• Parasites, Hosts and Diseases
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• 제38권1호
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• pp.1-7
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• 2000

In certain Asian countries, a third form of human Taenia, also known as the Asian Taenia, has been discovered. This Asian Taenia seems to be an intermediate between Taenia solium and T. saginata since in morphological terms it is similar to T. saginata, yet biologically, as it uses the same intermediate host (pigs) , it is more akin to T. solium. Taenia solium causes human cysticercosis, while T. saginata does not. It is not known whether the Asian taeniid is able to develop to the larval stage in humans or not. The arguments proposed by those authors who consider it unlikely that the Asian Taenia causes human cysticercosis are: (a) its molecular similarities with T. saginata: (b) the absence of cases of human cysticercosis in populations where the Asian adult is highly prevalent; and (c) the unsupporting results derived from an experimental infestation study. These three arguments are debated, although bearing in mind that at present there is still no clear scientific data to support that human cysticercosis can be caused by the Asian Taenia.

• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.51-54
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• 2013

Not only Taenia solium and Taenia saginata, but also Taenia asiatica infects humans. The last species is not included in the evaluation of the specificity of the immunodiagnostic techniques for taeniasis/cysticercosis. There is currently no specific immunodiagnostic method for T. asiatica available. Therefore, due to the fact that molecular techniques (the only tool to distinguish the 3 Taenia species) are normally not employed in routine diagnostic methods, the 2 questions concerning T. asiatica (its definite geographic distribution and its ability to cause human cysticercosis), remain open, turning T. asiatica into the most neglected agent of human taeniasis-cysticercosis.

• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.1-8
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• 2013

Taenia solium, T. saginata, and T. asiatica are taeniid tapeworms that cause taeniasis in humans and cysticercosis in intermediate host animals. Taeniases remain an important public health concerns in the world. Molecular diagnostic methods using PCR assays have been developed for rapid and accurate detection of human infecting taeniid tapeworms, including the use of sequence-specific DNA probes, PCR-RFLP, and multiplex PCR. More recently, DNA diagnosis using PCR based on histopathological specimens such as 10% formalin-fixed paraffin-embedded and stained sections mounted on slides has been applied to cestode infections. The mitochondrial gene sequence is believed to be a very useful molecular marker for not only studying evolutionary relationships among distantly related taxa, but also for investigating the phylo-biogeography of closely related species. The complete sequence of the human Taenia tapeworms mitochondrial genomes were determined, and its organization and structure were compared to other human-tropic Taenia tapeworms for which complete mitochondrial sequence data were available. The multiplex PCR assay with the Ta4978F, Ts5058F, Tso7421F, and Rev7915 primers will be useful for differential diagnosis, molecular characterization, and epidemiological surveys of human Taenia tapeworms.

• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.9-17
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• 2013

History and current status of human taeniasis in the Republic of Korea, due to Taenia solium, Taenia asiatica, and Taenia saginata, are briefly reviewed. Until the 1980s, human taeniasis had been quite common in various localities of Korea. A study from 1924 reported 12.0% egg prevalence in fecal examinations. Thereafter, the prevalence of Taenia spp. ranged from 3% to 14% depending on the time and locality. Jeju-do, where pigs were reared in a conventional way, was the highest endemic area of taeniasis. An analysis of internal transcribed spacer 2 and mitochondrial cytochrome c oxidase 1 genes of 68 taeniasis cases reported from 1935 to 2005 in Korea by a research group revealed the relative occurrence of the 3 Taenia spp. as follows: T. solium (4.4%), T. asiatica (75.0%), and T. saginata (20.6%). However, national surveys on intestinal helminths conducted every 5 years on randomly selected people revealed that the Taenia egg prevalence dropped from 1.9% in 1971 to 0.02% in 1997 and finally to 0.0% in 2004. With the exception of 3 egg-positive cases reported in 2008 and 2 worm-proven cases in 2011, no more cases have been officially recorded. Based on these surveys and also on other literature, it can be concluded that taeniasis has virtually disappeared from Korea, although a few sporadic cases may remain hidden. Human cysticercosis is also expected to disappear within a couple of decades in Korea.

• Parasites, Hosts and Diseases
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• 제30권1호
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• pp.21-24
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• 1992

Asian Taenia saginata낭미충에 의한 인체감염이 성립된다는 것을 실험적으로 확인하였다. 감염에 사용한 5개의 낭미충은 우리나라 돼지간에 자연감염되었던 것으로 청주 소재 도축장에서 얻은 것이었다. 감염 후 제76일에 활발한 운동성을 가진 수태편절이 자연배출되었다. 2년 후 치료하여 두마리의 성충을 회수하였다. 두절에는 소구가 없었고 수태편절의 자궁측지수는 16∼21개 이었으며 다른 부분은 형태학상으로 무구조충과 유사하였다. 돼지 간을 날로 먹으면 우리나라에서 Asian Taenia saginata에 감염될 수 있다는 것을 실험적으로 증명하였다.

• Parasites, Hosts and Diseases
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• 제47권1호
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• pp.73-77
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• 2009

Differential diagnosis of Taenia asiatica infection from other human taeniases by serology has been tested. An enzyme-linked immunoelectrotransfer blot (EITB) was applied to subjected human sera and tapeworm materials. Thirty-eight proteins reactive to serum IgG were observed between 121 and 10 kDa in adult worms, and more than 22 serum-reactive components between 97kDa and 21.5kDa were observed in eggs of T. asiatica. Antigens of adult T. asiatica revealed immunoblot bands between 120 and 21.5 kDa against T. asiatica infected sera. Antigens of adult Taenia saginata revealed 110-100, 66, 58-56, and 46 kDa immunoblot bands against T. asiatica infected sera. Antigens of adult Taenia solium also revealed 99-97, 68-66, and 46 kDa bands against T. asiatica infected sera. The immunoblot band of 21.5 kDa exhibited specificity to T. asiatica.

• Parasites, Hosts and Diseases
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• 제31권1호
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• pp.1-6
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• 1993

현재 인체에는 기새하는 Taenia 조충으로는 돼지고기 유구낭미층(Cysticercus cellulosae)을 먹어서 감염되는 Taenia solium Linnaeus 1785과 쇠고기의 무구낭미층(Cysticercus bovis)을 먹어서 감염되는 Taenia saginata Goeze 1782 두 종이 알려져 있다. 한편 인체에 기생하는 제 3의 Taenia 조충으로 최근 타이완, 한국, 인도내시아, 태국, 필리핀 등 아시아국가를 중심으로 발견되는 Asian Taenia saginata 조충은 돼지나 소의 간 또는 내장에 있는 내장형낭미충을 먹어서 감염되는 것으로 추정된다. 그러나 이러한 생활사상의 구분에도 불구하고 형태하적으로는 본충이 Taenia saginate Groeze 1782와 유사하기 때문에 아직 신종으로 인정되지 않은 상태이다. 이에 연구자들은 Asian Taenia saginata 조충의 형태학적 구분점을 새로이 발견하고 학명으로서 Taenia asiatica sp.n.(한국명:아시아조총)을 제시하고자 한다. 감별적으로는 1.선충의 두절에 있는 액취의 존재, 2. 성충의 수태편절에서 관찰되는 자궁세지의 수, 3.성충의 수태관절에서 관찰되는 미돌기의 존재 및 4.유추의 낭벽표면에서 관찰되는 사마귀양 구조가 광학 및 전자현경적으로 관찰되었다. 이중 '자궁세지'와 '미돌기'는 새로이 관찰하여 기재하는 구조물로서 처음으로 Taeniid의 종감별에 사용하였다.

• Parasites, Hosts and Diseases
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• 제46권4호
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• pp.235-241
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• 2008

Taeniasis has been known as one of the prevalent parasitic infections in Korea. Until recently, Taenia saginata had long been considered a dominant, and widely distributed species but epidemiological profiles of human Taenia species in Korea still remain unclear. In order to better understand distribution patterns of human Taenia tapeworms in Korea, partial nucleotide sequences of mitochondrial cox1 and ITS2 (internal transcribed spacer 2) were determined, along with morphological examinations, on 68 Taenia specimens obtained from university museum collections deposited since 1935. Genomic DNA was extracted from formalin-preserved specimens. Phylogenetic relationships among the genotypes (cox1 haplotype) detected in this study were inferred using the neighbor-joining method as a tree building method. Morphological and genetic analyses identified 3 specimens as T. solium, 51 specimens as T. asiatica, and 14 specimens as T. saginata. Our results indicate that all 3 Taenia tapeworms are sympatrically distributed in Korea with T. asiatica dominating over T. saginata and T. solium.

• Parasites, Hosts and Diseases
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• 제43권4호
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• pp.157-160
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• 2005

A 29kDa cysteine protease of Taenia solium metacestodes was purified by Mono Q anion-exchanger and Superose 6 HR gel filtration chromatography. The enzyme was effectively inhibited by cysteine protease inhibitors, such as iodoacetic acid (IAA) and trans-epoxy-succinyl-L-leucyl-amido (4-guanidino) butane (E-64) while inhibitors acting on serine- or metallo-proteases did not affect the enzyme activity. The purified enzyme degraded human immunoglobulin G (IgG), collagen and bovine serum albumin (BSA), but human IgG was more susceptible for proteolysis by the enzyme. To define the precise biological roles of the enzyme, more detailed biochemical and functional studies would be required.

• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.31-36
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• 2013

An overview of the epidemiological, biological, and clinical studies of Taenia and taeniasis in Taiwan for the past century is presented. The phenomenal observations that led to the discovery of Taenia asiatica as a new species, which differ from Taenia solium and Taenia saginata, are described. Parasitological surveys of the aborigines in Taiwan revealed a high prevalence of taeniasis, which might be due to the culture of eating raw liver of hunted wild boars. Chemotherapeutic deworming trials involving many patients with taeniasis were discussed. Praziquantel was found to be very effective, but sometimes complete worms could not be recovered from the feces after treatment, probably due to the dissolution of the proglottids. Atabrine, despite some side effects, can still be used, in properly controlled dosages, as the drug of choice for human T. asiatica infection if we need to recover the expelled worms for morphological examinations. Research results on the infection of T. asiatica eggs from Taiwan aborigines in experimental animals were also noted. Since the pig serve as the natural intermediate host of T. asiatica and the predilection site is the liver, a differential comparison of other parasitic pathogens that might cause apparently similar lesions is also presented.