The 2009-10 “Pandemic” Experience “This year, it’s a different flu season”
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Transcript of The 2009-10 “Pandemic” Experience “This year, it’s a different flu season”
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
30
40
50
60
70
80
20-Apr-09 20-May-09 20-Jun-09 20-Jul-09 20-Aug-09 20-Sep-09 20-Oct-09
Num
ber o
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