Transcript Slide 1

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
•
Anawrahta
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
Pegu Provincial
Hospitals
Pelu Jaghai
Dava Ghar
Anawrahta
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Influenza Laboratory Testing
National
Laboratory
PCR Diagnosis
Regional Laboratories
Serological Diagnosis
Closest WHO Reference
Laboratory is in a
neighboring country
No laboratory testing
Traditional Hospital Provincial 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:
a. Describe virus circulation and provide virus isolates for
vaccine development
b. Provide rapid response to seasonal outbreaks
c. Define the epidemiology and patterns of viral circulation
d. 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?
a.
b.
c.
d.
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
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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
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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
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Routine reports monthly
 Based on total counts of patients discharged with
pneumonia, ARI, or clinician-defined influenza
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Data presented by
 Age
 Gender
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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
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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: Answer:
Timeliness • 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?
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Data reporting, time from:
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Time interval between date of onset of fever and
specimen collection
Specimen testing, time from:
 From sentinel site to the next administrative level
 From administrative level to the national level
 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:
Answer:
• Large % of cases from only 2
Timeliness
hospitals
• Many hospitals not reporting
Acceptability
Representativeness 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 dataentry 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?
•
Answer:
Consider:
•No case definition limits
Timeliness
ability to
• Determine baseline
Acceptability
• Interpret trends
Representativeness
• Estimate rates of illness
Data Validity / Data Quality
• Assess risk factors
•Incomplete reporting by most
facilities
•Long refrigeration affects
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specimen quality
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
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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:
1.Representative of a
defined population
2.Reasonable logistics
within the hospital for
1.
2.
3.
Case identification
Specimen collection
Specimen transportation
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
3.Politically acceptable
4.Practically Feasible
5.Added benefit: Location in “high risk” location
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CDC/WHO SARI Case Definition
for persons > 5 years old
Lower respiratory tract illness consisting of ALL
of the following:
Sudden onset of fever over 38°C, AND
Cough or sore throat, AND
Shortness of breath or difficulty breathing, AND
Requiring hospital admission
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CDC/WHO Case Definition
for persons < 5 years old
Any child 2 months to 5 years of age with cough or difficult
breathing and:
 breathing faster than 50 breaths / minute (2 – 12 months)
 breathing faster than 40 breaths / minute ( 1 – 5 years)
or,
Any child 2 months to 5 years of age with cough or difficulty
breathing and any of the following general danger signs:
 Unable to drink or breastfeed
 Vomits everything
 Convulsions
 Lethargic or unconscious
 Chest indrawing or stridor in a calm child
AND Requiring hospitalization
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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?
a. The use of a SARI case definition provides some
standardization of reporting across hospitals and regions.
b. Testing defined SARI cases will yield circulating
pathogens and strains
c. Surveillance using a good SARI case definition will yield
a better understanding of epidemiology and burden of
respiratory disease
d. It could detect emergence of a new pathogen
e. All of the above
Answer: e.
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Question 6
True or False:
One drawback of Pegu’s case definition is that it
is not sensitive enough
Answer:
False. Pegu’s case definition is sensitive. This is
actually a drawback because the country’s single
national laboratory could become overwhelmed
with cases
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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?
Answer:
•Unique identification number*
•Consider:
•Medical record number*
General information
•Name (and parent’s name, if a minor)*
•Date of Birth*
•Sex*
•Address*
•Date of onset of symptoms*
•Date of collection of epidemiologic data*
•Part of an outbreak investigation
•Inpatient or outpatient
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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:
Answer:
General information
Specimen
Clinical signs, symptoms
• Fever >38*
• 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?
Answer:
• Occupation *
•Consider:
• Contact with:
General information
Specimen
Clinical signs, symptoms
Risk factor information •
• 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:
Answer:
General information
Specimen
Clinical signs, symptoms
Risk factor information
Pre-existing medical
• 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 Answer:
• Vaccination against influenza
Pre-existing medical
within the past year*
Treatment history
• 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)?
a.
b.
c.
d.
e.
f.
By counting cases
By creating a logistical network
By establishing case definitions and reporting criteria
By tapping into Pegu’s 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)
Answers
1.Travel within last 3 weeks to an area with known H5N1 circulation
2.Hospitalized for SARI
3.Meets the WHO suspect, probable, or confirmed H5N1case
definition
4.Close contact with WHO suspect, probable, or confirmed case
5.Occupational exposure
6.SARI in a previously healthy individual
7.Consumption of raw /undercooked poultry or wild bird products
8.Handling samples (animal or human) suspected of containing H5N1
virus in a laboratory or other setting
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 isn’t caused by
Influenza A (H5N1), but some other respiratory
pathogen that isn’t 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:
a. If they are in a family
b. If they all have a social connection
c. If they all ate cooked chicken
d. If they all have an occupational connection
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Answer: C
Question 13
Consider the following series of questions about potential
epidemiologic trigger criteria…
SARI in health care workers who care for patients with
______.
a.Pneumonia
b.Chronic respiratory disease
c.Poultry exposure
d.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
a.
b.
c.
d.
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
_____________.
a.
b.
c.
d.
aged 5-40
aged < 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.
a. True
b. 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.
Method
Description
Enhanced passive surveillance
a. Passive identification from media
reports, the public, professional groups,
and the WHO surveillance network
Communication with the general
population
b. Include these facilities in education
and awareness training to report trigger
criteria
Involvement of traditional medicine
hospitals
Rumor surveillance
c. Outreach to health care gatekeepers health care providers, laboratorians, drug
dispensers, traditional healers, religious
leaders, and others.
d. Public service messages in print,
radio, and television
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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 dieoff
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 Pegu’s 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, NGO’s, 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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Continue to Outbreak
Investigation Case Study
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