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Case Reports
. 2022 Mar 15;61(6):821-825.
doi: 10.2169/internalmedicine.8012-21. Epub 2021 Aug 31.

Trichuris trichiura Incidentally Detected by Colonoscopy and Identified by a Genetic Analysis

Yuto Ishizaki  1 , Kazumasa Kawashima  1 , Naohiko Gunji  1 , Michio Onizawa  1 , Takuto Hikichi  2 , Mitsuko Hasegawa  3   4 , Hiromasa Ohira  1
Affiliations
Case Reports

Trichuris trichiura Incidentally Detected by Colonoscopy and Identified by a Genetic Analysis

Yuto Ishizaki et al. Intern Med. .

Abstract

Although trichuriasis, a zoonotic disease, has recently become rare in Japan due to improved environmental hygiene, we herein report a 79-year-old man in whom a worm was incidentally found in the ascending colon during colonoscopy for positive fecal occult blood and was endoscopically removed. A genetic analysis identified the worm as Trichuris trichiura possessing mixed sequences from non-human primate and human origins. Despite controversy regarding Trichuris trichiura infection originating from Japanese macaques, according to some studies, it originates primarily from humans. This report suggests the efficacy of a genetic analysis for identifying infection sources.

Keywords: Trichuris trichiura; colonoscopy; genetic analysis; trichuriasis; zoonosis.

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Conflict of interest statement

The authors state that they have no Conflict of Interest (COI).

Figures

Figure 1.
Figure 1.
A white worm, approximately 10 mm in diameter, had penetrated the colon mucosa and was active in the ascending colon.
Figure 2.
Figure 2.
Histological specimen of the nematode (Hematoxylin and Eosin staining). (a) The marked areas are shown enlarged in b (dotted line boxed area) and c (solid line boxed area). (b) A series of basophilic cells (stichosomes) observed in the anterior part of the worm body. (c) Numerous eggs that were found at the posterior end of the worm body and the plug-like structure observed in the eggs.
Figure 3.
Figure 3.
Direct sequencing results of the 18S ribosomal RNA of the removed nematode from the patient. Only the 1,318th nucleotide sequence contained a guanine (G) of human origin (arrow). A: adenine, C: cytosine, T: thymine
See this image and copyright information in PMC

References

    1. World Health Organization. Guideline: preventive chemotherapy to control soil-transmitted helminth infections in at-risk groups [Internet]. 2017 [cited 2021 Apr 10]. Available from: http://apps.who.int/iris/bitstream/10665/258983/1/9789241550116-eng.pdf?... - PubMed
    1. Hasegawa M, Pilotte N, Kikuchi M, et al. . What does soil-transmitted helminth elimination look like? Results from a targeted molecular detection survey in Japan. Parasit Vectors 13: 1-11, 2020. - PMC - PubMed
    1. Arizono N, Yamada M, Tegoshi T, Onishi K. Molecular identification of oesophagostomum and trichuris eggs isolated from wild Japanese macaques. Korean J Parasitol 50: 253-257, 2012. - PMC - PubMed
    1. Wang DD, Wang XL, Wang XL, Wang S, An CL. Trichuriasis diagnosed by colonoscopy: case report and review of the literature spanning 22 years in mainland China. Int J Infect Dis 17: e1073-e1075, 2013. - PubMed
    1. Kado K, Naka H, Kiyose H, Sugiyama E, Shinonaga S. [Recent prevalence of intestinal parasites in the inhabitants of Tokyo and neighboring areas]. Kansenshogaku Zasshi (J Jpn Assoc Infect Dis) 60: 1317-1323, 1986. (in Japanese). - PubMed

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