Volume 192 - Issue 6
Comparison of adult patients hospitalised with pandemic (H1N1) 2009 influenza and seasonal influenza during the "PROTECT" phase of the pandemic response
Authors: Iain B Gosbell, Sebastiaan J van Hal, Peter M Spencer, Ya-Shu Chang and Peter W Collett
Med J Aust 2010; 192 (6): 356-358. || doi: 10.5694/j.1326-5377.2010.tb03546.x
Published online: 15 March 2010
Published online: 15 March 2010
In reply: Our study found that both subtypes of influenza caused substantial morbidity and mortality, but that there was no difference in outcomes between patients infected with seasonal and pandemic (H1N1) 2009 influenza.1
The large numbers of cases of pandemic (H1N1) 2009 infection, and especially those requiring intensive care unit (ICU) management, is not disputed — 37 537 cases, 655 ICU admissions and 191 deaths in Australia had been reported as of 18 December 2009.2 However, this is not a function of enhanced virulence of the pandemic strain, but rather a function of vast numbers of infected individuals in a naïve population.
The article by the Australian and New Zealand Intensive Care study investigators supports our conclusions, as they found no difference in outcome between pandemic (H1N1) 2009 and seasonal influenza.3 As specimens were tested in “real time”, RNA degradation is unlikely to have resulted in incorrect categorisation. The real impact of influenza has probably been under-reported before this pandemic, as virological testing of respiratory specimens has not been routine. Influenza per se is a significant disease, and thus appropriate planning, including resource allocation for ICU management and routine virological testing of respiratory specimens should be undertaken.
References
- Chang Y-S, van Hal SJ, Spencer PM, et al. Comparison of adult patients hospitalised with pandemic (H1N1) 2009 influenza and seasonal influenza during the “PROTECT” phase of the pandemic response. Med J Aust 2010; 192: 90-93.
- Australian Government Department of Health and Ageing. Australian influenza surveillance summary report no. 32, 2009, Reporting period: 12 December 2009 – 18 December 2009. Canberra: Department of Health and Ageing, 2009: 1-6. http://www.health.gov.au/internet/healthemergency/ publishing.nsf/Content/18D06BAC4644C98 DCA25763E00823442/$File/ozflu-no32-2009.pdf (accessed Feb 2010).
- The ANZIC Influenza Investigators. Critical care services and 2009 H1N1 influenza in Australia and New Zealand. N Engl J Med 2009; 361: 1925-1934. 0_pgfId-1995226