Gross and microscopic lesions in porcine fetuses infected with porcine reproductive and respiratory syndrome virus
Gross and microscopic lesions in porcine fetuses infected with porcine reproductive and respiratory syndrome virus
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DOI：
10.1177/104063879600800301
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发表时间：
1996-07-01
影响因子：
1.5
通讯作者：
Halbur, PG
中科院分区：
文献类型：
--
作者：
Lager, KM;Halbur, PG
猪繁殖与呼吸综合征病毒(PRRSV)导致的猪繁殖障碍的诊断是困难的，因为在流产或分娩之前死亡的胎儿中病毒迅速失活。在这份报告中，我们描述了在妊娠晚期经胎盘感染PRRSV的胎儿中发现的具有诊断价值的大体和显微病变。7头没有PRRSV特异性抗体的母猪和1头之前感染过PRRSV的母猪(#8)在妊娠90天或大约90天时经口鼻接种PRRSV疫苗。一头对照母猪(#9)在90DG时经口鼻暴露于假接种。母猪在暴露21天后被安乐死，并对胎儿进行病毒检测。1-7胎胎盘感染，其中6胎脐带肉眼可见损害。8、9胎均未发现胎盘感染或胎儿病变。脐带大体病变由1~2 cm的节段性出血区至全长受累的脐带，明显膨大并伴有明显出血。所有脐带肉眼损伤的活胎均为病毒感染，组织病理学检查显示为坏死性脐动脉炎伴动脉周围出血。这是感染PRRSV的胎儿中最一致的显微病变。母猪1-7有不同程度的子宫内膜炎和肌炎，提示PRRSV也可能诱发这些病变。对脐带进行仔细的大体和显微镜检查可能有助于诊断PRRSV引起的生殖衰竭。
Diagnosis of porcine reproductive and respiratory syndrome virus (PRRSV)-induced reproductive failure in swine is difficult because of the rapid inactivation of virus in fetuses that have died prior to abortion or farrowing. In this report, we describe gross and microscopic lesions of diagnostic value found in fetuses transplacentally infected with PRRSV during late gestation. Seven sows free of PRRSV-specific antibody and 1 sow (#8) that had been previously infected with PRRSV were oronasally exposed to a PRRSV inoculum at or about 90 days of gestation (DG). One control sow (#9) was oronasally exposed to a sham inoculum at 90 DG. Sows were euthanized 21 days postexposure, and fetuses were tested for virus. Transplacental infection was detected in litters 1-7, and gross lesions of the umbilical cord were observed in some fetuses in 6 of the 7 litters. No transplacental infection or fetal lesions were found in litters 8 and 9. The gross lesions in the umbilical cords ranged from segmental hemorrhagic areas 1-2 cm in length to a full length involvement of the cord, which was grossly distended with frank hemorrhage. All live fetuses that had gross lesions in the umbilical cord were viremic, and histopathologic examination revealed a necrotizing umbilical arteritis with periarterial hemorrhage. This was the most consistent microscopic lesion in fetuses infected with PRRSV. Sows 1-7 had endometritis and myometritis of various degrees, suggesting PRRSV also may induce these lesions. Careful gross and microscopic examination of the umbilical cord may aid in the diagnosis of PRRSV-induced reproductive failure.