Centre for Epidemiology and Risk Analysis, Veterinary Laboratories Agency (VLA), New Haw, Weybridge, Surrey KT15 3NB, United Kingdom.
Res Vet Sci. 2010 Jun;88(3):411-4. doi: 10.1016/j.rvsc.2009.12.010. Epub 2010 Jan 22.
Individual animal samples were collected from ten VTEC O157 positive farms approximately monthly over 11months to investigate the shedding of VTEC O157 by youngstock. VTEC O157 was isolated from 7.7% of the 6266 samples and 28.9% of the 1383 animals. On six of the farms VTEC O157 was isolated at multiple visits from several animals, whereas the remaining four farms had one or two positive animals at any one visit, with VTEC isolated from a maximum of four visits. A total of 92 animals were positive more than once (up to four sampling occasions) with a maximum of four negative samples between positive isolations. The results reveal a large variation in individual animal shedding patterns; the proportion of shedding animals on positive farms; and over time within the same farm. The lack of consistent shedding restricts the ability to target potential interventions to specific positive animals/groups or herds.
从十个 VTEC O157 阳性农场中每月大约采集一次个体动物样本，以研究幼畜的 VTEC O157 脱落情况。从 6266 个样本中分离出了 7.7%的 VTEC O157，从 1383 个动物中分离出了 28.9%的 VTEC O157。在六个农场中，VTEC O157 从多个动物身上多次分离出来，而其余四个农场在任何一次访问中都有一个或两个阳性动物，从最多四次访问中分离出了 VTEC。共有 92 只动物多次呈阳性（最多四次采样），在阳性分离物之间最多有四次阴性样本。结果表明，个体动物的脱落模式存在很大差异；阳性农场中脱落动物的比例；以及在同一农场内随时间的变化。缺乏一致的脱落限制了将潜在干预措施针对特定阳性动物/群体或畜群的能力。
