title: Influenza disease burden in adults by subtypes following the initial epidemic of pandemic H1N1 in Singapore.
abstract: Peaks of influenza activity in July 2009 and January 2010 were >90% pandemic H1N1 (pH1N1), but by May 2010, H3N2 predominated in hospital attendances (46·5%, versus 38·9% pH1N1); H3N2 hospital attendances were older (72·9% aged ≥60 years versus 13·5% for pH1N1), but the age-stratified proportions admitted for pneumonia ]were similar. As at the end of the third epidemic wave in Singapore, pH1N1 cases in hospital attendances were still markedly younger than cases of H3N2 or influenza B, with little evidence for any changes in severity.
authors: Department of Clinical Epidemiology, Communicable Disease Centre, Tan Tock Seng Hospital, Singapore. winmar_kyaw@yahoo.com.sg
authors: Mar K
authors: MK
authors: Win
authors: Mark I-C
authors: MI
authors: Chen
authors: Tim
authors: T
authors: Barkham
authors: Cui
authors: C
authors: Lin
authors: Adriana
authors: A
authors: Tan
authors: Raymond
authors: R
authors: Lin
authors: Yee-Sin
authors: YS
authors: Leo
mesh_terms: D000328:Adult; D000368:Aged; D017281:Cost of Illness; D005260:Female; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D007251:Influenza, Human / Q000191:economics* / Q000453:epidemiology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D012846:Singapore / Q000453:epidemiology; D055815:Young Adult