Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
Prev Vet Med. 2010 Dec 1;97(3-4):228-36. doi: 10.1016/j.prevetmed.2010.09.020.
Porcine circovirus type 2 (PCV2) can be vertically transmitted resulting in fetal infection with or without clinical signs and lesions. The primary objective of this study was to assess the prevalence of intrauterine PCV2 infection in clinically normal newborn piglets in conventional pork production facilities. Five commercial breeding herds located in the U.S. and Mexico were included in the study. A total of 125 sows and 3-5 neonatal piglets per sow were arbitrarily selected. Blood and colostrum samples were collected from sows. Blood was collected from piglets prior to suckling. All samples were analyzed for the presence of anti-PCV2 IgG antibodies and presence and amount of PCV2 DNA. In addition, PCV2 DNA positive samples were further subtyped into PCV2a and PCV2b. All (125/125) sow colostrum samples and 96.8% (121/125) of the sow serum samples and 21.4% (107/499) of the piglet pre-suckle serum samples were positive for anti-PCV2 IgG antibody. The overall PCV2 DNA prevalence was 47.2% (59/125) in sow serum, 40.8% (51/125) in sow colostrum, and 39.9% (199/499) in pre-suckle piglet serum. In the PCV2 DNA positive samples, PCV2b was detected at a higher frequency (69.5% for sow serum, 84.3% for sow colostrum, and 74.4% for piglet serum) compared to PCV2a (18.6% for sow serum, 9.8% for sow colostrum, and 15.6% for piglet serum). Concurrent PCV2a and PCV2b infection was detected in 11.9% of the sow serum, in 5.9% of the colostrum samples, and in 10.0% of the piglet serum samples. In conclusion, an unexpectedly high prevalence of PCV2 viremia was detected in healthy sows (serum and colostrum) and their pre-suckle piglets in the five breeding herds investigated and PCV2b was more prevalent than PCV2a. This information adds to the knowledge of PCV2 infection in breeding herds.
猪圆环病毒 2 型（PCV2）可垂直传播，导致胎儿感染，无论是否有临床症状和病变。本研究的主要目的是评估在常规猪肉生产设施中，临床正常新生仔猪的宫内 PCV2 感染率。该研究纳入了美国和墨西哥的 5 个商业繁殖场。每个繁殖场随机选择 125 头母猪和 3-5 头新生仔猪。采集母猪的血液和初乳样本，采集仔猪在哺乳前的血液样本。所有样本均分析是否存在抗 PCV2 IgG 抗体以及是否存在 PCV2 DNA 及其含量。此外，对 PCV2 DNA 阳性样本进行进一步亚分型为 PCV2a 和 PCV2b。所有（125/125）母猪初乳样本和 96.8%（121/125）母猪血清样本和 21.4%（107/499）仔猪预哺乳血清样本均为抗 PCV2 IgG 抗体阳性。母猪血清、母猪初乳和仔猪预哺乳血清中 PCV2 DNA 的总体流行率分别为 47.2%（59/125）、40.8%（51/125）和 39.9%（199/499）。在 PCV2 DNA 阳性样本中，PCV2b 的检出率高于 PCV2a（母猪血清为 69.5%、母猪初乳为 84.3%、仔猪血清为 74.4%；母猪血清为 18.6%、母猪初乳为 9.8%、仔猪血清为 15.6%）。在 11.9%的母猪血清、5.9%的初乳样本和 10.0%的仔猪血清样本中检测到 PCV2a 和 PCV2b 的混合感染。总之，在五个繁殖场调查的健康母猪（血清和初乳）及其预哺乳仔猪中，检测到 PCV2 血症的流行率出乎意料地高，且 PCV2b 比 PCV2a 更常见。这些信息增加了对繁殖场中 PCV2 感染的了解。
