-
The Korean Journal of Parasitology Jun 2011The present study was performed to determine the current infecion status of Metagonimus yokogawai metacercariae in sweetfish, Plecoglossus altivelis, collected from...
The present study was performed to determine the current infecion status of Metagonimus yokogawai metacercariae in sweetfish, Plecoglossus altivelis, collected from several streams in eastern and southern coastal areas of Korea. The sweetfish collected were artificially digested with pepsin-HCl solution and examined under a stereomicroscope in August and September, 2007. Out of 145 sweetfish collected from 10 streams in eastern coasts (Gangwon-do and Gye-ongsangbuk-do), 88 (60.7%) were infected with Metagonimus metacercariae. The average metacercarial density was 61 per infected fish. Among 141 sweetfish collected from 10 streams in southern coasts (Gyeongsangnam-do, Ulsan Metropolitan city, and Jeollanam-do), 140 (99.3%) were infected with Metagonimus metacercariae, and their average density was 949 per infected fish. The present study confirmed that M. yokogawai metacercariae are still prevalent in the sweetfish from several eastern and southern coastal localities. The prevalence and metacercarial density were much higher in the sweetfish from streams of southern coasts than in those of eastern coasts. Therefore, attention should be paid to this small fluke infection, and consumption of raw sweetfish naturally produced in these areas should be prohibited.
Topics: Animals; Fish Diseases; Heterophyidae; Korea; Metacercariae; Microscopy; Osmeriformes; Prevalence; Trematode Infections
PubMed: 21738272
DOI: 10.3347/kjp.2011.49.2.161 -
The Korean Journal of Parasitology Aug 2020Fish-borne heterophyid trematodes are known to have a zoonotic potential, since at least 30 species are able to infect humans worldwide, with a global infection of... (Review)
Review
Fish-borne heterophyid trematodes are known to have a zoonotic potential, since at least 30 species are able to infect humans worldwide, with a global infection of around 7 million people. In this paper, a 'state-of-the-art' review of the South American heterophyid species is provided, including classical and molecular taxonomy, parasite ecology, host-parasite interaction studies and a list of species and their hosts. There is still a lack of information on human infections in South America with undetected or unreported infections probably due to the information shortage and little attention by physicians to these small intestinal flukes. Molecular tools for specific diagnoses of South American heterophyid species are still to be defined. Additional new sequences of Pygidiopsis macrostomum, Ascocotyle pindoramensis and Ascocotyle longa from Brazil are also provided.
Topics: Animals; Cyanobacteria; DNA, Helminth; Fishes; Heterophyidae; Host-Parasite Interactions; Humans; Sequence Analysis, DNA; South America; Trematode Infections
PubMed: 32871631
DOI: 10.3347/kjp.2020.58.4.373 -
Parasite (Paris, France) 2024The heterophyid trematode Metagonimus romanicus (Ciurea, 1915) (Digenea) is redescribed on the basis of type material from domestic dogs (Canis familiaris) in Romania,... (Review)
Review
The heterophyid trematode Metagonimus romanicus (Ciurea, 1915) (Digenea) is redescribed on the basis of type material from domestic dogs (Canis familiaris) in Romania, vouchers from experimentally infected cats (Felis catus) and adults recovered from golden hamsters (Mesocricetus auratus) infected with metacercariae from scales of chub (Squalius cephalus) and common nase (Chondrostoma nasus) (Cypriniformes: Leuciscidae) in Hungary. This trematode, endemic to Europe and neighbouring regions (northwestern Türkiye), was previously misidentified as M. yokogawai (Katsurada, 1912), a zoonotic parasite of humans in East Asia. However, the two species differ considerably both genetically and morphologically, e.g., in the position of the ventral sucker, the presence of the prepharynx, the anterior extent of the vitelline follicles and the posterior extent of the uterus. Metagonimus ciureanus (Witenberg, 1929) (syn. Dexiogonimus ciureanus Witenberg, 1929), described from domestic cats and dogs in Israel, is a valid species distributed in the Middle East and Transcaucasia, which is also confirmed by molecular data. It differs from all Metagonimus species, including M. romanicus, in having symmetrical testes instead of the oblique testes of the other congeners. The zoonotic significance of M. romanicus and M. ciureanus is unclear, but appears to be low in Europe, mainly because raw or undercooked, whole fish with scales are generally not consumed. Accidental infection of fishermen by metacercariae in the scales when cleaning fish is more likely, but has never been reported. Remains of cyprinoids with scales infected with metacercariae of Metagonimus spp. can be an important natural source of infection for dogs, cats, and other carnivores, which can serve as a reservoir for these parasites.
Topics: Animals; Cats; Dogs; Female; Humans; Cyprinidae; Europe; Heterophyidae; Mesocricetus; Metacercariae; Middle East; Parasites; Trematoda; Trematode Infections
PubMed: 38551578
DOI: 10.1051/parasite/2024016 -
The Korean Journal of Parasitology Dec 1997We tried to compare the three kinds of Metagonimus species, M. yokogawai, Metagonimus Miyata type, and M. takahashii, which were known to be distributed in Korea with...
We tried to compare the three kinds of Metagonimus species, M. yokogawai, Metagonimus Miyata type, and M. takahashii, which were known to be distributed in Korea with polymerase chain reaction based-restriction fragment length polymorphism (PCR-RFLP) patterns. We amplified the internal transcribed spacer 1 (ITS1) site of ribosomal RNA and mitochondrial cytochrome c oxidase I (mCOI) gene. The restriction patterns of ITS1 gene with Rsa I, Alu I and Msp I showed multiple fragmented bands of different sizes between three kinds of Metagonimus. In case of mCOI gene, Rsa I and Alu I enzymes produced differentially fragmented band patterns. According to the parsimony analysis of PCR-RFLP patterns, the estimated genetic divergence between M. yokogawai and Metagonimus Miyata type was 0.034880, between Metagonimus Miyata type and M. takahashii was 0.028098, between M. yokogawai and M. takahashii was 0.018179. It is suggested that Metagonimus Miyata type may be separate species and evolutionize at the older time than the other two species.
Topics: Animals; Electron Transport Complex IV; Evolution, Molecular; Fishes; Genetic Variation; Heterophyidae; Korea; Mitochondria; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; RNA, Helminth; RNA, Ribosomal; Rats; Rats, Sprague-Dawley
PubMed: 9446909
DOI: 10.3347/kjp.1997.35.4.271 -
Parasites & Vectors Jan 2019Division of labour has evolved in many social animals where colonies consist of clones or close kin. It involves the performance of different tasks by morphologically... (Review)
Review
Division of labour has evolved in many social animals where colonies consist of clones or close kin. It involves the performance of different tasks by morphologically distinct castes, leading to increased colony fitness. Recently, a form of division of labour has been discovered in trematodes: clonal rediae inside the snail intermediate host belong either to a large-bodied reproductive caste, or to a much smaller and morphologically distinct 'soldier' caste which defends the colony against co-infecting trematodes. We review recent research on this phenomenon, focusing on its phylogenetic distribution, its possible evolutionary origins, and how division of labour functions to allow trematode colonies within their snail host to adjust to threats and changing conditions. To date, division of labour has been documented in 15 species from three families: Himasthlidae, Philophthalmidae and Heterophyidae. Although this list of species is certainly incomplete, the evidence suggests that division of labour has arisen independently more than once in the evolutionary history of trematodes. We propose a simple scenario for the gradual evolution of division of labour in trematodes facing a high risk of competition in a long-lived snail host. Starting with initial conditions prior to the origin of castes (size variation among rediae within a colony, size-dependent production of cercariae by rediae, and a trade-off between cercarial production and other functions, such as defence), maximising colony fitness (R) can lead to caste formation or the age-structured division of labour observed in some trematodes. Finally, we summarise recent research showing that caste ratios, i.e. relative numbers of reproductive and soldier rediae per colony, become more soldier-biased in colonies exposed to competition from another trematode species sharing the same snail, and also respond to other stressors threatening the host's survival or the colony itself. In addition, there is evidence of asymmetrical phenotypic plasticity among individual caste members: reproductives can assume defensive functions against competitors in the absence of soldiers, whereas soldiers are incapable of growing into reproductives if the latter's numbers are reduced. We conclude by highlighting future research directions, and the advantages of trematodes as model systems to study social evolution.
Topics: Adaptation, Physiological; Animals; Biological Evolution; Cercaria; Ecology; Phylogeny; Reproduction; Snails; Trematoda
PubMed: 30609937
DOI: 10.1186/s13071-018-3241-6 -
The Korean Journal of Parasitology Oct 2009Zoonotic parasites are animal parasites that can infect humans. The major zoonotic protozoa in the Republic of Korea are Babesia bovis, Chilomastix mesnili,... (Review)
Review
Zoonotic parasites are animal parasites that can infect humans. The major zoonotic protozoa in the Republic of Korea are Babesia bovis, Chilomastix mesnili, Cryptosporidium parvum, Endolimax nana, Entamoeba coli, Entamoeba hitolytica, Giardia lamblia, Iodamoeba bütschlii, Pneumocystis carinii, Sarcocystis cruzi, and Toxoplasma gondii. The major zoonotic helminths in Korea include trematodes, cestodes, and nematodes. Trematodes are Clonorchis sinensis, Echinostoma hortense, Echinostoma spp., Fasciola hepatica, Heterophyes nocens, Metagonimus yokogawai, and Paragonimus westermani. Cestodes are Diphyllobothrium latum, Dipylidium caninum, Echinococcus granulosus, Hymenolepis nana, Raillietina tetragona, sparganum (Spirometra spp.), Taenia saginata, T. solium, and T. asiatica. Nematodes are Ancylostoma caninum, Brugia malayi, Capillaria hepatica, Dirofilaria immitis, Gnathostoma dololesi, Gnathostoma spinigerum, Loa loa, Onchocerca gibsoni, Strongyloides stercoralis, Thelazia callipaeda, Trichinella spiralis, Trichostrongylus orientalis, Trichuris trichiura, and Trichuris vulpis. The one arthropod is Sarcoptes scabiei. Many of these parasites have disappeared or were in decline after the 1990's. Since the late 1990's, the important zoonotic protozoa have been C. parvum, E. nana, E. coli, E. hitolytica, G. lamblia, I. buetschlii, P. carinii and T. gondii. The important zoonotic helminths have been C. sinensis, H. nocens, M. yokogawai, P. westermani, D. latum, T. asiatica, sparganum, B. malayi, T. orientalis, T. callipaeda and T. spiralis. However, outbreaks of these parasites are only in a few endemic areas. The outbreaks of Enterobius vermicularis and head lice, human parasites, have recently increased in the kindergartens and primary schools in the Republic of Korea.
Topics: Animals; Humans; Parasites; Parasitic Diseases; Parasitic Diseases, Animal; Republic of Korea; Zoonoses
PubMed: 19885329
DOI: 10.3347/kjp.2009.47.S.S133 -
The Korean Journal of Parasitology Dec 2008The Tamjin River which flows from Jangheung-gun via Gangjin-gun to the South Sea was reported to be a highly endemic area of Metagonimus yokogawai infection in 1977 and...
The Tamjin River which flows from Jangheung-gun via Gangjin-gun to the South Sea was reported to be a highly endemic area of Metagonimus yokogawai infection in 1977 and 1985. However, there were no recent studies demonstrating how much change occurred in the endemicity, in terms of prevalence and worm burden, of metagonimiasis in this river basin. Thus, a small-scale epidemiological survey was carried out on some residents along the Tamjin River basin in order to determine the current status of M. yokogawai infection. A total of 48 fecal samples were collected and examined by the Kato-Katz thick smear and formalin-ether sedimentation techniques. The egg positive rate of all helminths was 50.0%, and that of M. yokogawai was 37.5%, followed by C. sinensis 22.9% and G. seoi 4.2%. To obtain the adult flukes of M. yokogawai, 6 egg positive cases were treated with praziquantel 10 mg/kg in a single dose and purged with magnesium sulfate. A total of 5,225 adult flukes (average 871 specimens per person) of M. yokogawai were collected from their diarrheic stools. Compared with the data reported in 1977 and 1985, the individual worm burdens appeared to have decreased remarkably, although the prevalence did not decrease at all. It is suggested that the endemicity of M. yokogawai infection along the Tamjin River has been reduced. To confirm this suggestion, the status of infection in snail and fish intermediate hosts should be investigated.
Topics: Adult; Animals; Endemic Diseases; Female; Heterophyidae; Humans; Korea; Male; Middle Aged; Rivers; Trematode Infections
PubMed: 19127339
DOI: 10.3347/kjp.2008.46.4.289 -
Parasites, Hosts and Diseases Feb 2024This article analyzed the infection characteristics of metacercariae of Metagonimus spp. (MsMc) in fish from 9 major water systems in Korea. A total of 19,568 fish in 87... (Review)
Review
This article analyzed the infection characteristics of metacercariae of Metagonimus spp. (MsMc) in fish from 9 major water systems in Korea. A total of 19,568 fish in 87 species were examined over a period of 10 years (2011-2020). MsMc were detected in fish from all 44 survey areas in 9 water systems. Most of the surveyed sites showed very low and low infection levels (66.7%), while 33.3% of the areas, such as Tamjin-gang and Seomjin-gang, revealed moderate and high infection levels. High endemicity depends on the abundance of susceptible fish species, especially sweet smelt (Plecoglosus altivelis). The susceptibility index (SI) with MsMc in index fish, Zacco spp., was very low and low levels in 62.0%, moderate in 28.0%, and high in 10.0% regions. The SI was highest in the following order: Yeongam-cheon (283.8), Hoeng-cheon (192.3), Togyo-jeosuji (131.2), Deokcheon-gang (119.1), and Joyang-gang (106.3). The recent infection status of MsMc in P. altivelis was analyzed by the survey localities. In addition, except for P. altivelis, 9 fish species were highly infected with MsMc in some survey areas, including Zacco platypus, Z. koreanus, Z. temminckii, Opsariichthys uncirostris, Rhynchocypris oxycephalus, Carassius auratus, Acheilognathus rhombeus, Onchorhynchus masou, and Tribolodon hakonensis. In Korea, 74 fish species (15 families) are collectively listed as second intermediate hosts of Metagonimus spp. This review provides several novel characteristics of MsMc infection and clarifies the fish species of second intermediate host of Metagonimus spp. in this country.
Topics: Animals; Cypriniformes; Heterophyidae; Metacercariae; Republic of Korea; Trematoda; Water
PubMed: 38443767
DOI: 10.3347/PHD.23096 -
Revue Scientifique Et Technique... Aug 1997A multitude of parasites have been reported in fish, but only a few species are capable of infecting humans. The most important of the helminths acquired by humans from... (Review)
Review
A multitude of parasites have been reported in fish, but only a few species are capable of infecting humans. The most important of the helminths acquired by humans from fish are the anisakid nematodes (particularly Anisakis simplex and Pseudoterranova decipiens), cestodes of the genus Diphyllobothrium and digenetic trematodes of the families Heterophyidae, Opisthorchiidae and Nanophyetidae. Seafood-associated infections by acanthocephalans are rarely reported in humans. All of the helminths mentioned above are associated with social-cultural and behavioural factors, in particular the consumption of raw or undercooked seafood. Measures can be taken during harvesting, processing or post-processing (e.g., by the consumer) to mitigate the risks of infection. The seafood industry and government authorities can apply various programmes to reduce these risks, including good manufacturing practices (GMPs) and hazard analysis and critical control point (HACCP) systems. Such measures may include avoiding particular harvest areas, sizes of fish, or even particular species of fish. The method of capture, handling and storage of the catch can directly affect the quality of the seafood with regard to the presence and numbers of parasites. The extent of processing--including heading and gutting, candling and trimming--and the type of product derived (fresh, frozen, salted or pickled) can all contribute to the control of the risks posed by helminths. The most effective means of killing the parasites are either freezing or heat inactivation.
Topics: Animals; Fish Diseases; Fishes; Food Handling; Helminthiasis; Helminthiasis, Animal; Humans; Public Health; Risk Factors
PubMed: 9501379
DOI: 10.20506/rst.16.2.1059 -
The Korean Journal of Parasitology Jun 1993Worm recovery rates and pathologic changes in small intestine of albino rats were observed after concurrent and challenge infections with metacercariae (MC) of Fibricola...
Worm recovery rates and pathologic changes in small intestine of albino rats were observed after concurrent and challenge infections with metacercariae (MC) of Fibricola seoulensis and Metagonimus yokogawai, and compared with those of single infection groups. Albino rats in concurrent infection group were killed 20 days after feeding with 1,000 MC of each fluke. Rats in challenge infection group were fed with 1,000 MC of F. seoulensis and challenged by 1,000 MC of M. yokogawai 10 days after primary infection, then killed 10 days thereafter. In concurrent infection group, mean number of F. seoulensis and M. yokogawai recovered, 250 and 118 respectively, were similar to those of single infection groups. However, more flukes were collected from the duodenum and less flukes were from the ileum than from single infection group. In challenge infection group, the recovery rate of F. seoulensis was similar to that of single infection group and the distribution of the flukes was similar to that of concurrent infection group. Mean number of M. yokogawai, 69, was significantly lower than that of single infection group. Its distribution, however, extended to the duodenum and most of the flukes were recovered from the jejunum. In concurrent infection group, villi of the duodenum were more markedly thickened, fused and shortened than those in F. seoulensis single infection group. The crypt epithelium appeared to be hyperplastic and inflammatory cell infiltration into the villous stroma was mild. Villous atrophy in the jejunum and ileum was milder than in M. yokogawai single infection group. In challenge infection group, the findings were similar to those of concurrent infection group.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Animals; Heterophyidae; Intestinal Diseases, Parasitic; Intestine, Small; Rats; Rats, Sprague-Dawley; Trematoda; Trematode Infections
PubMed: 8343452
DOI: 10.3347/kjp.1993.31.2.109