title: Aerosol transmission is an important mode of influenza A virus spread.
abstract: Influenza A viruses are believed to spread between humans through contact, large respiratory droplets and small particle droplet nuclei (aerosols), but the relative importance of each of these modes of transmission is unclear. Volunteer studies suggest that infections via aerosol transmission may have a higher risk of febrile illness. Here we apply a mathematical model to data from randomized controlled trials of hand hygiene and surgical face masks in Hong Kong and Bangkok households. In these particular environments, inferences on the relative importance of modes of transmission are facilitated by information on the timing of secondary infections and apparent differences in clinical presentation of secondary infections resulting from aerosol transmission. We find that aerosol transmission accounts for approximately half of all transmission events. This implies that measures to reduce transmission by contact or large droplets may not be sufficient to control influenza A virus transmission in households.
authors.affiliation: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China. bcowling@hku.hk
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Cowling
authors.forename: Dennis K M
authors.initials: DK
authors.lastname: Ip
authors.forename: Vicky J
authors.initials: VJ
authors.lastname: Fang
authors.forename: Piyarat
authors.initials: P
authors.lastname: Suntarattiwong
authors.forename: Sonja J
authors.initials: SJ
authors.lastname: Olsen
authors.forename: Jens
authors.initials: J
authors.lastname: Levy
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Uyeki
authors.forename: Gabriel M
authors.initials: GM
authors.lastname: Leung
authors.forename: J S
authors.initials: JS
authors.lastname: Malik Peiris
authors.forename: Tawee
authors.initials: T
authors.lastname: Chotpitayasunondh
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishiura
authors.forename: James
authors.initials: J
authors.lastname: Mark Simmerman
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D005191:Family Characteristics; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D009980:Influenza A virus / Q000502:physiology*; D007251:Influenza, Human / Q000453:epidemiology / Q000635:transmission* / Q000821:virology*; D008954:Models, Biological; D011336:Probability; D012307:Risk Factors; D013785:Thailand / Q000453:epidemiology
chemical_list: D000336:Aerosols