Clinical and epidemiological profile of patients with severe H1N1/09 pandemic influenza in Australia and New Zealand: an observational cohort study

Abstract

BackgroundPandemic influenza H1N1/09 emerged in April 2009 and spread widely in Australia and New Zealand. Although an unprecedented number of cases required intensive care, comparative community-based studies with seasonal influenza strains have not shown any significant differences in clinical symptoms or severity.MethodsThe authors performed active surveillance on confirmed influenza-related admissions and compared the clinical profile of patients with pandemic H1N1/09 influenza and patients with seasonal influenza at eight hospitals in Australia and one hospital in New Zealand.ResultsDuring the 1 July and 30 November 2009, 560 patients with confirmed influenza were admitted, of which 478 had H1N1/09, and 82 had other seasonal strains. Patients with H1N1/09 influenza were younger, were more likely to have fever and were more likely to be pregnant but less likely to have chronic obstructive pulmonary disease and ischaemic heart disease than patients with seasonal strains. Other clinical features and comorbidities were reported in similar proportions. Admission to intensive care was required in 22% of patients with H1N1/09 influenza and 12% in patients with other strains. Hospital mortality was 5% in patients with H1N1 influenza.ConclusionsThe clinical features of H1N1/09 influenza and seasonal strains were similar in hospitalised patients. A higher proportion of patients had comorbidities than had been reported in community-based studies. Although the overall mortality was similar, the authors found evidence that H1N1/09 caused severe disease in a higher proportion of hospitalised patients.

Hospitalization Fatality Risk of Influenza A(H1N1)pdm09: A Systematic Review and Meta-Analysis

“…In total, our analysis was based on reports from 48 countries or regions, specifically Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Colombia, Croatia, Denmark, Egypt, France, Germany, Greece, Hong Kong, India, Iran, Ireland, Israel, Italy, Japan, Kenya, Kuwait, Lithuania, Macau, Malaysia, Mexico, Morocco, the Netherlands, New Zealand, Norway, Oman, Pakistan, Poland, Romania, Saudi Arabia, Serbia, Singapore, South Korea, Spain, Sweden, Switzerland, Taiwan, Thailand, Turkey, the United Kingdom, and the United States (Web Figure 3). In addition, 1 publication estimated the HFR for 9 European countries (12), and 2 other publications reported on 2 and 4 specified countries (13,14). The numbers of hospitalized cases ranged from 21 to 12,923 (Web Figure 4).…”

Lessons learnt from the Indian H1N1 (swine flu) epidemic: Predictors of outcome based on epidemiological and clinical profile

“…Pandemic of H1N1 first emerged in 2009 April, which was started in Mexico and soon expanded globally. [45] In India, the first case was identified on 2009 May 16, in Hyderabad. [1]…”

Update on lung transplantation: programmes, patients and prospects

“…The importance of community viral infections post-transplant and their varying presentations require a vigilant approach regarding risk stratification and diagnostic/management decision including the commencement of early treatment protocols for influenza (oseltamavir and zanamavir being the only current readily available antivirals in an outpatient setting) even whilst waiting for confirmatory test results. This is especially true during outbreaks, epidemics and pandemics such as the relatively recent H1N1/09 influenza pandemic where the pre-test probability of a positive test result in a specific clinical scenario is relatively high [219,223,224]. Effective treatment protocols based on parenteral or nebulised ribavarin are available for RSV and parainfluenza, although, in general, these are more complicated to administer [225,226].…”