Pandemic Influenza: Pandemic Influenza: the “Mother of All Disasters”?

October 11, 2007Healthy Carolinians Annual Conference

Steve Cline, DDS, MPHSteve Cline, DDS, MPH

NC Division of Public HealthNC Division of Public Health

ObjectivesObjectives

Review the fundamentals of pandemic Review the fundamentals of pandemic influenzainfluenza

Assess the current threat of pandemic Assess the current threat of pandemic influenza influenza

Review influenza surveillance – How will Review influenza surveillance – How will we know?we know?

Discuss pandemic influenza preparedness Discuss pandemic influenza preparedness and response in North Carolinaand response in North Carolina

Types of Influenza VirusesTypes of Influenza Viruses

Influenza AInfluenza A– epidemic or pandemicepidemic or pandemic– animals and humansanimals and humans– differing pathogenicitiesdiffering pathogenicities– divided into subtypesdivided into subtypes

based on surface based on surface proteins (H & N)proteins (H & N)

144 combinations144 combinations

constantly mutateconstantly mutate

variation within subtypevariation within subtype

Influenza BInfluenza B– epidemicepidemic– humans (primarily)humans (primarily)– not divided into not divided into

subtypessubtypes

Influenza CInfluenza C– humanshumans– mild respiratory illnessmild respiratory illness

Seasonal Flu: Signs and SymptomsSeasonal Flu: Signs and Symptoms

FeverFever

HeadacheHeadache

Muscle achesMuscle aches

Extreme fatigueExtreme fatigue

Dry coughDry cough

Sore throatSore throat

Runny or stuffy noseRunny or stuffy nosehappycarpenter.blogs.com

Flu Fundamentals: Flu Fundamentals: Respiratory SpreadRespiratory Spread

Transmission: Transmission: Respiratory dropletsRespiratory droplets– Each infected person infects 2-3 othersEach infected person infects 2-3 others

Incubation period:Incubation period: 1 to 5 days from exposure 1 to 5 days from exposure to onset of symptomsto onset of symptoms

Communicability:Communicability: – 1-2 days before symptom onset1-2 days before symptom onset– 4-5 days after onset 4-5 days after onset

Timing:Timing: Peak usually occurs December Peak usually occurs December through March in North Americathrough March in North America

Deaths25,000 - 72,000

Hospitalizations114,000 - 257,500

Infections and illnesses50 - 60 million

Physician visits~ 25 million

Thompson WW et al. JAMA. 2003;289:179-86. Couch RB. Ann Intern Med. 2000;133:992-8. Patriarca PA. JAMA. 1999;282:75-7. ACIP. MMWR. 2004;53(RR06):1-40.

Seasonal Influenza ImpactSeasonal Influenza ImpactNC and US SocietyNC and US Society

NC730 - 2100

NC3300 - 7500

NC 730,000

NC 1.7 million

Pandemic InfluenzaPandemic Influenza

MajorMajor mutation occurs mutation occurs – Genetic reassortment of human and avian influenza virusesGenetic reassortment of human and avian influenza viruses– Direct animal (poultry) to human transmissionDirect animal (poultry) to human transmission

Results in new subtype of influenza A Results in new subtype of influenza A – Avian originAvian origin– Adapted to humansAdapted to humans– No immunity in the human populationNo immunity in the human population

Results in multiple Results in multiple simultaneous epidemics simultaneous epidemics worldwideworldwide with enormous numbers of deaths and with enormous numbers of deaths and illnessillness– Six to eight weeksSix to eight weeks– Multiple wavesMultiple waves

Pandemics of the 20Pandemics of the 20thth Century Century

YearYear SubtypeSubtype Impact in the Impact in the United StatesUnited States

1918-19 1918-19

Spanish fluSpanish flu

H1N1H1N1 550,000 deaths550,000 deaths

1957-581957-58

Asian fluAsian flu

H2N2H2N2 69,800 deaths69,800 deaths

1968-691968-69

Hong Kong flu Hong Kong flu

H3N2H3N2 33,800 deaths33,800 deaths

““Pandemic Watch”Pandemic Watch”

Avian InfluenzaAvian Influenza

Water birds are the natural reservoirWater birds are the natural reservoir– Carry virus in intestinesCarry virus in intestines

– Virus shed in feces and respiratory secretionsVirus shed in feces and respiratory secretions

– Usually do not get sickUsually do not get sick

Highly contagious among birds Highly contagious among birds

Most of no human health significanceMost of no human health significance

Pandemic “Prerequisites”Pandemic “Prerequisites”

Novel virus emergesNovel virus emerges

Novel virus causes disease in humansNovel virus causes disease in humans

Novel virus can be efficiently transmitted Novel virus can be efficiently transmitted person to personperson to person

Dr. Asamoa-Baah, Assistant Director General,WHO Communicable Diseases

WHO Pandemic PhasesWHO Pandemic Phases

H5N1 in HumansH5N1 in Humans

Current outbreak began December 2003Current outbreak began December 2003

Initially cases were limited to Southeast Initially cases were limited to Southeast AsiaAsia

Geographic distribution continuing to Geographic distribution continuing to expand in 2006expand in 2006– Human cases are now being reported in Human cases are now being reported in

Europe and AfricaEurope and Africa

Global Migration of H5N1Global Migration of H5N1

October 5, 2007

Backyard flocks

Direct Contact with PoultryDirect Contact with PoultryPrimary Risk FactorPrimary Risk Factor

Plucking and preparing Plucking and preparing diseased poultrydiseased poultry

Handling fighting cocksHandling fighting cocks

Playing with poultryPlaying with poultry

Consumption of duck’s Consumption of duck’s blood or possibly blood or possibly undercooked poultryundercooked poultry

““Pandemic Watch”Pandemic Watch”Global PerspectiveGlobal Perspective

Good newsGood news– No evidence of sustained person-to-person No evidence of sustained person-to-person

transmissiontransmission– Recent human cluster in Indonesia Recent human cluster in Indonesia notnot a a

major genetic shiftmajor genetic shift

Bad newsBad news– H5N1 virus continues to circulate widely in H5N1 virus continues to circulate widely in

Asia, Europe and AfricaAsia, Europe and Africa– Eradication of H5N1 in birds is difficultEradication of H5N1 in birds is difficult

““Pandemic Watch”Pandemic Watch”United StatesUnited States

No reported cases of H5N1No reported cases of H5N1– Migratory birdsMigratory birds– PoultryPoultry– HumansHumans

Other avian influenza viruses detected in Other avian influenza viruses detected in poultry in 2004poultry in 2004– H5N2H5N2 in Texas in Texas – H7N2H7N2 in Maryland in Maryland

Impact of an Influenza PandemicImpact of an Influenza Pandemic North CarolinaNorth Carolina

Planning AssumptionsPlanning Assumptions

1.4 million outpatient visits1.4 million outpatient visits

29,000 hospitalizations29,000 hospitalizations

6,700 deaths6,700 deaths

•Assuming 30% attack rate and NC population of 8.5 million people•Based on CDC software FluAid 2.0

Pandemic Influenza PlanningPandemic Influenza Planning

GoalsGoals– ReduceReduce morbidity morbidity – ReduceReduce mortality mortality– ReduceReduce social disruption social disruption

Pandemic Influenza PlanningPandemic Influenza Planning

ChallengesChallenges– WidespreadWidespread– Long durationLong duration– Health services overwhelmedHealth services overwhelmed– Shortages may occurShortages may occur

MedicationsMedications

EquipmentEquipment

Hospital bedsHospital beds

PersonnelPersonnel

Pandemic Preparedness ActivitiesPandemic Preparedness Activities

NC Pandemic Influenza Response PlanNC Pandemic Influenza Response PlanExercisesExercises– Eight tabletop exercises Jan-Feb 2006Eight tabletop exercises Jan-Feb 2006– Statewide full scale exercise May 2006Statewide full scale exercise May 2006– Total of 185 pan flu exercises 2006-2007Total of 185 pan flu exercises 2006-2007

Pandemic Influenza Ethics Task ForcePandemic Influenza Ethics Task ForceFederal Supplemental FundingFederal Supplemental Funding

North Carolina Pandemic North Carolina Pandemic Influenza Response PlanInfluenza Response Plan

Collaboration among many different groupsCollaboration among many different groups

First version posted to website October 2004First version posted to website October 2004

Modeled after other plansModeled after other plans– National Planning Guide (CDC)National Planning Guide (CDC)– NC SARS Response PlanNC SARS Response Plan

Revised version completed January 2006Revised version completed January 2006

Pandemic COOP May 2007Pandemic COOP May 2007

Core ComponentsCore ComponentsNC Pandemic PlanNC Pandemic Plan

Command and ControlCommand and Control

SurveillanceSurveillance

Vaccine Preparedness and ResponseVaccine Preparedness and Response

Antiviral Preparedness and ResponseAntiviral Preparedness and Response

Medical SurgeMedical Surge

Preparedness in Healthcare FacilitiesPreparedness in Healthcare Facilities

CommunicationCommunication

AppendicesAppendices NC Pandemic PlanNC Pandemic Plan

Supplements to core parts of planSupplements to core parts of plan““Stand alone” appendicesStand alone” appendices– Laboratory diagnosisLaboratory diagnosis– Community containmentCommunity containment– International travel guidelinesInternational travel guidelines– Mass fatality planMass fatality plan– Legal issuesLegal issues– Mental health Mental health

Local Health Department ToolkitLocal Health Department Toolkit NC Pandemic PlanNC Pandemic Plan

Roles by pandemic phaseRoles by pandemic phase

Determination of county-level impactDetermination of county-level impact

Influenza vaccine estimationInfluenza vaccine estimation

Designation of alternate care sitesDesignation of alternate care sites

Collaborations with local partnersCollaborations with local partners

Emergency Plans for Vulnerable PopulationsEmergency Plans for Vulnerable Populations

Goals of Community Mitigation in a Goals of Community Mitigation in a Pandemic Pandemic

1. Delay and flatten outbreak peak2. Reduce peak burden on healthcare infrastructure3. Reduce number of cases4. Buy time

DailyCases

#1

#2

#3

Days since First Case

No intervention

With interventions

Community Mitigation of Influenza:Community Mitigation of Influenza:Epidemiologic DataEpidemiologic Data

School closure helpful in flu outbreak, IsraelSchool closure helpful in flu outbreak, Israel– Significant decreases in children’s diagnoses of respiratory Significant decreases in children’s diagnoses of respiratory

infections (42%), visits to physicians (28%), emergency infections (42%), visits to physicians (28%), emergency

departments (28%), and medication purchases (35%).departments (28%), and medication purchases (35%).

Flu immunizaton of schoolchildren associated Flu immunizaton of schoolchildren associated with lower population illness rateswith lower population illness rates– Controlled trial, small towns in Michigan, 1968-69Controlled trial, small towns in Michigan, 1968-69– Immunization of children in Japan, 1962-87Immunization of children in Japan, 1962-87

Lower rates of isolation of influenza and other Lower rates of isolation of influenza and other respiratory viruses in Hong Kong in SARSrespiratory viruses in Hong Kong in SARS– Many social distancing measures, public mask useMany social distancing measures, public mask use

Reference: WHO Writing Group. Emerg Inf Dis 2006;12:81-7

Community Mitigation of Influenza:Community Mitigation of Influenza:Historical Information from 1918Historical Information from 1918

Forced isolation, quarantine, social distancing, Forced isolation, quarantine, social distancing, masks, travel restrictions seemed ineffective in masks, travel restrictions seemed ineffective in 1918, but 1918, but unclear if partially effectiveunclear if partially effective– WHO Writing Group. Emerg Inf Dis 2006;12:88-94WHO Writing Group. Emerg Inf Dis 2006;12:88-94

Recent hypothesis: Varying death rates in US Recent hypothesis: Varying death rates in US cities may have been due to differential cities may have been due to differential implementation of mitigation measuresimplementation of mitigation measures– Further historical study in progressFurther historical study in progress– Markel H, Univ. of Michigan Markel H, Univ. of Michigan

Weekly mortality data provided by Marc Lipsitch (personal communication)

1918 Death Rates: Philadelphia v St. Louis

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Summary: Community Mitigation of Summary: Community Mitigation of Pandemic Influenza, TLCPandemic Influenza, TLC

Home isolation of ill patients not needing hospitalizationHome isolation of ill patients not needing hospitalizationVoluntary home quarantine for household contactsVoluntary home quarantine for household contactsSocial distancing measuresSocial distancing measures– School closure and protective sequestration of children may have School closure and protective sequestration of children may have

profound impactprofound impact– Workplace COOP (liberal leave vs. closure)Workplace COOP (liberal leave vs. closure)– Limit public gatheringsLimit public gatherings

Personal infection control measuresPersonal infection control measures– Hand hygiene and cough etiquetteHand hygiene and cough etiquette– Mask use for ill personsMask use for ill persons

Disinfection of contaminated surfacesDisinfection of contaminated surfacesAntivirals for treatment & targeted prophylaxisAntivirals for treatment & targeted prophylaxis

Pandemic Influenza PlanningPandemic Influenza PlanningOngoing IssuesOngoing Issues

Strengthen local health department plansStrengthen local health department plans

Exercise pandemic influenza plansExercise pandemic influenza plans

Increase situational awareness outside of public Increase situational awareness outside of public healthhealth

Encourage planning among other entitiesEncourage planning among other entities– BusinessesBusinesses– SchoolsSchools– Volunteer organizations (Vulnerable Populations)Volunteer organizations (Vulnerable Populations)

www.ncpublichealth.com

www.ReadyNC.gov

Online ResourcesOnline Resourceswww.who.orgwww.who.orgwww.cdc.govwww.cdc.govwww.pandemicflu.govwww.pandemicflu.gov

www.ncpanflu.govwww.ncpanflu.govwww.ncpublichealth.comwww.ncpublichealth.comwww.readync.orgwww.readync.org

pandemicflu.plan@ncmail.netpandemicflu.plan@ncmail.net

ConclusionsConclusions

Forecasting the next pandemic is difficultForecasting the next pandemic is difficult

Current outbreaks of H5N1 pose an ongoing Current outbreaks of H5N1 pose an ongoing threatthreat

Pandemic influenza presents unique Pandemic influenza presents unique challenges for plannerschallenges for planners

Many different entities need to planMany different entities need to plan

Everyone has a roleEveryone has a role

Prevention and PlanningPrevention and Planning

It Begins At HomeIt Begins At Home

The more you prepare yourself and your The more you prepare yourself and your family, the more likely you can fulfill roles family, the more likely you can fulfill roles in an emergencyin an emergency

Questions?Questions?

Thank youSteve Cline, DDS,MPH

Deputy State Health DirectorNC Division of Public Health