bureau of emergency preparedness and response 88 years of influenza pandemics in 15 minutes peter c....

Bureau of Emergency Preparedness and Bureau of Emergency Preparedness and ResponseResponse

88 Years of Influenza 88 Years of Influenza Pandemics in 15 MinutesPandemics in 15 Minutes

Peter C. Kelly, M.D.Peter C. Kelly, M.D.Arizona Dept. of Health ServicesArizona Dept. of Health Services


It’s all about the virusIt’s all about the virus


Influenza VirusInfluenza Virus

RNA, 8 segmentsRNA, 8 segments Unstable,mutates Unstable,mutates

frequentlyfrequently Surface proteinsSurface proteins

• HemagglutininHemagglutinin• NeuraminidaseNeuraminidase

Niche in nature is Niche in nature is birdsbirds


Drift and ShiftDrift and Shift

Both refer to genetic changesBoth refer to genetic changes DriftDrift: Minor changes in H and N : Minor changes in H and N

antigens; occur annually or every few antigens; occur annually or every few yearsyears

Shift:Shift: Major change (30% or more) in Major change (30% or more) in H and/or N antigens; “new” virus. H and/or N antigens; “new” virus. Important for starting pandemicsImportant for starting pandemics


Influenza is GlobalInfluenza is Global


PandemicsPandemics


Required for Influenza PandemicRequired for Influenza Pandemic

““New” virus (antigenic shift)New” virus (antigenic shift)• Susceptible populationSusceptible population

Transmitted from animals to humansTransmitted from animals to humans

Cause disease in humansCause disease in humans

Efficient person to person transmissionEfficient person to person transmission


Influenza PandemicsInfluenza Pandemics

Have occurred for centuriesHave occurred for centuries Occur 11 to 42 years apartOccur 11 to 42 years apart

• Unpredictable but not randomUnpredictable but not random Attack rates of 10 to 40%Attack rates of 10 to 40% Excess mortalityExcess mortality But humanity survivesBut humanity survives


2020thth Century Century


1918-19 Pandemic1918-19 Pandemic

aka Spanish Fluaka Spanish Flu H1N1 virusH1N1 virus, , Genetics: “avian Genetics: “avian

like”like” First cases in USAFirst cases in USA Global spread ~1 Global spread ~1

yryr Mortality 20-50 Mortality 20-50

millionmillion USA 500,000USA 500,000


ImpactImpact

High mortalityHigh mortality Social disruptionSocial disruption

• BurialBurial• Public servicesPublic services• Events cancelledEvents cancelled

Spread along troop Spread along troop transport routestransport routes

Poor public health Poor public health responseresponse


Mortality and “Waves”Mortality and “Waves”Taubenberger, Morens. EID. 2006;12: 15-22.Taubenberger, Morens. EID. 2006;12: 15-22.


““the Mother of All Pandemics”the Mother of All Pandemics”Taubenberger, Morens.EID.2006;12:15-22Taubenberger, Morens.EID.2006;12:15-22

H1N1 1918 virus is the ancestor of H1N1 1918 virus is the ancestor of current influenza virusescurrent influenza viruses

Human and porcine lineage have Human and porcine lineage have some H1N1 genessome H1N1 genes

H3N2 virus retains some H1N1 genesH3N2 virus retains some H1N1 genes None of these as virulent as originalNone of these as virulent as original


1957-58 Influenza Pandemic1957-58 Influenza PandemicAsian InfluenzaAsian Influenza

H2N2 virusH2N2 virus: 3 new genes (H,N, PB1); : 3 new genes (H,N, PB1); 5 genes from 1918 H1N15 genes from 1918 H1N1

First cases in ChinaFirst cases in China Spread around world in 6 monthsSpread around world in 6 months 11stst wave: Fall’57 school age wave: Fall’57 school age 22ndnd wave: Jan’58 adults wave: Jan’58 adults 80,000 deaths in USA80,000 deaths in USA

• Very young and elderlyVery young and elderly


1968-69 Influenza Pandemic1968-69 Influenza PandemicHong Kong InfluenzaHong Kong Influenza

H3N2 VirusH3N2 Virus, 2 new , 2 new genes(H, PB1), 5 genes(H, PB1), 5 retained from retained from 1918. N2 from 1918. N2 from AsianAsian

Only 1 antigen Only 1 antigen shiftedshifted

Population has Population has some immunity to some immunity to N2N2


H3N2 InfluenzaH3N2 Influenza

Lowest mortality of 20Lowest mortality of 20thth cent. cent. pandemicspandemics• 34,000 deaths in USA34,000 deaths in USA

U shaped mortality curveU shaped mortality curve


Wave PhenomenonWave Phenomenon


Where are we now?Where are we now?

H3N2 era. Seasonal influenza. H3N2 era. Seasonal influenza. Antigenic drift. Annual vaccine. Antigenic drift. Annual vaccine. Mortality ~36,000Mortality ~36,000

SURPRISESURPRISE 2003 H5 N1 avian virus2003 H5 N1 avian virus Highly pathogenic in birds, especially Highly pathogenic in birds, especially

chickenschickens Almost world wide spread Almost world wide spread

(asia,africa,and europe)(asia,africa,and europe)


Humans and H5N1 HPAIHumans and H5N1 HPAI

Few cases in close contact with Few cases in close contact with chickenschickens• As of 7/14/06; 230 cases and 132 deathsAs of 7/14/06; 230 cases and 132 deaths

No efficient human to human No efficient human to human transmissiontransmission


Required for Influenza PandemicRequired for Influenza Pandemic

““New” virus (antigenic shift)New” virus (antigenic shift)• Susceptible populationSusceptible population

Transmitted from animals to humansTransmitted from animals to humans

Cause disease in humansCause disease in humans

Efficient person to person transmissionEfficient person to person transmission


Be an optimist!Be an optimist! Power of scientific inquiry Power of scientific inquiry WHO global surveillance is good and WHO global surveillance is good and

getting bettergetting better Communication and cooperation Communication and cooperation

among nations is better since SARSamong nations is better since SARS Vaccine development and production Vaccine development and production

methods are on a fast trackmethods are on a fast track

bureau of emergency preparedness and response 88 years of influenza pandemics in 15 minutes peter c....

Documents

virus slide

response influenza virus

release of virus

virus h1

influenza preparedness

response pandemics

virus cause disease

response drift