Pandemic Pandemic Influenza

ihea.org.au

Pandemic Pandemic Influenza

Pandemic

Influenza

Queensland Health

Communicable Diseases

Branch


INFLUENZA

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Mode of transmission

• Droplet: Virus is spread from person-to-person through

coughing & sneezing of infected respiratory secretions

• Airborne: From procedures that produce very fine

droplets that are released into the air & breathed-in

• Contact: Person touches respiratory droplets on another

person or contaminated surface & then touches their

own mouth, nose or eyes

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Seasonal influenza:

morbidity & mortality

• Globally: 250,000 to 500,000 deaths each year

• Hospital admissions in people > 65 years old or

in children < 5 years old

• Both of these age groups have weaker immune

systems

• >90% of all deaths occur in people 65 years or older

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Pandemic Influenza

An ever present threat

Pandemics result from Antigenic Shift - when

there is a major change in the virus type, to

which humans have little or no immunity

• Because there is no immunity, the virus spreads

easily, with high attack rates (e.g. 30% illness

rates), and possibly high rates of hospitalisation

& death

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Antigenic Shift

• SHIFT denotes MAJOR changes in

hemagglutinin and neuraminidase

molecules resulting from re-assortment of

gene segments involving two different

influenza viruses • PANDEMIC STRAIN

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Influenza Pandemics During the

20 th Century

Year Pandemic Attack rate Estimated

Mortality

Highest risk

Group

1918-1919 Spanish Flu

A(H1N1)

1957-1958 Asian Flu

A(H2N2)

1968-69 Hong Kong

Flu

A(H3N2)

28-90% 20-40

million

20-70% 1/2000 to

1/10,000

infections

25-30% 1/2000 to

1/10,000

infections

20-45 years,

especially

males

> 65 years

> 65 years

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N.B. “Bird flu” is not human flu

Bird flu is not

human flu…OK!

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H5N1 avian influenza in humans

• Nearly all human infections due to avian

influenza viruses have involved close contact

with ill or dying poultry

• Person-to-person transmission possible in only

a few instances: family carers of those very sick

• No documented cases in poultry cullers or

health care workers where protective measures

used

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Avian influenza: situation report

Widespread and spreading prevalence in migratory birds; broad

host range

Continued outbreaks among domestic poultry

Mammalian infection (cats, pigs, etc.) lethal

Virus is evolving

Sporadic human cases (330 reported cases since 2003)

• - most in young and healthy

• - case-fatality 60%

• - rare person-to-person transmission

X Sustained and rapid person-to-person transmission

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Will ‘bird flu’ cause the next

pandemic?

• “Bird Flu” A (H5N1 type) has killed millions of birds across Asia

since late 2003

• Millions of humans have been exposed

• Only 330 human infections and 202 human deaths

• Transmissible from human → human is rare

• Risk of it becoming a human “pandemic virus” is low, but probably

not zero

• Hence, given its widespread distribution in Asia (and now Europe &

perhaps Africa), preparedness is prudent…

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Is an influenza pandemic coming?

• A human influenza pandemic, due to

an influenza virus strain to which

humans have little immunity, is

considered inevitable & overdue

• The severity of illness in any such

pandemic can’t be predicted

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Pandemic influenza – the impact

High staff absenteeism (all levels)

- Between 30-50%

- sick, anxious, caring for ill family members

Possibility for significant disruption

– decreased capacity to maintain & deliver

services e.g. health, social services, transport,

catering, communications

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Estimates for next pandemic

Indicator

Population

WA Population (ABS 2006) 1,959,088

Attack rate 30% 587,726

Case fatality 2.3% 13,517

Absenteeism ~ 30-50%

Length of illness

~ 7 days

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Health Impacts

• A significant proportion of the population will be

unwell and unable to undertake normal daily

activities.

• People who are sick or required to be in home

quarantine will need support to stay at home

• Mental health issues may occur in the community as

a result of dealing with illness or death among family

members, interruption of critical community

services, loss of employment, and financial losses.

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Complacency is the enemy of

health protection!

www.cdc.gov/business/

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Strategy: Contain the spread of infection

Mathematical modelling suggests that

transmission rates can be significantly

reduced through implementing multiple

non-pharmaceutical interventions in

combination with the targeted use of

antivirals for treatment and prophylaxis,

but timing is critical.

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Strategy: Contain the spread of infection

Delay entry of the virus into Australia

Surveillance – sentinel surveillance, border control

Reduce transmission of the virus

Treat & isolate cases (hospitals and home)

Post-exposure antivirals & home quarantine contacts

Reduce exposure to the virus

Personal protection, social distancing measures

Reduce host susceptibility to the virus

Antivirals, vaccination

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Social distancing measures

• Closure of schools & day care centres

• Limiting public transport

• Limiting mass gatherings (e.g cancellation of

concerts, closure of cinemas)

• Workplace measures

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Infection Control Measures -

general

• Respiratory protection, cough etiquette

• Minimum 1 metre distance rule

• Hand washing

• Keeping home and work environments clean

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Infection Control Measures -

hospitals

• enhanced infection control (cleaning, PPE,

wand washing)

• isolation from non-infected people

• negative pressure rooms for aerosol

generating procedures

• excluding symptomatic staff from work

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Maintenance

Overseas Any Phase, Australia Phase 6b-6d

Widespread transmission across Australia, after which

infection rates begin to subside

• Goal: provide the best possible health care &

maintain social functioning

• Resources required to contain spread have been

exceeded.

• Individual response measures may no longer be

feasible

• Patient isolation & quarantining of contacts will

cease

• Response efforts will shift towards decreasing social

contact within groups

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Business Continuity Planning

Prioritize critical functions

• Identify functions that could be suspended

• Create guidelines to support critical areas and

functions

• Identify linkages with other organisations

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Business Continuity Planning

Focus on human resource issues

• Review IR policies

• Develop a succession plan for key management

• Identify staff needed to carry out critical functions

• Identify and address training needs

• Plan against absenteeism & a surge in demand for

services

• Build depth through cross training

• Plan for alternative work schedules

• Consider developing public-private partnerships

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