García-Dios David, Díaz Pablo, Remesar Susana, Viña Miguel, Martínez-Calabuig Néstor, Saldaña Ana, Díez-Baños Pablo, Panadero Rosario, Morrondo Patrocinio, López Ceferino Manuel
Faculty of Veterinary Sciences, Universidade de Santiago de Compostela, Investigación en Sanidad Animal: Galicia (Grupo INVESAGA), Lugo, Spain.
IBADER- Instituto de Biodiversidade Agraria e Desenvolvemento Rural, Lugo, Spain.
Ir Vet J. 2024 Nov 26;77(1):21. doi: 10.1186/s13620-024-00283-y.
Paramphistomids are ruminal trematodes that cause important losses in tropical and subtropical regions. However, their presence in Europe has increased significantly in recent decades. In northwestern Spain, this trend has been confirmed in cattle, but data in sheep are scarce and not updated. Moreover, the paramphistomid species affecting sheep in the area have never been molecularly identified. To evaluate the prevalence of paramphistomid infections in sheep from northwestern Spain, 826 faecal samples from 25 sheep farms were collected and analysed via coproscopic techniques. In addition, the rumens of 85 roe deer from the same area were examined to detect adult paramphistomids. The species present were molecularly identified. Multivariate analyses for identifying the risk factors affecting the prevalence and egg shedding of rumen flukes were also performed.
Overall, 14% of the animals and 44% of the flocks were positive; the mean egg count was 20.5 eggs per gram of faeces. In contrast, no adult paramphistomids were found in roe deer. Older sheep, those from farms located in the central climatic area, without water throughs available on pastures and using their own manure to fertilize, were considered significantly more susceptible to infection with paramphistomids. With respect to egg shedding, animals from 37 to 72 months of age, farms under semiextensive management, and those coinfected with Fasciola hepatica presented significantly greater egg counts. Molecular identification revealed 100% similarity with Calicophoron daubneyi sequences from other European and Mediterranean countries.
The present study confirms the increase in the prevalence of paramphistomid infections in sheep in the area with high dissemination of the parasite, as previously reported in cattle, and represents the first molecular identification of C. daubneyi in sheep from Spain. Our results demonstrate that special attention should be given to adult animals since they are the main carriers and are responsible for environmental contamination. In addition, detecting risk areas and applying effective control management measures such as the installation of watering points on pastures seems essential for limiting infections in livestock, especially in sheep, since they are susceptible to developing clinical paramphistomidosis at any time in their lives. The absence of adult flukes in roe deer suggests that they represent less suitable hosts for this trematode than cattle and sheep, although more robust studies monitoring the situation in sympatric areas with domestic ruminants are needed.
双口吸虫是瘤胃吸虫，在热带和亚热带地区造成重大损失。然而，近几十年来它们在欧洲的出现显著增加。在西班牙西北部，这一趋势在牛身上已得到证实，但绵羊方面的数据稀缺且未更新。此外，该地区影响绵羊的双口吸虫种类从未进行过分子鉴定。为评估西班牙西北部绵羊双口吸虫感染的流行情况，收集了来自25个养羊场的826份粪便样本，并通过粪便检查技术进行分析。此外，检查了同一地区85只狍的瘤胃，以检测成年双口吸虫。对存在的种类进行了分子鉴定。还进行了多变量分析，以确定影响瘤胃吸虫流行率和虫卵排泄的风险因素。
总体而言，14%的动物和44%的羊群呈阳性；平均每克粪便虫卵数为20.5个。相比之下，在狍中未发现成年双口吸虫。年龄较大的绵羊、来自中部气候区农场的绵羊、牧场没有饮水槽且使用自身粪便施肥的绵羊，被认为感染双口吸虫的易感性显著更高。关于虫卵排泄，37至72月龄的动物、半粗放管理的农场以及同时感染肝片吸虫的动物，其虫卵数显著更多。分子鉴定显示与来自其他欧洲和地中海国家的道氏杯殖吸虫序列有100%的相似性。
本研究证实了该地区绵羊双口吸虫感染流行率的上升，寄生虫传播广泛，如先前在牛身上所报道的那样，并且代表了西班牙绵羊道氏杯殖吸虫的首次分子鉴定。我们的结果表明，应特别关注成年动物，因为它们是主要携带者，并且造成环境污染。此外，检测风险区域并采取有效的控制管理措施，如在牧场安装饮水点，对于限制家畜尤其是绵羊的感染似乎至关重要，因为它们在生命中的任何时候都易患临床双口吸虫病。狍中未发现成年吸虫表明，与牛和绵羊相比，它们作为这种吸虫的宿主不太合适，尽管需要更有力的研究来监测与家养反刍动物同域地区的情况。
