Bartley David J, Andrews Leigh, Melville Lynsey A, McBean David, Skuce Philip, Morrison Alison A
Disease Control, Moredun Research Institute, Penicuik, UK.
Vet Rec. 2021 Aug;189(3):e137. doi: 10.1002/vetr.137. Epub 2021 Feb 19.
The Barber's Pole worm, Haemonchus contortus is of major concern to sheep producers, particularly in the southern hemisphere. This nematode is also commonly found in many sheep flocks in Northern hemisphere countries but is generally not associated with acute clinical pathology. As with other nematode species, the pattern of disease is changing in the United Kingdom. Changes in management practices, climate, anthelmintic resistance prevalence and parasite adaptation are possible factors thought to be responsible for this.
In the present study, a combination of traditional applied parasitological and molecular species identification techniques were used to assess the capability of H. contortus infective larvae to over-winter on pasture and infect lambs in early spring.
Adult and inhibited H. contortus worms were identified in previously worm-free tracer lambs that had grazed contaminated pasture in late winter/early spring (February/March).
The study illustrated the benefit of using classical applied parasitology techniques in conjunction with molecular species identification methods to explore the epidemiology of gastro-intestinal nematodes of livestock. This study also demonstrated that larvae were able to survive over-winter, albeit in small numbers, and potentially contaminate pastures earlier than previously considered in northern regions of the UK.
捻转血矛线虫（Haemonchus contortus）是绵羊养殖者主要关注的对象，在南半球尤其如此。这种线虫在北半球国家的许多羊群中也很常见，但一般与急性临床病理学无关。与其他线虫种类一样，英国的疾病模式正在发生变化。管理方式的改变、气候、抗驱虫药的流行情况以及寄生虫的适应性被认为是可能导致这种情况的因素。
在本研究中，结合传统的应用寄生虫学和分子物种鉴定技术，评估捻转血矛线虫感染性幼虫在牧场上越冬并在早春感染羔羊的能力。
在冬末/早春（2月/3月）放牧于受污染牧场的先前未感染过寄生虫的示踪羔羊体内，发现了成年和处于抑制状态的捻转血矛线虫。
该研究说明了将经典的应用寄生虫学技术与分子物种鉴定方法结合起来用于探究家畜胃肠道线虫流行病学的益处。该研究还表明，幼虫能够越冬，尽管数量很少，并且可能比英国北部此前认为的时间更早地污染牧场。
