title: Transmission of the highly pathogenic avian influenza virus H5N1 within flocks during the 2004 epidemic in Thailand.
abstract: This present study is the first to quantify the transmission of avian influenza virus H5N1 within flocks during the 2004 epidemic in Thailand. It uses the flock-level mortality data to estimate the transmission-rate parameter ( beta ) and the basic reproduction number (R(0)). The point estimates of beta varied from 2.26/day (95% confidence interval [CI], 2.01-2.55) for a 1-day infectious period to 0.66/day (95% CI, 0.50-0.87) for a 4-day infectious period, whereas the accompanying R(0) varied from 2.26 (95% CI, 2.01-2.55) to 2.64 (95% CI, 2.02-3.47). Although the point estimates of beta of backyard chickens and fighting cocks raised together were lower than those of laying hens and broiler chickens, this difference was not statistically significant. These results will enable us to assess the control measures in simulation studies. They also indicate that, for the elimination of the virus, a critical proportion of the susceptible poultry population in a flock (i.e., 80% of the population) needs to be vaccinated.
authors.affiliation: Department of Livestock Development, Ministry of Agriculture and Cooperatives, Bangkok, Thailand. ttiensin@gmail.com
authors.forename: Thanawat
authors.initials: T
authors.lastname: Tiensin
authors.forename: Mirjam
authors.initials: M
authors.lastname: Nielen
authors.forename: Hans
authors.initials: H
authors.lastname: Vernooij
authors.forename: Thaweesak
authors.initials: T
authors.lastname: Songserm
authors.forename: Wantanee
authors.initials: W
authors.lastname: Kalpravidh
authors.forename: Sirikan
authors.initials: S
authors.lastname: Chotiprasatintara
authors.forename: Arunee
authors.initials: A
authors.lastname: Chaisingh
authors.forename: Surapong
authors.initials: S
authors.lastname: Wongkasemjit
authors.forename: Karoon
authors.initials: K
authors.lastname: Chanachai
authors.forename: Weerapong
authors.initials: W
authors.lastname: Thanapongtham
authors.forename: Thinnarat
authors.initials: T
authors.lastname: Srisuvan
authors.forename: Arjan
authors.initials: A
authors.lastname: Stegeman
mesh_terms: D000818:Animals; D002645:Chickens / Q000821:virology*; D004196:Disease Outbreaks; D053124:Influenza A Virus, H5N1 Subtype / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000635:transmission* / Q000821:virology*; D009026:Mortality; D013785:Thailand