Vercruysse J, Claerebout E
Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B 9820 Merelbeke, Belgium.
Vet Parasitol. 2001 Jul 12;98(1-3):195-214. doi: 10.1016/s0304-4017(01)00431-9.
Helminth infections are an important cause of lost productivity in livestock world-wide, often necessitating anthelmintic treatment. However, a large part of the anthelmintics are used indiscriminately because the parasite levels are too low to justify treatment or because the treatments are not correctly programmed, resulting in undertreatment or overtreatment. The objective of this paper is to discuss possible thresholds for anthelmintic treatment of some of the more important helminth infections in livestock, i.e. gastrointestinal nematodes, lungworms and liver fluke, to promote a more appropriate use of anthelmintics. When possible, a distinction is made between therapeutic thresholds, production-based thresholds and preventive thresholds. A "therapeutic threshold" is intended to identify (an) animal(s) with parasite levels that necessitate immediate treatment. The therapeutic threshold is basically the diagnosis of clinical disease, and can be determined relatively easily for the parasites discussed in this paper. A "production-based threshold" is intended to measure the effects of sub-clinical parasitism on productivity parameters, such as weight gain and milk yield, before clinical disease occurs. Finally, a "preventive threshold" is meant to predict future infection levels, to enable the application of appropriate control measures.
蠕虫感染是导致全球牲畜生产力下降的一个重要原因，常常需要进行驱虫治疗。然而，很大一部分驱虫药被滥用，原因要么是寄生虫感染水平过低，进行治疗并不合理，要么是治疗方案安排不当，导致治疗不足或过度治疗。本文的目的是探讨对牲畜中一些较为重要的蠕虫感染（即胃肠线虫、肺线虫和肝片吸虫）进行驱虫治疗的可能阈值，以促进驱虫药的更合理使用。如有可能，区分了治疗阈值、基于生产的阈值和预防阈值。“治疗阈值”旨在识别寄生虫感染水平需要立即治疗的动物。治疗阈值基本上就是临床疾病的诊断，对于本文所讨论的寄生虫而言，相对容易确定。“基于生产的阈值”旨在衡量亚临床寄生虫感染在临床疾病出现之前对生产力参数（如体重增加和产奶量）的影响。最后，“预防阈值”旨在预测未来的感染水平，以便能够采取适当的控制措施。
