Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1600 S. 16th Street, Ames, IA 50011, USA.
Vet Microbiol. 2011 Apr 21;149(1-2):91-8. doi: 10.1016/j.vetmic.2010.10.020. Epub 2010 Nov 4.
The objective of this study was to determine the amount and infectivity of porcine circovirus type 2 (PCV2) shed in nasal, oral and fecal secretions following experimental infection. Fecal, oral and nasal swabs and blood were collected at regular intervals until 69 days post-inoculation (DPI) from five PCV2-experimentally inoculated pigs (Trial 1). To assess the infectivity of the PCV2 present in excretions, secretions, and on a hypodermic needle, 26 PCV2-naïve pigs (Trial 2) were inoculated with various samples obtained from Trial 1 pigs. In Trial 1, PCV2 DNA was detected in all sample types by 69 DPI. There were no differences in the amount of PCV2 DNA present in different sample types over time. In Trial 2, intraperitoneal inoculation with contaminated fecal, nasal and oral samples; intranasal inoculation of nasal secretions; and feces fed to naïve animals resulted in viremia and seroconversion. Viremia and microscopic lesions were noted in one animal injected using a contaminated needle. In conclusion, experimental PCV2 exposure results in a long term infection. PCV2 is shed in similar amounts by nasal, oral and fecal routes and is infectious to naïve pigs confirming that multiple routes of transmission are likely important in spread of PCV2 between pigs.
本研究的目的是确定在实验感染后，猪圆环病毒 2 型（PCV2）在鼻、口和粪便分泌物中的排出量和感染力。从 5 头经 PCV2 实验接种的猪（试验 1）中定期采集粪便、口腔和鼻腔拭子以及血液，直至接种后 69 天（DPI）。为评估排泄物、分泌物中和皮下注射针上存在的 PCV2 的感染力，将 26 头 PCV2 初免猪（试验 2）接种了从试验 1 猪获得的各种样本。在试验 1 中，所有样本类型在 69 DPI 时均检测到 PCV2 DNA。不同样本类型的 PCV2 DNA 含量随时间变化无差异。在试验 2 中，经污染的粪便、鼻腔和口腔样本腹腔内接种；鼻分泌物经鼻腔接种；以及用粪便喂给初免动物，导致病毒血症和血清转化。在使用污染的针注射的一只动物中观察到病毒血症和显微镜下病变。总之，实验性 PCV2 暴露会导致长期感染。鼻、口和粪便途径以相似的量排出 PCV2，对初免猪具有感染力，证实多种传播途径可能对 PCV2 在猪群之间的传播很重要。
