Section Development of Diagnostic Tools for Epizootic Diseases, Department of Virology, Veterinary and Agrochemical Research Centre, Ukkel, Belgium.
Transbound Emerg Dis. 2009 Dec;56(9-10):355-61. doi: 10.1111/j.1865-1682.2009.01092.x.
An EDTA-blood sample from a cow without clinical signs, which gave early birth to a newborn calf that died soon after delivery, was shown to be positive for bluetongue virus (BTV)-RNA using a group-specific real-time RT-PCR (RT-qPCR). In-house serotype-specific RT-qPCR assays for bluetongue virus serotype 1 (BTV-1), -6 and -8 all gave negative results. Subsequent assays were carried out using conventional (gel-based) RT-PCR primers for all 25 BTV serotypes and only two primer sets, both specific for BTV-11, gave bands of the expected size. The cDNAs generated were sequenced and comparisons of the genome segment 2 sequence with that of the modified 'live' vaccine strain of BTV-11 from South Africa showed 100% identity. A survey of all ruminants in a 1-km area around the first positive farm using a BTV-11 serotype-specific RT-qPCR revealed five other holdings with in total nine BTV-11 positive animals. A cross-sectional monitoring of dairy cattle in Belgium showed an overall prevalence of 3.8% on herd level and 0.2% on animal level. A BTV-11 has been introduced into the Belgian cattle herd during the 2008 vector season. The source of the infection and the way by which the virus was introduced are unknown.
从一头没有临床症状、早产且新生小牛很快死亡的奶牛采集的 EDTA 血样，使用群特异性实时 RT-PCR（RT-qPCR）显示为蓝舌病病毒（BTV）-RNA 阳性。针对蓝舌病病毒血清型 1（BTV-1）、6 和 8 的内部血清型特异性 RT-qPCR 检测均为阴性。随后使用针对所有 25 种 BTV 血清型的常规（基于凝胶）RT-PCR 引物进行了检测，只有两个引物组，均针对 BTV-11，产生了预期大小的条带。生成的 cDNA 进行了测序，并将基因组片段 2 的序列与南非改良的“活”疫苗株 BTV-11 进行比较，显示出 100%的同一性。对第一个阳性农场周围 1 公里范围内的所有反刍动物进行了 BTV-11 血清型特异性 RT-qPCR 调查，发现另外五个牧场共有 9 只 BTV-11 阳性动物。对比利时奶牛的横断面监测显示，在牛群水平上的总体流行率为 3.8%，在动物水平上为 0.2%。BTV-11 已在 2008 年的媒介季节传入比利时牛群。感染源和病毒传入的方式尚不清楚。
