Case Investigation of Avian Influenza Rapid Response Team Training in Southeast Asia
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
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
Pre-Investigation Planning the Response Investigation Case Definition Specimen Collection Case Finding Interviewing Contact Identification After the Investigation Evaluate Performance Reporting Data Management Creating an Epidemic Curve Assessing Transmission Writing a Summary Report Module Overview
Pre-Investigation Before you leave to investigate
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
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
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
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
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
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
Pre-Investigation: Communication • Veterinary Health Authority • Government Officials • Health Care personnel • Community • Non-governmental organizations • Laboratory
Case StudyPre-Investigation Before you leave to investigate
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 to population is 1:5,000 X
Objectives of a RRT Investigation • Assess the possibility of human-to-human transmission • Stop or slow the spread of pandemic influenza at the source • Minimize mortality and morbidity
Steps in Rapid Response Investigation • Conduct active case finding • Identify and follow-up with contacts • Collect samples for laboratory tests • Characterize illness and provide descriptive epidemiology • Investigate reservoir or source of infection • Report cases to provincial authorities • Implement immediate containment measures
Investigating a Suspect Case Evidence for H5N1 infection based on • Clinical findings • Epidemiological evidence • Laboratory testing
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
Case Definition Categories of case definitions for avian influenza A/H5 • Patient under Investigation • Possible Case • Probable Case • Confirmed Case
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
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
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
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
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.
Activity A: Is there an outbreak?Brainstorm and Role Play25 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
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, 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
Activity B: Plan the ResponseBrainstorm and Group DiscussionI. Logistics and DocumentationII. Communication You must plan how you will respond to the situation before you leave for the field.
Pre-Deployment Activity: Logistics and Documentation • 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? • What resources and supplies will you need to bring with you? Where will you obtain the resources?
Pre-Deployment Activity Communications Plan Determine: Who do you need to communicate with before you depart for the field? Who on your RRT is responsible for communicating with agencies and the media? Will there be communication/cultural barriers when you arrive in the field? How will you communicate with each other in the field?
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.
Case Definition Exercise Group Discussion Activity Using the data in Trainee Activities, address the questions provided below: • Do the cases meet case definition? • If so, how would they be classified? • Is any additional information needed to classify cases? If so, what? • How would case #2 move from its current classification to the next?
Specimen Collection Confirm the Diagnosis
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
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
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
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
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
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?
Who to Interview • Case-patient • Family members/Household contacts • Health care providers/Lay health workers
Interview Tips • Collect as much information as possible • Unstructured interviews • Generate list of contacts • Repeat critical questions for accuracy, validity and additional details
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
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
Activity D: Specimen Collection • What specimens need to be collected? • What specimens should have already been taken from the cases? When should any additional specimens be taken? • Should specimens be collected from the child’s grandfather? • What PPE does the nurse need to wear when collecting specimens from the child?