Influenza Surveillance Systems in an International Setting

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Influenza Surveillance Systems in an
International Setting

• Case Study 1

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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

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Outline

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

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Introduction
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Introduction to the Republic of Pegu

• Developing country
• Southeast Asia
• 21 provinces
• Population 50 million

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Geography
Monsoon climate
Bordered by 5 countries

• Population
• 75 rural
• No highway access

Migrants
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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

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

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

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Part I Routine Surveillance for Respiratory
Disease and Seasonal Influenza
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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.

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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

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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

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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

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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

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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

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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

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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

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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

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Question 3

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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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Your Recommendations

• Performance indicators for objective monitoring
  and evaluation
• Increase laboratory PCR testing
• Additional laboratory quality control

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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

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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
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CDC/WHO SARI Case Definitionfor persons gt 5
years old

• Lower respiratory tract illness consisting of ALL
  of the following
• Sudden onset of fever over 38C, AND
• Cough or sore throat, AND
• Shortness of breath or difficulty breathing, AND
• Requiring hospital admission

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CDC/WHO Case Definitionfor persons lt 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

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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.

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Question 6

• True or False
• One drawback of Pegus case definition is that it
  is not sensitive enough
• Answer
• False. Pegus case definition is sensitive. This
  is actually a drawback because the countrys
  single national laboratory could become
  overwhelmed with cases

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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 parents 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

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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

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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 gt38
• Cough
• Sore throat
• SOB/Difficulty breathing
• IMCI danger signs (per WHO protocols)
• Diarrhea

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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

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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

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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

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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

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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

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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

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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

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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

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

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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

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Question 10

• How might surveillance for seasonal influenza
  support efforts to recognize an emerging pandemic
  or detect human cases of Influenza A (H5N1)? 
• By counting cases
• By creating a logistical network
• By establishing case definitions and reporting
  criteria
• By tapping into Pegus health budget
• By enhancing laboratory capacity
• None of the above
• Answer b, d.

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Question 10 Additional Answers

• During a pandemic, data from the routine sentinel
  site surveillance system will help describe the
• Changing geographic location of the virus
• Trend in cases
• Severity of the pandemic

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Question 10 Key Points

• As routine SARI surveillance is instituted, data
  will be more complete and standardized
• Sentinel-based surveillance is feasible for most
  countries to track a pandemic

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Your Recommendations

• Clinicians at sentinel hospitals and non
  sentinel-site hospitals need to be trained in
  influenza A (H5N1) screening criteria
• Criteria can elevate index of suspicion about
  SARI cases
• Surveillance officer agrees that trigger criteria
  could help prioritize SARI cases for immediate
  laboratory testing

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Question 11

• True or False The proposed epidemiologic
  trigger criteria below could be used to
  prioritize SARI cases for immediate reporting and
  laboratory testing for Influenza A (H5N1)
• Travel within last 3 weeks to an area with known
  H5N1 circulation
• Hospitalized for SARI
• Meets the WHO suspect, probable, or confirmed
  H5N1case definition
• Close contact with WHO suspect, probable, or
  confirmed case
• Occupational exposure
• SARI in a previously healthy individual
• Consumption of raw /undercooked poultry or wild
  bird products
• Handling samples (animal or human) suspected of
  containing H5N1 virus in a laboratory or other
  setting

Answers   1. False 2. False 3. True 4. True 5.
True 6. False 7. True 8. True
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Chief Surveillance Officer Response

• What if the next pandemic isnt caused by
  Influenza A (H5N1), but some other respiratory
  pathogen that isnt associated with poultry or
  wild bird exposure?
• We should learn our lesson from SARS and design
  a system that can also detect a respiratory
  pathogen that is spreading between humans and
  causing severe disease.

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Question 12

• Consider the following series of questions about
  epidemiologic trigger criteria that might raise
  the index of suspicion about whether a
  respiratory pathogen of pandemic potential could
  be circulating in the population.
• Clusters of 2 or more SARI cases occurring within
  7-10 days of each other are suspicious under all
  circumstances EXCEPT
• If they are in a family
• If they all have a social connection
• If they all ate cooked chicken
• If they all have an occupational connection
• Answer C

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Question 13

• Consider the following series of questions about
  potential epidemiologic trigger criteria
• SARI in health care workers who care for patients
  with ______.
• Pneumonia
• Chronic respiratory disease
• Poultry exposure
• Previous hospitalization
• Answer a. Pneumonia

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Question 14

• Consider the following series of questions about
  potential epidemiologic trigger criteria
• Changes in the _________of SARI cases such as a
  shift in the age group affected or changes in
  mortality rates
• severity
• recommended treatment
• epidemiology
• clinical presentation
• Answer e. epidemiology

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Question 15

• Consider the following series of questions about
  potential epidemiologic trigger criteria
• Any unexplained death due to SARI in persons
  _____________.
• aged 5-40
• aged lt 5
• without underlying medical conditions
• in countries with known circulation of possible
  pandemic respiratory viruses
• Answer a.

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Question 16

• Consider the following series of questions about
  potential epidemiologic trigger criteria
• An increase in the numbers of cases occurring in
  a facility compared to the same season in a
  previous year is considered a potential trigger
  for raising the index of suspicion about whether
  a respiratory pathogen of pandemic potential
  could be circulating in the population.
• True
• False
• Answer a. True

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Questions 12-16 Key Points

• Surveillance for CLUSTERS of SARI is critical
• Even for an influenza A(H5N1) pandemic, most
  cases would not have a poultry link
• See Trigger Criteria Summary Handout

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Trigger Criteria Decisions

• National clinician education about trigger
  criteria and reporting
• At hospitals within the sentinel system
• At hospitals outside the sentinel system
• Cases meeting criteria
• Immediate notification to Provincial Medical
  Officer via toll-free phone number
• Oropharyngeal and nasopharyngeal swabs

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Finalize the Guidelines

• Trigger cases can facilitate timely diagnosis of
  other respiratory pathogens of pandemic
  potential, if negative for influenza
• Detailed laboratory testing algorithm is planned
• WHO case definitions used for international
  reporting purposes

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Laboratory Samples

• H5-positive poultry specimens
• From southeastern province, Pelu Jaghai
• Sent to WHO reference laboratory
• Province is rural
• Hospital care may not be sought
• Community-level surveillance needed

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Question 17

• How could Influenza A (H5N1) and pandemic early
  warning surveillance be expanded beyond the
  hospitals in Pegu? Match the method on the left
  with its description on the right.

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Pegu Accomplishments

• MOH will train a team in each province, using
  polio surveillance officer as bird flu person
• Surveillance foundations in place
• Case definitions
• WHO reporting
• Early warning system plans
• Trigger criteria for laboratory testing and
  public health investigation
• Gatekeeper training
• Sentinel sites

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The next day

• Pelu Jaghai reports another large poultry die-off
• In farms in backyard populations
• Specimens from Ministry of Agriculture sent to
  the National Laboratory
• Ministry of Health wants to establish active
  human surveillance

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Question 18

• Which of the following are surveillance
  enhancements for human disease that could be
  recommended for the affected province?
• Teach Pegus traditional healing methods to it
  regional epidemiologists
• Door to door surveillance for ill people and
  chickens
• Initiate school-wide influenza shots
• SARI surveillance among healthcare workers at
  local facilities
• Active case finding among the occupationally
  exposed
• Dismiss rumors of clusters within health care
  workers, families or village contacts
• Recruit private practices, NGOs, religious
  institutions, and schools into the surveillance
  system for H5N1 and pandemic trigger criteria
• Refresher training on reporting procedures
• Confirm availability of telephone reporting
  hotlines

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Question 18 Key Points

• Active surveillance is key in this context
• Make surveillance more active in the hospital and
  community settings
• Backyard poultry husbandry may not be known to
  authorities
• Poultry workers and community need to know
  importance of seeking treatment
• Make healthcare facilities aware of community
  education and reporting mechanisms
• Village health monitors and leaders can be
  important sources of information for outside
  investigators

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Later that evening

• You learn of two possible human cases in
  neighboring Dava Ghar province
• No poultry outbreaks have ever been reported
  here!
• You are asked to extend your stay and participate
  in the outbreak investigation
• You travel with the District Epidemiologist and
  two local officials to Dava Ghar Province

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