McAloon C I, McAloon C G, Tratalos J, O'Grady L, McGrath G, Guelbenzu M, Graham D A, O'Keeffe K, Barrett D J, More S J
Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin, D04 W6F6, Ireland.
Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin, D04 W6F6, Ireland.
J Dairy Sci. 2022 Jun;105(6):5410-5419. doi: 10.3168/jds.2021-21334. Epub 2022 Mar 26.
Mycoplasma bovis is a serious disease of cattle worldwide; mastitis, pneumonia, and arthritis are particularly important clinical presentations in dairy herds. Mycoplasma bovis was first identified in Ireland in 1994, and the reporting of Mycoplasma-associated disease has substantially increased over the last 5 years. Despite the presumed endemic nature of M. bovis in Ireland, there is a paucity of data on the prevalence of infection, and the effect of this disease on the dairy industry. The aim of this observational study was to estimate apparent herd prevalence for M. bovis in Irish dairy herds using routinely collected bulk milk surveillance samples and to assess risk factors for herd seropositivity. In autumn 2018, 1,500 herds out of the 16,858 herds that submitted bulk tank milk (BTM) samples to the Department of Agriculture testing laboratory for routine surveillance were randomly selected for further testing. A final data set of 1,313 sampled herds with a BTM ELISA result were used for the analysis. Testing was conducted using an indirect ELISA kit (ID Screen Mycoplasma bovis). Herd-level risk factors were used as explanatory variables to determine potential risk factors associated with positive herd status (reflecting past or current exposure to M. bovis). A total of 588 of the 1,313 BTM samples were positive to M. bovis, providing an apparent herd prevalence of 0.45 (95% CI: 0.42, 0.47) in Irish dairy herds in autumn 2018. Multivariable analysis was conducted using logistic regression. The final model identified herd size, the number of neighboring farms, in-degree and county as statistically significant risk factors for herd BTM seropositivity to M. bovis. The results suggest a high apparent herd prevalence of seropositivity to M. bovis, and evidence that M. bovis infection is now endemic in the Irish dairy sector. In addition, risk factors identified are closely aligned to what we would expect of an infectious disease. Awareness raising and education about this important disease is warranted given the widespread nature of exposure and likely infection in Irish herds. Further work on the validation of diagnostic tests for herd-level diagnosis should be undertaken as a matter of priority.
牛支原体是一种在全球范围内对牛群危害严重的疾病；乳腺炎、肺炎和关节炎是奶牛群中尤为重要的临床表现。牛支原体于1994年在爱尔兰首次被发现，在过去5年里，与支原体相关疾病的报告数量大幅增加。尽管牛支原体在爱尔兰被认为具有地方流行性，但关于感染率以及该疾病对乳制品行业影响的数据却很匮乏。这项观察性研究的目的是利用常规收集的散装牛奶监测样本估计爱尔兰奶牛群中牛支原体的表观畜群流行率，并评估畜群血清阳性的风险因素。2018年秋季，在向农业部检测实验室提交散装罐装牛奶（BTM）样本进行常规监测的16858个牛群中，随机选取了1500个牛群进行进一步检测。最终分析使用了1313个有BTM ELISA检测结果的抽样牛群的数据集。检测使用间接ELISA试剂盒（ID Screen Mycoplasma bovis）进行。畜群水平的风险因素被用作解释变量，以确定与阳性畜群状态（反映过去或当前接触牛支原体情况）相关的潜在风险因素。1313个BTM样本中共有588个对牛支原体呈阳性，2018年秋季爱尔兰奶牛群的表观畜群流行率为0.45（95%置信区间：0.42，0.47）。使用逻辑回归进行多变量分析。最终模型确定畜群规模、相邻农场数量、入度和郡县是畜群BTM对牛支原体血清阳性的统计学显著风险因素。结果表明牛支原体血清阳性的表观畜群流行率很高，且有证据表明牛支原体感染在爱尔兰乳制品行业已呈地方流行性。此外，所确定的风险因素与我们对传染病的预期密切相符。鉴于爱尔兰牛群中接触和可能感染的广泛程度，有必要提高对这种重要疾病的认识并开展相关教育。应优先开展进一步工作以验证用于畜群水平诊断的检测方法。
