Australian Health Management Plan for Pandemic Influenza

3.1 The Australian pandemic phases

It is likely that the development of a pandemic will move through a number of different phases as the virus becomes more adept at infecting humans, spreads around the globe, and throughout Australia. As each of these phases requires a different set of actions, identifying the phase is useful to guide decision-making and to ensure the most appropriate actions are being taken. It is important to consider that the situation could move very quickly between phases or that certain phases may not be detected in time for the actions specific to that phase to occur.

WHO has a set of pandemic phases that it uses to describe the global situation (phases 1–6). Australia uses the same numbering system as WHO to describe each phase; however, the Australian pandemic phases are designed to describe the situation in Australia and to guide Australia’s response. Thus, the Australian and the WHO phase may not always be the same.

The Australian phases describe whether the virus is in countries overseas (OS) or in Australia (AUS). Different response strategies may be used simultaneously in different parts of Australia, due to variations in the local stage of a pandemic. Having an Australian system means that actions can be taken in Australia before a change of phase is declared by the WHO.

The description of each phase and key actions that occur by phase are shown in Table 2.

Figure 2 gives an overview of the pandemic phases and illustrates the split between phases where the pandemic virus is:

• emerging overseas (left hand arm of the Y diagram) or
• emerging in Australia, or if there was early transmission of a virus with pandemic potential that is transmitted to Australia before a pandemic occurs overseas (right hand arm of the Y diagram).

The actions taken are quite different depending on whether the virus emerges overseas or in Australia, however, once the pandemic has begun in Australia (Phase 6) it becomes irrelevant where the virus first emerged. What will be important to Australia is the progress of the pandemic across the country, as this will guide the types of actions that are needed to reduce the impact and eventually control the pandemic.

Figure 2: Pandemic Phases



Table 2: Key actions by phase

Australian phase	Description	Key Actions
ALERT OS3	A novel virus with pandemic potential causes severe disease in humans who have had contact with infected animals. There is no effective transmission between humans. Novel virus has not arrived in Australia.	1. Alert: Increased vigilance for cases. Remaining alert to the risk of a pandemic and increased monitoring of the virus (to look for genetic mutations in the virus). 2. Support the overseas response to control the source. Working with the agriculture and health sectors in overseas affected countries to reduce the amount of the pandemic potential virus circulating in animals and to protect humans from infection. 3. Prepare: Increased pandemic preparedness activities.
DELAY OS4/OS5/OS6	Novel virus has not arrived in Australia. OS4 Small cluster of cases in one country overseas. OS5 Large cluster(s) of cases in only one or two countries overseas. OS6 Large cluster(s) of cases in more than two countries overseas.	1. Delay entry of the virus to Australia using border measures. 2. Support the overseas response to control the source. Try to avert a pandemic by rapid intervention in the affected areas. 3. Enhanced vigilance-Increased vigilance for cases (overseas and domestically) and increased monitoring of the virus (to look for genetic mutations in the virus). 4. Escalate preparedness activities for possible pandemic (that is, get ready to implement). 5. Stand-down the response if the pandemic is averted before it arrives in Australia.
CONTAIN AUS 6a	Pandemic virus has arrived in Australia causing small number of cases and/or small number of clusters.	1. Contain the establishment of the pandemic strain in Australia. 2. Ensure the health system is best able to cope with an influenza pandemic.
SUSTAIN AUS 6b	Pandemic virus is established in Australia and spreading in the community.	1. Sustain the response while we wait for a customised pandemic vaccine to become available. 2. Minimise transmission and maintain health services.
CONTROL AUS 6c	Customised pandemic vaccine widely available and is beginning to bring the pandemic under control.	1. Control the pandemic with vaccine. 2. Careful downscaling of response as the pandemic is brought under control, to an eventual standing down of control measures in recover.
RECOVER AUS 6d	Pandemic controlled in Australia but further waves may occur if the virus drifts and/or is re-imported into Australia.	1. Recover and restore the health system and return to ALERT phase as quickly as possible. 2. Enhanced vigilance for a subsequent wave. Increased vigilance for cases and increased monitoring of the virus (to look for genetic mutations).

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This information is current for 03 September, 2010
This information was issued on 05 December, 2008