Influenza Pandemic 2009

Pandemic (H1N1) 2009 influenza, a novel strain of influenza circulating in Mexico and the United States, first came to the attention of most Australians during the 2009 ANZAC Day weekend.

This report briefly outlines the ACT Health response to the pandemic in 2009 and the lessons learnt.

Influenza Pandemic 2009 Summary

In 2009 Swine Flu, officially known as pandemic (H1N1) 2009 influenza, was responsible for the first influenza pandemic in 41 years. Pandemic (H1N1) 2009 influenza, a novel strain of influenza circulating in Mexico and the United States, first came to the attention of most Australians during the 2009 ANZAC Day weekend. This report briefly outlines the ACT Health response to the pandemic in 2009.

The ACT Health response to pandemic (H1N1) 2009 influenza commenced on the ANZAC Day weekend following the announcement by the World Health Organisation (WHO) on 24 April 2009 of outbreaks of the novel virus strain in North America. Initially, the ACT Health response focused on provision of information and advice to GPs, hospitals and the community on the virus and preparations for an intensive public health response in line with national and ACT pandemic plans: the Australian Health Management Plan for Pandemic Influenza 2008 (AHMPPI) and the ACT Health Management Plan for Pandemic Influenza 2007 (ACTHMPPI).

The Public Health Emergency Operations Centre (PHEOC) was activated in early May and became the coordinating centre of the ACT's H1N1 response until September 2009. Dedicated Influenza Assessment Clinics were also set up at Canberra and Calvary Hospitals in early June to deal with overcrowding in emergency departments and GPs. Five pharmacies across the ACT were supplied with Oseltamivir from the ACT Medical Stockpile to meet the need for antivirals. ACT Pathology obtained access to pandemic (H1N1) 2009 influenza PCR testing to allow positive cases to be confirmed with relative speed.

The demand for Personal Protective Equipment (PPE) such as masks was considerable particularly from the non health sector. Decisions on the provision of PPE by ACT Health from the stockpile were based on the assessment of risk in line with the AHMPPI. While P2 masks were provided to front line health care workers for use while testing suspected cases of H1N1 influenza during the CONTAIN phase, groups from the non health care sector were not provided with PPE. This is consistent with the AHMPPI. Basic infection control measures such as regular hand washing, maintaining a distance of at least one metre from anyone who may be ill and regular cleaning of surfaces were promoted as the most effective measures for preventing transmission of influenza.

The pandemic (H1N1) 2009 influenza turned out to be virus that was mild in most people but serious in some. However, pressure on the health system was significant, particularly for GP practices, pathology laboratories, hospital emergency departments, intensive care units and the Health Protection Service (ACT Health's public health branch).

ACT Health received 940 notifications of confirmed pandemic H1N1 influenza between 25 May and 20 October 2009, a 400% increase in notifications for all strains of influenza when compared to 2008. This is considered to be an underestimate of actual cases, as testing for the virus was scaled down significantly in mid-June 2009 once Australia went in the PROTECT phase. Under PROTECT where the focus of disease control efforts changed to protect people most vulnerable to severe consequences of the disease.

The pattern of infection of pandemic (H1N1) 2009 influenza in the ACT was very similar to that seen in the rest of Australia. The median age of infection in the ACT was 22 years and 68% of cases were in people under 30 years of age. Relatively few cases were notified in people over 60 years of age as people in this age group had exposure to related influenza virus strains during the several decades before 1957.

A vaccine against pandemic (H1N1) 2009 influenza became available in September 2009, Since the vaccination program commenced on 30 September 2009 over 109,000 doses of vaccine have been distributed to ACT GPs and clinics to 26 March 2010. Notifications from reporting practices on doses administered indicate that over 20% of the ACT population has been vaccinated with the vaccine to 26 March 2010. Coverage rates are predicted to increase during 2010 as people are vaccinated with pandemic (H1N1) 2009 vaccine and the 2010 seasonal influenza vaccine which includes the pandemic strain.

While the circulation of pandemic (H1N1) 2009 influenza in Australia has receded over the spring and summer months of 2009/2010, Australia remains in the PROTECT phase and a second wave is expected during 2010. The second wave is not expected to be as severe as 2009 as the proportion of Australians immune to pandemic influenza continues to increase with vaccination. Free pandemic (H1N1) 2009 influenza vaccine remains available during 2010 and vaccination continues to be promoted in the ACT.

There were many lessons learnt from the 2009 response to the pandemic (H1N1) 2009 influenza. These lessons are being applied to ACT Health's preparations for the 2010 influenza season. Key lessons learnt and areas for improvement include:

  • Influenza surveillance systems need to be enhanced to assist early identification of influenza activity and to encompass ways to better measure the impact of influenza, such as emergency department presentations, hospitalisation, ICU bed use and deaths;
  • Communication the effective use of communication tools that provide timely, targeted health information to the community as well as the health sector should continue;
  • Influenza Assessment Clinic models were tested and key issues identified. Refinement of preferred models of establishment, operation and staffing is necessary;
  • Even though the pandemic was less severe than predicted the pressure on the health system was significant identifying the need for surge capacity planning;
  • Stakeholder involvement the value of strong links with key stakeholders (such as the Division of General Practice and the Department of Education) in distributing information and advice and the development and implementation of disease control protocols was reinforced and needs to be maintained.