Department of Large Animal Sciences, Faculty of Life Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870 Frederiksberg C, Denmark.
Vet Microbiol. 2012 Jun 15;157(3-4):253-63. doi: 10.1016/j.vetmic.2011.12.019. Epub 2011 Dec 22.
Presence of Mycobacterium avium subsp. paratuberculosis (MAP) in milk for human consumption is a concern due to its possible relationship with Crohn's disease in humans. Pasteurization effectively reduces the MAP load by four to five logs, but the efficacy depends on the MAP concentration, which depends on the prevalence among contributing herds and individuals. Considerable variation of MAP in bulk tank milk (BTM) and individual cow's milk (IM) is reported, but factors associated with MAP occurrence in milk at farm level have not been described. This study systematically reviewed published studies aiming at estimating the occurrence of MAP in on-farm BTM and IM by meta-analysis. A total of 692 articles were identified through electronic databases and initially screened using title and abstract. The quality of the 61 potentially relevant articles was assessed using full text and 31 articles were eventually included in the meta-analysis. The apparent prevalence (AP) of MAP in BTM and IM on farm were summarized in relation to strata defined by the test used to identify MAP and the infection status of the herds/animals. There was considerable inconsistency in the reporting, resulting in missing information potentially explaining the dispersion in the estimated AP. The overall AP and 95% confidence intervals based on PCR and culture of MAP were summarized to 0.10 (0.04-0.22) in BTM and 0.20 (0.12-0.32) in IM. Quantifying the MAP load in test-positive milk samples was not possible because very few articles provided quantitative information on individual samples.
人消费的牛奶中存在鸟分枝杆菌副结核亚种（MAP）令人担忧，因为它可能与人克罗恩病有关。巴氏杀菌可有效将 MAP 负荷减少四到五个对数，但功效取决于 MAP 浓度，而 MAP 浓度取决于供奶畜群和个体的流行率。据报道，大量牛奶（BTM）和个体奶牛奶（IM）中的 MAP 存在相当大的差异，但尚未描述与农场水平牛奶中 MAP 发生相关的因素。本研究通过荟萃分析系统综述了已发表的研究，旨在估计农场 BTM 和 IM 中 MAP 的发生情况。通过电子数据库共确定了 692 篇文章，并通过标题和摘要进行了初步筛选。使用全文评估了 61 篇可能相关文章的质量，最终有 31 篇文章纳入荟萃分析。根据用于鉴定 MAP 的检测方法和畜群/动物的感染状态，总结了 BTM 和 IM 中 MAP 的明显流行率（AP）。由于报告不一致，导致潜在的解释估计 AP 离散性的信息缺失。基于 MAP 的 PCR 和培养的总体 AP 和 95%置信区间总结为 BTM 中 0.10（0.04-0.22）和 IM 中 0.20（0.12-0.32）。由于很少有文章提供关于个体样本的定量信息，因此无法对阳性测试牛奶样本中的 MAP 负荷进行量化。
