Wang Yi, Yang Danchen Aaron, Zhao Kangning, Laven Richard, Jiang Ping, Yang Zhen
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, the Belt and Road International Sci-Tech Innovation Institute of Transboundary Animal Disease Diagnosis and Immunization, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Huanshan Group Co., Ltd, Qingdao 266061, China.
Prev Vet Med. 2023 Dec;221:106076. doi: 10.1016/j.prevetmed.2023.106076. Epub 2023 Nov 10.
Porcine circovirus type 3 (PCV3) is a newly described circovirus that has been identified in pig populations across the globe. The virus is associated with multiple diseases including reproductive and systemic diseases. As effective vaccines are lacking, surveillance is crucial for PCV3 control, but there are currently, few side-by-side comparisons of the efficacy of different samples for the detection of PCV3. This study collected four sample types, including colostrum, udder skin wipes, placental umbilical cord blood, and processing fluid from 134 litters in a sow farm from July to September 2021 for PCV3 detection based on quantitative PCR tests. Udder skin wipes showed the highest detection rates (76.9%), while 71.6% of the processing fluid, 49.3% of the placental umbilical cord, and 29.1% of the colostrum samples were positive. Logistic regression analysis suggested that the detection rates of udder skin wipes and processing fluid were similar (odds ratio for processing fluid vs udder skin wipes was 0.76, 95% confidence interval (CI) 0.43-1.32), but the two tests were probably not identifying the same population as infected, as the agreement between the samples was only moderate (Gwet's AC1: 0.65). In this study, we were able to demonstrate that PCV3 was present in the farrowing room throughout the period from birth to weaning using udder skin wipes, although viral load decreased over time. The odds of PCV3 detection in colostrum from 2-parity sows was three times higher (95% CI 1.4-6.8) than that of primiparous sows, while the odds of PCV3 detection in sows with mummified fetuses was 2.7 times higher (95% CI 1.1-6.6) than sows with no mummified fetuses. In conclusion, these results indicate that udder skin wipes have high detection rates in infected animals over the whole period from birth to weaning and would thus be suitable samples for PCV3 surveillance in the farrowing rooms.
猪圆环病毒3型（PCV3）是一种新发现的圆环病毒，已在全球猪群中被鉴定出来。该病毒与多种疾病有关，包括繁殖和全身性疾病。由于缺乏有效的疫苗，监测对于控制PCV3至关重要，但目前很少有不同样本检测PCV3功效的并列比较。本研究于2021年7月至9月从一个母猪场的134窝仔猪中收集了四种样本类型，包括初乳、乳房皮肤擦拭物、胎盘脐带血和加工液，用于基于定量PCR检测的PCV3检测。乳房皮肤擦拭物的检测率最高（76.9%），而加工液样本的阳性率为71.6%，胎盘脐带样本为49.3%，初乳样本为29.1%。逻辑回归分析表明，乳房皮肤擦拭物和加工液的检测率相似（加工液与乳房皮肤擦拭物的优势比为0.76，95%置信区间（CI）为0.43 - 1.32），但这两种检测可能并未识别出相同的感染群体，因为样本之间的一致性仅为中等（Gwet's AC1：0.65）。在本研究中，我们能够证明在分娩舍从出生到断奶的整个期间，使用乳房皮肤擦拭物可检测到PCV3，尽管病毒载量随时间下降。经产母猪初乳中检测到PCV3的几率比初产母猪高3倍（95% CI 1.4 - 6.8），而有木乃伊化胎儿的母猪检测到PCV3的几率比没有木乃伊化胎儿的母猪高2.7倍（95% CI 1.1 - 6.6）。总之，这些结果表明，乳房皮肤擦拭物在感染动物从出生到断奶的整个期间检测率较高，因此是分娩舍PCV3监测的合适样本。
