Risk Factors for Pandemic (H1N1) 2009 Seroconversion among Adults, Singapore, 2009

oleh: Wei-Yen Lim, Cynthia H.J. Chen, Yi Ma, Mark I.C. Chen, Vernon J.M. Lee, Alex R. Cook, Linda W.L. Tan, Norberto Flores Tabo, Ian Barr, Lin Cui, Raymond T.P. Lin, Yee Sin Leo, Kee Seng Chia

Format: Article
Diterbitkan: Centers for Disease Control and Prevention 2011-08-01

Deskripsi

A total of 828 community-dwelling adults were studied during the course of the pandemic (H1N1) 2009 outbreak in Singapore during June–September 2009. Baseline blood samples were obtained before the outbreak, and 2 additional samples were obtained during follow-up. Seroconversion was defined as a >4-fold increase in antibody titers to pandemic (H1N1) 2009, determined by using hemagglutination inhibition. Men were more likely than women to seroconvert (mean adjusted hazards ratio [HR] 2.23, mean 95% confidence interval [CI] 1.26–3.93); Malays were more likely than Chinese to seroconvert (HR 2.67, 95% CI 1.04–6.91). Travel outside Singapore during the study period was associated with seroconversion (HR 1.76, 95% CI 1.11–2.78) as was use of public transport (HR 1.81, 95% CI 1.05–3.09). High baseline antibody titers were associated with reduced seroconversion. This study suggests possible areas for intervention to reduce transmission during future influenza outbreaks.