Bitsch V, Rønsholt L
Department of Infectious Cattle Diseases, Danish Dairy Board, Aarhus, Denmark.
Vet Clin North Am Food Anim Pract. 1995 Nov;11(3):627-40. doi: 10.1016/s0749-0720(15)30471-0.
Successful control and eradication of BVDV infection presuppose sufficient knowledge of its epidemiology, particularly sources of infection and ways of transmission. Furthermore, it is crucial to have tests that can be trusted to give the true infection of individual animals and indicate the infection status of herds. PI animals are considered to be the main source of infection. In preliminary experiments in Denmark, it was found that eradication in herds could be based on the identification and removal of PI animals. Actual and possible means of herd-to-herd transmission of importance for infection control are reviewed. Special attention is paid to the possibility of airborne transmission, which must be anticipated in areas with high BVDV prevalence and a high cattle population density. BVDV control programs have been initiated only in the Scandinavian countries including Finland, where the occurrence of BVDV varies from a very low prevalence in Finland to a very high prevalence in Denmark. The BVDV programs in Finland, Norway, and Sweden are basically the same. The primary aim of each is the identification of the herds free from infection and prevention of introduction of the infection to these herds. A secondary aim is to reduce gradually the number of infected herds. In Denmark, which has a high prevalence of BVDV, the program is a combined control and eradication program, and different tests are used. The control programs in Scandinavian countries and the eradication program in Denmark are described together with the tests involved. With respect to control, special emphasis is given to herd tests applied to bulk tank milk or to specially selected blood samples to indicate the infection status of individual herds. The initial bulk tank milk testings were the main basis for the conclusions that in Finland, Norway, and Denmark approximately 1%, 9%, and 39% of the dairy herds, respectively, seemed to have PI animals. With respect to eradication, an ELISA developed in Denmark for demonstration of virus in blood has proved to be extremely reliable for identification of PI animals. The BVDV programs are generally voluntary, although in Norway, where BVD is a notifiable disease, restrictions have been placed on infected herds to prevent a further spread of the infection. The annual losses in Denmark from BVDV have been calculated to be approximately 100 million DKr (17 million dollars), whereas the total costs of the control and eradication program for a 3-year period including testing of trade animals are estimated to be approximately 160 million DKr (27 million dollars).
成功控制和根除牛病毒性腹泻病毒（BVDV）感染，前提是要充分了解其流行病学，尤其是感染源和传播途径。此外，拥有可信赖的检测方法至关重要，这些检测方法要能准确判断个体动物的真实感染情况，并表明畜群的感染状况。持续性感染（PI）动物被认为是主要感染源。在丹麦的初步实验中发现，畜群的根除可基于对PI动物的识别和清除。本文综述了对感染控制具有重要意义的畜群间实际和可能的传播途径。特别关注了空气传播的可能性，在BVDV流行率高且牛群密度大的地区必须考虑到这一点。BVDV控制计划仅在包括芬兰在内的斯堪的纳维亚国家启动，BVDV的发生率在芬兰非常低，而在丹麦则非常高。芬兰、挪威和瑞典的BVDV计划基本相同。每个计划的主要目标是识别无感染的畜群，并防止感染传入这些畜群。次要目标是逐步减少感染畜群的数量。在BVDV流行率高的丹麦，该计划是一个综合控制和根除计划，并使用了不同的检测方法。本文介绍了斯堪的纳维亚国家的控制计划和丹麦的根除计划以及所涉及的检测方法。关于控制，特别强调了对大罐牛奶或特别挑选的血样进行畜群检测，以表明个体畜群的感染状况。最初的大罐牛奶检测是得出以下结论的主要依据：在芬兰、挪威和丹麦，分别约有1%、9%和39%的奶牛群似乎有PI动物。关于根除，丹麦开发的一种用于检测血液中病毒的酶联免疫吸附测定（ELISA）已被证明在识别PI动物方面极其可靠。BVDV计划通常是自愿性的，不过在挪威，BVD是一种应通报的疾病，对感染畜群实施了限制，以防止感染进一步传播。据计算，丹麦每年因BVDV造成的损失约为1亿丹麦克朗（1700万美元），而包括对贸易动物进行检测在内的为期3年的控制和根除计划的总成本估计约为1.6亿丹麦克朗（2700万美元）。
