The 2009-10 “Pandemic” Experience

“This year, it’s a different flu season”

What are We Preparing For?

• A public health emergency that is inevitable but unpredictable in timing and epidemiology

• Short lead time: - presence in Canada < 3 months - 1st peak in illness within 5-7 months

• Outbreaks will occur simultaneously in multiple locations, in multiple waves

• Limited resources will need to be prioritized

• Extremely high demand for information

History ofInfluenza Pandemics

Year Influenza A Strain

1847 ?

1889 - 1890 H2N2

1899 - 1900 H3N2 1918 - 1919 H1N1 Spanish flu 1957 H2N2 Asian flu

1968 H3N2 Hong Kong flu

2009 H1N1 ??

Pandemic Mortality

No. of deaths Death rateWorldwide Canada per 100,000 pop.

1918-19 40-50 m 50-60,000 218

1957 1-2 m 7,000 22

1968 1 m 3,000 14

Historical Analysis - 1918-19 Pandemic (“Spanish Flu”)

• Public health units overwhelmed

• Traditional measures were largely unsuccessful

• Quarantine, “community lockdown” did not limit spread

• Major failure: Lack of honest communication

World Health Organization (WHO) Alert Periods and

PhasesPeriod Phase Description

Interpandemic Period*

Phase 1 No new influenza virus subtypes have been detected in humans. An influenza virus subtype that has caused human infection may be present in animals. If present in animals, the risk* of human infection is considered to be low.

Phase 2 No new influenza virus subtypes have been detected in humans. However, a circulating animal influenza virus subtype poses a substantial risk of human disease.

Pandemic Alert Period**

Phase 3 Human infection(s) with a new subtype, but no human-to-human spread, or at most rare instances of spread to a close contact.

Phase 4 Small cluster(s) with limited human-to-human transmission but spread is highly localized, suggesting that the virus is not well adapted to humans.

Phase 5 Larger cluster(s) but human-to-human spread still localized, suggesting that the virus is becoming increasingly better adapted to humans, but may not yet be fully transmissible (substantial pandemic risk).

Pandemic Period Phase 6 Increased and sustained transmission in general population.

Postpandemic Period

Return to interpandemic period

Pandemic Influenza Phases

Source: WHO Global Influenza Programme 2009

Whole of Society Approach to Pandemic Preparedness

Source: WHO Global

Influenza Programme

2009

Ontario’s Pandemic Planning • Activities correspond to the WHO pandemic phases (Inter-

pandemic, Pandemic Alert and Pandemic)• Aligned with direction in Canadian Pandemic Influenza Plan • Provides detail on federal, provincial and local

roles/responsibilities and commitments• Includes an ethical framework for decision-making • Focuses on the health care system’s preparedness and

readiness, including stocking supplies and equipment • Supports and guides community response and includes a

number tools designed to undertake effective local planning and preparedness.

• Continues to be updated and improved with emerging clinical, epidemiological, and operational information.

Local Planning

• Peterborough Interagency Pandemic Planning Team

• Annual Exercises and Conferences• Peterborough Community Influenza

Assessment Committee• Municipal Emergency Planning• Internal Pandemic Planning

Committees

PIPPT Objectives

• To facilitate and strengthen collaboration with all key stakeholders.

• To facilitate in the development, integration and ongoing maintenance of local pandemic influenza plans.

• To ensure that pandemic plans for Peterborough are consistent with national and provincial plans and reflect local needs.

• To ensure clarity of roles in an influenza pandemic.• To facilitate training, education, and/or support for

the design, testing and implementation of local pandemic influenza plans.

WHO Non-PharmaceuticalInterventions (2006)

• National / community and international guidance

• Isolation of cases, quarantine of contacts (during Alert)

• SARS strategies not likely to work in a pandemic

• Exit screening, health advisories recommended

• Consider school closures• Do not encourage* nor

discourage masks

Key Strategies for Reducing Spread and Impact

• Public health measures and infection control - respiratory etiquette, hand hygiene and self

care• Vaccination - the primary preventive measure

but not likely available until after first wave• Antivirals - the only virus-specific intervention

until vaccine is available • Maintaining health, emergency and social

services• Maintaining public awareness and facilitating

acceptance of response strategy

SO WHY IS INFLUENZA SUCH A PROBLEM?

HaemagglutininHaemagglutinine.g. H1, H2, H3e.g. H1, H2, H3

NeuraminidaseNeuraminidasee.g. N1, N2e.g. N1, N2

Laver WG, Bischofberger N, Webster RG. Disarming flu viruses, Sci Am 1999;January.

Segmented RNA genomeSegmented RNA genome

M2 ProteinM2 Protein

Influenza Virus Structure and Surface Proteins

ABC of Human Influenza

PANDEMIC

Novel VirusNo ResistanceHuman to Human TransmissionSevere Disease

Type Type AA

Type Type BB Type Type

CCAnnual Flu Epidemics

acute respiratory viral infection caused by members of the Orthomyxoviridae family

Influenza Virus: Promiscuity!!

The Ecology of Influenza A Viruses

• Influenza viruses in their natural reservoirs are in evolutionary stasis • Rapid evolution occurs

after transfer to new hosts

Source: Lou Donofrio, OMAFRA

Principles of Influenza Transmission

• Contact with respiratory secretions and large droplets appears to account for most transmissions of influenza

• Both influenza A and B can survive on hard, non-porous surfaces for 24-48 hours, on cloth or paper for 8-12 hours and on hands for 5 minutes

• Transmission by airborne route is controversial and unproven for humans

Novel H1N1 Influenza A (2009)

Characteristics: a disease of younger peoplesignificant numbers of people are likely to be

afflicted the illness is at worst like a seasonal influenzasevere disease occurs but is not commonoverall mortality is low risk groups: co-morbidities, remote

communities, pregnant women

DR I. M. GEMMILL, MD, CCFP, FRCP(C)

Pandemic (H1N1) influenza is the most common flu virus circulating

worldwide:

• The overwhelming majority worldwide of persons infected with pH1N1 continue to experience uncomplicated influenza-like illness, with full recovery within a week – even without medical treatment.

All confirmed cases of Influenza A in Ontario by week, 2004-2010†

pH1N1 Deaths In Children

Hospitalized cases in Ontario by age group and gender, April 13 to October

28, 2009

Incidence of hospitalization and death due to pH1N1 in Ontario, April 13 to October

28, 2009

Provincial Update• Some health units reported very high

rates of H1N1 activity (several indicators)• Positivity of respiratory specimens ranged

from 20% to 60%• Increased school absenteeism noted and

now returned to baseline (n=14 in Peterborough, Nov 2/09)

• Emergency Departments busier with ILI and respiratory symptoms

Local Update

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20-Apr-09 20-May-09 20-Jun-09 20-Jul-09 20-Aug-09 20-Sep-09 20-Oct-09

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f ED

vis

its

Fever/ILI

Respiratory Symptoms

Figure 1: Visits to the PRHC emergency demartment for respiratory symptoms or influenza -like illnesses (April 20, 2009 - November 1, 2009).

PCCHU Emergency Response

• IMS implemented in April. Resumed in October

• Communications, Liaison and Safety Officers• Operations includes surveillance, case and

outbreak management, health sector liaison, public enquiry, vaccine delivery

• Logistics includes staffing, training and clinics support

• Planning includes pregnant and vulnerable populations, and assessment centres

• F&A includes procurement, IT support• Essential services being delivered

pH1N1 Vaccine

• Based on influenza A/California/07/2009 (H1 N1)-like strain (X-179A).

• Different vaccines are being used in different countries

• In Canada, GSK will supply up to 50,000,000 doses

• Most will be an adjuvanted European style vaccine

• A limited amount will be a traditional unadjuvanted formulation

• ‘Vaccine will be available to every person who wants or needs it.’

pH1N1 Vaccine Formulations unadjuvanted: for pregnant women and

healthy 10 – 64 year oldssimilar to seasonal vaccine formulations15 μg nH1N1 antigengood seroconversion in adults

adjuvanted with AS03 ((Arepandrix™)allows over 75% reduction in antigen (3.75

μg)similar seroconversion rates in adults (better

in children, seniors)

pH1N1 Vaccine

• Roll-out in community, and at PRHC, began October 26

• High risk groups targeted first, while supplies of vaccine still limited

• City and County site clinics offered daily (Mon-Sat)

• School-based clinics • College and University clinics

Risk/Crisis Communications• When perceived risk is high but known

risk is low, strategy must allay fears• Uncertainty and scientific complexity

could be a losing formula• Judged on extent of preventative

measures and degree of preparation (either too little or too much)

• Response speed and effectiveness critical to success