The impact of the pandemic influenza a(H1N1) 2009 virus on seasonal influenza a viruses in the southern hemisphere, 2009
Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research (ICPMR), Westmead Hospital, Westmead, NSW, Australia; School of Paediatrics and Child Health, University of Western Australia, Princess Margaret Hospital, Subiaco, WA, Australia; World Health Organisation Collaborating Centre for Reference and Research on Influenza, Victorian Infectious Diseases Reference Laboratory (VIDRL), North Melbourne, VIC, Australia; Victorian Infectious Diseases Reference Laboratory (VIDRL), North Melbourne, VIC, Australia; Pathwest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, WA, Australia; World Health Organisation National Influenza Centre, Institute of Environmental Science and Research, Wellington, New Zealand; National Institute for Communicable Diseases, Sandringham, Johannesburg, South Africa
Data collected over winter 2009 by five World Health Organisation National Influenza Centres in the southern hemisphere were used to examine the circulation of pandemic and seasonal influenza A strains during the first pandemic wave in the southern hemisphere. There is compelling evidence that the pandemic influenza A(H1N1) 2009 virus significantly displaced seasonal influenza A(H1N1) and, to a lesser extent, A(H3N2) viruses circulating in the southern hemisphere. Complete replacement of seasonal influenza A strains, however, was not observed during the first pandemic wave.
2009 H1N1 influenza; article; disease course; disease surveillance; human; infection prevention; Influenza virus A H3N2; nonhuman; pandemic influenza; prevalence; seasonal influenza; Southern Hemisphere; virus detection; virus strain; Geography; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza, Human; Pandemics; Seasons; World Health Organization