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Infectious Diseases of Poverty Jun 2024Digenetic trematodes, including blood flukes, intestinal flukes, liver flukes, lung flukes, and pancreatic flukes, are highly diverse and distributed widely. They affect... (Review)
Review
BACKGROUND
Digenetic trematodes, including blood flukes, intestinal flukes, liver flukes, lung flukes, and pancreatic flukes, are highly diverse and distributed widely. They affect at least 200 million people worldwide, so better understanding of their global distribution and prevalence are crucial for controlling and preventing human trematodiosis. Hence, this scoping review aims to conduct a comprehensive investigation on the spatio-temporal distribution and epidemiology of some important zoonotic digenetic trematodes.
METHODS
We conducted a scoping review by searching PubMed, Web of Science, Google Scholar, China National Knowledge Infrastructure, and Wanfang databases for articles, reviews, and case reports of zoonotic digenetic trematodes, without any restrictions on the year of publication. We followed the inclusion and exclusion criteria to identify relevant studies. And relevant information of the identified studies were collected and summarized.
RESULTS
We identified a total of 470 articles that met the inclusion criteria and were included in the review finally. Our analysis revealed the prevalence and global distribution of species in Schistosoma, Echinostoma, Isthmiophora, Echinochasmus, Paragonimus, Opisthorchiidae, Fasciolidae, Heterophyidae, and Eurytrema. Although some flukes are distributed worldwide, developing countries in Asia and Africa are still the most prevalent areas. Furthermore, there were some overlaps between the distribution of zoonotic digenetic trematodes from the same genus, and the prevalence of some zoonotic digenetic trematodes was not entirely consistent with their global distribution. The temporal disparities in zoonotic digenetic trematodes may attribute to the environmental changes. The gaps in our knowledge of the epidemiology and control of zoonotic digenetic trematodes indicate the need for large cohort studies in most countries.
CONCLUSIONS
This review provides important insights into the prevalence and global distribution of some zoonotic digenetic trematodes, firstly reveals spatio-temporal disparities in these digenetic trematodes. Countries with higher prevalence rate could be potential sources of transmitting diseases to other areas and are threat for possible outbreaks in the future. Therefore, continued global efforts to control and prevent human trematodiosis, and more international collaborations are necessary in the future.
Topics: Animals; Zoonoses; Trematode Infections; Humans; Trematoda; Prevalence; Global Health
PubMed: 38877531
DOI: 10.1186/s40249-024-01208-1 -
Parasitology Research Mar 2016Metagonimus Katsurada, 1912 is a genus of small intestinal parasites. The genus comprises eight species, primarily from far-eastern Asia, with two exceptions reported...
Metagonimus Katsurada, 1912 is a genus of small intestinal parasites. The genus comprises eight species, primarily from far-eastern Asia, with two exceptions reported from Europe. Metagonimus yokogawai, the most widespread species, is the main agent responsible for the intestinal disease, metagonimiasis, in Japan and some other East Asian countries. On the basis of the ratio of the size of the ventral and oral suckers, Metagonimus has traditionally been morphologically divided into two groups; however, the genus has not been extensively studied using molecular data. To reveal phylogenetic relationships within Metagonimus based on molecular data, we analyzed six of the seven species present in Asia using samples collected in central Japan. Maximum likelihood and Bayesian analyses of a combined 28S ribosomal DNA (rDNA), internal transcribed spacer 2 (ITS2), and mitochondrial cox1 gene sequence dataset separated the six species into two well-supported clades. One clade comprised M. yokogawai, M. takahashii, M. miyatai, and M. hakubaensis, whereas the other consisted of M. otsurui and M. katsuradai. Genetic distances calculated from 28S rDNA and ITS2 nucleotide sequences and a comparison of the predicted amino acid sequences of cox1 gene suggested that M. otsurui and M. katsuradai may have diverged recently. None of the four main morphological characters used to delimit species of Metagonimus (i.e., sucker ratio, positions of the uterus and testes, and distribution of vitelline follicles) was consistent with the distribution of species in the molecular tree.
Topics: Animals; DNA, Ribosomal Spacer; Electron Transport Complex IV; Female; Heterophyidae; Japan; Phylogeny; RNA, Ribosomal, 28S; Species Specificity
PubMed: 26614357
DOI: 10.1007/s00436-015-4843-y -
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 -
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 -
Experimental Parasitology Apr 2024Helminth infections and their components has been recognized to have a positive impact on the immune system. This study aimed to investigate the potential of Metagonimus...
Helminth infections and their components has been recognized to have a positive impact on the immune system. This study aimed to investigate the potential of Metagonimus yokogawai-derived proteins (MYp) to provide protection against ankylosing spondylitis (AS) through modulation of immune responses. The cytotoxicity of MYp at various doses was first assessed using MTS and flow cytometry. Peripheral blood mononuclear cells (PBMCs) were collected from AS patients, and the production of inflammatory cytokines was analyzed through flow cytometry. In the experiments with SKG mice, MYp or vehicle was administered and inflammation was evaluated through immunohistochemistry and enzyme-linked immunosorbent assay. The results showed that MYp did not decrease cell viability of PBMCs even after 48 h. Additionally, the frequencies of IFN-γ and IL-17A producing cells were significantly reduced after MYp treatment in the PBMC cultures. Furthermore, MYp treatment significantly suppressed arthritis and enthesitis in the SKG mouse model. The results suggest the first evidence that MYp can effectively alleviate clinical symptoms and restore cytokine balance in patients with AS.
Topics: Humans; Animals; Mice; Spondylitis, Ankylosing; Leukocytes, Mononuclear; Heterophyidae; Cytokines; Inflammation
PubMed: 38369180
DOI: 10.1016/j.exppara.2024.108718 -
Acta Tropica Aug 2015We conducted an epidemiological survey to determine the status of heterophyid fluke infections among people residing along the Boseong River, Gokseong-gun, South Korea...
We conducted an epidemiological survey to determine the status of heterophyid fluke infections among people residing along the Boseong River, Gokseong-gun, South Korea (= Korea) from October 2011 to February 2012. Fecal specimens were collected from 115 (male 51, female 64) people and examined for intestinal helminth eggs using the Kato-Katz thick smear technique. The eggs of Metagonimus yokogawai together with other Metagonimus spp. were detected in 28 (24.3%) cases. Eleven egg positive people were treated with 10mg/kg praziquantel followed by MgSO4 purging in order to recover the adult flukes. Whole consecutive diarrheic stools were collected individually 4-5 times. Adult flukes recovered were 66,499 specimens (6045.4/positive case) of M. yokogawai, 343 (38.1) of Metagonimus miyatai, 3293 (299.4) of Metagonimus takahashii, 81 (20.3) of Heterophyes nocens, 6 (3.0) of Heterophyopsis continua, and 1 (1.0) of Stictodora fuscata. The results indicated that the surveyed area is a highly endemic area of metagonimiasis (three Metagonimus species) with low-grade mixed infections of 3 other heterophyid flukes. The infected people experienced variable degrees of gastrointestinal discomfort and indigestion. They consumed raw freshwater and brackish water fish, including sweetfish and mullets. It is strongly recommended that people residing in the survey area avoid eating raw fish to prevent M. yokogawai and other heterophyid infections.
Topics: Adolescent; Adult; Aged; Animals; Anthelmintics; Child; Diet; Eggs; Feces; Female; Fishes; Heterophyidae; Humans; Magnesium Sulfate; Male; Middle Aged; Praziquantel; Prevalence; Raw Foods; Republic of Korea; Rivers; Saline Waters; Surveys and Questionnaires; Trematoda; Trematode Infections; Young Adult
PubMed: 25944352
DOI: 10.1016/j.actatropica.2015.04.025 -
Parasitology International Oct 2022A nationwide fish survey was conducted in Japan to detect metacercariae of the genus Metagonimus (Trematoda: Heterophyidae). The metacercariae were subjected to DNA...
A nationwide fish survey was conducted in Japan to detect metacercariae of the genus Metagonimus (Trematoda: Heterophyidae). The metacercariae were subjected to DNA barcoding for molecular species identification. A phylogeny inferred from the sequences of mitochondrial cytochrome c oxidase subunit 1 (cox1) prompted us to recognize three cryptic species complexes (i.e., the M. miyatai complex, the M. takahashii complex, and the M. katsuradai complex). Each complex included one or two undescribed species. For morphological description, adult flukes of each species were raised through the experimental infections of immunosuppressed mice. We propose M. saitoi n. sp., M. kogai n. sp., M. shimazui n. sp., and M. kinoi n. sp., based on their phylogeny, morphology, biogeography, and ecology (host-parasite relationships). The originally described species, M. miyatai, was split into M. miyatai sensu stricto and M. saitoi n. sp. The former is distributed mainly in eastern Japan and uses the sweetfish (Plecoglossus altivelis) and daces (Pseudaspius hakonensis and Ps. sachalinensis) as principal second intermediate hosts, while the latter is in western Japan and its principal fish hosts are the dark chub (Nipponocypris temminckii) and the pale chub (Opsariichthys platypus). The present survey resolves a long-standing controversy on the microtaxonomy of Metagonimus in Japan since the first discovery of Metagonimus yokogawai in 1912, and shows that 10 species of Metagonimus are still distributed in Japan, although human metagonimiasis is almost eradicated.
Topics: Animals; Fishes; Heterophyidae; Japan; Metacercariae; Mice; Trematoda; Trematode Infections
PubMed: 35643322
DOI: 10.1016/j.parint.2022.102605 -
The Journal of Veterinary Medical... Jun 2021The definitive hosts of Metagonimus hakubaensis are reported to be hamsters, rats, mice, dogs, cats, chickens, and quails in experimental infection and Japanese water...
The definitive hosts of Metagonimus hakubaensis are reported to be hamsters, rats, mice, dogs, cats, chickens, and quails in experimental infection and Japanese water shrews in natural infection. Here we report that raccoon dogs are new natural definitive hosts of M. hakubaensis, based on morphological and molecular analyses of Metagonimus flukes collected from the host species from Aomori Prefecture, Japan. Moreover, M. hakubaensis recovered from raccoon dogs showed higher fecundity than those recovered from Japanese water shrews. Therefore, raccoon dogs were considered as a more suitable natural definitive host of M. hakubaensis than Japanese water shrews.
Topics: Animals; Cats; Chickens; Cricetinae; Heterophyidae; Japan; Mice; Raccoon Dogs; Rats; Trematoda
PubMed: 33840724
DOI: 10.1292/jvms.20-0700 -
Foodborne Pathogens and Disease Aug 2017To investigate the metacercarial infections of fishborne zoonotic trematodes (FZT), a total of 6815 freshwater fish (in representing 13 species of 5 families) were...
To investigate the metacercarial infections of fishborne zoonotic trematodes (FZT), a total of 6815 freshwater fish (in representing 13 species of 5 families) were collected from Songhua river (n = 2636), Nenjiang river (n = 1935), Mudanjiang river (n = 301), and other lakes or ponds (n = 1943) in 36 representative regions in Heilongjiang Province, China, from August 2012 to December 2015. Metacercariae of four FZT species, that is, Clonorchis sinensis, Metorchis orientalis, Isthmiophora hortensis, and Metagonimus yokogawai, metacercariae were detected in the examination by the artificial digestion method. As the partial data for C. sinensis were previously reported, the remaining three FZT species are to be treated in this study. The overall prevalence of M. orientalis, I. hortensis, and M. yokogawai, metacercariae was 10.54%, 0.28%, and 1.35%, respectively. Metacercariae of M. orientalis were detected in seven fish species, that is, Pseudorasbora parva, Hemiculter leucisculus, Saurogobio dabryi, Rhynchocypris lagowskii, Carassius auratus, Rhodeus ocellatus and Perccottus glehnii. Their prevalences were the highest in false dace, P. parva (26.81%), and in fish from Songhua river (17.94%). Metacercariae of I. hortensis were detected in only one fish species, Misgurnus anguillicaudatus, from Nenjiang river only. Metacercariae of M. yokogawai were detected in three fish species, that is, P. parva, H. leucisculus and S. dabryi. Their prevalences were the highest in sharpbelly, H. leucisculus (6.05%), and in fish from Mudanjiang river (5.65%). This study first demonstrated the existence of M. orientalis, I. hortensis, and M. yokogawai in freshwater fish from Heilongjiang Province, posing a major public health concern. Eight fish species, namely M. anguillicaudatus, P. parva, H. leucisculus, S. dabryi, R. lagowskii, C. auratus, R. ocellatus, and P. glehnii, cannot be eaten raw. Moreover, the findings of this study not only extended the second intermediate host range of FZT, but also improve the information of the distribution of FZT in China.
Topics: Animals; China; Fish Diseases; Fishes; Fresh Water; Humans; Lakes; Metacercariae; Prevalence; Public Health; Rivers; Trematoda; Trematode Infections; Zoonoses
PubMed: 28737961
DOI: 10.1089/fpd.2016.2249 -
Acta Tropica Aug 2014This study confirmed the prevalence of the intestinal fluke Haplorchis taichui (Trematoda: Heterophyidae) among people and fish in Luang Prabang Province, Lao PDR. Fecal...
This study confirmed the prevalence of the intestinal fluke Haplorchis taichui (Trematoda: Heterophyidae) among people and fish in Luang Prabang Province, Lao PDR. Fecal specimens were collected from 559 riparian people (229 males and 330 females), residing in 4 Districts (Luang Prabang, Xieng Ngeun, Pak Ou, and Nam Bak) and were examined by the Kato-Katz fecal smear technique. The overall helminth egg positive rate was 64.9%. The positive rate for small trematode eggs (STE), which may include H. taichui and other heterophyids, Opisthorchis viverrini, and lecithodendriids, was 15.2%. For recovery of adult helminths, 10 STE-positive people were treated with 40mg/kg praziquantel and 15mg/kg pyrantel pamoate, and then purged. Mixed infections with 3 Haplorchis species (H. taichui, H. pumilio, and H. yokogawai), a species of cestode (Taenia saginata), and several species of nematodes including Enterobius vermicularis and hookworms were found. The worm load for trematodes was exclusively high for H. taichui with an average of 7691 specimens per infected person, followed by H. yokogawai (8.3 specimens) and H. pumilio (4.1 specimens). Out of 207 freshwater fish (17 species) purchased in a market in Luang Prabang District, 138 (67%) harboured H. taichui metacercariae (metacercarial burden per fish; 520). Lower prevalence of fish and lower metacercarial density were observed for H. yokogawai (52% and 50 per fish, respectively) and H. pumilio (18% and 3 per fish, respectively). STE found in the surveyed population of Luang Prabang Province were verified to be those of intestinal fukes, particularly H. taichui.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Feces; Female; Fish Diseases; Humans; Laos; Male; Middle Aged; Morpholines; Parasite Egg Count; Trematoda; Trematode Infections; Young Adult
PubMed: 24754919
DOI: 10.1016/j.actatropica.2014.04.020