Transcript What is Avian Influenza? - Commonwealth Safety Management Forum

Avian Influenza Pandemic
An OHS Perspective
Presentation to the
Commonwealth Safety Management Forum
23 November 2006
Brian Ewert
Presentation Overview
Part 1:
• What is Avian Influenza?
• Avian Influenza within
Australia
• 20th Century Pandemics
• 21st Century Epidemic
• H5N1 History &
Epidemiology
Presentation Overview
Part 2:
• The Key Facts
• What is the Risk?
• Antivirals
• Vaccines
Presentation Overview
Part 3:
• Pandemic Preparedness
Part 4:
• OHS Considerations
Part 5:
• CSMF Assistance
Part 6:
• Open Forum
Part 1
What is Avian Influenza?
Avian Influenza within Australia
20th Century Pandemics
21st Century Epidemic
H5N1 History & Epidemiology
What is Avian Influenza?
An infectious viral disease that
primarily affects birds:
& less commonly:
• chickens
• rats
• turkeys
• ferrets
• pheasants
• white rabbits
• quail
• pigs
• pigeons
• tigers
• ducks
• leopards
• geese
• domestic cats
• guinea fowl
• ostriches
& rarely:
• sea birds
• humans
• migratory waterfowl
What is Avian Influenza?
There are numerous strains and subtypes of the virus.
Strains vary from low to highly pathogenic.
Highly pathogenic avian influenza was first identified 1878.
4 strains are known to cause human infection.
Only H5N1 is currently linked to severe human infection
and death (rare).
All human cases of avian influenza have coincided with
outbreaks in poultry.
Avian Influenza within Australia
Historically Australia has experienced avian influenza
‘outbreaks’:
1976
1985
1992
1994
1997
Melbourne Suburbs, Victoria
Bendigo, Victoria
Bendigo, Victoria
Lowood, Queensland
Tamworth, New South Wales
(H7N7 strain)
(H7N7 strain)
(H7N3 strain)
(H7N3 strain)
(H7N4 strain)
To date no human avian influenza cases have been
reported within Australia.
Avian Influenza within Australia
Highly pathogenic avian influenza in humans is subject to
quarantine control (Quarantine Act 1908).
Since February 2004:
• Australia’s ‘pandemic alert phase’ has remained
unchanged (‘Australia 0’ – no circulating animal influenza
subtypes in Australia that have caused human disease)
compared with
• the Global ‘pandemic alert phase’ has remained
unchanged (‘Overseas 3’ – human infection overseas
with new subtypes but no human to human spread or at
most rare instances of spread to a close contact)
th
20
Century Pandemics
1918 – 1919 ‘Spanish Influenza’:
• H1N1 strain
• estimated 40 – 50 million deaths
1957 – 1958 ‘Asian Influenza’:
• H2N2 strain
• estimated 2 million deaths
1968 – 1969 ‘Hong Kong Influenza’:
• H3N2 strain
• estimated 1 million deaths
th
20
Century Pandemics
31 influenza pandemics have occurred since the middle
ages.
On average an influenza pandemic occurs every 30 years.
st
21
Century Epidemic
2002 – 2003 ‘Severe Acute Respiratory Syndrome’:
• 26 countries (Western Pacific regional focus)
• coronavirus (not avian influenza)
• 8098 ‘probable’ cases (774 deaths)
• raised awareness of the social and economic impacts of
epidemics
H5N1 History & Epidemiology
1997 ‘Avian Influenza’:
• Hong Kong
• 18 cases (6 deaths)
• notably 1.5 million birds were culled within 3 days
2003 ‘Avian Influenza’:
• China & Vietnam
• 4 cases (4 deaths)
H5N1 History & Epidemiology
2004 ‘Avian Influenza’:
• Thailand & Vietnam
• 46 cases (32 deaths)
2005 ‘Avian Influenza’:
• Cambodia, China, Indonesia, Thailand & Vietnam
• 97 cases (42 deaths)
H5N1 History & Epidemiology
2006 (to 13 November 2006) ‘Avian Influenza’:
• Azerbaijan, Cambodia, China, Djibouti, Egypt, Indonesia,
Iraq, Thailand & Turkey
• 111 cases (75 deaths)
Since 2003, human H5N1 mortality rate approximates 60%.
H5N1 History & Epidemiology
H5N1 History & Epidemiology
H5N1 History & Epidemiology
H5N1 History & Epidemiology
H5N1 History & Epidemiology
Part 2
The Key Facts
What is the Risk?
Antivirals
Vaccines
The Key Facts
Avian influenza and human influenza are different
diseases.
Type ‘A’ influenza viruses:
• occur in birds and mammals (humans)
• cause ‘flu’
• can cause a pandemic (rare)
Avian influenza is a type ‘A’ virus.
The Key Facts
Type ‘B’ influenza viruses:
• occur in humans and dogs
• cause seasonal ‘flu’
• do not cause pandemics
Type ‘C’ influenza viruses:
• occur in humans only
• cause the common ‘cold’
• do not cause pandemics
The Key Facts
Human avian influenza (H5N1 crossing the species barrier)
is primarily attributable to direct human contact with
infected birds:
• slaughtering, defeathering, butchering and preparation of
infected poultry for consumption
• children playing in areas frequented by infected poultry
• domestic utilisation of water contaminated by the
carcasses of dead infected birds
• chickens/ducks/turkeys/geese… penned together in
unhygienic conditions spreading infection
The Key Facts
The Key Facts
Human to human transmission:
• is possible
• in rare cases is suspected (2004 Thailand – ill child to
mother, and 2006 Indonesia – amongst 8 family
members)
• has not been sustained
Importantly:
• H5N1 has yet to acquire the ability to spread efficiently
amongst humans
The Key Facts
If avian influenza pandemic was to occur:
• it is most likely to occur overseas amongst poverty
stricken rural and periurban communities
• any spread to Australia would most likely be attributable
to international travellers
Avian influenza may not evolve into a pandemic virus.
It is not possible to predict if/when a pandemic may occur.
What is the Risk?
If the avian influenza mutates (emergence of a ‘new’ strain)
there is a risk of:
• human to human transmission
• virus rapidly spreading
• severe infection persisting and recurring in waves
• from ‘status quo’ to influenza epidemic and possibly a
pandemic within 20 – 30 day window
Antivirals
Clinical data supporting the effectiveness of antivirals as a
treatment of avian influenza is limited.
Antivirals may shorten the duration and lessen the
symptoms of avian influenza.
Timing of administration appears critical (48 hour ‘window’).
Unnecessary antiviral use is linked with drug resistance.
Antivirals are currently available by prescription only.
Vaccines
Vaccines trigger an immune response bolstering the body’s
ability to ‘fight’ an infection.
Vaccine production cannot usually commence until a virus
‘outbreak’ (the virus strain must first be identified).
Large scale vaccine availability is unlikely until after the first
wave of infections.
Part 3
Pandemic Preparedness
Pandemic Preparedness
8 steps to preparing for a pandemic:
1.
Obtain senior management commitment and secure
allocation of resources.
2.
Form a pandemic planning team.
3.
Develop pandemic business continuity plans.
4.
Form a ‘crisis’ pandemic management team (with
requisite delegations).
Pandemic Preparedness
5.
Undertake workforce planning (skills inventory).
6.
Develop and implement an employee communication
strategy.
7.
Test the effectiveness of preparations.
8.
Test employee confidence.
Part 4
OHS Considerations:
Employer’s Duty of Care
Employees’ Duty of Care
Consultation
Risk Management and Hierarchy of Controls
OHS Considerations
Under Part 2 ‘OHS Act’, employers are required to:
• take all reasonably practicable steps to protect the health
and safety at work of their employees.
Therefore:
• employers should anticipate risks associated with a
potential influenza pandemic (ie: risk management)
• health and safety of employees should be integrated into
business continuity planning for pandemic influenza
However, in a pandemic scenario what constitutes
‘reasonably practicable’?
OHS Considerations
Under Part 2 ‘OHS Act’, employees are required to:
•
cooperate with their employer’s reasonable
instructions and policies (including risk control)
•
take all reasonably practicable steps to ensure any
action or omission does not create or increase a risk to
health and safety
Therefore:
•
employees should comply with the pandemic health
advice and emergency directives issued by their
employer and employers should ensure directives
comply with public health advice/emergency measures
OHS Considerations
Under Part 3 ‘OHS Act’, employers are required to:
• consult employees when assessing risks to health and
safety
Therefore:
• employers should consult widely utilising existing
workplace arrangements (HSR and OHS Committees)
• employers should provide accurate and current
information and education to employees addressing how
a pandemic influenza may affect their work
arrangements
OHS Considerations
Risks associated with an influenza pandemic can be
categorised into:
• the direct risks of infection (contact, airborne droplet and
aerosol transmission)
• indirect risks arising from changes to usual work
arrangements
Question: How useful is the traditional ‘hierarchy of
controls’ when planning for a pandemic (where do
antivirals/vaccines ‘fit’)?
OHS Considerations
Elimination – ?
Substitution – ?
Isolation – ‘clinical’ quarantine
Engineering – improve ‘natural’ ventilation of enclosed
workplaces
Administration – cough etiquette, promotion of personal
hygiene, additional workplace cleaning, home quarantine
PPE – mask/goggles/gloves/gowns
Part 5
Commonwealth
Safety
Management
Forum:
How can you assist?
CSMF
Challenge:
• integrating OHS risk management into business
continuity plans (an employer responsibility)
Objectives:
• assist with across-government consultation (emphasis
on health, safety and welfare of employees)
• develop consistent whole-of-government OHS ‘people
management’ influenza pandemic guidelines
CSMF
•
•
•
•
•
•
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Scope:
social distancing
• managing staff who
become ill at work
cough etiquette
• provision & utilisation of
personal hygiene
PPE
cleaning/disinfecting the
• home quarantine
workplace
• managing psychological
managing workplace
anxiety
entry
• emergency HR
teleworking
delegations
contract management
• training & communication
minimising unnecessary
• …
absenteeism
Open Forum
Questions & Answers
Discussion
Nominations – CSMF AIP Sub-Committee
Enquiries:
Brian Ewert
6225 8963
[email protected]