title: Impact of a porcine epidemic diarrhea outbreak on swine productivity in Japan: a retrospective cohort study.
abstract: The objective was to investigate porcine epidemic diarrhea (PED) outbreak that occurred in 2014 in Japan and its effects on herd-level productivity using a data recording system (PigINFO). The study herds were selected from farrow-to-finish herds (n=99) that entered in the PigINFO system between July 2013 and March 2015. From 1 April to 30 June 2014 (PED epidemic), any herds with clinical signs of PED and feces positive for porcine epidemic diarrhea virus (PEDV) on polymerase chain reaction analysis and/or immunohistochemical staining were defined as PED-positive (n=38). They were further classified into those with long PED periods (L-PED-positive; n=28) and those with short PED periods (S-PED-positive; n=10). Herds with no clinical signs of PED were classified as PED-negative (n=61). Herd-level production data, including preweaning mortality (%; PRWM), postweaning mortality (%; POWM), pigs weaned per litter (PWL), pigs born alive per litter, litters per mated female per year and pigs marketed per sow (MP), were calculated every 3 months during study period. During the PED epidemic, L-PED-positive herds had significantly higher PRWM and POWM than PED-negative herds, and L-PED-positive and S-PED-positive herds had significantly lower PWL. During October-December 2014, L-PED-positive herds had significantly fewer MP than PED-negative herds. The PED outbreak increased mortality and consequently reduced the numbers of marketed pigs. The rapid control of an outbreak is important for reducing the financial losses arising from PED infections.
authors.affiliation: Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, Tsukuba, Ibaraki 305-0856, Japan.
authors.forename: Itsuro
authors.initials: I
authors.lastname: Yamane
authors.forename: Hisanori
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Sayoko
authors.initials: S
authors.lastname: Ishizeki
authors.forename: Yugo
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Hanako
authors.initials: H
authors.lastname: Okumura
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Okubo
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Kure
authors.forename: Yuiko
authors.initials: Y
authors.lastname: Hayakawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Furukawa
authors.forename: Munetaka
authors.initials: M
authors.lastname: Ooi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Mizukami
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Ito
mesh_terms: D000822:Animal Husbandry / Q000706:statistics & numerical data*; D000818:Animals; D018352:Coronavirus Infections / Q000453:epidemiology / Q000662:veterinary*; D004196:Disease Outbreaks / Q000662:veterinary*; D005260:Female; D007564:Japan / Q000453:epidemiology; D008297:Male; D053485:Porcine epidemic diarrhea virus; D012189:Retrospective Studies; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000821:virology