H1N1 Influenza AH1N1 Influenza A

Julie Casani, MD, MPHJulie Casani, MD, MPH

Public Health Preparedness and Public Health Preparedness and ResponseResponse

How Flu SpreadsHow Flu Spreads

Most spread through coughing and sneezingMost spread through coughing and sneezing Contact transmission also importantContact transmission also important

Hand to hand, contaminated surfacesHand to hand, contaminated surfaces

Airborne transmission also possibleAirborne transmission also possible

Weber & Stilianakis, Journal of Infection 57(5): 361-Weber & Stilianakis, Journal of Infection 57(5): 361-7373

Influenza Survival on the Influenza Survival on the Environmental Surfaces Environmental Surfaces

Hard surfaces: Hard surfaces: 12–48 hours12–48 hours

Cloth/paper:Cloth/paper: 8–12 hours8–12 hours

Hands:Hands: 5 minutes5 minutes

Survives longer with low humidity, low UVSurvives longer with low humidity, low UV

Novel Influenza Virus InfectionNovel Influenza Virus Infection

Human infection with influenza A virus Human infection with influenza A virus subtype different from the circulating subtype different from the circulating human subtypeshuman subtypes

Pandemic InfluenzaPandemic Influenza

Three Conditions:Three Conditions:

1.1. Novel virus (all or most susceptible)Novel virus (all or most susceptible)

2.2. Transmissible from person to personTransmissible from person to person

3.3. Wide geographic spreadWide geographic spread

Impact of Past Influenza Impact of Past Influenza PandemicsPandemics

Pandemic, or Antigenic Shift

Excess Deaths in US Populations Affected

1918-19(A/H1N1)

500,000 Persons <65 years

1957-58(A/H2N2)

70,000 Infants, elderly

1968-69(A/H3N2)

36,000 Infants, elderly

1977-78(A/H1N1)

8,300 Young (persons <20)

Summary of EventsSummary of Events

March 28–30, 2009: 2 children from March 28–30, 2009: 2 children from California seen for influenza-like illnessCalifornia seen for influenza-like illness Same influenza A (H1N1) virus; not previously Same influenza A (H1N1) virus; not previously

recognized among swine or humanrecognized among swine or human

April 26, 2009: US Government declares April 26, 2009: US Government declares Public Health EmergencyPublic Health Emergency

June 11, 2009: WHO declares pandemicJune 11, 2009: WHO declares pandemic Infections occurring around the worldInfections occurring around the world

What’s in a Name?What’s in a Name?

Swine fluSwine flu Swine-origin influenza virus (S-OIV) Swine-origin influenza virus (S-OIV) Mexican fluMexican flu American fluAmerican flu H1N1H1N1 Novel H1N1Novel H1N1 2009 H1N12009 H1N1 Pandemic H1N1Pandemic H1N1 Others?Others?

Where We Are NowWhere We Are Now

WHO Phase 6 PandemicWHO Phase 6 Pandemic Determined by global spread, not severityDetermined by global spread, not severity

Above normal flu activity across NCAbove normal flu activity across NC ““Second wave” in FallSecond wave” in Fall

Likely mixed season with many strains Likely mixed season with many strains circulatingcirculating

Monitoring for increased transmissibility, Monitoring for increased transmissibility, increased virulenceincreased virulence

* Skewed by testing of more severe cass* Skewed by testing of more severe cass

Pandemic H1N1: Clinical Pandemic H1N1: Clinical FeaturesFeatures

Most cases uncomplicated, typical Most cases uncomplicated, typical influenza-like illness (ILI)influenza-like illness (ILI)

Diarrhea and vomiting might be more Diarrhea and vomiting might be more prominent than with seasonal fluprominent than with seasonal flu

As of late July, 2009:As of late July, 2009: 12% reported US cases hospitalized* 12% reported US cases hospitalized* 0.7% reported US cases died*0.7% reported US cases died*

HospitalizationsHospitalizations

Detailed clinical data presented on >200 Detailed clinical data presented on >200 hospitalized patients (CDC)hospitalized patients (CDC) 43 (21%) admitted ICU43 (21%) admitted ICU 17 (8%) died17 (8%) died

Median time from onset of illness to Median time from onset of illness to hospital admissionhospital admission 3 days (range 1-14 days)3 days (range 1-14 days)

Median length of stayMedian length of stay 3 days (range 1-53)3 days (range 1-53)

Novel H1N1 Case CountsNovel H1N1 Case CountsNorth Carolina (September 9, 2009)

Confirmed/Probable Cases

Hospitalizations 198

Deaths 9

United States (August 30, 2009)

Hospitalizations 9,079

Deaths 593

WHO Reports (August 30, 2009)

Total Cases (168 Countries) > 254,206

Deaths At least 2,837

Cleveland

Buncombe

Anson

Ashe

Beaufort

Bertie

Bladen

Brunswick

Burke

Caldwell

Carteret

Caswell

CatawbaChatham

Cherokee Clay

Columbus

Dare

Davie

Duplin

Forsyth Franklin

Gaston

Gates

Graham

Greene

Guilford

Halifax

Harnett

Hertford

Hoke

Hyde

Iredell

Jackson

Johnston

Jones

Lee

Lenoir

McDowell

Macon

MadisonMartin

Moore

Nash

Onslow

Orange

Pamlico

Pender

Person

Pitt

Polk

Randolph

Robeson

Rockingham

Rowan

Rutherford

Sampson

Scotland

Stanly

Stokes

Surry

Swain

Transylvania

Tyrrell

Union

Wake

Warren

Washington

Watauga

Wayne

Wilkes

Wilson

Yadkin

Yancey

Chowan

PasquotankPerquimans

CamdenCurrituck

MontgomeryHenderson

GranvilleVance

Durham

Mecklenburg

LincolnCabarrus

RichmondCumberland

Alexander

Craven

Haywood

Alleghany

Mitchell AveryAlamance

Davidson Edgecombe

New Hanover

Confirmed NC Cases by County of Confirmed NC Cases by County of ResidenceResidence

August 12, 2009August 12, 2009

Confirmed Cases, N=687 (75 counties)

Northampton

Influenza SurveillanceInfluenza Surveillance

Relies on:Relies on:

1.1. Surveillance for influenza-like illness (ILI)Surveillance for influenza-like illness (ILI)• Sentinel Provider NetworkSentinel Provider Network• Electronic syndromic surveillanceElectronic syndromic surveillance

2.2. Systematic laboratory testing Systematic laboratory testing

3.3. Morbidity and mortality monitoring Morbidity and mortality monitoring

Pandemic H1N1 Testing in NCPandemic H1N1 Testing in NC

Testing at State Laboratory of Public HealthTesting at State Laboratory of Public Health Hospitalized patients with ILIHospitalized patients with ILI Patients with ILI seen by sentinel providersPatients with ILI seen by sentinel providers

Algorithm for clinicians at Algorithm for clinicians at www.flu.nc.govwww.flu.nc.gov

Testing also performed at some Testing also performed at some commercial and hospital-based laboratoriescommercial and hospital-based laboratories

Rapid Flu Tests and Novel Rapid Flu Tests and Novel H1N1H1N1

Sensitivity ranges 10–70% for novel H1N1Sensitivity ranges 10–70% for novel H1N1 Low negative predictive valueLow negative predictive value If negative, cannot be used to rule out If negative, cannot be used to rule out

novel H1N1 infection novel H1N1 infection

High specificity High specificity Good positive predictive value Good positive predictive value only ifonly if novel novel

H1N1 prevalent in the communityH1N1 prevalent in the community

Pandemic Flu Testing: Take Pandemic Flu Testing: Take HomeHome

Treatment and control measure Treatment and control measure decisions should be decisions should be based on based on clinical and epidemiologic clinical and epidemiologic informationinformation; not on testing; not on testing

Pandemic Mitigation StrategiesPandemic Mitigation Strategies

VaccinationVaccination Targeted antiviral treatment and Targeted antiviral treatment and

prophylaxisprophylaxis Nonpharmaceutical interventionsNonpharmaceutical interventions

• Hand hygiene, respiratory etiquetteHand hygiene, respiratory etiquette• Isolation and quarantineIsolation and quarantine• Social distancing (school dismissal, Social distancing (school dismissal,

cancellation of large gatherings, teleworking, cancellation of large gatherings, teleworking, etc.)etc.)

Pandemic Mitigation StrategiesPandemic Mitigation Strategies

Mitigation strategies guided by severity of Mitigation strategies guided by severity of illnessillness

Pandemic H1N1 VaccinePandemic H1N1 Vaccine

Monovalent vaccine Monovalent vaccine Separate from seasonal vaccineSeparate from seasonal vaccine Likely two doses, 3–4 weeks apartLikely two doses, 3–4 weeks apart

Five manufacturersFive manufacturers Live attenuated vaccine available (~15%)Live attenuated vaccine available (~15%)

Clinical trials in progress, evaluatingClinical trials in progress, evaluating Safety / adverse eventsSafety / adverse events Interval between dosesInterval between doses Administration with seasonal vaccineAdministration with seasonal vaccine

*Planning assumptions*Planning assumptions

Pandemic Vaccine Availability*Pandemic Vaccine Availability*

Considering “early roll out” of some doses Considering “early roll out” of some doses in late September in late September

First large bolus expected mid-OctoberFirst large bolus expected mid-October

Near-Weekly shipmentsNear-Weekly shipments Total amount dependent on uptakeTotal amount dependent on uptake

Pandemic Vaccine DistributionPandemic Vaccine Distribution

Vaccinators:Vaccinators: providers who agree to provide vaccineproviders who agree to provide vaccine Local Health DepartmentsLocal Health Departments Hospitals (for health care workers)Hospitals (for health care workers)

Vaccine costs:Vaccine costs: Vaccine freeVaccine free Administration feesAdministration fees

Pandemic Vaccine: Priority Pandemic Vaccine: Priority GroupsGroups

Pregnant womenPregnant women

People who live with or care for children People who live with or care for children younger than 6 months of ageyounger than 6 months of age

Health care and emergency services workersHealth care and emergency services workers

Persons 6 months through 24 years of agePersons 6 months through 24 years of age

People 25 through 64 years of age at high People 25 through 64 years of age at high risk for complications of influenzarisk for complications of influenza

High Risk for ComplicationsHigh Risk for Complications

Chronic pulmonary, cardiovascular, renal, Chronic pulmonary, cardiovascular, renal, hepatic, hematologic, neurologic, hepatic, hematologic, neurologic, neuromuscular, or metabolic disorders neuromuscular, or metabolic disorders

ImmunosuppressionImmunosuppression

Persons younger than 19 years of age who Persons younger than 19 years of age who are receiving long-term aspirin therapy are receiving long-term aspirin therapy

Residents of nursing homes and other Residents of nursing homes and other chronic-care facilitieschronic-care facilities

Seasonal Influenza VaccineSeasonal Influenza Vaccine

Available Available now!now! Should not delay Should not delay

Recommended forRecommended for Children 6 months – 18 yearsChildren 6 months – 18 years Adults ≥50 yearsAdults ≥50 years Pregnant womenPregnant women Health care workersHealth care workers Persons with certain medical conditionsPersons with certain medical conditions Household contacts of children <5, adults >50, Household contacts of children <5, adults >50,

persons with certain medical conditionspersons with certain medical conditions

Community MitigationCommunity Mitigation

Recommendations based on disease severityRecommendations based on disease severity

Guidance issued for specific settingsGuidance issued for specific settings SchoolsSchools CampsCamps WorkplaceWorkplace Health care facilitiesHealth care facilities Long-term care facilities Long-term care facilities

www.flu.nc.govwww.flu.nc.gov and and www.cdc.gov/h1n1fluwww.cdc.gov/h1n1flu

School Guidance: “Similar School Guidance: “Similar Severity”Severity”

Stay home when sickStay home when sick At least 24 hours after fever resolves without At least 24 hours after fever resolves without

use of fever-reducing medicinesuse of fever-reducing medicines Separate ill students/staffSeparate ill students/staff Emphasize hand hygieneEmphasize hand hygiene Routine environmental cleaningRoutine environmental cleaning Early treatment of high-risk students and staffEarly treatment of high-risk students and staff Consider of Consider of selectiveselective dismissal of schools with dismissal of schools with

predominantly high-risk studentspredominantly high-risk students

*Consistent with SHEA/APIC/IDSA recommendatio*Consistent with SHEA/APIC/IDSA recommendationsns

Health Care Settings: Health Care Settings: NC Recommendations*NC Recommendations*

Standard precautionsStandard precautions Gown, gloves, mask, eye protection as warrantedGown, gloves, mask, eye protection as warranted

Droplet precautionsDroplet precautions Surgical maskSurgical mask

Private room or cohortingPrivate room or cohorting Strict hand hygiene and respiratory etiquetteStrict hand hygiene and respiratory etiquette Restriction of ill healthcare workers & visitorsRestriction of ill healthcare workers & visitors Airborne precautions for aerosol-generating Airborne precautions for aerosol-generating

proceduresprocedures

Specific Sector PlanningSpecific Sector Planning

Dept of CorrectionsDept of Corrections EMSEMS Law Enforcement-Judicial TTXLaw Enforcement-Judicial TTX

What some locales are doing What some locales are doing

Seasonal flu vaccine messages as “hold” Seasonal flu vaccine messages as “hold” messagesmessages

Planning for absenteesPlanning for absentees Coordination for homebound peopleCoordination for homebound people Scrolling marquees on gov’t TV panelsScrolling marquees on gov’t TV panels Alamance Reads projectAlamance Reads project

ResourcesResources

www.flu.nc.govwww.flu.nc.gov

www.cdc.gov/h1n1fluwww.cdc.gov/h1n1flu

www.pandemicflu.govwww.pandemicflu.gov

Questions?Questions?