Open AccessEpidemiologic and virologic assessment of the 2009 influenza A (H1N1) pandemic on selected temperate countries in the Southern Hemisphere: Argentina, Australia, Chile, New Zealand and South Africa
Author(s) -
Van Kerkhove Maria D.,
Mounts Anthony W.,
Mall Sabine,
Vandemaele Katelijn A.H.,
Chamberland Mary,
dos Santos Thais,
Fitzner Julia,
Widdowson MarcAlain,
Michalove Jennifer,
Bresee Joseph,
Olsen Sonja J.,
Quick Linda,
Baumeister Elsa,
Carlino Luis O.,
Savy Vilma,
Uez Osvaldo,
Owen Rhonda,
Ghani Fatima,
Paterson Bev,
Forde Andrea,
Fasce Rodrigo,
Torres Graciela,
Andrade Winston,
Bustos Patricia,
Mora Judith,
Gonzalez Claudia,
Olea Andrea,
Sotomayor Viviana,
Najera De Ferrari Manuel,
Burgos Alejandra,
Hunt Darren,
Huang Q. Sue,
Jennings Lance C.,
Macfarlane Malcolm,
Lopez Liza D.,
McArthur Colin,
Cohen Cheryl,
Archer Brett,
Blumberg Lucille,
Cengimbo Ayanda,
Makunga Chuma,
McAnerney Jo,
Msimang Veerle,
Naidoo Dhamari,
Puren Adrian,
Schoub Barry,
Thomas Juno,
Venter Marietjie
Publication year - 2011
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/j.1750-2659.2011.00249.x
Subject(s) - pandemic , seasonal influenza , transmission (telecommunications) , medicine , demography , southern hemisphere , population , influenza a virus , geography , environmental health , disease , covid-19 , virology , virus , infectious disease (medical specialty) , biology , ecology , sociology , electrical engineering , engineering
Please cite this paper as: Van Kerkhove et al. (2011) Epidemiologic and virologic assessment of the 2009 influenza A (H1N1) pandemic on selected temperate countries in the Southern Hemisphere: Argentina, Australia, Chile, New Zealand and South Africa. Influenza and Other Respiratory Viruses 5(6), e487–e498. Introduction and Setting Our analysis compares the most comprehensive epidemiologic and virologic surveillance data compiled to date for laboratory‐confirmed H1N1pdm patients between 1 April 2009 ‐ 31 January 2010 from five temperate countries in the Southern Hemisphere–Argentina, Australia, Chile, New Zealand, and South Africa. Objective We evaluate transmission dynamics, indicators of severity, and describe the co‐circulation of H1N1pdm with seasonal influenza viruses. Results In the five countries, H1N1pdm became the predominant influenza strain within weeks of initial detection. South Africa was unique, first experiencing a seasonal H3N2 wave, followed by a distinct H1N1pdm wave. Compared with the 2007 and 2008 influenza seasons, the peak of influenza‐like illness (ILI) activity in four of the five countries was 3‐6 times higher with peak ILI consultation rates ranging from 35/1,000 consultations/week in Australia to 275/100,000 population/week in New Zealand. Transmission was similar in all countries with the reproductive rate ranging from 1.2–1.6. The median age of patients in all countries increased with increasing severity of disease, 4–14% of all hospitalized cases required critical care, and 26–68% of fatal patients were reported to have ≥1 chronic medical condition. Compared with seasonal influenza, there was a notable downward shift in age among severe cases with the highest population‐based hospitalization rates among children <5 years old. National population‐based mortality rates ranged from 0.8–1.5/100,000. Conclusions The difficulty experienced in tracking the progress of the pandemic globally, estimating its severity early on, and comparing information across countries argues for improved routine surveillance and standardization of investigative approaches and data reporting methods.