory – Swabs, needles, cooler, ice, viral transport media 10 Pre-Investigation: Supplies • Educational – Brochures, posters, with influenza safety information – Easy to read – Guidelines for contacts, family members • PPE – Masks, gloves, gown, cap, goggles • Decontamination – Solution for decontaminating homes or hospital rooms 11 Pre-Investigation: Communication • Veterinary Health Authority • Government Officials • Health Care personnel • Community • Non-governmental organizations • Laboratory 12 Case Study Pre-Investigation Before you leave to investigate 13 Case Study: Pao Mai Province • Province located in northern part of country • Peaceful region with little political instability • Many earn income through backyard chicken farming • Poor Infrastructure • Ratio of physicians X to population is 1:5,000 14 Rapid Response Team (RRT) Investigation 15 Objectives of a RRT Investigation • Assess the possibility of human-tohuman transmission • Stop or slow the spread of pandemic influenza at the source • Minimize mortality and morbidity 16 Steps in Rapid Response Investigation 1. 2. 3. 4. Conduct active case finding Identify and follow-up with contacts Collect samples for laboratory tests Characterize illness and provide descriptive epidemiology 5. Investigate reservoir or source of infection 6. Report cases to provincial authorities 7. Implement immediate containment measures 17 Investigating a Suspect Case Evidence for H5N1 infection based on – Clinical findings – Epidemiological evidence – Laboratory testing 18 Case Definitions 19 Case Definitions • “Standardizes” the investigation • Clear criteria for being a case (symptoms or lab results) • Is unique to outbreak but is based on objective measures 20 Case Definition Categories of case definitions for avian influenza A/H5 • Patient under Investigation • Possible Case • Probable Case • Confirmed Case 21 Case Definitions for Influenza A/H5 Patient Under Investigation • Any individual reporting: – Fever (temperature above 38º C) And one or more of these symptoms – Cough – Sore throat – Shortness of breath 22 Case Definitions for Influenza A/H5 Possible Case • A “patient under investigation” who ALSO has one or more of the following: – Lab test for Influenza A (not including subtype) – Contact in past 14 days with confirmed case of Influenza A/H5 – Contact in past 14 days with sick birds – Worked in lab where there is processing of samples from persons/animals with Influenza A 23 Case Definitions for Influenza A/H5 Probable Case • Any “patient under investigation” or possible case who ALSO has – In-country laboratory evidence for influenza A/H5 24 Case Definitions for Influenza A/H5 Confirmed Case • Laboratory testing demonstrates 1 or more of following – – – – Positive viral culture for A/H5 Positive PCR for A/H5 IFA Test positive for A/H5 At least 4-fold rise in A/H5 in paired serum samples 25 Pre-Investigation and Case Definition Activities 26 Case Study: Background DATE: JULY 13th • A staff doctor at Pao Mai Provincial Hospital notifies the Provincial Health Office that they have admitted 2 previously healthy persons with severe respiratory illness. • The doctor is concerned that his patients may have avian influenza, as there are rumors that poultry outbreaks are occurring all over the province. 27 Activity A: Is there an outbreak? Brainstorm and Role Play 25 Minutes • If you had received this call, what additional information would you want to receive from the treating physician? • What would the conversation between the physician and the RRT member sound like? Conduct a role play 28 Background on Cases DATE: JULY 13th • Two cases are related – A 55 year-old grandmother – Her 5 year-old grandson • The cases reside in the same house with the child’s grandfather in a small mountain village • The grandmother is the child’s primary caretaker • The child was brought to the hospital two days ago with the following symptoms: fever, 29 cough, diarrhea and shortness of breath Background: Case History DATE: JULY 13th • Shortly after admission on July 11th, the child rapidly decompensated requiring intubation and ventilatory support • His grandmother was by his bedside when she also became ill. • Child’s mother lives outside the province but arrived at hospital yesterday. • Child’s grandfather denies symptoms. • The treating physician requests assistance from public health authorities 30 Activity B: Plan the Response Brainstorm and Group Discussion I. Logistics and Documentation II. Communication You must plan how you will respond to the situation before you leave for the field. 31 Pre-Deployment Activity: Logistics and Documentation 1. 2. 3. 4. 5. Who are the members of the team? Where will you go? How will you get there? What is the security situation? What documentation do you need to bring with you? What forms will you need? 6. What resources and supplies will you need to bring with you? Where will you obtain the resources? 32 Pre-Deployment Activity Communications Plan Determine: 1. Who do you need to communicate with before you depart for the field? 2. Who on your RRT is responsible for communicating with agencies and the media? 3. Will there be communication/cultural barriers when you arrive in the field? 4. How will you communicate with each other in the field? 33 Activity C: Case Definition Group Discussion JULY 14th • Your RRT arrives at Pao Mai and goes directly to the hospital to begin the investigation. • The available medical charts and chest x-rays for the suspect AI cases are provided to the RRT. 34 Case Definition Exercise Group Discussion Activity Using the data in Trainee Activities, address the questions provided below: 1. Do the cases meet case definition? • If so, how would they be classified? 2. Is any additional information needed to classify cases? If so, what? 3. How would case #2 move from its current classification to the next? 35 Specimen Collection Confirm the Diagnosis 36 Review Laboratory Module • How to safely and correctly collect specimens – Who to collect from – What samples to collect – What to wear – How to transport specimen – Procedures for diagnosis 37 What to Collect Preferred specimens • Nasal swabs • Throat swabs • When possible: Nasopharyngeal aspirates Other specimens • Posterior pharyngeal swabs • Nasal washes • Acute and convalescent serum Collect the sample on several different days 38 Laboratory Testing If positive test for Influenza A and/or suspicion of avian influenza: • Sub-type at in-country laboratory • Non-approved laboratories – Forward samples to National Influenza Centre – Inform WHO Office in country • Confirmatory testing should be conducted at a WHO approved laboratory 39 Case Finding 40 Why is Case Finding Important? • Ensure you have identified as many cases as possible • Case finding may provide information about human-to-human transmission • Any cases related in time and space to initial cluster or case 41 How to Find Cases • Consider all possible symptomatic persons as cases at the beginning of an investigation – Visit health facilities, homes of neighbors and adjacent communities – Public information messages in the affected communities 42 Common Challenges to Case Finding • Even with case finding, all cases may not be identified – Physician may not suspect avian influenza – Some infected persons may not seek medical attention What are some other potential barriers to finding cases in the Pao Mai Province? 43 Case Finding Interview 44 Who to Interview • Case-patient • Family members/Household contacts • Health care providers/Lay health workers 45 Interview Tips • Collect as much information as possible – Unstructured interviews – Generate list of contacts • Repeat critical questions for accuracy, validity and additional details 46 Interview Tips • Be friendly, but professional • Identify yourself and your institution • Explain purpose of interview • Stress importance of information you will collect • Inform respondents that all information will be kept confidential • If appropriate, conduct interview in private 47 Type of Information to Collect • Demographic information: age, sex contact details • Clinical information: signs & symptoms, physical exam, vitals, date of onset, hospital admission • Exposure history: occupational exposure, travel, animal exposure 48 Specimen Collection and Case Finding Activities 49 Activity D: Specimen Collection 1. What specimens need to be collected? 2. What specimens should have already been taken from the cases? When should any additional specimens be taken? 3. Should specimens be collected from the child’s grandfather? 4. What PPE does the nurse need to wear when collecting specimens from the child? 50 Activity E: Case Finding Group Discussion • How would the RRT find out if there are additional cases? • Consider the following: – – – – Locations/settings for case finding Who you might like to interview Questions the RRT would ask potential cases Need for PPE while conducting interviews 51 Case Finding Interview Activity Role-Play • See one, do one and teach one! – Observe a case finding interview – Select a partner and take turns practicing the administration of a standardized case finding questionnaire. – After completing the questionnaire, critique each other’s performance. 52 Contact Identification 53 What is Contact Identification? The identification and diagnosis of persons who may have come into close contact with an infected individual 54 Purpose of Contact Identification • Find new cases that meet case definition • Provide interventions for exposed individuals to decrease risk of illness and interrupt further transmission – Antivirals (Oseltamivir) – Precautionary Information 55 How to Identify Contacts 1. Review patient’s activities for the 7 days before onset of symptoms 2. Based on activities, identify all close contacts (within 1 meter) 3. Verify all information collected 56 Key Information to Gather • Who did case come into close contact with? • What activities was case doing? • Where did this take place? • When did case come into contact with this person? • Contact’s Address and Phone Number • Contact’s Health Status 57 • Contact’s Gender, Occupation, Age General Guidelines for Interviewing Contacts • Do not alarm contacts • Communicate precautionary information • Refer symptomatic individuals to clinic • Consider if Personal Protective Equipment is necessary 58 Information to Gather from Contact • Demographic and contact information – Name, Address – Occupation, age, gender • Exposure History – Contact with case-patient – Other high-risk exposures • Physical Exam and Clinical information – Temperature – Presence of sore throat, coughing – Signs and symptoms 59 Monitoring and Managing Contacts • Monitor for signs of illness for at least 7 days after contact with case – Encourage self-health monitoring – Instruct to report onset of symptoms – Visit or phone daily to monitor for illness • Request voluntary home quarantine of all contacts for at least 7 days • Consider antiviral prophylaxis 60 Prioritize Contact Identification • If number of contacts is large focus on: – Contacts of laboratory confirmed cases – Contacts with extended duration and closeness to case – Contacts that are at high risk, such as those involved in unprotected care of case – Contacts from large gatherings and/or school that case attended 61 Reporting: Informing Those who Need to Know 62 Inform Those who Need to Know • Local Level • National Level • International Level 63 Inform Those who Need to Know • Insert Local and/or National Reporting Requirements (country-specific) 64 Inform Those who Need to Know • International Health Regulations (IHR) – Compulsory notification of highly-pathogenic strains of avian influenza – Vaccination and food safety of poultry products • Compliance with these standards is required to strengthen early detection, reporting, and response 65 Contact Identification Group Discussion and Reporting Group Discussion Activities 66 Activity G: Contact Identification Group Discussion • Develop a village-based system to monitor and manage contacts. Address: 1. What is your definition of a close contact? 2. Who will receive prophylaxis, if available? 3. How long should contacts remain at home voluntarily during quarantine? 4. Monitoring contacts for signs of illness 67 Activity H: Reporting Discussion Questions Local Level: Who is responsible for submitting AI case reports? When should this be done? 68 Reporting Activity Discussion Questions: National Level: Who in your country needs to be updated on the progress of the investigation and receive the final report on number of cases? Who is responsible for assuring that this occurs? 69 Reporting Activity Discussion Questions: International Level: What international agencies need to be informed of suspect human cases? Who in your country is responsible for notifying international authorities? 70 Managing Data on Cases and Contacts 71 Data Management • Line listing • Record keeping • Validation and Cross-Checking 72 Line Listing An organized way to view all cases in an investigation Case Age Sex Status # Occupation 1 5 M Probable Child Yes 7 July 2 55 F Possible Caretaker of case #1 Yes 9 July 3 48 M Possible Poultry Farmer No 7 July Information included: Difficult Date of Onset breathing • Demographic • Clinical • Exposure 73 How to Create a Line List • Add new cases as they are identified • Update case information throughout the investigation • Number of variables to include will depend on available data, nature of investigation 74 How to Create a Line List Always include: • Components of case definition • Case name, identifying number • Date of symptom onset, specimen collection date May also include additional information: • Age, gender, occupation, risk factors 75 How to Create a Line List • Create a table in which each row represents a case and each column represents a variable of interest – Variables: Demographics (age), symptoms, exposures Cases Variable 1 Variable 2 Variable 3 Case 1 Case 2 Case 3 76 Record Keeping • Where will records be kept? • How will records be kept? • Who is assigned to record keeping? • Maintain confidentiality 77 Validation and Cross-Checking • Check line lists against medical charts and interviews • Validation – Ask same question in different ways – Ask same question at different times – Ensure answers are consistent 78 Creating an Epidemic Curve 79 What is an Epidemic Curve and How Can it Help in an Outbreak? An epidemic curve (‘Epi’ curve) is a graph or picture of the number of cases of illness by the date of illness onset 80 What is an Epidemic Curve and How Can it Help in an Outbreak? Provides information characteristics of an outbreak: – Magnitude – Pattern of spread – Outliers (case outside expected time frame) – Time trend – Exposure and/or disease incubation period 81 How do I Make an Epi Curve? • Plot the number of cases of disease reported during an outbreak on the yaxis • Plot the time or date of illness onset on the x-axis 82 How do I Make an Epi Curve? • Technical tips – Time unit for x-axis depends upon the time from exposure to illness onset (incubation period) – Begin with a unit approximately one quarter the length of the incubation period – If the incubation period is not known, graph several epi curves with different time units 83 How do I Make an Epi Curve? • Usually the day of illness onset is the best unit for the x-axis – If the incubation period is very short, hour of onset may be more appropriate – If the incubation period or outbreak is very long, week or month may be more appropriate 84 How do I Make an Epi Curve? • No space between categories on the x axis • Label each axis • Provide a descriptive title • Include the pre-epidemic period to show the baseline number of cases 85 Data Management and Epidemic Curve Actvities 86 Activity I: Linelist & Cross-checking Exercise July 15th • An incomplete linelist and an update on the status of the Pao Mai outbreak is provided in your student guide • Find any errors in the completed sample linelisting provided in your student guide. 87 Activity J: Epidemic Curve Activity Create an epidemic curve using the data from the case study (Summary data on next slide) 88 Summary of Data from Case Study • Date of Onset • Number of Cases (When symptoms began) July 7th July 8th July 9th July 10th July 16th 1 confirmed (Case #3) 1 confirmed (Case #1) 2 possible (Cases #5 & #6) 1 probable (Case #7) 1 confirmed (Case #4) 89 Discussion Questions Based on this epi curve: 1. What is the estimated incubation period? 2. When did the outbreak peak according to the epi curve? 3. Are there any outliers? If so, what might explain them? 90 Epi Curve for Outbreak H5N1 Outbreak Epi Curve, July 2006 Number of cases 3 2 Confirmed Probable Possible 1 0 4- 5- 6- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Date 91 Assessing Human to Human Transmission 92 Current Status of H5N1 Transmission • Now – Human-to-human transmission of Influenza A/H5 highly ineffective – Has occurred only among very close contacts • In the future – Virus could mutate and pass between humans – Global outbreak could occur 93 Assessing Human to Human Transmission • Cases occur close together in time and place among individuals who had close contact with a human case – Family members or health care workers • Onset between two cases falls within the incubation period • No alternative source of exposure is found 94 When a Cluster May Exist • 3 or more people with moderate or severe acute respiratory illness – Unexplained by other causes – May have died from the illness – Onset within 7-10 days of each other AND • History strongly suggesting exposure to H5N1 virus 95 Epidemic Curves and Transmission Assess whether human-to-human transmission is occurring – Epi curve pattern for infectious agent transmitted between people – Epi curve pattern for infectious agent transmitted from one source to people 96 Example Epi Curve for Human to Human Transmission 97 Example Epi Curve for Human Cases from Single Source 98 Case Study Conclusion 99 Outbreak Ends in Pao Mai 1 September 2006 • H5N1 cases identified = 6 • RRT interviewed 52 possible case contacts – 96% of these received antiviral prophylaxis • Deaths = 5 • Case Fatality Rate = 83% X 100 Writing a Summary Report 101 Why communicate the findings? • A document for action – Control and prevention measures • • • • To share new insights Documents the investigation To assist other nations districts or countries with investigation Inform the public – Prevents future outbreaks 102 Content of a Summary Report • • • • • • • • • Summary Introduction and Background Outbreak Description Methods and Results Discussion Lessons Learned Recommendations Acknowledgements Supporting Documentation 103 Human-to-Human Transmission and Summary Report Activities 104 Activity K: Assessing Human to Human Transmission Which are likely human-to-human transmission? Why? • • • • • • 5 year-old child 13 y.o. female neighbor of farmer Poultry farmer Farmer’s apprentice Physician at Pao Mai Hospital 82 y.o. female neighbor of family cluster 105 Activity K: Assessing Human to Human Transmission: Problem Solving Review the four scenarios in your guide and consider the possibility of human to human transmission for each. 106 Activity L: Summary Report Activity • Fill out the WHO daily situation report. • Over the outbreak, these reports can be used to create a summary report. 107 After the Investigation 108 Evaluate Performance 109 Why Evaluate the Investigation • To summarize the events that occurred • To learn from experience – Make recommendations for future investigations – Take lessons from what worked well – Take lessons from mistakes 110 What to Evaluate • Timeliness of response • Completeness of the investigation • Accuracy of the data 111 Timeliness of Deployment • Response time Notification Arrive at location • Ideal: about 24 hours • Delays – Assembling team – Finding supplies – Getting to location • How could response time be improved? 112 Timeliness: Investigation and Initial Assessment Report Arrival in field Deliver initial assessment report • Initial report – Oral or written – May receive feedback on how to proceed • Delays – Interviews, initial investigation – Poor communication in team – Too busy 113 Timeliness: Investigation and Final Assessment Report Arrival in field Deliver final assessment report • Final report – Oral or written – Summary and recommendations • Delays – Follow-up interviews – Containment measures – Poor data management 114 Timeliness: Final Report End of field investigation Official investigation report • Official record of investigation • Delays – Back to “normal” work – Lack of motivation 115 Completeness • Necessary activities completed? – Team assembled and worked well – Interviews – Case definitions – Data collection – Reports • Data collected from questionnaires complete? 116 Accuracy of Data • Data management • Validation and cross checking • A report based on incomplete or inaccurate data is not informative! 117 Example 118 SARS Outbreak April 2004 • 10 April, 2004 – A woman in Anhui province, Eastern China, has been admitted to the hospital with severe respiratory symptoms and fever – Another patient in the hospital develops similar symptoms • 12 April, 2004 – The woman is suspected of having SARS and is transferred to a hospital in Beijing – A rapid response team is deployed to investigate this patient, her exposures, and her contacts 119 SARS Questionnaire Demographic Information 120 SARS Questionnaire Clinical Information 121 Linelist Case Age Sex Status # Occupation Difficult Respiratory breathing Distress 1 26 F Confirmed Post-graduate laboratory worker Yes Yes 2 31 M Confirmed Laboratory researcher Yes Yes 3 53 F Probable Doctor. Mother of lab worker Yes Yes 4 20 F Probable Nurse Yes No 5 45 M Probable Unknown. Father of nurse Yes Yes 6 44 F Possible Unknown. Mother of nurse Yes No 122 List of Contacts Name Age Gender Occupation 1 23 M Lab worker 2 48 M Doctor 3 62 F 4 20 5 Contact information Symptoms XXXX No XXXXX No Housewife XXX Yes M Student XXX No 28 M Secretary XXXX No 6 33 F Nurse XXX No 7 31 F Nurse XXXXX Yes 123 Summary Report: May 2, 2004 Background. This section describes when the case first presented to the hospital and how the ministry of health was informed of the possibility of SARS Methods. Here the team described the hospitals visited in Beijing and Anhui province, the interviews they conducted, and the medical research laboratory they visited. Outcome and Control Measures. In this section, the team described the number of additional cases and contacts they found, their status, and what control measures were put into place to control the outbreak. This included isolating nearly 160 exposed persons and temporarily closing the research laboratory. Conclusions. In this section, the team describes the good and bad points of their investigation, and makes recommendations for preventing future outbreaks and for making future outbreak investigations better. 124 Evaluating Timeliness, Completeness, and Accuracy Activity 125 Activity M: Evaluate Group Performance Group Discussion Review and critique these documents from an investigation: 1. Completed questionnaire from interview with index patient 2. Linelistings of Cases and Contacts 3. The summary report for the investigation 126 Glossary Linelist An organized list of all cases in an outbreak investigation that shows key characteristics for each case, including demographic, clinical, and exposure information. Epidemic Curve (Epi curve) A graph (histogram) of the number of cases of illness on the y-axis by the date of illness onset on the x-axis. Time intervals on the x-axis will vary by disease and incubation period. Outlier Any value that is markedly smaller or larger than other values in a data set. Contact identification / Contact tracing The identification and medical assessment of persons who may have come into close contact with an infected individual. 127 Glossary Case finding The process of determining if more cases of a particular disease under investigation exist. Case definition A set of objective criteria for who should be considered a case and who should not, often including a list of symptoms or results from laboratory tests. Incubation period The time interval between the initial exposure to infection and the appearance of the first symptom or sign of disease. 128 References and Resources • WHO pandemic influenza draft protocol for rapid response and containment. Updated March 2006. http://www.who.int/csr/disease/avian_influenza/guide lines/pandemicfluprotocol_17.03a.pdf • Epidemiology of WHO-confirmed human cases of avian A(H5N1) infection. June 2006, Weekly Epidemiological Record vol. 81(26): 249–260. http://www.who.int/csr/disease/avian_influenza/guide lines/wer8126/en/index.html 129