title: Interpreting the transmissibility of the avian influenza A(H7N9) infection from 2013 to 2015 in Zhejiang Province, China.
abstract: Three epidemic waves of human influenza A(H7N9) were documented in several different provinces in China between 2013 and 2015. With limited understanding of the potential for human-to-human transmission, it was difficult to implement control measures efficiently or to inform the public adequately about the application of interventions. In this study, the human-to-human transmission rate for the epidemics that occurred between 2013 and 2015 in Zhejiang Province, China, was analysed. The reproduction number (R), a key indicator of transmission intensity, was estimated by fitting the number of infections from poultry to humans and from humans to humans into a mathematical model. The posterior mean R for human-to-human transmission was estimated to be 0·27, with a 95% credible interval of 0·14-0·44 for the first wave, whereas the posterior mean Rs decreased to 0·15 in the second and third waves. Overall, these estimates indicate that a human H7N9 pandemic is unlikely to occur in Zhejiang. The reductions in the viral transmissibility and the number of poultry-transmitted infections after the first epidemic may be attributable to the various intervention measures taken, including changes in the extent of closures of live poultry markets.
authors.affiliation: JC School of Public Health and Primary Care,The Chinese University of Hong Kong,Hong Kong SAR,China.
authors.forename: K C
authors.initials: KC
authors.lastname: Chong
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention,Hangzhou,China.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention,Hangzhou,China.
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention,Hangzhou,China.
authors.forename: J
authors.initials: J
authors.lastname: Cai
authors.affiliation: JC School of Public Health and Primary Care,The Chinese University of Hong Kong,Hong Kong SAR,China.
authors.forename: X
authors.initials: X
authors.lastname: Su
authors.affiliation: JC School of Public Health and Primary Care,The Chinese University of Hong Kong,Hong Kong SAR,China.
authors.forename: B C
authors.identifier: 0000-0002-7238-845X
authors.initials: BC
authors.lastname: Zee
authors.affiliation: JC School of Public Health and Primary Care,The Chinese University of Hong Kong,Hong Kong SAR,China.
authors.forename: G
authors.initials: G
authors.lastname: Tam
authors.affiliation: JC School of Public Health and Primary Care,The Chinese University of Hong Kong,Hong Kong SAR,China.
authors.forename: M H
authors.initials: MH
authors.lastname: Wang
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention,Hangzhou,China.
authors.forename: E
authors.initials: E
authors.lastname: Chen
mesh_terms: D050936:Basic Reproduction Number; D002681:China / Q000453:epidemiology; D018562:Disease Transmission, Infectious; D058872:Epidemics; D006801:Humans; D064766:Influenza A Virus, H7N9 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology / Q000635:transmission* / Q000821:virology*; D008962:Models, Theoretical
keywords: Influenza A; Susceptible-Infected-Removed (SIR) model; mathematical modelling