Tamminen Lena-Mari, Fransson Helena, Tråvén Madeleine, Aspán Anna, Alenius Stefan, Emanuelson Ulf, Dreimanis Ilmars, Törnquist Mats, Eriksson Erik
Section of Ruminant Medicine and Epidemiology, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Department of Microbiology, National Veterinary Institute, Uppsala, Sweden.
Vet Rec. 2018 May 5;182(18):516. doi: 10.1136/vr.104223. Epub 2018 Feb 14.
In 2007, human infections with a hypervirulent strain of verocytotoxin-producing O157:H7 increased in Sweden and especially in the Halland County. A connection between the cases and a local beef cattle farm with an on-farm abattoir and meat processing plant was established. In this observational study the control measures implemented on the infected farm and the dynamics of infection in the herd are described. In May 2008, when measures were initiated and animals put to pasture, the prevalence of positive individuals was 40 per cent and 18 carcasses out of 24 slaughtered animals were contaminated. During summer the monthly prevalence of positive carcasses varied between 8 and 41 per cent and at turning-in 22 out of 258 individually sampled animals were shedding the pathogen. After January 2009 no positive carcasses were found at slaughter and follow-up samplings of environment and individuals remained negative until the study period ended in May 2010. The results indicate that on-farm measures have potential to reduce the prevalence of the pathogen in a long-term perspective. However, as self-clearance cannot be excluded the effectiveness of the suggested measures needs to be confirmed.
2007年，瑞典，尤其是哈兰省，产志贺毒素的O157:H7超强毒株导致的人类感染病例有所增加。已证实这些病例与当地一家拥有农场屠宰场和肉类加工厂的肉牛养殖场之间存在关联。在这项观察性研究中，描述了在受感染农场实施的控制措施以及畜群中的感染动态。2008年5月，当开始采取措施并让动物放牧时，阳性个体的患病率为40%，在屠宰的24头动物中，有18具 carcasses 受到污染。夏季期间，阳性 carcasses 的月度患病率在8%至41%之间变化，在转入时，258只单独采样的动物中有22只排出病原体。2009年1月之后，屠宰时未发现阳性 carcasses，对环境和个体的后续采样在2010年5月研究期结束前一直呈阴性。结果表明，从长期来看，农场措施有可能降低病原体的患病率。然而，由于不能排除自我清除的可能性，建议措施的有效性需要得到证实。
