Pandemic or Panic?Pandemic or Panic?Influenza A (H1N1)Influenza A (H1N1)

Jennifer HughesJennifer HughesMay 21, 2009May 21, 2009

OutlineOutline

► Influenza outbreaks, epidemics and Influenza outbreaks, epidemics and pandemicspandemics

►Epidemiology of novel H1N1 SOIVEpidemiology of novel H1N1 SOIV►Our local pictureOur local picture►VaccineVaccine►Things you should know about Things you should know about

treatmenttreatment

Epidemic: Epidemic:

From the Greek From the Greek epiepi (upon) + (upon) + demosdemos (people): affecting a disproportionately (people): affecting a disproportionately large number of individuals within a large number of individuals within a population at the same time.population at the same time.

Pandemic:Pandemic:

panpan (all) + (all) + demosdemos (people): (people):

occurring over a wide geographic area.occurring over a wide geographic area.

InfluenzaInfluenza

►High attack ratesHigh attack rates►Low mortality (on average) – 0.1% - Low mortality (on average) – 0.1% -

20%20%►More people have died from influenza More people have died from influenza

in a short period time than from any in a short period time than from any other disease.other disease.

►Affects birds and mammalsAffects birds and mammals

Influenza AInfluenza A

►Surface glycoproteins:Surface glycoproteins: HA (hemoagglutinins)HA (hemoagglutinins) NA (neuraminidases)NA (neuraminidases)

►H1, H2, H3H1, H2, H3►N1, N2 N1, N2

A typical flu yearA typical flu year

►Two flu seasons (one per hemisphere)Two flu seasons (one per hemisphere)►2-5 million cases of severe illness2-5 million cases of severe illness►500,000 deaths worldwide500,000 deaths worldwide►Annual pandemic?Annual pandemic?

Putting it in perspectivePutting it in perspective

PandemiPandemicc

DateDate DeathDeathss

SubtypSubtypee

PandemiPandemic indexc index

SpanishSpanish

FluFlu1918-1918-19201920

20-100 20-100 millionmillion

H1N1H1N1 55

Asian FluAsian Flu 1957-1957-19581958

1-1.5 1-1.5 millionmillion

H2N2H2N2 22

Hong Hong Kong FluKong Flu

1968-1968-19691969

0.75-1 0.75-1 millionmillion

H3N2H3N2 22

Remember H5N1 ?Remember H5N1 ?

►Avian-adapted, highly pathogenic Avian-adapted, highly pathogenic ►Endemic and panzootic in birdsEndemic and panzootic in birds►Not efficiently or sustainably transmitted Not efficiently or sustainably transmitted

to humans or between humansto humans or between humans►2008 : 44 cases, 33 deaths (75% 2008 : 44 cases, 33 deaths (75%

mortality)mortality)►2009: 29 cases, 11 deaths (38% 2009: 29 cases, 11 deaths (38%

mortality)mortality)

SARS for comparisonSARS for comparison

►SARS coronavirusSARS coronavirus►Near pandemic between Nov 2002 – Near pandemic between Nov 2002 –

July 2003July 2003►8096 cases, 774 deaths8096 cases, 774 deaths►Case fatality rate 9.6%Case fatality rate 9.6%►Last human case 2003Last human case 2003►““fully contained”fully contained”

yy

Tracing the beginningTracing the beginning

►March 18 – Mexico reports increase in March 18 – Mexico reports increase in late-season ILIlate-season ILI

►April 21 samples are sent to CDC to April 21 samples are sent to CDC to confirmconfirm

►First death April 13 First death April 13 Diabetic woman from OaxacaDiabetic woman from Oaxaca

►2 Children San Diego country 2 Children San Diego country diagnosed April 24diagnosed April 24

MexicoMexico

►3648 cases3648 cases►72 deaths72 deaths►Hospitalization rates high in young Hospitalization rates high in young

peoplepeople►Surveillance challengingSurveillance challenging

H1N1 outbreak: what is H1N1 outbreak: what is knownknown

►Novel virus (to animals and humans)Novel virus (to animals and humans)►No pre-existing immunityNo pre-existing immunity►More contagious than seasonal More contagious than seasonal

influenzainfluenza►Primary attack rate 35%Primary attack rate 35%►Unclear originUnclear origin

►Mild illness (except Mexico)Mild illness (except Mexico)► Severe and lethal cases seen in younger Severe and lethal cases seen in younger

patientspatients ► Case fatality rate estimate of 0.3-1.4%Case fatality rate estimate of 0.3-1.4%► Could result in 6-12 million deathsCould result in 6-12 million deaths

WHO Rapid Pandemic Assessment CollaborationWHO Rapid Pandemic Assessment Collaboration

The current H1N1 SOIV The current H1N1 SOIV situation…situation…

►21 May 2009 06:00 21 May 2009 06:00 41 countries 41 countries 11 034 cases11 034 cases 85 deaths85 deaths 791 cases since May 20791 cases since May 20 5 new deaths5 new deaths

Surveillance in CanadaSurveillance in CanadaProvince/Province/

territoryterritoryNew Cases New Cases

(lab-confirmed) (lab-confirmed) Total casesTotal cases Total deathsTotal deaths

BCBC 1414 100100 00

AlbertaAlberta 1919 8686 11

SaskSask 3030 4949 00

ManitobaManitoba 22 6464 00

OntarioOntario 9797 284284 00

QuebecQuebec 5959 106106 00

New BrunswickNew Brunswick 00 22 00

Nova ScotiaNova Scotia 22 6868 00

PEIPEI 00 33 00

NewfoundlandNewfoundland 00 00 00

YukonYukon 00 11 00

NWTNWT 00 00 00

NunavutNunavut 00 00 00

TotalTotal 223223 719719 11

Alberta’s casesAlberta’s cases

►30 had traveled to affected areas; 30 had traveled to affected areas; ►9 in contact with travelers9 in contact with travelers►16 no travel history16 no travel history►31 cases have travel/exposure 31 cases have travel/exposure

histories to be determined. histories to be determined. ►Median 33 years of ageMedian 33 years of age

Gift Lake, AlbertaGift Lake, Alberta

►Woman in 30s with chronic underlying Woman in 30s with chronic underlying medical conditionsmedical conditions

►No travel to MexicoNo travel to Mexico►Household contact + H1N1 SOIVHousehold contact + H1N1 SOIV►Died in Edmonton April 28, 2009Died in Edmonton April 28, 2009►Autopsy report May 14 : inconclusive Autopsy report May 14 : inconclusive

about role of H1N1about role of H1N1

Reverse Zoonosis in AlbertaReverse Zoonosis in Alberta

►Rocky Mountain HouseRocky Mountain House►2200 pigs under quarantine2200 pigs under quarantine►““some” animals had Influenza A H1N1some” animals had Influenza A H1N1►From carpenter who traveled to From carpenter who traveled to

MexicoMexico►500 culled for overcrowding500 culled for overcrowding

TestingTesting

►NP swab or aspirate NP swab or aspirate ►M5 Universal Transport MediumM5 Universal Transport Medium►““Influenza testing” on ProvLab req Influenza testing” on ProvLab req

(mark as “EI 236”)(mark as “EI 236”)►Prov Lab requisitionProv Lab requisition

Across the RegionAcross the Region

►PLCPLC►ACHACH►FMCFMC►RGHRGH

Laboratory Diagnosis Laboratory Diagnosis

► Confirmed case definition:Confirmed case definition: RT-PCRRT-PCR Viral cultureViral culture 4 x increase in H1N1 specific neutralizing AB4 x increase in H1N1 specific neutralizing AB

► Probable case:Probable case: Positive testing for influenza APositive testing for influenza A Untypable, with/without clinical sxUntypable, with/without clinical sx

ReportingReporting

►Mild ILI – report if you swabbed themMild ILI – report if you swabbed them►Severe - call MOH on callSevere - call MOH on call►Positive results followed by public Positive results followed by public

healthhealth

Infection Prevention & Infection Prevention & ControlControl

►PatientsPatients►Health care workersHealth care workers

Site to siteSite to site

Respiratory PrecautionsRespiratory Precautions

►Within 2 m of patientWithin 2 m of patient►Surgical maskSurgical mask

Patient is compliant with resp hygienePatient is compliant with resp hygiene Weak or no coughWeak or no cough

►N95 maskN95 mask Aerosol-generating medical proceduresAerosol-generating medical procedures Non-compliant patientNon-compliant patient

Swine Flu Kit for $39.95 Swine Flu Kit for $39.95 (+ $8.95 (+ $8.95

shipping)shipping)

VaccineVaccine

►Current seasonal flu vaccine: no Current seasonal flu vaccine: no immunityimmunity

►H1N1 vax available in 5-6 monthsH1N1 vax available in 5-6 months►Global capacity of 1-2 billion doses/yearGlobal capacity of 1-2 billion doses/year►Will not be incorporated into seasonal Will not be incorporated into seasonal

vaccinevaccine►1 vs 2 doses?1 vs 2 doses?►Federal gov + GlaxoSmithKline have Federal gov + GlaxoSmithKline have

signed a deal for Canadian Productionsigned a deal for Canadian Production

TreatmentTreatment

►Oseltamivir (Tamiflu): RocheOseltamivir (Tamiflu): Roche►Zanamivir (Relenza) : GlaxoSmithKlineZanamivir (Relenza) : GlaxoSmithKline►Neuraminidase inhibitor : prevents virion Neuraminidase inhibitor : prevents virion

release from infected cellsrelease from infected cells►Age-based, weight-based dosing in childrenAge-based, weight-based dosing in children►Pregnancy Category CPregnancy Category C►Most effective when started within 48 hoursMost effective when started within 48 hours

OseltamivirOseltamivir

► 25-30% reduction in symptom duration25-30% reduction in symptom duration► 59% reduction in hospitalization59% reduction in hospitalization► 63% reduction in antimicrobial use63% reduction in antimicrobial use► 1 day reduction in work days lost1 day reduction in work days lost

► Reduction in mortality (OR 0.21, p<0.03)Reduction in mortality (OR 0.21, p<0.03)

Statement on influenza vaccination for the 2008-2009 season. An Advisory Committee Statement (ACS). Can Commun Dis Rep 2008 Jul 15;34(ACS-3):1-46.  Available at:  http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/08pdf/acs-3.pdf

Centers for Disease Control and Prevention. Antiviral agents for seasonal influenza:  dosage. 2009 [updated 2009 Feb 11, cited 2009 Mar 20]. Available at:

http://www.cdc.gov/flu/professionals/antivirals/dosage.htm

Oseltamivir in CanadaOseltamivir in Canada

►NOT RECOMMENDED for treatment or NOT RECOMMENDED for treatment or prophylaxis of mild casesprophylaxis of mild cases

►Tamiflu use should be consistent with Tamiflu use should be consistent with use for seasonal influenzause for seasonal influenza

Indications for TamifluIndications for Tamiflu

► All hospitalized patients with All hospitalized patients with confirmed, probable or suspected confirmed, probable or suspected influenza (novel or seasonal) influenza (novel or seasonal)

► Patients who are at higher risk for Patients who are at higher risk for seasonal influenza complicationsseasonal influenza complications

Indications for TamifluIndications for Tamiflu► Influenza-like illness ►< 48 hours onset►High risk of influenza-related complications

► cardiac or pulmonary disorderscardiac or pulmonary disorders► diabetes mellitusdiabetes mellitus► cancercancer► immunodeficiencyimmunodeficiency► renal diseaserenal disease► anemia or hemoglobinopathyanemia or hemoglobinopathy► conditions that compromise the management of respiratory secretionsconditions that compromise the management of respiratory secretions► children with conditions treated for long periods with acetylsalicylic children with conditions treated for long periods with acetylsalicylic

acidacid► children < 2 yearschildren < 2 years► pregnant womenpregnant women► > 65 years> 65 years

Who should get PEP?Who should get PEP?

►Close contact of case (suspected, Close contact of case (suspected, probable and confirmed)probable and confirmed)

►High risk for complications of influenzaHigh risk for complications of influenza►Health care workers with recognized, Health care workers with recognized,

unprotected close contact exposureunprotected close contact exposure►During infectious period (Day 0 – Day During infectious period (Day 0 – Day

7)7)

Influenza Antiviral DosingInfluenza Antiviral Dosing

Canada’s pandemic planCanada’s pandemic plan

►Stockpile to treat 17.5% of population Stockpile to treat 17.5% of population ►55.7 million doses stockpiled in Canada55.7 million doses stockpiled in Canada►5 million doses of zanamivir5 million doses of zanamivir►Alberta would get ~10%Alberta would get ~10%

Canadian Pandemic Influenza Plan for the Health Sector :The Use of Antiviral Drugs During a Pandemic. Public Health Agency of Canada. May 12, 2009.

Oseltamivir in the RegionOseltamivir in the Region

►Available for purchase by prescriptionAvailable for purchase by prescription►NOT a restricted medicationNOT a restricted medication►Hospitals and outpatient pharmacies Hospitals and outpatient pharmacies

have stockpile for MOH caseshave stockpile for MOH cases

Neuraminidase ResistanceNeuraminidase Resistance

►HIN1 SOIVHIN1 SOIV 101 isolates : 0 % resistance to 101 isolates : 0 % resistance to

neuraminidase inhibitorsneuraminidase inhibitors 96 isolates : 100% resistance to 96 isolates : 100% resistance to

adamantanesadamantanes

http://www.cdc.gov/h1n1flu/recommendations.htm#table2http://www.cdc.gov/h1n1flu/recommendations.htm#table2

Speculating on the futureSpeculating on the future

►Clinical spectrum not yet fully Clinical spectrum not yet fully apparentapparent

►Spread to southern Spread to southern hemisphere/interaction with seasonal hemisphere/interaction with seasonal fluflu

►Antigenic drift of influenza virusesAntigenic drift of influenza viruses

►H5N1 avian influenza + H1N1 = H5N1 avian influenza + H1N1 = “Armageddon Virus”“Armageddon Virus”

Assessing the severity of an Assessing the severity of an influenza pandemicinfluenza pandemic

► Inherent virulenceInherent virulence►Population vulnerabilityPopulation vulnerability►Waves of spreadWaves of spread

8 gene segments commonly and 8 gene segments commonly and unpredictably mutateunpredictably mutate

►Capacity to respondCapacity to respond

► WHO Phase 5: sustained community-level WHO Phase 5: sustained community-level outbreaks in at least two countries in one WHO outbreaks in at least two countries in one WHO region. region.

► Pandemic is “imminent”Pandemic is “imminent”► Currently “sustained community-level outbreak”Currently “sustained community-level outbreak”

Staving off a pandemic?Staving off a pandemic?

►May 18, 2009:May 18, 2009:

Britain, Japan, China, US and others urge Britain, Japan, China, US and others urge WHO to change its definition of a WHO to change its definition of a pandemic to reflect the virulence of a pandemic to reflect the virulence of a disease, not just how far it spreads around disease, not just how far it spreads around the world. the world.

SummarySummary

►First wave of the outbreak appears mildFirst wave of the outbreak appears mild►Future is unpredictableFuture is unpredictable►Still on upswing of epidemiological curveStill on upswing of epidemiological curve►Vaccine is still months awayVaccine is still months away►Oseltamivir and zanamivir work… for nowOseltamivir and zanamivir work… for now►Major political and economic impacts of Major political and economic impacts of

pandemicpandemic

ReferencesReferencesPublic Health Agency of Canada. FightFlu. Http://www. Fightflu.ca. Access May 20, 2009.Public Health Agency of Canada. FightFlu. Http://www. Fightflu.ca. Access May 20, 2009.

The Lancet: H1N1 Resource Centre: The Lancet: H1N1 Resource Centre: http://www.thelancet.com/H1N1-fluhttp://www.thelancet.com/H1N1-flu

McGeer A, Green KA, Plevneshi A, et al. Antiviral therapy and outcomes of influenza requiring hospitalization in Ontario, Canada. Clin Infect Dis 2007;45:1568-75.

Kaiser I, Wat C, Mills T, et al. Impact of oseltamivir treatment on influenza-related lower respiratory tract complications and hospitalizations. Arch Intern Med 2003;163:1667-72.

Cooper NJ, Sutton AJ, Abrams KR , et al. Effectiveness of neuraminidase inhibitors in treatmentand prevention of influenza A or B: systematic review and meta-analysis of controlled trials.BMJ 2003;326:1-7.

Canadian Pandemic Influenza Plan for the Health Sector: The Use of Antiviral Drugs During a Pandemic. Annex E. Public Health Agency of Canada. May 12, 2009. http://www.phac-aspc.gc.ca/cpip-pclcpi/pdf-e/annex_e0513-eng.pdf

Aoki FY , Macleod MD, Paggiaro P, et al. Early administration of oral oseltamivir increases the benefits of influenza treatment. J Antimicrob Chemother 2003;51:123-9.

Balicer RD , Huerta M, Davidovitch N, et al. Cost benefit of stockpiling drugs for influenza pandemic. Emerg Infect Dis 2005;11:1280-2.