Pipestone Research, Pipestone Holdings, Pipestone, MN 56164, USA.
Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA.
Viruses. 2022 Feb 11;14(2):375. doi: 10.3390/v14020375.
Porcine reproductive and respiratory syndrome (PRRS) is an economically devastating disease of swine in many parts of the world. Porcine reproductive and respiratory syndrome virus (PRRSV) type 1 is endemic in Europe, and prevalence of the subtypes differ spatially. In this study, we investigated a severe PRRS outbreak reported in 30 farms located in eastern Russia that belong to a large swine production company in the region that was also experiencing a pseudorabies outbreak in the system. Data included 28 ORF5 sequences from samples across 18 of the 25 infected sites, reverse transcriptase real-time polymerase chain reaction (RT-qPCR) results from diagnostic testing, reports of clinical signs, and animal movement records. We observed that the outbreak was due to two distinct variants of wildtype PRRSV type 1 subtype 1 with an average genetic distance of 15%. Results suggest that the wildtype PRRSV variants were introduced into the region around 2019, before affecting this production system (i.e., sow farms, nurseries, and finisher farms). Clinical signs did not differ between the variants, but they did differ by stage of pig production. Biosecurity lapses, including movement of animals from infected farms contributed to disease spread.
猪繁殖与呼吸综合征（PRRS）是世界许多地区对猪具有严重经济危害性的疾病。猪繁殖与呼吸综合征病毒（PRRSV）1 型在欧洲流行，其亚型的流行情况在空间上存在差异。在本研究中，我们调查了在俄罗斯东部报告的 30 个农场的严重 PRRS 暴发，这些农场属于该地区的一家大型养猪生产公司，该公司的系统中也发生了伪狂犬病暴发。数据包括来自 25 个感染地点中 18 个地点的样本的 28 个 ORF5 序列、来自诊断检测的逆转录实时聚合酶链反应（RT-qPCR）结果、临床症状报告和动物移动记录。我们观察到，暴发是由两种不同的野生型 PRRSV 1 型 1 亚型的变体引起的，平均遗传距离为 15%。结果表明，野生型 PRRSV 变体于 2019 年前后引入该地区，然后才影响该生产系统（即母猪场、保育场和育肥场）。两种变体的临床症状没有差异，但在猪生产的不同阶段存在差异。生物安全漏洞，包括从感染农场转移动物，导致了疾病的传播。
