• Parasites, Hosts and Diseases
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• v.24 no.1
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• pp.71-76
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• 1986

Eggs of Echinestoma sp. were found from two patients who were hospitalized between Oct. and Dec. 1985. Single dose of 10 mg/kg of praziquantel was prescribed to each patient and after purgation with magnesium salt seuen and two adult worms of Echinostoma cinetorchis in respect were recovered from patients. The first case was a 54-year-old male residing at Chungju City in Chungbuk Province. He was hospitalized because of severe weight loss and frequent urination. The second case was a 71-year-old male residing at Chungsun-Kun in Kangwon Province, and hospitalized due to suspected lung cancer. The average size of the eggs found in the stools was $98{\times}63{\mu}m$ (the first case) and $100{\times}67{\mu\textrm{m}}$ (the second case) respectively, and total nine worms collected were identified as E. cinetorchis.

• Parasites, Hosts and Diseases
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• v.26 no.1
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• pp.61-64
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• 1988

A human case of Echinostoma cinetorchii infection was found in Seoul Paik Hospital on August, 1987. Large trematode eggs, $98.9{\times}62.7{\mu\textrm{m}}$ in average size, were detected in stool examination. The eggs had a small.sired operculum and abopercular wrinkling. After treatment with praziquantel (single dose of 16.2mg/kg) and purgation with magnesium citrate, an adult fluke was collected. It was 8.0 mm long, equipped with 37 collar spines around head crown, and had only one testis just behind the Mehlis' gland. It was identified as E. cinetorchis Ando et Ozaki, 1923. The patient is an 18-year old man residing in Seoul, and was hospitalized due to nephritis. He had eaten raw meat juice of fresh water fishes such as top minnows (Orygias Satipes) and loaches, or tadpoles, which are considered possible source of this fluke infection. This is the 4th human case of E, cineterchis infection in Korea.

• Parasites, Hosts and Diseases
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• v.28 no.4
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• pp.221-234
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• 1990

The present study was performed to know the epidemiological statug of echinostomiasis in the Chungju Reservoir and upper streams of Namhan River, together with an experimental study on the life history o( Echinostoma hortense. The stool specimens of 169 inhabitants and 473 junior high school students from 5 different villages revealed 3(0.5%) echinostomatid egg Positive cases. E. hortense adult worms were recovered from one patient after a treatment and purgation. For the other two patients, it was presumed that one had 2. hortense and another E. cinetorchis infection, based on the morphology of eggs. Five kinds of freshwater snails(168 Radix auricularia coreane, 534 Physa arutp, 144 Hippeutis cnntori, 56 Cipcngopaludina chinensis malleata and 125 Semiiulcospira nediila glebus) examined for the cercariae of echinostomes showed negative results. Ten kinds of freshwater fishes examined for E. herten-'emetacercariae revealed positive rates as Misgurnus anguillicaudatus 40.5%, Odentobutis obscura interrupta 20.3%, Moroco onycephalus 3.9%, and Coreoperca hawamebari 2.0%. In the experimental study, the metacercariae of E. horlense were infected to rats, eggs were collected from adult worms and cultivated, and miracidia were obtained. The miracidia were artificially infected to freshwater snails (R. auricularia), and cercarial shedding was studied. It was revealed that, when the snails were kept at a low temperature ($24^{\circ}C$), only 523 cercariae (on average) were produced during 24 hrs, while they were at a high temperature ($30^{\circ}C$), as many as 9, 990 cercariae (on average) were shed during the same time. The experimental infection of E. hortense cercariae to freshwater fishes was successful in 0. obscura interrupta 52.0%, M. anguillicaudatus 30.3%, C. kawamebari 27.0%, Cobitis lutheri 15.0%, M. cxycephazus 7.3%, Pseudogobio esocinus 4.3%, Squalidus cereanus 2.0%, Zccco platypus 1.3%, and Pungtungia herzi 1.3%. However, infection was not successful to snails, C. chinensis. It has been proved that the Chungju Reservoir and upper streams of Namhan riyrr are endemic areas of echinostomiasis, especially of E. horfense, and snails such as R. auritulerie coreana and fishes such as O. obscura interrupts, M. gnguillicgudgtus, and others are taking the role of 6rst and second intermediate hosts, respectively.

• Parasites, Hosts and Diseases
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• v.28 no.4
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• pp.235-240
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• 1990

During an investigation on intestinal flukes of house rats in Yangyang-gun, Kangwon-do, a total of 6 species of trematodes belonging to 3 families; Echinostom-atidae (Echinostoma hortense, E. cinetorchis, E. revolutum and Echinoparyphium recurvatum), Diplostomidae (Fibricoza seoulensis) and Plagiorchiidae (Plagiorchis muris), were recovered from two adult rats. E. revolutum and E. recurvatum were new trematode faunae of rats in Korea. 5. revolutum had an elongated body, 5.3∼6.Omm long and 1.0∼1.3mm wide. The total number of collar spines was 35∼37 including 5 end group ones on each ventral corner. Its coiled uterus contained numerous eggs.5. recurvatum also had an elongated body, 3.5∼4.7 mm long and 0.50∼0.65 mm wide. It had total 45 collar spines including 4 end group ones. The uterus toras short with only a few eggs. It has been first confirmed by this study that E. revolutum and E. recurvatum are indigenously distributed among house rats in Korea. Kef lords: Echinostoma revolutum, Echinoparyphium recurvatum. new fauna. house rats, Yangyang-gun ( Kangwon-do )

• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.149-156
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• 1994

An epidemiological study fur the Intestinal trematode infection of the villagers was done In Koje-myon, Kochang-gun, Kyongsangnam-do, Korea in March, 1994. Of 116 stool specimens examined, total helmlnthic ova positive cases were 13 (11.2%) and cumulative ova positive cases 21 (18.1%): Echinostoma hortense 11 cases (9.5%), Metngonimus sp. 6 cases (5.2%), and Clonorchis sinensis 4 cases (3.4%). After the treatment and purgation, variable numbers of E. hokene, 6 to 227 per person, were collected from 7 echlnostome egg Positive cases, together with M. tokohoshii In 6 cases. Three adult flukes of E. cinetorchis were collected from one person and one Stellantchasmw jnlcatus was recovered from another case. This mountainous village was proved to be one of the endemic foci of echlnostomlasis In Korea.

• Parasites, Hosts and Diseases
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• v.58 no.4
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• pp.343-371
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• 2020

Echinostoma flukes armed with 37 collar spines on their head collar are called as 37-collar-spined Echinostoma spp. (group) or 'Echinostoma revolutum group'. At least 56 nominal species have been described in this group. However, many of them were morphologically close to and difficult to distinguish from the other, thus synonymized with the others. However, some of the synonymies were disagreed by other researchers, and taxonomic debates have been continued. Fortunately, recent development of molecular techniques, in particular, sequencing of the mitochondrial (nad1 and cox1) and nuclear genes (ITS region; ITS1-5.8S-ITS2), has enabled us to obtain highly useful data on phylogenetic relationships of these 37-collar-spined Echinostoma spp. Thus, 16 different species are currently acknowledged to be valid worldwide, which include E. revolutum, E. bolschewense, E. caproni, E. cinetorchis, E. deserticum, E. lindoense, E. luisreyi, E. mekongi, E. miyagawai, E. nasincovae, E. novaezealandense, E. paraensei, E. paraulum, E. robustum, E. trivolvis, and Echinostoma sp. IG of Georgieva et al., 2013. The validity of the other 10 species is retained until further evaluation, including molecular analyses; E. acuticauda, E. barbosai, E. chloephagae, E. echinatum, E. jurini, E. nudicaudatum, E. parvocirrus, E. pinnicaudatum, E. ralli, and E. rodriguesi. In this review, the history of discovery and taxonomic debates on these 26 valid or validity-retained species are briefly reviewed.

• Parasites, Hosts and Diseases
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• v.58 no.4
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• pp.431-443
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• 2020

Echinostoma mekongi n. sp. (Digenea: Echinostomatidae) is described based on adult flukes collected from humans residing along the Mekong River in Cambodia. Total 256 flukes were collected from the diarrheic stool of 6 echinostome egg positive villagers in Kratie and Takeo Province after praziquantel treatment and purging. Adults of the new species were 9.0-13.1 (av. 11.3) mm in length and 1.3-2.5 (1.9) mm in maximum width and characterized by having a head collar armed with 37 collar spines (dorsal spines arranged in 2 alternative rows), including 5 end group spines. The eggs in feces and worm uterus were 98-132 (117) ㎛ long and 62-90 (75) ㎛ wide. These morphological features closely resembled those of Echinostoma revolutum, E. miyagawai, and several other 37-collar-spined Echinostoma species. However, sequencing of the nuclear ITS (ITS1-5.8S rRNA-ITS2) and 2 mitochondrial genes, cox1 and nad1, revealed unique features distinct from E. revolutum and also from other 37-collar-spined Echinostoma group available in GenBank (E. bolschewense, E. caproni, E. cinetorchis, E. deserticum, E. miyagawai, E. nasincovae, E. novaezealandense, E. paraensei, E. paraulum, E. robustum, E. trivolvis, and Echinostoma sp. IG). Thus, we assigned our flukes as a new species, E. mekongi. The new species revealed marked variation in the morphology of testes (globular or lobulated), and smaller head collar, collar spines, oral and ventral suckers, and cirrus sac compared to E. revolutum and E. miyagawai. Epidemiological studies regarding the geographical distribution and its life history, including the source of human infections, remain to be performed.

• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.65-74
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• 1992

The tegumental ultrastructure of juvenile and adult Echinostoma cinetorchis (Trematoda: Echinostomatidae) was observed by scanning electron microscopy. Three-day (juvenile) and 16-day (adult) worms were harvested from rats (Sprague-Dawley) experimentally fed the metacercariae from the laboratory-infected fresh water snail, Hippeutis cantori. The worms were fifed with 2.5% glutaraldehyde, processed routinely, and observed by an ISI Korea DS-130 scanning electron microscope. The 3-day old juvenile worms were elongated and ventrally curved, with their ventral sucker near the anterior two-fifths of the body. The head crown was bearing 37∼38 collar spines arranged in a zigzag pattern. The lips of the oral and ventral suckers had 8 and 5 type II sensory papillae respectively, and bewteen the spines, a few type III papillae were observed. Tongue or spade-shape spines were distributed anteriorly to the ventral sucker, whereas peg-like spines were distributed posteriorly and became sparse toward the posterior body. The spines of the dorsal surface were similar to those of the ventral surface. The 16-day old adults were leaf-like, and their oral and ventral suckers were located very closely. Aspinous head crown, oral and ventral suckers had type II and type III sensory papillae, and numerous type I papillae were distributed on the tegument anterior to the ventral sucker. Scale-like spines, with broad base and round tip, were distributed densely on the tegument anterior to the ventral sucker but they became sparse posteriorly. At the dorsal surface, spines were observed at times only at the anterior body. The results showed that the tegument of E. cinetorchis is similar to that of other echinostomes, but differs in the number and arrangement of collar spines, shape and distribution of tegumenal spines, and type and distribution of sensory papillae.