Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Institute of Nutritional Physiology 'Oskar Kellner', Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.
Int J Parasitol Drugs Drug Resist. 2023 Dec;23:1-9. doi: 10.1016/j.ijpddr.2023.07.003. Epub 2023 Jul 24.
Reports of Ascaridia galli in laying hens in Europe have increased since the ban on conventional battery cages in 2012. As this parasite is transmitted directly via the faecal-oral route by parasite eggs containing a larva, it is reasonable to assume that the escalating problem is related to the increased exposure now occurring in modern welfare-friendly cage-free housing systems. On many farms, A. galli reappears in subsequent flocks, even though the birds have no access to the outdoors, biosecurity is high and empty houses are cleaned and disinfected during downtime. Since the egg production cycle lasts only ≈80 weeks and recombinant antigen production for helminth vaccines has not yet been solved, the development of a vaccine seems to be an unrealistic option. Therefore, disrupting the life cycle of the parasite by other means, including the strategic use of dewormers, appears to be the key to controlling infection. Of concern is that only one class of anthelmintics is licenced for poultry in Europe and that are usually administered indiscriminately through the birds' drinking water and often too late when the parasite is already established. If current calendar-based parasite control strategies are not changed, there is a risk that resistance to anthelmintics may develop, as has already been demonstrated with nematodes in livestock. We insist that treatments can be more effective and the risk of developing drug resistance can be mitigated if we invest in a better understanding of A. galli responses to more prudent and judicious use of anthelmintics. This review identifies knowledge gaps and highlights aspects of sustainable parasite control that require further research to support commercial egg producers.
自 2012 年禁止传统的笼养方式以来，欧洲产蛋鸡中寄生蛔虫的报告有所增加。由于这种寄生虫是通过含有幼虫的寄生虫卵通过粪-口途径直接传播的，因此可以合理地假设，不断加剧的问题与现代福利友好型无笼饲养系统中日益增加的暴露有关。在许多农场，即使鸟类无法接触室外、生物安全措施很高且在停机期间空房都已清洁和消毒，寄生蛔虫仍会在后续鸡群中重新出现。由于产蛋周期仅持续 ≈80 周，并且尚未解决寄生虫疫苗的重组抗原生产问题，因此疫苗的开发似乎不太现实。因此，通过其他方式（包括驱虫剂的战略性使用）破坏寄生虫的生命周期，似乎是控制感染的关键。令人担忧的是，在欧洲，只有一类驱虫剂被许可用于家禽，而且通常通过鸟类的饮用水进行无差别给药，并且通常在寄生虫已经建立时给药太晚。如果不改变当前基于日历的寄生虫控制策略，就有可能像在牲畜中已经证明的那样，对驱虫剂产生抗药性。我们坚持认为，如果我们投资于更好地了解寄生蛔虫对更谨慎和明智地使用驱虫剂的反应，治疗可以更有效，并且可以减轻产生抗药性的风险。本综述确定了知识差距，并强调了需要进一步研究的可持续寄生虫控制方面，以支持商业蛋鸡生产者。
