Suzuki J, Murata R, Sadamasu K, Araki J
Division of Clinical Microbiology, Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Tokyo, Japan.
J Helminthol. 2010 Dec;84(4):434-40. doi: 10.1017/S0022149X10000155. Epub 2010 Mar 25.
We investigated the risk of diphyllobothriasis from ingestion of wild Pacific salmon in Japan by surveying Diphyllobothrium plerocercoids in 182 salmon samples obtained from Japan. The plerocercoids were not detected in chum salmon (Oncorhynchus keta) (0/26), called Akizake in Japan, caught between September and November. However, the detection rate of plerocercoids in chum salmon, called Tokishirazu in Japan, caught between early April and June, was 51.1% (24/47) with an average of two plerocercoid larvae per fish. The detection rates of cherry salmon (Oncorhynchus masou) and pink salmon (Oncorhynchus gorbuscha) were 12.2% (10/82) and 18.5% (5/27), respectively, and the average number of plerocercoids per fish was 0.45 (37 larvae/82 fishes) and 0.22 larvae (6 larvae/27 fishes), respectively. Plerocercoids isolated from O. keta and O. masou were identified as Diphyllobothrium nihonkaiense on the basis of molecular analysis of the cox1 and nad3 genes. Moreover, four tapeworms (three from O. keta and one from O. masou) were obtained by infecting golden hamsters with plerocercoids. The morphological features of these tapeworms were similar to those of D. nihonkaiense isolated from humans. Therefore, we think that O. keta and not O. masou is the most important source of plerocercoid infections in Japan.
我们通过对从日本采集的182份鲑鱼样本中的阔节裂头绦虫裂头蚴进行调查，研究了在日本因食用野生太平洋鲑鱼而感染阔节裂头绦虫病的风险。在9月至11月捕获的被称为秋鲑（Oncorhynchus keta）（日语为アキザケ）的鲑鱼样本中未检测到裂头蚴（0/26）。然而，在4月初至6月捕获的被称为トキシラズ的鲑鱼样本中，裂头蚴的检出率为51.1%（24/47），平均每条鱼有两条裂头蚴幼虫。樱鳟（Oncorhynchus masou）和细鳞大麻哈鱼（Oncorhynchus gorbuscha）的检出率分别为12.2%（10/82）和18.5%（5/27），每条鱼的裂头蚴平均数量分别为0.45（37条幼虫/82条鱼）和0.22条幼虫（6条幼虫/27条鱼）。基于cox1和nad3基因的分子分析，从秋鲑和樱鳟中分离出的裂头蚴被鉴定为日本阔节裂头绦虫。此外，通过用裂头蚴感染金黄仓鼠获得了4条绦虫（3条来自秋鲑，1条来自樱鳟）。这些绦虫的形态特征与从人体分离出的日本阔节裂头绦虫相似。因此，我们认为秋鲑而非樱鳟是日本裂头蚴感染的最重要来源。
