title: Epidemic of equine influenza among vaccinated racehorses in Japan in 2007.
abstract: On August 2007, we encountered equine influenza epidemic by Florida sub-lineage strain (H3N8) in Japan Racing Association's facilities where 4142 racehorses in total were stabled. The number of new febrile cases sharply increased, but the occurrence was rapidly calmed down within 2 weeks. The morbidity rate in these facilities was 12.8% and the subclinical infection rate of healthy racehorses examined by rapid antigen detection tests was 19.4% at the early stage of epidemic. The serological studies along with the low morbidity rate and the existence of numbers of asymptomatically infected racehorses, suggested that the cross-reactivity of the antibodies provided by vaccination against the epidemic strain contributed to reducing the morbidity rate and duration of epidemic.
authors.affiliation: Epizootic Research Center, Equine Research Institute, Japan Racing Association, Tochigi, Japan. takashi_yamanaka@jra.go.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamanaka
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Niwa
authors.forename: Koji
authors.initials: K
authors.lastname: Tsujimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
authors.forename: Tomio
authors.initials: T
authors.lastname: Matsumura
mesh_terms: D000818:Animals; D019295:Computational Biology; D004196:Disease Outbreaks / Q000662:veterinary*; D006734:Horse Diseases / Q000453:epidemiology*; D006736:Horses; D053123:Influenza A Virus, H3N8 Subtype; D007564:Japan / Q000453:epidemiology; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000662:veterinary*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012699:Serology; D014765:Viral Vaccines
chemical_list: D014765:Viral Vaccines