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The Australian response: pandemic influenza preparedness

John S Horvath, Moira McKinnon and Leslee Roberts
Med J Aust 2006; 185 (10): S35. || doi: 10.5694/j.1326-5377.2006.tb00704.x
Published online: 20 November 2006

In Australia, the peak of the “Spanish flu” pandemic occurred in mid June 1919. In that week, 1315 people were being treated for influenza in hospitals in New South Wales. Of those, fewer than 900 survived. By November that year, the pandemic for Australia was essentially over, but nationwide it had taken more than 10 000 lives.1

Two other influenza pandemics reached Australia’s shores, one in 1957 and one in 1968. These were less severe and affected primarily the vulnerable: the young, the elderly, pregnant women, and people with chronic diseases.

In 1997, in Hong Kong, a disease with high mortality swept through poultry; 18 people came down with a severe respiratory illness and six died. An identical strain of influenza A virus, H5N1, was detected in the chickens and in the infected humans. Hong Kong authorities reacted with widespread culling of all chickens. It seemed the virus had been beaten.

In 2003, the virus re-emerged in Thailand and Vietnam, spreading rapidly through poultry flocks. Human cases occurred, but in all but one case there was clear contact with poultry. Intensive efforts at culling poultry in affected areas seemed to halt the spread. However, in May 2005, the virus was discovered in many bird species in the Qinghai province of western China. From there, it has spread across Europe and down into the Middle East and Africa. More than 150 million birds have been destroyed and more than 200 people infected. The mortality rate of what is termed “avian influenza” or “bird flu” in humans is greater than 50%.2,3

Indonesia is currently the country most affected by bird flu. Outbreaks in poultry have occurred in most provinces. Sporadic human cases continue to occur. A cluster of seven cases in one family in a village in Sumatra gave rise to worldwide concern. It was considered likely that human-to-human transmission had occurred.2

Influenza A/H5N1 has three of the four elements to cause a pandemic. It is novel (there is little immunity in the population), it can infect humans, and it causes severe disease. It has not yet gained the fourth and essential characteristic to cause a human pandemic — the ability to efficiently transmit from human to human.

Even if H5N1 never gains the ability to cause a pandemic, it is likely that new respiratory influenza and non-influenza viruses will continue to emerge. The severe acute respiratory syndrome virus, from the corona virus family, was one such emergent virus that caught the world by surprise.

The Australian response

The Australian Government has reacted quickly to the pandemic threat caused by the H5N1 virus. Since 2003, it has committed more than $600 million to pandemic preparedness. This includes $156 million to the Asia-Pacific region to develop capacity for response.

In Australia, a “whole of government” approach has been adopted. This recognises that health protection decisions that may be taken in response to a pandemic, particularly in regard to border control, quarantine and school closures, will affect society beyond direct health. The response to a pandemic needs to consider areas as diverse as food supply, energy supply, and overall business continuity. In short, pandemic planning is a continual and extensive process. Plans need to be updated and fine-tuned as new evidence becomes available.

The Australian health response plan is detailed in the Australian health management plan for pandemic influenza (AHMPPI). This document is aimed at the general public. It is accompanied by several technical annexes: the Interim infection control guidelines for pandemic influenza in healthcare and community settings and the Interim national pandemic influenza clinical guidelines have been published; the Guidelines for management of pandemic influenza in primary care settings are close to finalisation.

A key part of pandemic preparation and response is communication. This involves education, operational communication, and management of data and information. The Department of Health and Ageing has published a Communications strategy overview, which details important considerations and actions for each phase of an influenza pandemic.

The AHMPPI, the annexes, the communications strategy and additional information are available on the Department of Health and Ageing website <http://www.health.gov.au>.

The health response

The strategy for response in Australia is based on containment. This means that all effort will be made to delay the entry of the pandemic virus strain into Australia and to contain any outbreaks that do occur. This will allow time to produce a matched vaccine. If the pandemic cannot be contained, the strategy will shift to support maintenance of social functioning.

The actions at each phase of the pandemic (Box 1) are outlined in the AHMPPI. The current global designation of phase by the World Health Organization is alert level 3 (Overseas 3). Australia is technically in Phase 0.

Public health interventions

A person with influenza infects one to two other people. This is far less than the infectivity of, for example, polio or measles, in which one person may infect on average five and 10 others, respectively.6 The spread of influenza is largely due to its very short incubation period. This means if an infected person can be identified early and quarantined then the chance of that person causing an epidemic is greatly reduced.

The Australian Government has commissioned experts in Australia to model the effect of public health interventions on the spread of a pandemic. The results indicate that the use of quarantine, social distancing, and personal hygiene could have a significant effect in slowing and reducing the impact of a pandemic.7 The addition of antivirals greatly assists in the “ring fencing” of an outbreak. The results of this modelling have been echoed by international studies.8-11

Social distancing refers to all non-pharmaceutical methods of infection control. It includes reducing contacts in the community by not holding mass gatherings and by encouraging individuals to keep distance from others in communal settings. It also includes personal hygiene such as frequent hand washing, cough and sneeze etiquette, and reduction in close human contact (no kissing, no hugging). Social distancing is an extremely effective tool, particularly when applied both in the community and in the home.7,8

The combined effect of quarantine, social distancing, and targeted use of antivirals may allow a pandemic to be controlled or prevented from taking off in Australia for more than a year.7-11

The future

The world has changed since previous pandemics. Faster, cheaper international travel and more densely populated countries potentially make it easier for disease to spread. Economies are more interdependent, and many businesses, including medical practices, operate on a “just in time” basis for the delivery of essential supplies, often from overseas.

Nonetheless, governments and communities are better prepared than ever to respond effectively to a pandemic. Awareness of the need for continuity planning among businesses is high.

It may be that the world has already averted a pandemic by the actions it has taken in response to H5N1, such as extensive culling of poultry and isolation of infected humans. Yet all preparations may seem insufficient if the world comes face to face with a rapidly spreading novel virus like the one that emerged in 1918. Rapid detection of human-to-human transmission, early and intensive implementation of containment measures, and the development and deployment of effective vaccine are our best strategies for responding.

1 Pandemic phases

Period

Global phase

Australian phase

Description of phase


Inter-pandemic

Aus 0

No circulating animal influenza subtypes in Australia that have caused human disease


1

Overseas 1

Animal infection overseas: the risk of human infection or disease is considered low


Aus 1

Animal infection in Australia: the risk of human infection or disease is considered low


Pandemic alert

2

Overseas 2

Animal infection overseas: substantial risk of human disease


Aus 2

Animal infection in Australia: substantial risk of human disease


3

Overseas 3

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


Aus 3

Human infection in Australia with new subtype(s) but no human-to-human spread or at most rare instances of spread to a close contact


4

Overseas 4

Human infection overseas: small cluster(s) consistent with limited human-to-human transmission, spread highly localised, suggesting the virus is not well adapted to humans


Aus 4

Human infection in Australia: small cluster(s) consistent with limited human-to-human transmission, spread highly localised, suggesting the virus is not well adapted to humans


5

Overseas 5

Human infection overseas: larger cluster(s) but human-to-human transmission still localised, suggesting the virus is becoming increasingly better adapted to humans, but may not yet be fully adapted (substantial pandemic risk)


Aus 5

Human infection in Australia: larger cluster(s) but human-to-human transmission still localised, suggesting the virus is becoming increasingly better adapted to humans, but may not yet be fully adapted (substantial pandemic risk)


Pandemic

6

Overseas 6

Pandemic overseas — not in Australia; increased and sustained transmission in general population


Aus 6a

Pandemic in Australia: localised (one area of country)


Aus 6b

Pandemic in Australia: widespread


Aus 6c

Pandemic in Australia: subsided


Aus 6d

Pandemic in Australia: next wave


Reproduced from the Australian health management plan for pandemic influenza.

  • John S Horvath1
  • Moira McKinnon2
  • Leslee Roberts3

  • Department of Health and Ageing, Canberra, ACT.


Correspondence: moira.mckinnon@three.com.au

Competing interests:

None identified.

  • 1. Paton RT. Report of the Director-General of Public Health to the Honorable The Minister of Public Health. Section V. Report on the influenza epidemic in New South Wales in 1919. Sydney: NSW Health Department, 1920.
  • 2. World Health Organization. Epidemic and pandemic alert and response: avian influenza. http://www.who.int/csr/disease/avian_influenza/en/index.html (accessed Jul 2006).
  • 3. Webster RG, Peiris M, Chen H, Guan Y. H5N1 outbreaks and enzootic influenza. Emerg Infect Dis 2006; 12: 3-8.
  • 4. Cooper NJ, Sutton AJ, Abrams KR, et al. Effectiveness of neuraminidase inhibitors in treatment and prevention of influenza A and B: systematic review and meta-analyses of randomised controlled trials. BMJ 2003; 326: 1235-1240.
  • 5. Jefferson T, Demicheli V, Deeks J, Rivetti D. Neuraminidase inhibitors for preventing and treating influenza in healthy adults (Cochrane review). The Cochrane Library, Issue 2, 2005. Chichester, UK: John Wiley & Sons, Ltd.
  • 6. Centers for Disease Control and Prevention. Smallpox: disease, prevention, and intervention. Module 1. History and epidemiology of global smallpox eradication [course notes]. http://www.bt.cdc.gov/agent/smallpox/training/overview/ (accessed Oct 2006).
  • 7. Becker NG, Glass K, Barnes B, et al. Using mathematical models to assess responses to an outbreak of an emerged viral respiratory disease. Final report to the Department of Health and Ageing. Canberra: National Centre for Epidemiology and Population Health, Australian National University, 2006.
  • 8. Wu JT, Riley S, Fraser C, Leung G. Reducing the impact of the next influenza pandemic using household-based public health interventions. PLoS Med 2006; 3: e361.
  • 9. Glass RJ, Glass LM, Beyeler WE. Local mitigation strategies for pandemic influenza: prepared for the Department of Homeland Security under the National Infrastructure Simulation and Analysis Center. Report no. SAND2005–7955J. Washington, DC: Department of Homeland Security, 2005.
  • 10. Longini IM Jr, Nizam A, Xu S, et al. Containing pandemic influenza at the source. Science 2005; 309: 1083-1087.
  • 11. Ferguson NM, Cummings DAT, Cauchemez S, et al. Strategies for containing an emerging influenza pandemic in Southeast Asia. Nature 2005; 437: 209-214.

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