title: Seroepidemiologic effects of influenza A(H1N1)pdm09 in Australia, New Zealand, and Singapore.
abstract: To estimate population attack rates of influenza A(H1N1)pdm2009 in the Southern Hemisphere during June-August 2009, we conducted several serologic studies. We pooled individual-level data from studies using hemagglutination inhibition assays performed in Australia, New Zealand, and Singapore. We determined seropositive proportions (titer ≥40) for each study region by age-group and sex in pre- and postpandemic phases, as defined by jurisdictional notification data. After exclusions, the pooled database consisted of, 4,414 prepandemic assays and 7,715 postpandemic assays. In the prepandemic phase, older age groups showed greater seropositive proportions, with age-standardized, community-based proportions ranging from 3.5% in Singapore to 11.9% in New Zealand. In the postpandemic phase, seropositive proportions ranged from 17.5% in Singapore to 30.8% in New Zealand, with highest proportions seen in school-aged children. Pregnancy and residential care were associated with lower postpandemic seropositivity, whereas Aboriginal and Torres Strait Islander Australians and Pacific Peoples of New Zealand had greater postpandemic seropositivity.
authors.affiliation: Melbourne Sleep Disorders Centre, East Melbourne, Victoria, Australia. james@msdc.com.au
authors.forename: James M
authors.initials: JM
authors.lastname: Trauer
authors.forename: Don
authors.initials: D
authors.lastname: Bandaranayake
authors.forename: Robert
authors.initials: R
authors.lastname: Booy
authors.forename: Mark I
authors.initials: MI
authors.lastname: Chen
authors.forename: Michelle
authors.initials: M
authors.lastname: Cretikos
authors.forename: Gary K
authors.initials: GK
authors.lastname: Dowse
authors.forename: Dominic E
authors.initials: DE
authors.lastname: Dwyer
authors.forename: Michael E
authors.initials: ME
authors.lastname: Greenberg
authors.forename: Q Sue
authors.initials: QS
authors.lastname: Huang
authors.forename: Gulam
authors.initials: G
authors.lastname: Khandaker
authors.forename: Jen
authors.initials: J
authors.lastname: Kok
authors.forename: Karen L
authors.initials: KL
authors.lastname: Laurie
authors.forename: Vernon J
authors.initials: VJ
authors.lastname: Lee
authors.forename: Jodie
authors.initials: J
authors.lastname: McVernon
authors.forename: Scott
authors.initials: S
authors.lastname: Walter
authors.forename: Peter G
authors.initials: PG
authors.lastname: Markey
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D001315:Australia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D015994:Incidence; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000502:physiology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000208:ethnology / Q000276:immunology / Q000821:virology; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D058873:Pandemics; D011247:Pregnancy; D016036:Seroepidemiologic Studies; D012846:Singapore / Q000453:epidemiology; D000095283:Australian Aboriginal and Torres Strait Islander Peoples
chemical_list: D000914:Antibodies, Viral