• BMB Reports
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• 제49권11호
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• pp.590-597
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• 2016

Parasitic diseases remain an unarguable public health problem worldwide. Liver fluke Clonorchis sinensis is a high risk pathogenic parasitic helminth which is endemic predominantly in Asian countries, including Korea, China, Taiwan, Vietnam, and the far eastern parts of Russia, and is still actively transmitted. According to the earlier $8^{th}$ National Survey on the Prevalence of Intestinal Parasitic Infections in 2012, C. sinensis was revealed as the parasite with highest prevalence of 1.86% in general population among all parasite species surveyed in Korea. This fluke is now classified under one of the definite Group 1 human biological agents (carcinogens) by International Agency of Research on Cancer (IARC) along with two other parasites, Opisthorchis viverrini and Schistosoma haematobium. C. sinensis infestation is mainly linked to liver and biliary disorders, especially cholangiocarcinoma (CCA). For the purposes of this mini-review, we will only focus on C. sinensis and review pathogenesis and carcinogenesis of clonorchiasis, disease condition by C. sinensis infestation, and association between C. sinensis infestation and CCA. In this presentation, we briefly consider the current scientific status for progression of CCA by heavy C. sinensis infestation from the food-borne trematode and development of CCA.

• Parasites, Hosts and Diseases
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• 제33권1호
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• pp.61-64
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• 1995

참굴큰입흡충(Gymnophalloides seoi)은 참굴이 매개하는 우리 나라 고유의 인체기생 장흡충의 하나로서, 전남 신안군 도서 지방에서 큰 유행지가 발견된 바 있다. 이 흡충은 췌장 질환과의 관계가 의심되어 의학적 관심의 대상이 되고 있다 이번 증례 보고에서는 당뇨병과 동반된 흥미있는 G. seoi감염 2례를 발견하여 보고하고자 한다. 환자들은 당뇨병 치료를 위해 내원하였으며 내원시 대변검사에서 참굴큰입흡충류(gymnophallid)의 충란이 검출되었다 프라지콴텔 및 하제를 투여한 후 충체를 수집한 결과 G. seoi 충체 772마리 및 10마리가 각각 검출되었다. 증례 I은 62세 남자로 G. seoi의 유행지 부근인 목포에 거주하고 있었고, 증례 II는 인천에 거주하고 있으면서 참굴을 날로 즐겨 먹었다고 하였다. 이 증례들을 볼 때 G. seoi감염이 당뇨병과 어떠한 상관관계를 가지고 있을 가능성을 시사하였다.

• Parasites, Hosts and Diseases
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• 제54권2호
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• pp.173-179
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• 2016

Echinostoma hortense (Digenea: Echinostomatidae) is one of the intestinal flukes with medical importance in humans. However, the mitochondrial (mt) genome of this fluke has not been known yet. The present study has determined the complete mt genome sequences of E. hortense and assessed the phylogenetic relationships with other digenean species for which the complete mt genome sequences are available in GenBank using concatenated amino acid sequences inferred from 12 protein-coding genes. The mt genome of E. hortense contained 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 non-coding region. The length of the mt genome of E. hortense was 14,994 bp, which was somewhat smaller than those of other trematode species. Phylogenetic analyses based on concatenated nucleotide sequence datasets for all 12 protein-coding genes using maximum parsimony (MP) method showed that E. hortense and Hypoderaeum conoideum gathered together, and they were closer to each other than to Fasciolidae and other echinostomatid trematodes. The availability of the complete mt genome sequences of E. hortense provides important genetic markers for diagnostics, population genetics, and evolutionary studies of digeneans.

• Parasites, Hosts and Diseases
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• 제55권4호
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• pp.451-455
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• 2017

Echinostoma cinetorchis is an oriental intestinal fluke causing significant pathological damage to the small intestine. The aim of this study was to determine a full-length cDNA sequence of E. cinetorchis endoribonuclease (RNase H; EcRNH) and to elucidate its molecular biological characters. EcRNH consisted of 308 amino acids and showed low similarity to endoribonucleases of other parasites (<40%). EcRNH had an active site centered on a putative DDEED motif instead of DEDD conserved in other species. A recombinant EcRNH produced as a soluble form in Escherichia coli showed enzymatic activity to cleave the 3'-O-P bond of RNA in a DNA-RNA duplex, producing 3'-hydroxyl and 5'-phosphate. These findings may contribute to develop antisense oligonucleotides which could damage echinostomes and other flukes.

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.249-257
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• 2009

A survey was performed to investigate the infection status of fishborne trematode (FBT) metacercariae in freshwater fish from Guangxi Zhuang Autonomous Region, China. A total of 307 freshwater fish of 31 species were collected from 5 administrative regions of Guangxi Zhuang Autonomous Region. They were examined by artificial digestion method from July 2003 to August 2004. No metacercariae were detected in fish from Fusui-xian. In fish from Mashan-xian and a market in Nanning, 3 species of metacercariae, Haplorchis taichui, Haplorchis pumilio, and Centrocestus formosanus, were mainly detected. Metacercariae (8 in number) of Clonorchis sinensis were found in 1 Chanodichthys dabryi purchased from a market in Nanning. In fish from Yangshuo, Metagonimus yokogawai metacercariae were detected from all 18 fish species examined. Total 13 C. sinensis metacercariae were found in 3 out of 10 Hemibarbus maculatus from Yangshuo. All7 Zacco platypus from Yangshuo were infected with 8-112 Echinochasmus perfoliatus metacercariae. In fish from Binyang-xian, H. pumilo metacercariae were mainly detected in all 5 fish species examined, and only 1 metacercaria of C. sinensis was found in a Hemiculter leucisculus. From the above results, it was confirmed that some species of freshwater fish play a role of second intermediate hosts for FBT in Guangxi Zhuang Autonomous Region, China. In particular, 4 species of intestinal flukes, M. yokogawai, H. taichui, H. pumilio, and C. formosanus, were prevalent in fish hosts, whereas C.sinensis metacercariae were detected only in 3 fish species.

• Parasites, Hosts and Diseases
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• 제58권3호
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• pp.333-338
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• 2020

A small survey was performed to investigate the recent infection status of Clonorchis sinensis and other zoonotic trematode metacercariae in freshwater fish from a local market of Yen Bai city, Yen Bai province, northern Vietnam. A total of 118 fish in 7 species were examined by the artificial digestion method on March 2016. The metacercariae of 4 species of zoonotic trematodes, i.e., C. sinensis, Haplorchis pumilio, Haplorchis taichui, and Centrocestus formosanus, were detected. The metacercariae of C. sinensis were found in 62 (69.7%) out of 89 fish (5 species), and their intensity of infection was very high, 81.2 per fish infected. Prevalences of 3 intestinal flukes, H. pumilio, H. taichui and C. formosanus, were 75.0%, 47.6%, and 31.7% in positive fish species, respectively, with the metacercarial intensities of 15.5, 10.3, and 2.2 per fish infected. From the above results, it has been confirmed that various species of freshwater fish continue to play the role of the infection source of C. sinensis and other zoonotic trematodes in Yen Bai city, Yen Bai province, northern Vietnam. It is of particular note that the prevalence and intensity of C. sinensis metacercariae are much higher than those reported in previous studies in fish in northern Vietnam.

• Parasites, Hosts and Diseases
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• 제22권1호
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• pp.43-50
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• 1984

이형흡충류의 하나인 Stellantchasmus falcatu에 의한 인체기생 2례가 praziquantel투약후 성충을 수집함으로써 화인되었다. 환자는 서울에 거주하는 24세 (제 1례) 및 55세 (제 2례) 남여로 제 1페는 설사, 복통 등 소화기증상과 불정맥(arrhythmia) 등 심식증상을 호소하면서 대편내에 광절렬류조충란이 양성이었고 제 2례는 소화불량과 조충류 편절 배출을 호소하였다. 조충감염 치료를 위해 praziquantel 15∼20mg/kg를 투여하고 MgSO4 30g으로 충체배출을 유도한 바 배출된 조충을 각각 확인하였다. 그러나 나머지 설사편을 입체해부현미경으로 세밀히 조사한 결과 제 1례에서는 188마리의 S. falcatus와 다른 3종의 이형흡충류가, 제 2례에서는 5마리의 S. falcatus가 수집되었다. 환자들은 숭어(Mugil cephalus) 등 반염수9을 회로 먹었다고 하며 이들이 감염원일 것으로 추측되었다.

• Parasites, Hosts and Diseases
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• 제45권1호
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• pp.33-38
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• 2007

To know the prevalence of heterophyid trematodes among inhabitants of a southern coastal village, i.e., Sacho-ri, Gangjin-gun, Jeollanam-do(Province), 82 stool samples were examined on helminth eggs and protozoan cysts using Kato-Katz and formalin-ether sedimentation techniques. Total 33 people(40.2%) were positive for trematodes(Heterophyes nocens; 15 people, Pygidiopsis summa; 3, Metagonimus sp.; 4, Clonorchis sinensis; 7, Gymnophalloides seoi; 6) and/or protozoa(Entamoeba coli; 3). Among intestinal trematode egg positive cases, 17 were treated with praziquantel and their whole diarrheic stools were collected after purgation. Adult flukes of H. nocens(number of specimens=1,294), P. summa(386), Stellantchasmus falcatus(5), Stictodora lari(4), and Heterophyopsis continua(1) were collected using a stereomicroscope. To know the source of human H. nocens infections in this village, metacercarial infections in mullets(10) were examined and most H. nocens metacercariae(101/105, 96.2%) were found in the trunk portion. From above results, the surveyed coastal village has been newly known as an endemic focus of human H. nocens infection and consuming raw mullets was the presumable source of human heterophyid infections.

• Parasites, Hosts and Diseases
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• 제46권2호
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• pp.77-82
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• 2008

Fishborne zoonotic metacercariae have not been reported from brackish water and marine fish from Vietnam waters although these parasites are common in the country's freshwater fish. Both wild-caught and cultured grouper (Epinephelus coioides and Epinephelus bleekeri), and mullet (Mugil cephalus) from brackish and marine waters located in Khanh Hoa province in central coastal Vietnam were examined, and found positive for zoonotic trematode metacercariae. From grouper, Heterophyopsis continua and Procerovum varium were recovered. The prevalence of H. continua ranged from 2.0 to 6.0% and that for P. varium ranged from 11.6 to 15.8%. Mullet were infected with Pygidiopsis summa and H. continua; both of these species are new records for Vietnam. The prevalence of P. summa in mullet was generally high, ranging from 17.6 to 75.5%, and was significantly higher than the prevalence of H. continua (2.5 to 32.4%). There were no significant differences in the prevalence of metacercariae between grouper from natural or cultured habitats, indicating that the highest risk of infection occurs in the wild-caught state prior to their placement in culture. Further, there was no difference in metacercarial prevalence between the 2 species of grouper. Infected wild-caught seed were only observed from January to October. Monthly variation in prevalence suggests seasonal variation in mullet infections occurs in this region with the highest transmission taking place from October to December. Basic investigations on the ecology and epidemiology of these intestinal flukes need to be carried out to determine their significance as a public health problem and the aspects of their biology that may be vulnerable to control interventions.

• Parasites, Hosts and Diseases
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• 제22권1호
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• pp.37-42
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• 1984

이형흡충류의 하나인 Heterophyes heterophkes nocens에 의한 인체감염 2례가 치료후 충체를 얻세(제1예) 및 24세(제2예) 남자로 전남 고흥군 해안마을이 고향이거나 현재 거주지이며 제1예는 상복부 통증 및 소화불량 등의 증상을, 제2예는 EKG검사상 불정맥 및 ventricular premature be각 등 심장 기능이상과 설사, 복통 등 소화기 증상을 호소하였다. 1983연 4월 및 8월에 bithionol 30mg/kg 또는 prasiquantel 15mg/kg을 투여하고 설사편을 입체해부현미경하에서 검사한 바 각각 35및 67마리의 H. heterophyes noces가 수집되었다. 대편검사 또는 충체검사상 제 1예는 간흡충이, 제2예는 3종의 다른 이형흡충류와 광절렬두조충이 동시 감염되어 있었다. 환자들은 H. heterophyes nocens의 중간숙주인 숭어 (Mugil cephalus), 농어 (Lateolalabrax japonicus) 및 문절망둑(Acanthogobius navimanus) 등 반염수산 어류를 회로 먹은 정력이 있었다.