Yoshida Kyoko, Saito Masahiko, Sumiyoshi Akiko, Makino Hiroki, Tashiro Michiyo, Ichikawa-Seki Madoka
Department of Infectious Diseases, Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22 Honkomagomge, Bunkyo, Tokyo, 113-8677, Japan.
Department of General Medicine, Iwate Prefectural Central Hospital, 1-4-1 Ueda, Morioka, Iwate, 020-0066, Japan.
J Infect Chemother. 2025 Oct;31(10):102815. doi: 10.1016/j.jiac.2025.102815. Epub 2025 Sep 22.
Diphyllobothriosis is a tapeworm infection and is associated with the consumption of raw or undercooked fish. Among causative pathogens of human tapeworm infection, Dibothriocephalus nihonkaiensis is the second most prevalent species, contributing to over 2000 cases of human infection annually. Although D. nihonkaiensis is primarily distributed in the northern Pacific region, several cases have recently been reported from other parts of the world, including the United States. As there is a concern regarding the further spread of D. nihonkaiensis infection, accurate diagnosis and understanding related complications is essential. Although Dibothriocephalus latus, one of the major species involved in human diphyllobothriasis, is widely recognized to occasionally accompany vitamin B deficiency, to the best of our knowledge, a case of D. nihonkaiensis with decreased vitamin B level has not been previously reported. However, the issue of vitamin B12 deficiency caused by tapeworms should be discussed carefully because the two species were not separated before 1986. We herein report the first case of molecularly proven D. nihonkaiensis infection in Japan associated with vitamin B deficiency. The case was a 19-year-old male without any significant past history. The patient presented with tapeworm excretion at 2 months following raw trout fish consumption. At the initial visit, his laboratory data showed a slightly decreased vitamin B level; however, anemia was not noted. Two months later, his vitamin B level further decreased; however, it spontaneously resolved following anthelmintic treatment. This case provides valuable insights into the clinical picture of D. nihonkaiensis infection.
阔节裂头绦虫病是一种由绦虫感染引起的疾病，与食用生的或未煮熟的鱼类有关。在人类绦虫感染的病原体中，日本阔节裂头绦虫是第二常见的物种，每年导致超过2000例人类感染。虽然日本阔节裂头绦虫主要分布在北太平洋地区，但最近在世界其他地区，包括美国，也报告了几例病例。由于担心日本阔节裂头绦虫感染的进一步传播，准确的诊断和了解相关并发症至关重要。虽然人类阔节裂头绦虫病的主要病原体之一——阔节裂头绦虫，普遍被认为偶尔会伴有维生素B缺乏，但据我们所知，此前尚未报告过维生素B水平降低的日本阔节裂头绦虫病例。然而，由于这两个物种在1986年之前没有被区分开来，绦虫引起维生素B12缺乏的问题应该仔细讨论。我们在此报告日本首例经分子证实的与维生素B缺乏相关的日本阔节裂头绦虫感染病例。该病例为一名19岁男性，既往无重大病史。患者在食用生鳟鱼2个月后出现绦虫排出。初诊时，他的实验室数据显示维生素B水平略有下降；然而，未发现贫血。两个月后，他的维生素B水平进一步下降；然而，驱虫治疗后自发恢复。该病例为日本阔节裂头绦虫感染的临床表现提供了有价值的见解。
