Via: The New England Journal of Medicine. Original post published on-line at: http://content.nejm.org/cgi/content/full/NEJMp0910445 on Nov. 25, 2009.
Authors: James F. Bishop, M.D., Mary P. Murnane, B.A., and Rhonda Owen, B.Sc.
“When the World Health Organization declared a “public health emergency of international concern” on April 25, 2009, after the emergence in Mexico of pandemic influenza A (H1N1) virus, Australia activated its well-rehearsed plan for response to pandemic influenza.1 The Australian Health Management Plan for Pandemic Influenza is a strategic outline, based on evidence and international best practices, of actions and interventions that the health care community should consider taking during a pandemic. It describes the planning assumptions, the phases of a response, and the key actions that minimize a pandemic’s effects on the population and the health care community. Over the subsequent 6 weeks, the implementation of border-control measures — including requirements that travelers entering Australia declare whether they have symptoms of influenza or have been in contact with someone with severe respiratory illness and that contacts of persons with known influenza be traced — gave the health care community time to learn more about the natural history of the new influenza strain.2
The groups that had been identified worldwide as the most vulnerable to poor outcomes were pregnant women, indigenous populations, and persons with gross obesity or serious underlying medical conditions. Australia pursued a modified version of its national plan for pandemic influenza, under which such persons and those with rapidly progressing influenza and respiratory distress were targeted for early outpatient-based treatment with antiviral medication and careful follow-up by primary care physicians and hospitals. Additional public health mitigation measures included opening the national stockpile of antiviral medication, providing personal protective equipment to general practitioners, issuing public messages recommending self-quarantine at home for persons with influenza-like illness, and launching public-awareness campaigns aimed at reducing droplet spread of the disease.
This first wave of 2009 pandemic influenza A (H1N1) virus infection lasted about 18 weeks in Australia, from mid-May to late September 2009 (see graph).3 Consultations for influenza-like illness in general practices and emergency departments peaked at 34 and 38 per 1000 consultations, respectively. The percentage of clinical isolates that tested positive for influenza A peaked at 38 to 65% in the various states and territories, and the 2009 H1N1 virus accounted for 90% of influenza A isolates by week 8 (see maps). Rates of absenteeism from work and school were similar to those seen in 2007, the year in which Australia had its worst recent influenza season. The rate of hospitalizations was 23 per 100,000 population, with indigenous Australians overrepresented (16%) and about 13% of all patients who were hospitalized being admitted to intensive care units (ICUs). The highest rate of hospitalization occurred among children under 5 years of age. Boys younger than 5 years of age were hospitalized at rate of 67.9 per 100,000 population, and girls in that age group at a rate of 54.1 per 100,000 population, as compared with 51.1 per 100,000 population in this age group during previous influenza seasons. The median length of stay was 3 days, with 19% of patients being hospitalized for more than 7 days…..”
**Read the entire, original post here: http://content.nejm.org/cgi/content/full/NEJMp0910445
