Pons-Bordas C, Hazenberg A, Hernandez-Gonzalez A, Pool R V, Covelo P, Sánchez-Hermosin P, López A, Saavedra C, Fraija-Fernández N, Fernández M, Aznar F J
Marine Zoology Unit, Science Park, University of Valencia, PO Box 22085, 46071Valencia, Spain.
Spanish Institute of Oceanography, Oceanographic Center of Vigo, PO Box 1552, 36390Vigo (Pontevedra), Spain.
J Helminthol. 2020 Feb 26;94:e127. doi: 10.1017/S0022149X20000115.
Species of Anisakis typically infect the stomach of cetaceans worldwide, often causing ulcerative lesions that may compromise the host's health. These nematodes also cause anisakiasis or allergic reactions in humans. To assess the risks of this emerging zoonosis, data on long-term changes in Anisakis infections in cetaceans are necessary. Here, we compare the prevalence and severity of ulcerative lesions caused by Anisakis spp. in five cetacean species stranded along the north-west Spanish coast in 2017-2018 with published data from 1991-1996. Open ulcers were found in 32/43 short-beaked common dolphins, Delphinus delphis; 3/5 striped dolphins, Stenella coeruleoalba; 1/7 bottlenose dolphins, Tursiops truncatus; and 1/3 harbour porpoises, Phocoena phocoena meridionalis; a single individual of long-finned pilot whale, Globicephala melas, was found uninfected. In common dolphins, the mean abundance of open ulcers per host was 1.1 (95% confidence interval: 0.8-1.3), with a maximum diameter (mean ± standard deviation) of 25.4 ± 16.9 mm. Stomachs with scars or extensive fibrosis putatively associated with Anisakis were detected in 14 and five animals, respectively. A molecular analysis based on the mitochondrial cytochrome c oxidase II gene using 18 worms from three cetacean species revealed single or mixed infections of Anisakis simplex sensu stricto and Anisakis pegreffii. Compared with the period 1991-1996, we found a strong increase of prevalence, abundance and extension of ulcerative lesions in most cetacean species. Anisakis populations could have increased in the study area over the last decades, although we cannot rule out that a higher environmental stress has also boosted the pathological effects of these parasites.
异尖线虫属的物种通常感染全球范围内鲸类动物的胃部，常常引发溃疡性病变，这可能会损害宿主的健康。这些线虫还会在人类身上引发异尖线虫病或过敏反应。为了评估这种新出现的人畜共患病的风险，有必要获取鲸类动物体内异尖线虫感染长期变化的数据。在此，我们将2017 - 2018年在西班牙西北海岸搁浅的五种鲸类动物中由异尖线虫属引发的溃疡性病变的患病率和严重程度与1991 - 1996年公布的数据进行了比较。在43只短吻普通海豚（瓶鼻海豚）中有32只发现了开放性溃疡；5只条纹海豚中有3只；7只宽吻海豚中有1只；3只港湾鼠海豚中有1只；发现1只长鳍领航鲸未被感染。在普通海豚中，每只宿主开放性溃疡的平均丰度为1.1（95%置信区间：0.8 - 1.3），最大直径（平均值±标准差）为25.4±16.9毫米。分别在14只和5只动物中检测到了推测与异尖线虫有关的有疤痕或广泛纤维化的胃部。基于线粒体细胞色素c氧化酶II基因对来自三种鲸类动物的18条线虫进行的分子分析显示，存在单纯异尖线虫和派氏异尖线虫的单一感染或混合感染。与1991 - 1996年期间相比，我们发现大多数鲸类动物中溃疡性病变的患病率、丰度和范围都有显著增加。在过去几十年里，研究区域内异尖线虫的数量可能有所增加，尽管我们不能排除更高的环境压力也增强了这些寄生虫的病理效应。
