Pillars R B, Grooms D L, Woltanski J A, Blair E
Center for Comparative Epidemiology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
Prev Vet Med. 2009 Jun 1;89(3-4):191-6. doi: 10.1016/j.prevetmed.2009.02.022. Epub 2009 Apr 8.
A cross-sectional, stratified random survey of Michigan dairy herds was conducted to estimate the prevalence of herds infected with Mycobacterium avium paratuberculosis (MAP), the causative agent of Johne's disease, in Michigan using targeted environmental sampling. One pooled sample each from the primary manure storage area and a high-traffic common cow area from each herd was collected and cultured for MAP using the ESP culture system II. A herd was classified as positive if at least one sample was culture positive for MAP. State, agricultural district, and herd size stratum prevalence were calculated. Information on past MAP testing and cattle purchase history was collected, and logistic regression was performed to determine their importance to the MAP status of the herd. One hundred twenty-seven herds were contacted, and 94 agreed to participate in the study. The environment of 38 (40.4%) herds cultured positive for MAP. MAP was found in all herds (n = 15) with greater than 200 lactating cows. Herds that had tested for MAP or purchased cattle in the previous 5 years were 4.6 and 3.1 times, respectively, more likely to be infected than herds that had not. MAP continues to be prevalent on Michigan dairy farms, especially those with greater than 200 lactating cows. The environmental sampling protocol used in this study is an economically attractive alternative for monitoring herd level prevalence and the progress of Johne's disease control programs at the state or national level. Implementation of such a program would aid states in monitoring Johne's control program progress, and guide changes over time.
为了通过有针对性的环境采样来估计密歇根州感染副结核分枝杆菌（MAP）（约翰氏病的病原体）的奶牛场的患病率，对密歇根州的奶牛场进行了一项横断面分层随机调查。从每个牛群的主要粪便储存区和一个高流量的普通奶牛活动区各采集一个混合样本，并使用ESP培养系统II对其进行MAP培养。如果至少有一个样本MAP培养呈阳性，则该牛群被归类为阳性。计算了州、农业区和牛群规模分层的患病率。收集了过去MAP检测和牛只购买历史的信息，并进行了逻辑回归分析以确定它们对牛群MAP感染状况的重要性。联系了127个牛群，其中94个同意参与研究。38个（40.4%）牛群的环境样本MAP培养呈阳性。在所有拥有超过200头泌乳奶牛的牛群（n = 15）中都发现了MAP。在过去5年中进行过MAP检测或购买过牛只的牛群感染的可能性分别是未进行检测或购买的牛群的4.6倍和3.1倍。MAP在密歇根州的奶牛场中仍然很普遍，尤其是那些拥有超过200头泌乳奶牛的农场。本研究中使用的环境采样方案是一种经济上有吸引力的替代方法，可用于监测牛群层面的患病率以及州或国家层面约翰氏病控制计划的进展情况。实施这样一个计划将有助于各州监测约翰氏病控制计划的进展，并随着时间的推移指导相关变化。
