Velkers F C, Bouma A, Matthijs M G R, Koch G, Westendorp S T, Stegeman J A
Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, PO Box 80.151, 3508 TD Utrecht, The Netherlands.
Vet Rec. 2006 Sep 23;159(13):403-5. doi: 10.1136/vr.159.13.403.
This case report describes the course of an outbreak of avian influenza on a Dutch turkey farm. When clinical signs were observed their cause remained unclear. However, serum samples taken for the monitoring campaign launched during the epidemic of highly pathogenic avian influenza in 2003, showed that all the remaining turkeys were seropositive against an H7 strain of avian influenza virus, and the virus was subsequently isolated from stored carcases. The results of a reverse-transcriptase pcr showed that a H7N3 strain was involved, and it was characterised as of low pathogenicity. However, its intravenous pathogenicity index was 2.4, characterising it as of high pathogenicity, suggesting that a mixture of strains of low and high pathogenicity may have been present in the isolate. The outbreak remained limited to three farms.
本病例报告描述了荷兰一个火鸡养殖场禽流感疫情的发展过程。当观察到临床症状时，其病因仍不明确。然而，在2003年高致病性禽流感疫情期间开展的监测活动中采集的血清样本显示，所有剩余火鸡对禽流感病毒H7毒株血清呈阳性，随后从储存的 carcasses 中分离出该病毒。逆转录酶聚合酶链反应结果显示涉及H7N3毒株，其被鉴定为低致病性。然而，其静脉内致病性指数为2.4，表明具有高致病性，这表明分离株中可能存在低致病性和高致病性毒株的混合。疫情仅局限于三个养殖场。 （注：carcases这个词原文可能有误，推测应该是carcasses，意为“尸体、 carcasses” ，翻译时已按正确的推测翻译）
