Broad objectives: To study the community transmission dynamics of influenza in a subtropical city state.
Specific aims of this proposal: To assess the efficacy of face masks and/or hand hygiene in reducing household transmission of influenza. Summary of proposed study: Design and subjects: A cluster randomized controlled trial of 1,477 households where one resident has symptoms of influenza-like-illness (index patient). The 1,477 households will include 1,477 index patients and 4,136 'secondary contacts'. After recruitment of an index patient, a study nurse will visit the household to administer the intervention, and will revisit after 3, 6 and 9 days. We will conduct an initial pilot involving 120 households to confirm feasibility and logistics before implementation of the main study. Interventions: 1, placebo (educational talk on upper respiratory tract illness self-care); 2, placebo plus distribution of free masks and education on their use; 3, placebo plus distribution of alcohol hand rubs/dispensers and education on hand hygiene; 4, placebo plus face masks and alcohol rubs/dispensers hand hygiene interventions. Instruments: Initial assessment of influenza in an index patient will be made using the QuickVue rapid diagnostic test. Clinical influenza in secondary contacts will be assessed by self-reported symptoms. Nose and throat swabs will be collected from index patients and secondary contacts for laboratory confirmation of influenza. Main outcome measures: The proportion of secondary contacts with influenza (laboratory definition where samples are available, otherwise clinical definition) during the 10 days following randomization. Relevance: The results of this study will have important implications for influenza prevention in the community locally and globally. Moreover in light of recent fears of a new influenza pandemic, our results will inform public health policy on non-pharmaceutical interventions in a subtropical Chinese setting.

National Institute of Health (NIH)
National Center for Infectious Diseases (CID)
Research Project--Cooperative Agreements (U01)
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Special Emphasis Panel (ZCI1-FXR (13))
Program Officer
Messmer, Trudy
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University of Hong Kong
Hong Kong
Hong Kong
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Wardell, R; Prem, K; Cowling, B J et al. (2017) The role of symptomatic presentation in influenza A transmission risk. Epidemiol Infect 145:723-727
Cowling, Benjamin J; Ip, Dennis K M; Fang, Vicky J et al. (2014) Modes of transmission of influenza B virus in households. PLoS One 9:e108850
Lau, Lincoln L H; Ip, Dennis K M; Nishiura, Hiroshi et al. (2013) Heterogeneity in viral shedding among individuals with medically attended influenza A virus infection. J Infect Dis 207:1281-5
Cowling, Benjamin J; Ip, Dennis K M; Fang, Vicky J et al. (2013) Aerosol transmission is an important mode of influenza A virus spread. Nat Commun 4:1935
Ip, Dennis K M; Schutten, Martin; Fang, Vicky J et al. (2012) Validation of self-swab for virologic confirmation of influenza virus infections in a community setting. J Infect Dis 205:631-4
Lau, Lincoln L H; Cowling, Benjamin J; Fang, Vicky J et al. (2010) Viral shedding and clinical illness in naturally acquired influenza virus infections. J Infect Dis 201:1509-16
Ng, Sophia; Cowling, Benjamin J; Fang, Vicky J et al. (2010) Effects of oseltamivir treatment on duration of clinical illness and viral shedding and household transmission of influenza virus. Clin Infect Dis 50:707-14
Cowling, Benjamin J; Fang, Vicky J; Riley, Steven et al. (2009) Estimation of the serial interval of influenza. Epidemiology 20:344-7
Cowling, Benjamin J; Chan, Kwok-Hung; Fang, Vicky J et al. (2009) Facemasks and hand hygiene to prevent influenza transmission in households: a cluster randomized trial. Ann Intern Med 151:437-46
Cheng, Calvin K Y; Cowling, Benjamin J; Chan, Kwok Hung et al. (2009) Factors affecting QuickVue Influenza A + B rapid test performance in the community setting. Diagn Microbiol Infect Dis 65:35-41

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