Wildlife Ecology & Health group (WEH) and Servei d'Ecopatologia de Fauna Salvatge (SEFaS), Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Dipartimento di Scienze Veterinarie, Università di Torino, Torino, Italy.
Transbound Emerg Dis. 2021 Jul;68(4):2589-2594. doi: 10.1111/tbed.13865. Epub 2020 Oct 14.
Fasciola hepatica is a liver parasite of ruminants whose distribution is determined by its intermediate host, the freshwater snail Galba truncatula. In Europe, F. hepatica is mostly associated with lowlands. Infection from sympatric domestic reservoirs is rarely reported in wild mountain ungulates. This study explores F. hepatica in a multi-host system in a European alpine area. Serum samples (n = 1,209) from Pyrenean chamois (Rupicapra p. pyrenaica), European mouflon (Ovis aries musimon), domestic sheep (Ovis aries) and domestic cattle (Bos taurus) were collected in the National Game Reserve of Freser-Setcases (NGRFS) in Catalonia, Northeastern Spain, from 2008 to 2019, and tested for antibodies against F. hepatica. During the same period, the livers of 214 chamois hunted in the NGRFS were inspected for F. hepatica and associated pathological changes. Finally, 907 freshwater snails were collected in summer 2016 between 1559 and 2,224 metres above sea level (asl) in the NGRFS, and F. hepatica DNA sought by PCR. Antibodies against F. hepatica were detected in all four species, with a higher prevalence in cattle and sheep than in chamois. Fasciola hepatica and hepatic lesions were concurrently observed in 13/214 of the chamois livers inspected (6.1%, CI95 2.9%-9.3%). Fasciola hepatica DNA was detected in one out of the 907 snails (0.1%, Cl95 0.1% - 0.3%; Ct value 33.3) and collected at 2054 m asl. Fasciola hepatica was consistently detected in a high mountain multi-host system, suggesting that its life cycle is completed and that it occurs endemically at the highest elevation reported in Europe. Transhumant livestock are the likely source in this alpine ecosystem, which according to rare occurrence of F. hepatica DNA in G. truncatula is still a suboptimal habitat for F. hepatica life cycle. Studying parasites at their highest distribution range can be useful to monitor climate change in seasonal mountain environments.
肝片形吸虫是一种寄生在反刍动物肝脏的寄生虫，其分布范围由其中间宿主——淡水蜗牛 Galba truncatula 决定。在欧洲，肝片形吸虫主要与低地有关。在野生山地有蹄类动物中，很少有报道称其与同域的家养动物有关。本研究在欧洲阿尔卑斯地区的多宿主系统中探索了肝片形吸虫。2008 年至 2019 年，在西班牙东北部加泰罗尼亚的弗雷泽-塞卡斯国家猎物保护区（NGRFS），从比利牛斯野山羊（Rupicapra p. pyrenaica）、欧洲盘羊（Ovis aries musimon）、家养绵羊（Ovis aries）和家养牛（Bos taurus）中采集了 1209 份血清样本，并检测了针对肝片形吸虫的抗体。同期，检查了 NGRFS 中 214 只被猎杀的野山羊的肝脏是否存在肝片形吸虫和相关病变。最后，2016 年夏季，在 NGRFS 海拔 1559 至 2224 米之间共采集了 907 只淡水蜗牛，通过 PCR 寻找肝片形吸虫的 DNA。在这四个物种中都检测到了针对肝片形吸虫的抗体，牛和绵羊的流行率高于野山羊。在检查的 214 只野山羊肝脏中，有 13 只（6.1%，95%置信区间 2.9%-9.3%）同时存在肝片形吸虫和肝脏病变。在 907 只蜗牛中检测到一只蜗牛携带肝片形吸虫 DNA（0.1%，95%置信区间 0.1% - 0.3%；Ct 值 33.3），采集于海拔 2054 米处。在高山多宿主系统中，肝片形吸虫一直被检测到，这表明其生命周期已经完成，并且在欧洲报道的最高海拔处存在地方性流行。迁徙牲畜可能是该高山生态系统中的传染源，根据 Galba truncatula 中肝片形吸虫 DNA 的罕见出现情况，它仍然是肝片形吸虫生命周期的次优栖息地。在季节性山地环境中，研究寄生虫的最高分布范围有助于监测气候变化。
