Influenza Influenza SurveillanceSurveillance
Danae Bixler, MD, MPHDanae Bixler, MD, MPH
Infectious Disease Infectious Disease Epidemiology ProgramEpidemiology Program
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ObjectivesObjectives
Understand surveillance for… Understand surveillance for… Seasonal influenza Seasonal influenza
ILIILI Laboratory reportingLaboratory reporting Sentinel provider systemSentinel provider system Pediatric death reportingPediatric death reporting Hospital dataHospital data
Avian highly pathogenic H5N1Avian highly pathogenic H5N1 Pandemic influenzaPandemic influenza
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Seasonal InfluenzaSeasonal Influenza
US:US: 36,000 deaths36,000 deaths 226,000 hospitalizations226,000 hospitalizations
Symptoms (2-7 days)Symptoms (2-7 days) fever, chills, sweats headache, arthralgia, myalgia coryza, sore throat, and cough
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Seasonal InfluenzaSeasonal Influenza
Influenza-like illnessInfluenza-like illness Reportable from providers weeklyReportable from providers weekly Fever Fever >> 100 + cough or sore throat 100 + cough or sore throat Over - represents influenzaOver - represents influenza Under - reportedUnder - reported
Laboratory confirmedLaboratory confirmed Reportable from laboratories weekly Reportable from laboratories weekly
(aggregate)(aggregate) Highly sensitive and specificHighly sensitive and specific Under – represents influenzaUnder – represents influenza
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Other Sources of DataOther Sources of Data
Sentinel ProvidersSentinel Providers Report ILI weekly to CDCReport ILI weekly to CDC
High maintenanceHigh maintenance 50% of providers report 50% of the time50% of providers report 50% of the time
Submit specimensSubmit specimens Vital records, hospital dataVital records, hospital data
Non-specific codingNon-specific coding DelayedDelayed
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Deaths from Pneumonia and Influenza* by MMWR Week, West Virginia Residents, 2000-2005
Source: West Virginia Vital Records*Underlying Cause of Death = ICD-10 Codes J10 - J18
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53
MMWR Week
Nu
mb
er o
f D
eath
s
2000
2001
2002
2003
2004
2005
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Weekly Admissions to Hospital with a Primary Discharge Diagnosis of Influenza or Pneumonia,
West Virginia, 2000 - 2005; N=89,957Source: West Virginia Health Care Authority
0
100
200
300
400
500
600
700
800
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53
MMWR Week of Admission
Nu
mb
er o
f A
dm
issi
on
s 2000
2001
2002
2003
2004
2005
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Also Reportable … Pediatric Also Reportable … Pediatric Death from Influenza Death from Influenza
(Age<18)(Age<18)within 1 week to local health departmentwithin 1 week to local health department
Source: N Engl J Med 2005;
353:2559-67.
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MMWR Week of Onset of Influenza Among Hospitalized Patients by Influenza Type,
(N=305)
0
10
20
30
40
50
60
46 47 48 49 50 51 52 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
2007 2008MMWR Week
Nu
mb
er o
f Cas
es
Influenza B
Influenza A
2007-2008 Hospital 2007-2008 Hospital StudyStudy
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Risk Factors Among Hospitalized Influenza Cases, (N=305)
157
103
85
62
38
24
0 50 100 150 200
≥ 1 Risk Factor
Chronic Heart Disease
Diabetes
Chronic Lung Disease
Renal Disease
Asthma
Number of Cases
WVDHHR/BPH/DSDC/IDEP13
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Avian InfluenzaAvian Influenza
387 cases and 245 deaths as of 387 cases and 245 deaths as of 9/10/20089/10/2008 CFR = 63%CFR = 63%
Signs and Symptoms:Signs and Symptoms: High feverHigh fever Dyspnea, respiratory distressDyspnea, respiratory distress (+/-) GI symptoms (+/-) GI symptoms Pneumonia / ARDSPneumonia / ARDS Multi-organ failureMulti-organ failure
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Avian Influenza Screening Avian Influenza Screening Criteria*Criteria*
*Under revision (CDC)*Under revision (CDC) Severe respiratory illnessSevere respiratory illness AND AND Epidemiological evidenceEpidemiological evidence
TravelTravel to a country with human or animal to a country with human or animal cases ANDcases AND
ExposureExposure:: Direct contact with Direct contact with
Sick or dead poultry Sick or dead poultry Poultry fecesPoultry feces Sick or dead birdsSick or dead birds A person hospitalized or deceased from severe A person hospitalized or deceased from severe
unexplained respiratory illnessunexplained respiratory illness Consumption of raw / undercooked poultryConsumption of raw / undercooked poultry
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Areas reporting confirmed H5N1 Areas reporting confirmed H5N1 avian influenza in poultry and wild avian influenza in poultry and wild
birds since 2003birds since 2003
status as of 23.09.2008 (latest available update from WHO)status as of 23.09.2008 (latest available update from WHO)
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Pandemic InfluenzaPandemic Influenza
1918-1919 pandemic Typical onset of influenza, Rapid progression
fever cough dyspnea cyanosis
CXR: widespread infiltrates Pneumonia / ARDS
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Annual Average Mortality in Annual Average Mortality in Pandemic and Pandemic and
Interpandemic Years, Interpandemic Years, United States, 1918 - 1991United States, 1918 - 1991
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Age-Specific Attack Rates for Pandemic (1918) and Interpandemic (1928-1929)
Influenza
0
5
10
15
20
25
30
35
40
45
<11
to 4
5 to
9
10 to
14
15 to
19
20 to
24
25 to
29
30 to
34
35 to
39
40 to
44
45 to
49
50 to
54
55 to
59
60 to
64
65 t
o 69
70 to
74
>75
Age Group
Att
ack
Rat
e (%
) 1918 Pandemic
1928 - 1929Interpandemic
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Current WHO phase of Current WHO phase of pandemic alert pandemic alert
current as of 9/30/2008 (WHO)current as of 9/30/2008 (WHO)
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Early Outbreak Early Outbreak Reporting RequirementsReporting Requirementshttp://www.wvidep.org/Portals/31/PDFs/IDEP/influenza/http://www.wvidep.org/Portals/31/PDFs/IDEP/influenza/
APPENDIX%202%20Pandemic%20Influenza%20SurveillanceAPPENDIX%202%20Pandemic%20Influenza%20Surveillance%20and%20Response_.pdf%20and%20Response_.pdf
Immediately report: Individual cases of pandemic strain
influenza: Fever > 100 ºC; and Cough or sore throat or shortness of breath;
and Laboratory evidence of pandemic strain
infection (criteria TBD). Deaths from pandemic strain influenza.
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Established OutbreakReporting Requirementshttp://www.wvidep.org/Portals/31/PDFs/IDEP/influenza/http://www.wvidep.org/Portals/31/PDFs/IDEP/influenza/
APPENDIX%202%20Pandemic%20Influenza%20SurveillanceAPPENDIX%202%20Pandemic%20Influenza%20Surveillance%20and%20Response_.pdf%20and%20Response_.pdf
Individual providers- report aggregate cases of influenza-like illness: Fever > 100° F (36°C) and Cough or sore throat or shortness of breath
without another identified cause. Hospitals shall report (daily):
New admissions for pandemic influenza Fever > 100 ºC; and Cough or sore throat or shortness of breath without
another identified cause. New admissions for pneumonia or influenza. New deaths from pandemic influenza
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For more information…For more information…
IDEP: IDEP: http://www.wvidep.org/AZIndexofInfectiousDiseases/Influenza/tabid/1518/Default.aspx Protocols – please review / commentProtocols – please review / comment Surveillance data Surveillance data Information sheetsInformation sheets Avian and pandemic guidanceAvian and pandemic guidance
CDC: CDC: http://www.cdc.gov/flu/ WHO: WHO:
http://www.who.int/topics/influenza/en/
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AcknowledgementAcknowledgement Flu Study team members, 2008 - Flu Study team members, 2008 -
20092009 West Virginia Bureau for Public HealthWest Virginia Bureau for Public Health
Kay Shamblin, RN, BSN Kay Shamblin, RN, BSN Caroline Williams, MD Caroline Williams, MD Carolyn Winkler, RN Carolyn Winkler, RN Mary Myers, RN Mary Myers, RN Allie Clay, RN Allie Clay, RN Thein Shwe, MPH, MS, MBBSThein Shwe, MPH, MS, MBBS
Charleston Area Medical CenterCharleston Area Medical Center Deana Samms, BS, MA, CICDeana Samms, BS, MA, CIC
Microsoft Office PowerPoint 97-2003 Pres