Li H, Snowder G, Crawford T B
Animal Diseases Research Unit, USDA, Agriculture Research Service, Pullman, WA 99164, USA.
Vet Microbiol. 1999 Mar 1;65(2):167-72. doi: 10.1016/s0378-1135(98)00287-9.
The study was designed to better define the variables affecting the success of the establishment of ovine herpesvirus 2 (OHV-2)-free sheep flocks. A total of 38 lambs born to OHV-2-positive ewes was selected and divided into four groups. Three groups of 10 lambs each were separated from the positive ewes at 2, 2.5 and 3 months of age, respectively, and maintained in isolation facilities. One group of eight remained in the positive flock as controls. Peripheral blood samples from each lamb were examined regularly by PCR for OHV-2 DNA. All lambs (100%) that were weaned and maintained in isolation from the ages of 2, 2.5 and 3 months remained negative until the termination of the experiment at 1 year of age. One lamb was discovered to be PCR-positive on the day of isolation at 2.5 months of age, and was promptly removed from the isolation group. In contrast, all lambs (100%) that remained with the flock became PCR-positive by 6 months of age. The data confirmed that, with rare exceptions, separation of lambs from OHV-2 infected animals at around 2 months of age reliably yields OHV-2-free sheep. Appropriate PCR monitoring will enable the rare exceptions to be removed from the group, and is recommended as a safety measure.
本研究旨在更好地确定影响建立无绵羊疱疹病毒2型（OHV-2）羊群成功的变量。总共挑选了38只OHV-2阳性母羊所生的羔羊，并将其分为四组。每组10只羔羊的三组分别在2、2.5和3月龄时与阳性母羊分开，并饲养在隔离设施中。一组八只羔羊留在阳性羊群中作为对照。通过PCR定期检测每只羔羊外周血样本中的OHV-2 DNA。所有在2、2.5和3月龄断奶并隔离饲养的羔羊（100%）直到1岁实验结束时均保持阴性。有一只羔羊在2.5月龄隔离当天被检测出PCR阳性，并立即从隔离组中移除。相比之下，所有留在羊群中的羔羊在6月龄时均变为PCR阳性。数据证实，除极少数例外情况外，在约2月龄时将羔羊与感染OHV-2的动物分开可可靠地培育出无OHV-2的绵羊。适当的PCR监测将使极少数例外情况的羔羊从组中移除，建议将其作为一项安全措施。
