Infection Status with Digenetic Trematode Metacercariae in Fishes from Coastal Lakes in Gangwon-do, Republic of Korea

The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from coastal lakes in Gangwon-do, the Republic of Korea (Korea). All fishes collected in 5 lakes were examined with the artificial digestion method. More than 10 species, i.e., Metagonimus spp., Pygidiopsis summa, Centrocestus armatus, Metorchis orientalis, M. taiwanensis, Clinostomum complanatum, Echinostoma spp., Stictodora spp., Diplostomum sp. and Diplostomid No. 1. by Morita (1960), of DTM were detected in fishes from 5 coastal lakes in Gangwon-do. Metagonimus spp. metacercariae were found in 52 (41.3%) out of 126 sea rundace, Tribolodon hakonensis, from 5 lakes, and their density was 14.6 per fish infected. P. summa metacercariae were detected in 48 (84.2%) out of 57 mullets from 5 lakes, and their density was 316 per fish infected. C. armatus metacercariae were detected in 7 (14.6%) T. hakonensis and 3 (15.0%) Tridentiger brevispinis from Hyang-ho, and 5 (19.2%) Acanthogobius flavimanus from Gyeongpo-ho. Stictodora spp. metacercariae were found in 4 fish species, i.e., Tridentiger obscurus, Tridentiger trigonocephalus, Chelon haematocheilus, and Acanthogobius lactipes, from Gyeongpo-ho. Total 15 C. complanatum metacercariae were detected in 2 (9.1%) crucian carp, Carassius auratus, from Songji-ho. M. taiwanensis metacercariae were found in T. hakonensis from Hyang-ho and Gyeongpo-ho and in Pseudorasbora parva from Gyeongpo-ho. Total 11 M. orientalis metacercariae were detected in 3 (6.3%) T. hakonensis from Hyang-ho. From the above results, it was confirmed that various species of DTM are infected in fishes from coastal lakes in Gangwon-do, Korea.

Infection Status with Clinostomum complanatum Metacercariae in Fish from Water Systems of Nakdong-gang (River) in Korea

The infection status of Clinostomum complanatum metacercariae (CcMc) was broadly surveyed in fishes from water systems of Nakdong-gang (River) in the Republic of Korea (Korea) for 5 years. All 4,468 fishes collected were individually examined by the artificial digestion methods. No CcMc were detected in fishes from Naeseongcheon in Yecheon-gun, Gigyecheon in Gyeongju-si, Gyeongsangbuk-do, and Hamancheon in Haman-gun, Gyeongsangnam-do. In fishes from Wicheon in Gunwi-gun, Gyeongsangbuk-do, CcMc were detected in 180 (15.4%) out of 1,168 fishes and their intensity was 5.8 per fish infected. The prevalences with CcMc in positive fish species from 3 other surveyed areas, i.e., Banbyeoncheon in Yeongyang-gun, Nakdong-gang in Sangju-si and Hoecheon in Goryeong-gun, in Gyeongsangbuk-do were 19.3%, 33.3%, and 19.0% and their intensities were 1.5, 17.6, and 2.6 per fish infected respectively. In fishes from Yangcheon in Sancheong-gun, Gyeongsangnam-do, CcMc were detected in 811 (45.6%) out of 1,779 fishes examined and their intensity was 9.8 per fish infected. The prevalence was most high in Squalidus spp. (97.7%) and followed by acheilognathinid fish (66.8%), Pungtungia herzi (52.0%), rasborinid fish (39.6%) and Hemibarbus spp. (25.9%) from Yangcheon. The intensity was also most high in Squalidus spp. (27.0). The endemicity with CcMc was very low in fishes from water systems of Nakdong-gang in the east coast of Korea. Conclusively, it is confirmed that various fish species act as the second intermediate hosts of C. complanatum, and the endemicities of CcMc are more or less different by the fish species and group from Yangcheon, in Sancheong-gun, Gyeongsangnam-do, Korea.

A Case of Unexpected Clinostomum complanatum Infection Initially Presenting as Foreign Body in Pharynx

A 46-year old man visited our outpatient clinic with complaint of foreign body sensation in throat after consuming raw freshwater fish 5 days ago. Laryngoscopic examination revealed a motile worm attached on posterior pharyngeal wall. The worm was removed using biopsy forceps under transnasal endoscopy and evidently identified as Clinostomum complanatum after microscopic examination. Patient’s subjective foreign body sensation of throat and hyperemia of laryngeal mucosa remained for approximately 2 weeks post-removal, which were eventually resolved after administration of non-steroidal anti-inflammatory drug and anti-refluxant drug for 2 weeks. Treatment was ended at three weeks since the first visit. C. complanatum infections in humans are rare, and only four cases have been reported in Korea. Symptoms resembling pharyngitis or laryngitis occurs by consumption of raw, infected freshwater fish and treatment is done by mechanically removing the parasite.

A Case of Endoscopically Treated Laryngopharyngitis Resulting from Clinostomum complanatum Infection / 대한소화기학회지

A 46-year-old woman visited our hospital presenting throat pain and globus sensation. The symptoms occurred seven days after eating raw perch and mullet. An endoscopy under sedation showed a fluke―with an approximate length of 4.8 mm and width of 1.5 mm―on the left aryepiglottic fold, with active motility on the mucosa. It was extracted from the larynx using biopsy forceps and was identified as Clinostomum complanatum. To the best of our knowledge, this is the second reported case of human infection with Clinostomum complanatum diagnosed and treated by an endoscopy in Korea. Endoscopy is a useful tool in the diagnosis and treatment of patients at risk for parasitic infections complaining of throat pain.

A Case of Pharyngitis Caused by Clinostomum complanatum / 대한이비인후과학회지

A 13-year-old female patient visited the otolaryngology clinic with complaints of a moving foreign body sensation in her throat. The patient used to eat raw fish and she had eaten mullet sashimi a week before. During laryngoscopy for the pharynx and larynx, a motile fluke was found attached to the posterolateral nasopharyngeal wall. The worm was easily removed and identified as Clinostomum complanatum (C. complanatum) after morphological observation. C. complanatum is a digenetic trematode which usually infects fish-eating birds. Human infection by C. complanatum is very rare, and if a human eats infected raw fish, the worm can be on the pharyngeal or laryngeal mucosa. Human cases of parasitic C. complanatum infection have been reported twice in Korea, with the present report being the first case in the otolaryngology field.

Incidence and histopathology of encysted progenetic metacercaria of Clinostomum complanatum (Digenea：Clinostomidae) in Channa punctatus and its development in experimental host

Objective: To study the incidence of encysted progenetic metacercariae of Clinostomum complanatum (C. complanatum) in Channa punctatus (C. punctatus), associated histopathology and the experimental infection to laboratory chicken to obtain ovigerous adult worms. Methods:Live C. punctatus were brought from local fish market of Aligarh, India, dissected and examined on a monthly basis for the presence of C. complanatum cysts. For histochemistry, infected tissue sections with attached cysts were processed for haematoxylene and eosin staining. Cysts were aseptically fed to 4 day old leghorn chicken to obtain adult worms. Mechanically excysted metacercaria and the ovigerous adult worms were stained in carmine to prepare permanent slides. Results: One year survey for the infection of encysted progenetic metacercaria of C. complanatum in C. punctatus revealed the prevalence, intensity and abundance of 24.7%, 2.27 and 0.608, respectively. Histopathology showed heavy infiltration of immune cells at the site of cyst attachment and some tissue damage was also evident. Following feeding to experimental chicken, about 41.07%of the encysted metacercariae were able to excyst and migrate back to bucco-pharyngeal region where they tenaciously attached and fed on blood, and transformed into ovigerous adult worms from 62 hours onwards of post infection. Conclusions:The parasite is potentially pathogenic to the host, and the availability of a suitable intermediate host can be a contributing factor for the occurrence of C. complanatum metacercaria either in the excysted or encysted form, indicating loose host specificity and zoonotic potential.

A Human Case of Clinostomum complanatum Infection in Korea

A 33-year-old Korean man visited a medical clinic with complaints of throat discomfort and pain for one week. The symptoms occurred one day after eating raw brackish water fish, perch. Endoscopy revealed a fluke, about 5 mm in length, attaching to and peristaltically moving on the surface of the mucosa at the arytenoid region of the larynx. Microscopically, the testes were triangular, tandem, and separated by the uterus. The ovary and cirrus pouch were placed apart from median line between testes. Numerous blood cells were observed in the ceca. The worm was identified to be Clinostomum complanatum. This is the second human case of clinostomiasis in Korea.

Digenetic trematode parasites of Loricariichthys platymetopon (Loricariidae, Siluriformes) of the upper Paraná river floodplain, Brazil - DOI: 10.4025/actascibiolsci.v29i3.508 / Trematódeos digenéticos parasitas de Loricariichthys platymetopon (Loricariidae, Siluriformes) da planície de inundação do alto rio Paraná, Brasil - DOI: 10.4025/actascibiolsci.v29i3.508

Two species of digenetic trematodes were found to parasitize Loricariichthys platymetopon Isbrücker & Nijssen, 1979, collected at the Upper Paraná River floodplain, Brazil. Crocodilicola pseudostoma was found in the digestive tract and Clinostomum complanatum occurred on the surface of the body. This is the first record of Crocodilicola pseudostoma in this host.

Este trabalho apresenta o registro de duas espécies de trematódeos digenéticos parasitas de Loricariichthys platymetopon Isbrücker and Nijssen, 1979, coletados na planície de inundação do Alto rio Paraná, Brasil. Foi registrada a presença de Crocodilicola pseudostoma no trato intestinal e Clinostomum complanatum encontrado na superfície do corpo. Crocodilicola pseudostoma é registrado pela primeira vez neste hospedeiro.