Case Investigation of Avian Influenza

1
Case Investigation of Avian Influenza

Rapid Response Team Training in Southeast Asia
2
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

3
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

4
Module Overview

• 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

5
Pre-Investigation

• Before you leave to investigate

6
Pre-InvestigationGather 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

7
Pre-InvestigationPlan the Response

• Bring RRT together
• Refer to Team Composition module for roles and
  responsibilities of RRT members
• Discuss each persons roles and responsibilities

8
Pre-InvestigationDocumentation

• Information already gathered
• Location of case, date of illness onset, clinical
  or exposure details
• List of contacts
• Case reporting forms
• Standardized questionnaires

9
Pre-InvestigationResources

• 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

10
Pre-InvestigationSupplies

• Epidemiological
• Reporting forms
• Notebook (or laptop) for recording data
• Medical
• Antiviral medication (if available)
• Laboratory
• Swabs, needles, cooler, ice, viral transport media

11
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

12
Pre-Investigation Communication

• Veterinary Health Authority
• Government Officials
• Health Care personnel
• Community
• Non-governmental organizations
• Laboratory

13
Case StudyPre-Investigation

• Before you leave to investigate

14
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 15,000

X
15
Rapid Response Team (RRT) Investigation
16
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

17
Steps in Rapid Response Investigation

1. Conduct active case finding
2. Identify and follow-up with contacts
3. Collect samples for laboratory tests
4. Characterize illness and provide descriptive
   epidemiology
5. Investigate reservoir or source of infection
6. Report cases to provincial authorities
7. Implement immediate containment measures

18
Investigating a Suspect Case

• Evidence for H5N1 infection based on
• Clinical findings
• Epidemiological evidence
• Laboratory testing

19
Case Definitions
20
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

21
Case Definition

• Categories of case definitions for avian
  influenza A/H5
• Patient under Investigation
• Possible Case
• Probable Case
• Confirmed Case

22
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

23
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

24
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

25
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

26
Pre-Investigation and Case Definition Activities
27
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.

28
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

29
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
  childs grandfather in a small mountain village
• The grandmother is the childs primary caretaker
• The child was brought to the hospital two days
  ago with the following symptoms fever, cough,
  diarrhea and shortness of breath

30
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.
• Childs mother lives outside the province but
  arrived at hospital yesterday.
• Childs grandfather denies symptoms.
• The treating physician requests assistance from
  public health authorities

31
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.

32
Pre-Deployment Activity Logistics and
Documentation

1. Who are the members of the team?
2. Where will you go?
3. How will you get there?
4. What is the security situation?
5. 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?

33
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?

34
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.

35
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?

36
Specimen Collection

• Confirm the Diagnosis

37
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

38
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

39
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

40
Case Finding
41
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

42
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

43
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?

44
Case Finding Interview
45
Who to Interview

• Case-patient
• Family members/Household contacts
• Health care providers/Lay health workers

46
Interview Tips

• Collect as much information as possible
• Unstructured interviews
• Generate list of contacts
• Repeat critical questions for accuracy, validity
  and additional details

47
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

48
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

49
Specimen Collection and Case FindingActivities
50
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 childs
  grandfather?
• What PPE does the nurse need to wear when
  collecting specimens from the child?

51
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

52
Case Finding Interview ActivityRole-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
  others performance.

53
Contact Identification
54
What is Contact Identification?

• The identification and diagnosis of persons who
  may have come into close contact with an infected
  individual

55
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

56
How to Identify Contacts

• Review patients 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

57
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?
• Contacts Address and Phone Number
• Contacts Health Status
• Contacts Gender, Occupation, Age

58
General Guidelines for Interviewing Contacts

• Do not alarm contacts
• Communicate precautionary information
• Refer symptomatic individuals to clinic
• Consider if Personal Protective Equipment is
  necessary

59
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

60
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

61
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

62
ReportingInforming Those who Need to Know
63
Inform Those who Need to Know

• Local Level
• National Level
• International Level

64
Inform Those who Need to Know

• Insert Local and/or National Reporting
  Requirements (country-specific)

65
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

66
Contact Identification Group Discussion and
Reporting Group DiscussionActivities
67
Activity GContact Identification Group
Discussion

• Develop a village-based system to monitor and
  manage contacts. Address
• What is your definition of a close contact?
• Who will receive prophylaxis, if available?
• How long should contacts remain at home
  voluntarily during quarantine?
• Monitoring contacts for signs of illness

68
Activity HReporting

• Discussion Questions
• Local Level Who is responsible for submitting AI
  case reports? When should this be done?

69
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?

70
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?

71
Managing Data on Cases and Contacts
72
Data Management

• Line listing
• Record keeping
• Validation and Cross-Checking

73
Line Listing
An organized way to view all cases in an
investigation
Case Age Sex Status Occupation Difficult breathing Date of Onset
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

• Demographic
• Clinical
• Exposure

Information included
74
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

75
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

76
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
77
Record Keeping

• Where will records be kept?
• How will records be kept?
• Who is assigned to record keeping?
• Maintain confidentiality

78
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

79
Creating an Epidemic Curve
80
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

81
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

82
How do I Make an Epi Curve?

• Plot the number of cases of disease reported
  during an outbreak on the y-axis
• Plot the time or date of illness onset on the
  x-axis

83
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

84
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

85
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

86
Data ManagementandEpidemic CurveActvities
87
Activity ILinelist 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.

88
Activity JEpidemic Curve Activity

• Create an epidemic curve using the data from
  the case study
• (Summary data on next slide)

89
Summary of Data from Case Study

• Date of Onset
• (When symptoms began)
• July 7th
• July 8th
• July 9th
• July 10th
• July 16th

• Number of Cases
• 1 confirmed (Case 3)
• 1 confirmed (Case 1)
• 2 possible (Cases 5 6)
• 1 probable (Case 7)
• 1 confirmed (Case 4)

90
Discussion Questions

• Based on this epi curve
• What is the estimated incubation period?
• When did the outbreak peak according to the epi
  curve?
• Are there any outliers? If so, what might explain
  them?

91
Epi Curve for Outbreak
92
Assessing Human to Human Transmission
93
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

94
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

95
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

96
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

97
Example Epi Curve for Human to Human Transmission
98
Example Epi Curve for Human Cases from Single
Source
99
Case Study Conclusion
100
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
101
Writing a Summary Report
102
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

103
Content of a Summary Report

• Summary
• Introduction and Background
• Outbreak Description
• Methods and Results
• Discussion
• Lessons Learned
• Recommendations
• Acknowledgements
• Supporting Documentation

104
Human-to-Human Transmission andSummary Report
Activities
105
Activity KAssessing 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
• Farmers apprentice
• Physician at Pao Mai Hospital
• 82 y.o. female neighbor of family cluster

106
Activity KAssessing Human to Human
Transmission Problem Solving

• Review the four scenarios in your guide and
  consider the possibility of human to human
  transmission for each.

107
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.

108
After the Investigation
109
Evaluate Performance
110
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

111
What to Evaluate

• Timeliness of response
• Completeness of the investigation
• Accuracy of the data

112
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?

113
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

114
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

115
Timeliness Final Report

• End of field Official investigation
  investigation report
• Official record of investigation
• Delays
• Back to normal work
• Lack of motivation

116
Completeness

• Necessary activities completed?
• Team assembled and worked well
• Interviews
• Case definitions
• Data collection
• Reports
• Data collected from questionnaires complete?

117
Accuracy of Data

• Data management
• Validation and cross checking
• A report based on incomplete or inaccurate data
  is not informative!

118
Example
119
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

120
SARS QuestionnaireDemographic Information
121
SARS QuestionnaireClinical Information
122
Linelist
Case Age Sex Status Occupation Difficult breathing Respiratory 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
123
List of Contacts
Name Age Gender Occupation Contact information Symptoms
1 23 M Lab worker XXXX No
2 48 M Doctor XXXXX No
3 62 F Housewife XXX Yes
4 20 M Student XXX No
5 28 M Secretary XXXX No
6 33 F Nurse XXX No
7 31 F Nurse XXXXX Yes
124
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.

125
Evaluating Timeliness, Completeness, and Accuracy
Activity
126
Activity MEvaluate Group Performance Group
Discussion

• Review and critique these documents from an
  investigation
• Completed questionnaire from interview with index
  patient
• Linelistings of Cases and Contacts
• The summary report for the investigation

127
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.

128
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.

129
References and Resources

• WHO pandemic influenza draft protocol for rapid
  response and containment. Updated March 2006.
  http//www.who.int/csr/disease/avian_influenza/gui
  delines/pandemicfluprotocol_17.03a.pdf
• Epidemiology of WHO-confirmed human cases of
  avian A(H5N1) infection. June 2006, Weekly
  Epidemiological Record vol. 81(26) 249260.
  http//www.who.int/csr/disease/avian_influenza/gui
  delines/wer8126/en/index.html