Myxobolus cerebralis, the myxozoan parasite responsible for whirling disease in salmonids, was first introduced into the United States in 1958 and has since spread across the country, causing severe declines in wild trout populations in the intermountain western United States. The recent detection of the parasite in Alaska is further evidence of the species' capability to invade and colonize new habitat. This study qualitatively assesses the risk of further spread and establishment of M. cerebralis in Alaska. We examine four potential routes of dissemination: human movement of fish, natural dispersal by salmonid predators and straying salmon, recreational activities, and commercial seafood processing. Potential for establishment was evaluated by examining water temperatures, spatial and temporal overlap of hosts, and the distribution and genetic composition of the oligochaete host, Tubifex tubifex. The most likely pathway of M. cerebralis transport in Alaska is human movement of fish by stocking. The extent of M. cerebralis infection in Alaskan salmonid populations is unknown, but if the parasite becomes dispersed, conditions are appropriate for establishment and propagation of the parasite life cycle in areas of south-central Alaska. The probability of further establishment is greatest in Ship Creek, where the abundance of susceptible T. tubifex, the presence of susceptible rainbow trout Oncorhynchus mykiss, and the proximity of this system to the known area of infection make conditions particularly suitable for spread of the parasite.

中文翻译：

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阿拉斯加非本地鲑鱼寄生虫Myxobolus brainisin的传播潜力

Myxobolus brainis 是一种导致鲑鱼旋转病的粘液动物寄生虫，于 1958 年首次被引入美国，此后传播到全国，导致美国西部山间地区的野生鳟鱼种群严重下降。最近在阿拉斯加发现的寄生虫进一步证明了该物种有能力入侵和殖民新的栖息地。本研究定性地评估了在阿拉斯加进一步传播和建立大脑分支杆菌的风险。我们研究了四种潜在的传播途径：鱼类的人类运动、鲑鱼捕食者和流浪鲑鱼的自然传播、娱乐活动和商业海鲜加工。通过检查水温、宿主的空间和时间重叠来评估建立的潜力，寡毛纲宿主 Tubifex tubifex 的分布和遗传组成。在阿拉斯加最可能的 M. brainis 运输途径是人类通过放养来移动鱼类。阿拉斯加鲑鱼种群中大脑分枝杆菌的感染程度尚不清楚，但如果寄生虫分散，则条件适合于阿拉斯加中南部地区寄生虫生命周期的建立和繁殖。Ship Creek 进一步建立的可能性最大，那里易感的 T. tubifex 丰富，易感的虹鳟 Oncorhynchus mykiss 的存在，以及该系统与已知感染区域的接近，使得条件特别适合寄生虫的传播. 阿拉斯加的大脑运输是人类通过放养鱼的运动。阿拉斯加鲑鱼种群中大脑分枝杆菌的感染程度尚不清楚，但如果寄生虫分散，则条件适合于阿拉斯加中南部地区寄生虫生命周期的建立和繁殖。Ship Creek 进一步建立的可能性最大，那里易感的 T. tubifex 丰富，易感的虹鳟 Oncorhynchus mykiss 的存在，以及该系统与已知感染区域的接近，使得条件特别适合寄生虫的传播. 阿拉斯加的大脑运输是人类通过放养鱼的运动。阿拉斯加鲑鱼种群中大脑分枝杆菌的感染程度尚不清楚，但如果寄生虫分散，则条件适合于阿拉斯加中南部地区寄生虫生命周期的建立和繁殖。Ship Creek 进一步建立的可能性最大，那里易感的 T. tubifex 丰富，易感的虹鳟 Oncorhynchus mykiss 的存在，以及该系统与已知感染区域的接近，使得条件特别适合寄生虫的传播. 条件适合于阿拉斯加中南部地区寄生虫生命周期的建立和传播。Ship Creek 进一步建立的可能性最大，那里易感的 T. tubifex 丰富，易感的虹鳟 Oncorhynchus mykiss 的存在，以及该系统与已知感染区域的接近，使得条件特别适合寄生虫的传播. 条件适合于阿拉斯加中南部地区寄生虫生命周期的建立和传播。Ship Creek 进一步建立的可能性最大，那里易感的 T. tubifex 丰富，易感的虹鳟 Oncorhynchus mykiss 的存在，以及该系统与已知感染区域的接近，使得条件特别适合寄生虫的传播.