Byrne Andrew W, Graham Jordon, McConville James, Milne Georgina, McDowell Stanley, Hanna Robert E B, Guelbenzu-Gonzalo Maria
Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, UK.
School of Biological Sciences, Queens University Belfast, Belfast, UK.
Parasitol Res. 2018 Sep;117(9):2725-2733. doi: 10.1007/s00436-018-5961-0. Epub 2018 Jun 14.
Bovine fasciolosis, caused by the infection of the trematode parasite Fasciola hepatica, remains a problem in dairy herds causing significant production losses. In this study, bulk milk tank samples were utilised to generate a comprehensive survey of the variation in liver fluke exposure over the four seasons of 2016 in Northern Ireland (NI). Samples were tested using an antibody ELISA test; within-herd prevalence levels were categorised relative to sample-to-positive ratio (S/P%). Overall, 1494 herds (~ 50% of all active dairy farms in NI) were sampled. In total, 5750 samples were tested with 91% of herds having a sample result for each season. The proportion of herds with evidence of liver fluke exposure was very high across the year, with 93.03% of all bulk milk samples having some indication of liver fluke antibody presence. A high proportion of samples (2187/5750; 38.03%) fell within the highest infection class (indicating high within-herd prevalence). There was significant seasonal variation in the mean S/P%. A multivariable random effect ordinal logit model suggested that the greatest probability of being in a higher infection class was in winter, whilst the lowest was recorded during summer. There was a significant negative association between increasing herd liver fluke infection class and herd size. Furthermore, there was significant variation in infection levels across regions of Northern Ireland, with higher infection levels in northern administrative areas. This study demonstrates the very high liver fluke exposure in this region of Europe, and that risk is not equally distributed spatially or across seasons in dairy herds.
由吸虫寄生虫肝片吸虫感染引起的牛片形吸虫病，仍然是奶牛群中的一个问题，会造成重大的生产损失。在本研究中，利用储奶罐样本对北爱尔兰（NI）2016年四个季节肝吸虫暴露情况的变化进行了全面调查。使用抗体ELISA检测对样本进行检测；根据样本与阳性比例（S/P%）对牛群内的流行水平进行分类。总体而言，对1494个牛群（约占NI所有活跃奶牛场的50%）进行了采样。总共检测了5750个样本，91%的牛群每个季节都有样本检测结果。全年有肝吸虫暴露迹象的牛群比例非常高，所有储奶罐样本中有93.03%显示有肝吸虫抗体存在的迹象。很大一部分样本（2187/5750；38.03%）属于最高感染类别（表明牛群内流行率高）。平均S/P%存在显著的季节变化。一个多变量随机效应有序logit模型表明，处于较高感染类别的最大概率出现在冬季，而最低概率出现在夏季。牛群肝吸虫感染类别增加与牛群规模之间存在显著的负相关。此外，北爱尔兰各地区的感染水平存在显著差异，北部行政区的感染水平较高。这项研究表明，在欧洲这个地区，肝吸虫暴露率非常高，而且奶牛群中的风险在空间上或不同季节的分布并不均匀。
