Koike Naoki, Mai Thi Ngan, Shirai Mamoru, Kubo Meiko, Hata Kazuhiro, Marumoto Nobuyuki, Watanabe Shinji, Sasaki Yosuke, Mitoma Shuya, Notsu Kosuke, Okabayashi Tamaki, Wiratsudakul Anuwat, Kabali Emmanuel, Norimine Junzo, Sekiguchi Satoshi
Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.
Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-1692, Japan.
J Vet Med Sci. 2018 Nov 23;80(11):1782-1786. doi: 10.1292/jvms.18-0132. Epub 2018 Oct 2.
The purpose of this study was to detect porcine epidemic diarrhea virus (PEDV) subclinically infected pigs shipped from non-case farms to slaughterhouses. Systematic sampling was conducted at two slaughterhouses. A total of 1,556 blood samples were collected from 80 case and non-case farms from pigs over 6 months old. Blood samples were centrifuged to obtain sera. Serial serum dilutions were subjected to serological examination for PEDV presence using Neutralization test (NT). The cut-off titer was set at titer of 1:2 dilution and farms with at least one positive sample in duplicate were classified as PED-positive farms. Several non-case farms (9.4%, 6/64) and 100% (16/16) of the case farms were indeed positive for PEDV. The proportion of seropositive animals from case farms was 63.7%, significantly different from that of non-case farms (4.3%, P<0.05). In both case and non-case farms, the proportion of seropositive animals in farrow-to-finish farms was significantly higher than in wean-to-finish farms (P<0.05). Seropositive animals in non-case farms were detected by NT in a sero-survey by sampling at slaughterhouses. Therefore, subclinically infected pigs should be considered prior to shipment.
本研究的目的是检测从非疫情猪场运往屠宰场的亚临床感染猪流行性腹泻病毒（PEDV）的猪。在两家屠宰场进行了系统抽样。从80个疫情猪场和非疫情猪场6月龄以上的猪中总共采集了1556份血样。血样经离心获得血清。采用中和试验（NT）对血清进行系列稀释，以检测PEDV的存在。截断效价设定为1:2稀释效价，至少有一份重复阳性样本的猪场被归类为PED阳性猪场。几个非疫情猪场（9.4%，6/64）和100%（16/16）的疫情猪场确实PEDV呈阳性。疫情猪场血清阳性动物的比例为63.7%，与非疫情猪场（4.3%）有显著差异（P<0.05）。在疫情猪场和非疫情猪场中，从仔猪到育肥猪的猪场血清阳性动物的比例均显著高于断奶到育肥猪的猪场（P<0.05）。在屠宰场抽样的血清学调查中，通过NT检测到非疫情猪场中的血清阳性动物。因此，在运输前应考虑亚临床感染猪。
