The present study was performed to describe 2 human cases infected by the horsehair worm, Parachordodes sp., in Japan. Two gordiid worms were collected in the vomit and excreta of an 80-year-old woman in November 2009 in Kyoto city, and in the mouth of 1-year-old boy in December 2009 in Nara city, Japan, respectively. Both worms were males having bifurcated posterior ends and male gonads in cross sectional specimens. They were identified as Parachordodes sp. (Nematomorpha: Chordodidae) based on the characteristic morphologies of cross sections and areoles in the cuticle. DNA analysis on 18S rRNA partial sequence arrangements was also carried out and both worms were assumed to be close to the genus Paragordionus based on tree analysis, and far from Gordius sp. which has already been reported in humans in Japan. DNA sequencing of the Parachordodes worm does not appear on the database; therefore, more information on the gene sequences of the genus Parachordodes from humans, animals, or intermediates is required.
Aged, 80 and over ; Animals ; Cluster Analysis ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Female ; Helminthiasis/*diagnosis/*parasitology/pathology ; Helminths/anatomy & histology/classification/genetics/*isolation & purification ; Humans ; Infant ; Japan ; Male ; Microscopy ; Phylogeny ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA

The present study investigated characteristics of 24 parasite infection cases detected during colonoscopy in a regional hospital from January 2001 to December 2008. Sixteen patients were confirmed with Trichuris trichiura infection, 6 patients were with Ascaris lumbricoides infection, 1 patient with Enterobius vermicularis infection, and 1 patient with Anisakis infection. Among them, 7 patients (43.8%) were asymptomatic. Colonoscopy findings were normal in 18 patients (75.0%). Among the patients with T. trichiura infection, colonoscopy showed several erosions in 2 patients (8.3%) and non-specific inflammation of the affected segment of the colon in 3 patients (12.5%). In 1 patient with anisakiasis, colonoscopy revealed a markedly swollen colonic wall. Stool examinations were performed before treatment in 7 patients (29.2%) and were all negative for parasite eggs or worms. These results suggest that colonoscopy is a useful diagnostic approach for parasitic infections even for asymptomatic patients and for patients with negative stool examinations.
Adult ; Aged, 80 and over ; Animals ; Anisakis/isolation & purification ; Ascaris lumbricoides/isolation & purification ; *Colonoscopy ; Enterobius/isolation & purification ; Feces/parasitology ; Female ; Helminthiasis/*diagnosis/*epidemiology/pathology ; Hospitals ; Humans ; Intestinal Diseases, Parasitic/*diagnosis/*epidemiology/pathology ; Male ; Middle Aged ; Republic of Korea ; Trichuris/isolation & purification ; Young Adult