Ellis J A, Bratanich A, Clark E G, Allan G, Meehan B, Haines D M, Harding J, West K H, Krakowka S, Konoby C, Hassard L, Martin K, McNeilly F
Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon Canada.
J Vet Diagn Invest. 2000 Jan;12(1):21-7. doi: 10.1177/104063870001200104.
Postweaning multisystemic wasting syndrome (PMWS) is an emerging disease in swine. Recently, the disease has been reproduced with inocula containing a newly described porcine circovirus (PCV), designated PCV 2, and porcine parvovirus (PPV). In order to determine if these viruses interact in naturally acquired PMWS, affected tissues from field cases were examined by immunohistochemistry (IHC) and polymerase chain reaction (PCR) for PCV 2 and PPV, as well as by PCR for the other recognized porcine circovirus, PCV 1. Porcine circovirus 2 was detected by PCR or IHC in affected fixed or frozen tissues from 69 of 69 cases of PMWS collected over 3 years from 25 farms. Porcine parvovirus was detected in 12 of the same cases, and PCV 1 was detected in 9 of 69; however, an apparent decrease was found in the sensitivity of the PCRs used to detect the latter 2 viruses when fixed tissue from the same cases were compared with the use of frozen tissues. Porcine circovirus 2 was not detected by PCR in affected tissues from 16 age-matched pigs that had Streptococcus suis-associated disease. Electron microscopic examination of plasma pooled from 15 pigs with PMWS revealed the presence of PCV and PPV, whereas these viruses were not observed in pooled plasma from 5 age-matched clinically normal pigs. These results confirm and extend previous findings documenting a consistent association of PCV 2 with PMWS. As well, infection by PPV or PCV 1 or both may be an important cofactor in the pathogenesis of some, but apparently not all, cases of PMWS.
断奶后多系统消耗综合征（PMWS）是猪群中一种新出现的疾病。最近，用含有一种新描述的猪圆环病毒（命名为PCV 2）和猪细小病毒（PPV）的接种物复制出了该疾病。为了确定这些病毒在自然发生的PMWS中是否相互作用，对来自田间病例的受影响组织进行了免疫组织化学（IHC）检测以及针对PCV 2和PPV的聚合酶链反应（PCR），同时还针对另一种公认的猪圆环病毒PCV 1进行了PCR检测。在3年时间里从25个猪场收集的69例PMWS病例的受影响固定或冷冻组织中，通过PCR或IHC检测到了PCV 2。在其中12例相同病例中检测到了猪细小病毒，在69例中的9例中检测到了PCV 1；然而，当将相同病例的固定组织与冷冻组织用于检测后两种病毒时，发现用于检测后两种病毒的PCR敏感性明显降低。在16头患有猪链球菌相关疾病的年龄匹配猪的受影响组织中，未通过PCR检测到PCV 2。对15头患有PMWS的猪的血浆进行电镜检查发现存在PCV和PPV，而在5头年龄匹配的临床正常猪的混合血浆中未观察到这些病毒。这些结果证实并扩展了先前的发现，记录了PCV 2与PMWS之间始终存在的关联。此外，PPV或PCV 1或两者的感染可能是某些（但显然不是所有）PMWS病例发病机制中的一个重要辅助因素。
