• Parasites, Hosts and Diseases
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• v.38 no.1
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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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• v.51 no.1
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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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• v.51 no.1
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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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• v.51 no.1
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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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• v.30 no.1
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• pp.21-24
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• 1992

The infectivity of metacestodes of Asian Taenia saginata, now tentatively called Taenia saginata taiwanensis, in human host was confirmed. The metacestodes used in experimental infection were collected from the livers of naturally infected domestic pigs at an abattoir in Cheongju City, Korea. The first gravid proglottid was spontaneously discharged 76 days after infection. Two worms were recovered two years later by chemotherapy. The scolex was unarmed. The number of main uterine branches, varying from 16 to 21, was similar to that of classical Taenia saginata. The liver of pigs was confirmed to be an infection source of Asian T. saginata in Korea.

• Parasites, Hosts and Diseases
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• v.47 no.1
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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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• v.31 no.1
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• pp.1-6
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• 1993

Among taenited tapeworms inferting humans though pork or beef, Taenia solium Linnaeus 1758 and Taenia sagina Goeze 1782 have already been. Based on the morphologic characteristics of adult and metacestodes of Asian Taenia saginata, the third kind of human taeniid tapeworm konwn to disdute in Asian counteries, a new spscies name of Taenia asiatica is proposed. In addition to the known biology in their intermediate hosts, T.asiatica was diffierent morphologically from Taenia saginata Goeze 1782 in having the unarmed rostellum on the scolex of adlut, the large number of 'unterinetwigs' and the existence of 'posterior protuberance'. These structures in the gravid proglottids were used as taxonmic keys in taeniid tapeworms for the first time. T. asiatica metacestode (Cysticercus viscerotropica)was different morphologically from T. saginata metacestode (Cysticercus bovis) in having wartlike formations on external surface of the bladder wall.

• Parasites, Hosts and Diseases
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• v.46 no.4
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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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• v.43 no.4 s.136
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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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• v.51 no.1
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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.