• Parasites, Hosts and Diseases
• /
• v.53 no.5
• /
• pp.627-639
• /
• 2015

Metagonimus yokogawai (Katsurada, 1912) Katsurada, 1912 (Trematoda: Heterophyidae) is parasitic in the small intestine of mammals including man and birds in Far Eastern Russia, Korea, Japan, China, and Taiwan. In the present study, the metacercariae and adults of M. yokogawai were redescribed to designate a neotype of this fluke together with reviews of previous studies including study histories from the first discovery to now. We particularly, attempted to review the study histories and morphological descriptions of M. yokogawai for the species validity, and compared with the morphological characteristics and life cycles of the closely related species, Metagonimus takahashii and Metagonimus miyatai. Finally, we proposed a differential key for the 8 known Metagonimus species distributed in East Asia. Metacercariae were obtained from the body muscles of sweetfish (Plecoglossus altivelis) collected in the Asahi River at Takebe-cho, Kita-ku, Okayama City, Okayama Prefecture, Japan. Adults were recovered from the small intestine of Syrian golden hamsters, to which the metacercariae had been fed 14 days before. A neotype was selected out of the present adult specimens. The Asahi River at Takebo-cho became the type locality of M. yokogawai. In conclusion, the present review shows that M. yokogawai, M. takahashii, and M. miyatai are valid and discriminated by means of morphological characteristics.

• Parasites, Hosts and Diseases
• /
• v.30 no.2
• /
• pp.75-82
• /
• 1992

The surface ultrastructure of Heterephyes nocens (Trematoda: Heterophyidae) was studied by scanning electron microscopy(SEM), The adult worms were recovered from experimentally infected cats and from a naturally infected patient. They were leaf-like, ventrally concave, and ovoid or lyriform in shape. Ciliated knob-like sensory papillae (type I) were observed in single or grouped forms on and around the oral sucker, whereas non-ciliated round swellings (type II papillae) were seen on the lip of the ventral sucker, The tegumental spines around the oral sucker were 5∼9 pointed, whereas those between the two suckers were 12∼17 pointed. yentrolaterally, three groups of 5∼6 type I papillae were located between the oral and ventral suckers, with single ones alternating between them. The genital sucker was protruded or depressed, depending on the contraction state of the nukes, and the gonotyl spine number ranged 50∼60. The number of tip points of tegumental spines was decreased posteriorly; finally they became 1∼3 pointed. On the dorsal surface, 4 groups of 4∼5 type I papillae were symmetrically located on both lateral sides, and the shape and distribution of tegumental spines were similar to those of the ventral surface. Although the tegumental ultrastructure of H. nocens was generally similar to those of other heterophyids, the genital sucker morphology including the number of gonotyl spines and/or the distribution pattern of tegumental spines and sensory papillae were suggested to be the characteristic features of H. necens.

• The Korean Journal of Malacology
• /
• v.30 no.3
• /
• pp.295-298
• /
• 2014

Finless porpoise is the one of porpoises in Korean waters that frequently observed in the coastal area. This study reported parasite infection cases of stranded finless porpoise, Neophocaena asiaeorientalis which was stranded on the Saemangeum Dyke on the west coast of Korea 21 May, 2012. The finless porpoise was male, and estimated at 8 years old. Parasites were found in abdominal cavity, skull and lung. The parasites were identified as nematode, trematoda and lungworm. Nematoda in abdominal cavity was Crassicauda sp. Trematoda found in the skull was indentified Nasitrema sp. Lungworm in lung seemed one of genus Pseudaliids. Anisakis spp. has not been found.

• Parasites, Hosts and Diseases
• /
• v.52 no.1
• /
• pp.27-33
• /
• 2014

Mucosal immune responses against Pygidiopsis summa (Trematoda: Heterophyidae) infection were studied in ICR mice. Experimental groups consisted of group 1 (uninfected controls), group 2 (infection with 200 metacercariae), and group 3 (immunosuppression with Depo-Medrol and infection with 200 metacercariae). Worms were recovered in the small intestine at days 1, 3, 5, and 7 post-infection (PI). Intestinal intraepithelial lymphocytes (IEL), mast cells, and goblet cells were counted in intestinal tissue sections stained with Giemsa, astra-blue, and periodic acid-Schiff, respectively. Mucosal IgA levels were measured by ELISA. Expulsion of P. summa from the mouse intestine began to occur from days 3-5 PI which sustained until day 7 PI. The worm expulsion was positively correlated with proliferation of IEL, mast cells, goblet cells, and increase of IgA, although in the case of mast cells significant increase was seen only at day 7 PI. Immunosuppression suppressed all these immune effectors and inhibited worm reduction in the intestine until day 7 PI. The results suggested that various immune effectors which include IEL, goblet cells, mast cells, and IgA play roles in regulating the intestinal mucosal immunity of ICR mice against P. summa infection.

• Journal of Veterinary Clinics
• /
• v.36 no.6
• /
• pp.330-335
• /
• 2019

Apharyngostrigea ibis (Trematoda: Strigeidae) were obtained from the small intestine of two black-crowned night herons (Nycticorax nycticorax) and three grey herons (Ardea cinerea jouyi) between July 2006 and September 2018 in Daejeon metropolitan city and Kangwon province, Republic of Korea. The body is covered with a relatively thick cuticle, devoid of spines, and bipartite. The body measures at 2.3-3.33 × 0.86-1.20 mm, and the fore-body is ventrally concave. The oral sucker leads into a short esophagus that is devoid of a muscular pharynx. The worm was studied with a scanning electron microscope for the first time resulting in the detection of a pair of lappets located at the bilateral portion of the oral sucker. This is the first record of A. ibis in the Republic of Korea.

• Parasites, Hosts and Diseases
• /
• v.57 no.4
• /
• pp.451-456
• /
• 2019

Adult specimens of Echinochasmus caninus n. comb. (Verma, 1935) (Trematoda: Echinostomatidae) (syn. Episthmium caninum Yamaguti, 1958) were recovered from 11 riparian people who resided along the Mekong River in Khammouane Province, Lao PDR. In fecal examinations done by the Kato-Katz technique, the cases revealed eggs of Opisthorchis viverrini/minute intestinal flukes, hookworms, and in 2 cases echinostome eggs. To recover the adult helminths, praziquantel 30-40 mg/kg and pyrantel pamoate 10-15 mg/kg in a single dose were given and purged with magnesium salts. Various species of trematodes (including O. viverrini and Haplorchis spp.), cestodes, and nematodes were recovered from their diarrheic stools. Among the trematodes, small echinostome flukes (n=42; av. 3.8 specimens per case) of 0.7-1.2 mm in length are subjected in this study. They are morphologically characterized by having 24 collar spines interrupted dorsally and anterior extension of vitellaria from the cirrus sac or genital pore level to the posterior end of the body. Particularly based on this extensive distribution of vitellaria, the specific diagnosis was made as Echinochasmus caninus. The cases were co-infected with various other helminth parasites; thus, clinical manifestations specific for this echinostome infection were difficult to determine. The present paper describes for the first time human E. caninus infections in Lao PDR. Our cases marked the 4-14th human infections with this echinostome around the world following the 3 previous cases reported from Thailand.

• Fisheries and Aquatic Sciences
• /
• v.2 no.1
• /
• pp.32-35
• /
• 1999

During the course of studying the helminth fauna from the fishes of the Korean coastal waters, two bucephalid species, Dolichoenterum longissimum Ozaki, 1924 and Prosorhynchus aculeatus Odhner, 1905, were collected from the alimentary canal of the conger eel, Conger myriaster. D. longissimum was characterized by having the ovary between the testes, and 7-8 horn-like projections on the ventral side of rhynchus. P. aculeatus was distinguished from the other species by the location of the mouth or the opening position of the excretory vesicle. These two bucephalid digeneans are new to the Korean fauna.

• Journal of Environmental Health Sciences
• /
• v.30 no.4
• /
• pp.344-346
• /
• 2004

During a survey of the helminth parasites of fresh water fishes in Willamette River, metacercariae of Neascus spp. were found on examination of muscle, spinal cord, fin and skin of Chiselmouth, Acrocheilus alutaceus. One hundred percent of 19 Chiselmouth examined were found to be infected with digenetic trematodes. The prevalence of infection was higher in muscle, varying from $95\%\;and\;100\%$. Higher levels were present in muscle, such that the $100\%$ level being found in upper anterior, lower anterior and posterior. Small numbers of metacercariae were found on the fin and skin. The commonest sites of infection were the musculature and spinal cord. Intensities of Neascus spp. metacercariae tended to be and high levels in muscle and spinal cord. Those were low levels occurred in the fin and skin. There was a high degree of Neascus spp. in the occurrence of digenetic trematode from Chiselmouth.

• Journal of Food Hygiene and Safety
• /
• v.12 no.4
• /
• pp.300-303
• /
• 1997

The present study was carried out to know the distribution of freshwater mollusk on the chinese liver fluke in the middle of August, 1997 at the upper area of Kyungan stream located in Yongin Kun, Kyungki province. The snails were collected from the shallow and irrigation route in a rural area located along the upper area of Kyungan stream. The snails collected by hand were brought to the laboratory and cercariae naturally shed from the snails, Parafossarulus manchouricus were examined. Parafossarulus manchouricus is medically important intermediated host of the transmission of digenetic trematoda to human. Each snail was placed in aerated tap water for the detection of ceracariae and examined for expelled cercariae. Infection rate of the cercariae of Clonorchis sinensis was 3 (1.5%) among 195 individuals collected in the habitat. The identification of the cercaria of Clonorchis sinensis was performed as described by Komiya and Tajimi.

• Parasites, Hosts and Diseases
• /
• v.27 no.4
• /
• pp.249-252
• /
• 1989

Fibricola cratera is a strigeoid trematode indigenous to North America that, heretofore, was known only to infect wild mammals. Herein, it is reported that an experimental inoculation of a human volunteer produced a patellt infection that lasted 40 months. Symptoms of epigastric discomfort, loose stools and flatulence occurred over the first year of infection and ameliorated thereafter. Eggs per gram of stool were low (${\leq}2$) throughout the course of infection and were not detected by the standard technique of formalin-ether concentration. To monitor infection, the entire stool sample was examined each month after sieving through No. 10 (pore size 2 mm) and 100 (pore size $145{\;}{\mu\textrm{m}}$) sieves and collecting eggs on a No. 325 (pore size $45{\;}{\mu\textrm{m}}$) sieve. This is the first report of a North American strigeoid trematode capable of maturing in a human and is only the second species of strigeoid known to do so. The other species is F. seoulensis which has been implicated in 26 human infections in Korea.