Taenia Asiatica

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Keeseon S. Eom - One of the best experts on this subject based on the ideXlab platform.

  • Taenia Asiatica: Historical overview of Taeniasis and cysticercosis with molecular characterization.
    Advances in Parasitology, 2020
    Co-Authors: Keeseon S. Eom, Han Jong Rim, Hyeong-kyu Jeon
    Abstract:

    Asian Taenia is a human-infecting Taenia tapeworm known as Taenia Asiatica following morphological examination of adult and larval stages of the tapeworm by Eom and Rim (1993). The life cycle of T. Asiatica differs from that of T. saginata in its intermediate host (pigs versus cattle) as well as in the infected organs (liver versus muscle). T. Asiatica can be differentiated from T. solium and T. saginata by examination of morphological characteristics such as the scolex, mature and gravid proglottids in the adult stage, and the scolex and bladder surface in the larval stage. T. Asiatica has been identified in Korea, Taiwan, the Philippines, China, Thailand, Indonesia, Vietnam, Japan, Lao PDR, Nepal and India. The molecular tools employed for T. Asiatica identification have been developed to differentiate T. Asiatica from other human-infecting Taenia tapeworms based on genetic information such as nucleotide sequence of mitochondrial genes, nuclear ribosomal genes and nuclear genes that lead to development of the subsequent molecular techniques, such as PCR-RFLP, PCR-RAPD, BESST-base, LAMP and qPCR. Investigation of the phylogenetic relationships among human Taenia species revealed that T. Asiatica is a sister species with T. saginata, which is genetically more similar than other Taenia species in terms of the nucleotide sequences of cox1, nad1 and 28S rDNA. The mitochondrial genomes of human Taenia tapeworms comprise 13,703bp (T. Asiatica), 13,670bp (T. saginata) and 13,709bp (T. solium), and contain 36 genes including 12 protein-coding genes, 2 ribosomal RNAs (rRNAs, a small and a large subunit), and 22 transfer RNAs (tRNAs). Sequence differences in the full genome of T. Asiatica and T. saginata mitochondria is 4.6%, while T. solium differs by 11%. Hox gene orthology in T. Asiatica was established by comparative analysis with Platyhelminthes Hox genes. T. Asiatica Hox revealed six Hox orthologs including two lab/Hox1, two Hox3, one Dfd/Hox4 and one Lox/Lox4. Hybridization between T. Asiatica and T. saginata was definitely observed in these species which are sympatrically endemic in the regions of Korea, Thailand, China and Lao PDR. Comparative analyses of T. Asiatica, T. saginata and T. solium genomes were also reported with genome features. Taenia asiaticus nomen novum was proposed for T. AsiaticaEom and Rim, 1993 which is a homonym of T. Asiatica Linstow, 1901 (Davaineidae).

  • First ultrastructural data on the human tapeworm Taenia Asiatica eggs by scanning and transmission electron microscopy (SEM, TEM)
    Parasitology Research, 2016
    Co-Authors: M. Teresa Galán-puchades, Yichao Yang, Antonio Marcilla, Seongjun Choe, Hansol Park, Antonio Osuna, Keeseon S. Eom
    Abstract:

    Humans are definitive hosts of three species of the Taenia genus, namely Taenia solium, Taenia saginata and Taenia Asiatica. The relative novelty of the latter explains the lack of knowledge concerning certain relevant aspects related to this parasite, such as its definite geographical distribution and whether its eggs can infect humans or not. So far, only the eggs of T. solium are known to be infective for humans, producing cysticercosis. Although eggs contain the infective stage, the oncosphere, there is a lack of research on the ultrastructure of eggs of human taeniids. We show, for the first time, the ultrastructure of eggs of T. Asiatica by means of SEM and TEM analyses. We detected all the envelopes, namely the egg shell, vitelline layer, outer embryophoric membrane, embryophore, granular layer, basal membrane, oncospheral membrane and oncospheral tegument. Hooks surrounded by myofibrils and glycogen-like particles, the two types of secretory granules of the penetration glands, as well as several nuclei and mitochondria were also revealed in the oncospheres. In addition to the already known structures in eggs from other Taenia species, the presence of two types of small vesicles is described herein, possibly corresponding to exosomes and ectosomes because of their shape and size, which could participate in the host/parasite intercellular communication.

  • Molecular Approaches to Taenia Asiatica
    The Korean Journal of Parasitology, 2013
    Co-Authors: Hyeong-kyu Jeon, Keeseon S. Eom
    Abstract:

    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.

  • Geographical Distribution of Taenia Asiatica and Related Species
    The Korean Journal of Parasitology, 2009
    Co-Authors: Keeseon S. Eom, Hyeong-kyu Jeon, Han Jong Rim
    Abstract:

    Geographical information of Taenia Asiatica is reviewed together with that of T. solium and T. saginata. Current distribution of T. Asiatica was found to be mostly from Asian countries: the Republic of Korea, China, Taiwan, Indonesia, and Thailand. Molecular genotypic techniques have found out more countries with T. Asiatica from Japan, the Philippines, and Vietnam. Specimens used in this paper were collected from around the world and mostly during international collaboration projects of Korean foundations for parasite control activities (1995-2009) in developing countries.

  • Immunoblot Patterns of Taenia Asiatica Taeniasis
    The Korean Journal of Parasitology, 2009
    Co-Authors: Hyeong-kyu Jeon, Keeseon S. Eom
    Abstract:

    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 97 kDa and 21.5 kDa 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.

Akira Ito - One of the best experts on this subject based on the ideXlab platform.

  • Taeniasis and cysticercosis in Asia: A review with emphasis on molecular approaches and local lifestyles.
    Acta Tropica, 2019
    Co-Authors: Akira Ito, Tetsuya Yanagida, Paron Dekumyoy, Munehiro Okamoto, Toni Wandra, Christine M. Budke
    Abstract:

    Abstract Taeniasis is an important parasitic condition in Asia, especially since all three human-infecting Taenia spp., Taenia solium, Taenia saginata, and Taenia Asiatica are found in this region. These three species are believed to be sympatrically distributed, with the largest disease burden found in remote and rural areas where people raise pigs and cattle in a traditional manner. Recent studies revealed that T. Asiatica and T. saginata are genetically-related sister species that are not completely reproductively isolated from each other. Current evidence indicates that most T. Asiatica adult worms are hybrid-derived descendants. Moving forward, nuclear DNA analysis will be critical in further assessing the species circulating locally. Lifestyle choices, such as the consumption of undercooked meat, are important in maintaining the life cycles of these parasites. In addition, poor hygiene and sanitation, in highly endemic areas, make disease control difficult, resulting in the need for sustainable education programs. An overview of the present situation of Taeniasis and cysticercosis in Asia is provided, followed by a discussion of molecular approaches to species assessment and the impact of human lifestyles on parasite transmission.

  • The present situation of human Taeniases and cysticercosis in Asia.
    Recent Patents on Anti-Infective Drug Discovery, 2015
    Co-Authors: Akira Ito, Agathe Nkouawa, Paron Dekumyoy, Munehiro Okamoto, Toni Wandra, Christine M. Budke
    Abstract:

    Three human Taenia species, Taenia solium, Taenia saginata, and Taenia Asiatica, are endemic in rural regions of Asia, with these species sympatrically distributed in parts of Thailand and China. The pork tapeworm, T. solium, is the most pathogenic to humans, causing cysticercosis and neurocysticercosis (NCC). Due to its public health impact, T. solium Taeniasis/cysticercosis is one of 17 neglected tropical diseases (NTDs) prioritized by the World Health Organization. In this review, the current status of Taeniasis and NCC in several Asian countries will be presented as will possible prevention and control strategies. Among the known T. solium endemic areas in Asia, Bali, Indonesia is of high importance due to the risk of tourists becoming infected. Therefore, special attention will be given to ongoing control initiatives in Bali.

  • REVIEW TaeniaSIS AND CYSTICERCOSIS IN ASIA AND THE PACIFIC: PRESENT STATE OF KNOWLEDGE AND PERSPECTIVES
    2015
    Co-Authors: Akira Ito, Minoru Nakao, Yasuhito Sako, Munehiro Okamoto, Hiroshi Yamasaki, Thomas Suroso, Toni W, Kazuhiro Nakaya
    Abstract:

    Abstract. Several topics on Taeniasis and cysticercosis in Asia and the Pacific are overviewed. In Asia and the Pacific, three human taeniid species have been recognized: Taenia solium, Taenia saginata and Taenia Asiatica. The first topic is on evolution of T. solium. Mitochondrial DNA polymorphisms of T. solium worldwide are discussed with emphasis of two specific genotypes: American-African and Asian. The second topic is recent major advances in sero- and molecular-diagnosis of T. solium cysticercosis in humans, pigs and dogs. The third is the present situation of T. solium Taeniasis/cysticercosis in Papua (Irian Jaya), Indonesia. The forth is the present situation of T. solium cysticercosis and T. saginata Taeniasis in Bali, Indonesia. The fifth is the present situation of T. Asiatica Taeniasis in Asia and the Pacific and in North Sumatra, Indonesia. The sixth is on the debate of the exact definition of T. Asiatica. Because T. Asiatica can not be differentiated from T. saginata morphologically, it is time to re-evaluate T. saginata in Asia and the Pacific. New and broad-based surveys across this region are necessary from epidemiological and public health perspectives, based on evidence

  • Genotypic relationships between Taenia saginata, Taenia Asiatica and their hybrids
    Parasitology, 2013
    Co-Authors: Kanako Yamane, Jitra Waikagul, Xingwang Chen, Minoru Nakao, Agathe Nkouawa, Yasuhito Sako, Tetsuya Yanagida, Paron Dekumyoy, Akira Ito
    Abstract:

    SUMMARY Partial sequences of the DNA polymerase delta (pold) gene from Taenia saginata-like adult worms were sequenced.Phylogeneticanalysisrevealedthatpoldgenesequenceswereclearlydividedintotwoclades,differingfromeachotherinfiveto seven nucleotides. There is little doubt that T. saginata and Taenia Asiatica were once separated into two distinct taxa ashas been concluded in previous studies. On the other hand, most of the adult worms, which were identified as T. AsiaticausingmitochondrialDNA,werehomozygousforanallelethatoriginatedfromthealleleofT.saginataviasinglenucleotidesubstitution. These results indicate that most of the adult worms, which had been called T. Asiatica, are not actually ‘pureT. Asiatica’ but instead originated from the hybridization of ‘pure T. saginata’ and ‘pure T. Asiatica’.Key words: Taenia saginata, Taenia Asiatica, hybrid, nuclear-mitochondrial discordance, pold gene. INTRODUCTION The genus Taenia consists of nearly 50 species(Loos-Frank, 2000; Hoberg, 2006; Rossin et al.2010; Haukisalmi et al. 2011), including three cur-rentlyidentified‘humanTaenia’spp.(Hoberg,2006),Taenia solium, T. saginata and T. Asiatica. T. soliumis one of the most important cestodes concerninghumanhealth,butT.saginataandT.Asiaticaarealsoimportant for the zootechnical and veterinary sci-ences due to their being a common source of econ-omic loss; their larval stages, T. saginata parasitizethe muscle of cattle, while those of T. Asiaticaparasitize the viscera of pig.It has been a long-standing puzzle that adulttaeniid tapeworms expelled from people in Asiancountries seemed to be T. saginata, although thesepeople ate pork rather than beef (Fan, 1988;Simanjuntak et al. 1997; Ito et al. 2003). Taiwan,Indonesian and Korean researchers energeticallystudied the T. saginata-like tapeworm, includingexperimental infections, and concluded that thisparasite was an independent new species (Chao andFan, 1986; Fan et al. 1990a,b,c). Several othersworking on molecular differences between‘Asian Taenia’ and T. saginata rejected this idea(Zarlenga et al. 1991; Bowles and McManus, 1994;Simanjuntak et al. 1997). In 1993, Eom and Rim(1993) described this Asian Taenia as a new species,T. Asiatica, based on morphological observations.However, due to the morphological similarity and avery small difference in the mitochondrial DNAsequences between T. saginata and T. Asiatica, it hasbeen debated whether these two taxa belong tothe same species or are indeed two distinct species(Eom et al. 2002; Hoberg, 2002; Flisser et al. 2004;Okamoto et al. 2007).Because there are many species concepts, the defi-nition of a species is also varied. Of these, the bio-logicalspeciesconceptisthemostwidelyaccepted.Itdefines species in terms of their ability to interbreed.For instance, Mayr (1996)defined a species asfollows: ‘species are groups of interbreeding naturalpopulations that are reproductively isolated fromother such groups.’ In other words, if reproductiveisolation is incomplete, hybridization betweenspecies that were considered to be distinct speciesshould occur. And if hybridization occurred once,nuclear-mitochondrial discordance should be de-tected in their descendants.In previous reports, four adult worms showingnuclear-mitochondrial discordance were found in

  • Taeniases and cysticercosis in Indonesia: past and present situations.
    Parasitology, 2013
    Co-Authors: Toni Wandra, Yasuhito Sako, Akira Ito, Nyoman Sadra Dharmawan, Kadek Swastika, Munehiro Okamoto
    Abstract:

    The main aim of this study is to overview the past and present situations of human Taeniases and cysticercosis in Indonesia and including future perspectives. Through joint projects from 1996, we have confirmed the occurrence of Taenia saginata (beef tapeworm) in Bali, of Taenia solium (pork tapeworm) mainly in Papua and sporadically in Bali, and of Taenia Asiatica in North Sumatra. These Taeniases were caused through eating uncooked pork and pig viscera for T. solium and T. Asiatica , respectively, and beef for T. saginata . The distribution of these tapeworms in Indonesia is basically highly restricted by the traditional cultural and religious backgrounds in each island. T. saginata is relatively common in Bali although people consume pork ‘ lawar’ more than beef ‘ lawar’ . Taeniases due to T. saginata or T. Asiatica and T. solium and cysticercosis due to T. solium have also been sporadically reported in some other islands. Among these species, T. solium is exceptional since humans can be infected not only by larval stages (cysticerci) in pork but also by eggs released from human tapeworm carriers. Cysticercosis has been confirmed in Indonesia in humans, pigs and even dogs.

Toni Wandra - One of the best experts on this subject based on the ideXlab platform.

  • Identification of a previously unidentified endemic region for Taeniasis in North Sumatra, Indonesia.
    Acta Tropica, 2019
    Co-Authors: Umar Zein, Toni Wandra, Sahat Siregar, Indra Janis, Abdul Harris Pane, Jan Maurisdo Purba, Teguh Wahyu Sardjono, Kadek Swastika, Hadyanto Lim, Tetsuya Yanagida
    Abstract:

    In North Sumatra, Indonesia, Taeniasis has previously been reported solely from Samosir Island located in Lake Toba. In 2014, however, three individuals were identified with Taeniasis after voluntarily reporting for treatment, stimulating a subsequent investigation conducted in 2017. This investigation indicated that a previously unidentified endemic area exists in Simalungun District. Molecular analysis showed the worms to be hybrid-derived descendants of Taenia Asiatica and Taenia saginata, which is consistent with specimens identified previously from Samosir Island.

  • Taeniasis and cysticercosis in Asia: A review with emphasis on molecular approaches and local lifestyles.
    Acta Tropica, 2019
    Co-Authors: Akira Ito, Tetsuya Yanagida, Paron Dekumyoy, Munehiro Okamoto, Toni Wandra, Christine M. Budke
    Abstract:

    Abstract Taeniasis is an important parasitic condition in Asia, especially since all three human-infecting Taenia spp., Taenia solium, Taenia saginata, and Taenia Asiatica are found in this region. These three species are believed to be sympatrically distributed, with the largest disease burden found in remote and rural areas where people raise pigs and cattle in a traditional manner. Recent studies revealed that T. Asiatica and T. saginata are genetically-related sister species that are not completely reproductively isolated from each other. Current evidence indicates that most T. Asiatica adult worms are hybrid-derived descendants. Moving forward, nuclear DNA analysis will be critical in further assessing the species circulating locally. Lifestyle choices, such as the consumption of undercooked meat, are important in maintaining the life cycles of these parasites. In addition, poor hygiene and sanitation, in highly endemic areas, make disease control difficult, resulting in the need for sustainable education programs. An overview of the present situation of Taeniasis and cysticercosis in Asia is provided, followed by a discussion of molecular approaches to species assessment and the impact of human lifestyles on parasite transmission.

  • The present situation of human Taeniases and cysticercosis in Asia.
    Recent Patents on Anti-Infective Drug Discovery, 2015
    Co-Authors: Akira Ito, Agathe Nkouawa, Paron Dekumyoy, Munehiro Okamoto, Toni Wandra, Christine M. Budke
    Abstract:

    Three human Taenia species, Taenia solium, Taenia saginata, and Taenia Asiatica, are endemic in rural regions of Asia, with these species sympatrically distributed in parts of Thailand and China. The pork tapeworm, T. solium, is the most pathogenic to humans, causing cysticercosis and neurocysticercosis (NCC). Due to its public health impact, T. solium Taeniasis/cysticercosis is one of 17 neglected tropical diseases (NTDs) prioritized by the World Health Organization. In this review, the current status of Taeniasis and NCC in several Asian countries will be presented as will possible prevention and control strategies. Among the known T. solium endemic areas in Asia, Bali, Indonesia is of high importance due to the risk of tourists becoming infected. Therefore, special attention will be given to ongoing control initiatives in Bali.

  • Taeniases and cysticercosis in Indonesia: past and present situations.
    Parasitology, 2013
    Co-Authors: Toni Wandra, Yasuhito Sako, Akira Ito, Nyoman Sadra Dharmawan, Kadek Swastika, Munehiro Okamoto
    Abstract:

    The main aim of this study is to overview the past and present situations of human Taeniases and cysticercosis in Indonesia and including future perspectives. Through joint projects from 1996, we have confirmed the occurrence of Taenia saginata (beef tapeworm) in Bali, of Taenia solium (pork tapeworm) mainly in Papua and sporadically in Bali, and of Taenia Asiatica in North Sumatra. These Taeniases were caused through eating uncooked pork and pig viscera for T. solium and T. Asiatica , respectively, and beef for T. saginata . The distribution of these tapeworms in Indonesia is basically highly restricted by the traditional cultural and religious backgrounds in each island. T. saginata is relatively common in Bali although people consume pork ‘ lawar’ more than beef ‘ lawar’ . Taeniases due to T. saginata or T. Asiatica and T. solium and cysticercosis due to T. solium have also been sporadically reported in some other islands. Among these species, T. solium is exceptional since humans can be infected not only by larval stages (cysticerci) in pork but also by eggs released from human tapeworm carriers. Cysticercosis has been confirmed in Indonesia in humans, pigs and even dogs.

  • Taeniasis/cysticercosis in Bali, Indonesia
    The Southeast Asian journal of tropical medicine and public health, 2011
    Co-Authors: Toni Wandra, Putu Sutisna, Nyoman Sadra Dharmawan, Aa Raka Sudewi, Hemma Yulfi, Dewi Masyithah Darlan, I Kadek Swastika, I Nengah Kapti, Gina Samaan, Marcello Otake Sato
    Abstract:

    Taenia solium and Taenia saginata are found in humans in Bali, Indonesia. During a field survey of 660 people in Bali from 2002-2009 of Taeniasis /cysticercosis cases using mitochondrial DNA confirmation of the species, we detected 80 cases of T. saginata Taeniasis, 2 dual T. saginata/T. solium infections with T. solium meta- cestodes in the brain and 12 neurocysticercosis (NCC) cases at Sanglah Hospital, Denpasar. Although the prevalence of NCC in Bali is low, sporadic cases are still present. There is no Taenia Asiatica in Bali. We summarize here the field survey findings of Taeniasis, including 1 dual infection with Taeniasis and cysticercosis in 2007, and the reason why there are no T. Asiatica cases and we describe 3 NCC cases admitted to Sanglah Hospital, Denpasar, Bali in 2004. Diagnosis was based on anamnesis, clinical examination, including CT Scan, histopathological, sero- logical and mitochondrial DNA examinations. In order to prevent unexpected symptomatic NCC after treatment with praziquantel, we recommend introducing a rapid test to confirm Taeniasis carriers and cysticercosis cases as a tool for real time diagnosis.

M. Teresa Galán-puchades - One of the best experts on this subject based on the ideXlab platform.

  • Updating Taenia Asiatica in humans and pigs
    Parasitology Research, 2016
    Co-Authors: M. Teresa Galán-puchades, Màrius V. Fuentes
    Abstract:

    An epidemiological study on Taeniasis and cysticercosis in northern India has recently updated the epidemiology of Taenia Asiatica . Practically, all the detected cases of Taeniasis were caused by T. Asiatica , cited for the first time in humans in that country. The finding widens the geographical distribution of T. Asiatica , a species wrongly considered an exclusive South-Eastern Asian parasite. Due to the introduction of molecular techniques in Taenia diagnosis, the species is slowly showing its true distribution. A human Taenia species with cosmopolitan hosts (the same as the other two Taenia species) but limited to a specific geographical area and not affected by globalisation would certainly be hard to believe. Regarding cysticercosis, there is a remarkable finding concerning T. Asiatica pig cysticercosis, specifically the presence of the cysticercus of T. Asiatica not only in the liver (its preferential infection site) but also in muscle. This is the first time that the cysticercus of T. Asiatica has been found in muscle in a naturally infected pig. This fact is actually relevant since people are at a greater risk of becoming infected by T. Asiatica than previously expected since the liver is no longer the only site of pig infection. The Taenia species causing Taenia saginata -like Taeniasis around the world, as well as pig and human cysticercosis, should always be molecularly confirmed since T. Asiatica could be involved.

  • First ultrastructural data on the human tapeworm Taenia Asiatica eggs by scanning and transmission electron microscopy (SEM, TEM)
    Parasitology Research, 2016
    Co-Authors: M. Teresa Galán-puchades, Yichao Yang, Antonio Marcilla, Seongjun Choe, Hansol Park, Antonio Osuna, Keeseon S. Eom
    Abstract:

    Humans are definitive hosts of three species of the Taenia genus, namely Taenia solium, Taenia saginata and Taenia Asiatica. The relative novelty of the latter explains the lack of knowledge concerning certain relevant aspects related to this parasite, such as its definite geographical distribution and whether its eggs can infect humans or not. So far, only the eggs of T. solium are known to be infective for humans, producing cysticercosis. Although eggs contain the infective stage, the oncosphere, there is a lack of research on the ultrastructure of eggs of human taeniids. We show, for the first time, the ultrastructure of eggs of T. Asiatica by means of SEM and TEM analyses. We detected all the envelopes, namely the egg shell, vitelline layer, outer embryophoric membrane, embryophore, granular layer, basal membrane, oncospheral membrane and oncospheral tegument. Hooks surrounded by myofibrils and glycogen-like particles, the two types of secretory granules of the penetration glands, as well as several nuclei and mitochondria were also revealed in the oncospheres. In addition to the already known structures in eggs from other Taenia species, the presence of two types of small vesicles is described herein, possibly corresponding to exosomes and ectosomes because of their shape and size, which could participate in the host/parasite intercellular communication.

  • Taenia Asiatica: the Most Neglected Human Taenia and the Possibility of Cysticercosis
    The Korean Journal of Parasitology, 2013
    Co-Authors: M. Teresa Galán-puchades, Mario V. Fuentes
    Abstract:

    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.

  • Human Cysticercosis and Larval Tropism of Taenia Asiatica
    Parasitology Today, 2000
    Co-Authors: M. Teresa Galán-puchades, Màrius V. Fuentes
    Abstract:

    Taenia solium, T. saginata and the recently discovered T. Asiatica1xTaiwan Taenia and Taeniasis. Fan, P.C. Parasitol. Today. 1988; 4: 86–88Abstract | Full Text PDF | PubMed | Scopus (61)See all References, 2xMorphologic descriptions of Taenia Asiatica sp. n.. Eom, K.S. and Rim, H.J. Korean J. Parasitol. 1993; 31: 1–6Crossref | PubMedSee all References, 3xMorphological description of Taenia saginata Asiatica (Cyclophyllidea: Taeniidae) from man in Asia. Fan, P.C. et al. J. Helminthol. 1995; 69: 299–303Crossref | PubMed | Scopus (44)See all References, are species of taeniid cestodes whose adult stages are known to infect humans. Less clear is whether the eggs of T. Asiatica also infect humans (as those of T. solium do, causing cysticercosis and the fatal neurocysticercosis) or whether the species is similar to T. saginata whose eggs do not cause infections in humans.Although evidence does exist in support of infective egg stages4xCysticercosis in Asian-Pacific regions. Ito, A. Parasitol. Today. 1992; 8: 182–183Abstract | Full Text PDF | PubMed | Scopus (17)See all References, 5xTaeniasis/cysticercosis in Indonesia as an emerging disease. Simanjuntak, G.M. et al. Parasitol. Today. 1997; : 321–323Abstract | Full Text PDFSee all References, it is also disputed for two main reasons6xGenetic characterization of the Asian Taenia, a newly described taeniid cestode of humans. Bowles, J. and McManus, D.P. Am. J. Trop. Med. Hyg. 1994; 50: 33–44PubMedSee all References, 7xAsian (Taiwan) Taenia: species or strain?. McManus, D.P. and Bowles, J. Parasitol. Today. 1994; 10: 273–275Abstract | Full Text PDF | PubMed | Scopus (20)See all References, 8xFailure of experimental infection of baboons (Papio hamadryas) with the eggs of Asian Taenia. Fall, E.H. et al. J. Helminthol. 1995; 69: 367–368Crossref | PubMed | Scopus (2)See all References. First, T. Asiatica is more closely related to T. saginata at the molecular level than to any other taeniid; if T. saginata does not cause human cysticercosis, then the same could be said of T. Asiatica. Second, observations of human populations where T. Asiatica adults are highly prevalent show no evidence of human cysticercosis or neurocysticercosis (eg. Taiwan, and Samosir Island, Indonesia). We would like to discuss further reasons why such observations might be incorrect.First, although molecular affinities between T. Asiatica and T. saginata are very close, the egg infectivity of the two species is quite different; the natural hosts of T. saginata are cattle, while those of T. Asiatica are pigs (the same intermediate host for human cysticercosis-producing T. solium). Second, the absence of cysticercosis or neurocysticercosis in these human populations may merely suggest a low prevalence of T. solium. We, however, believe that it is an erroneous indicator of whether the eggs of T. Asiatica can infect humans.So, are there similarities between T. solium and T. Asiatica that could be used to indicate whether eggs of T. Asiatica infect humans? Again, subtle differences between the two species suggest that this is not the case. First, tropism and size of the larval forms differ between the two species. The larva of T. solium (Cysticercus cellulosae) in pigs exhibits no defined tropism9xExperimental infection of an isolate of Taenia solium from Hainan in domestic animals. Fan, P.C. et al. J. Helminthol. 1994; 68: 265–266Crossref | PubMed | Scopus (11)See all References9 and larval size ranges from 5 to 15 mm (Ref. 10xMorphological types of Taenia solium cysticerci. Rabiela, M.T. et al. Parasitol. Today. 1989; 5: 357–359Abstract | Full Text PDF | PubMed | Scopus (21)See all References10). In contrast, the larva of T. Asiatica (C. viscerotropica) in the pig (and other experimental intermediate hosts such as calves, goats and monkeys)1xTaiwan Taenia and Taeniasis. Fan, P.C. Parasitol. Today. 1988; 4: 86–88Abstract | Full Text PDF | PubMed | Scopus (61)See all References, 11xStudies on Taeniasis in Taiwan. VI. Is Taenia saginata from Taiwan, Korea and Indonesia a new species?. Fan, P.C. et al. Chinese J. Parasitol. 1988; 1: 56–70See all References, exhibits marked liver tropism, while reaching a larval size of approximately 2 mm1xTaiwan Taenia and Taeniasis. Fan, P.C. Parasitol. Today. 1988; 4: 86–88Abstract | Full Text PDF | PubMed | Scopus (61)See all References, 2xMorphologic descriptions of Taenia Asiatica sp. n.. Eom, K.S. and Rim, H.J. Korean J. Parasitol. 1993; 31: 1–6Crossref | PubMedSee all References. This suggests that if C. viscerotropica follows the same developmental course in humans as in other intermediate hosts, then it would preferentially parasitize the liver, causing hepatic cysticercosis, with smaller larvae being present than if C. cellulosae were the infective agent. Such cases of hepatic cysticercosis could be symptomatic or not, depending on larval number and location within the liver (although hepatic/gastrointestinal manifestations may occur). It could be assumed that such clinical symptoms would be more related to the initial stages of cystic hydatidosis than to the classical cysticercosis or neurocysticercosis caused by T. solium. Therefore, where T. Asiatica is prevalent in human populations, the absence of classical evidence of cysticercosis should not be taken as indication of the lack of human cysticercosis caused by this parasite.The clinical risk of this possible larval parasitization by T. Asiatica could be similar to that of classical cysticercosis, but only if the larvae also reach other locations within humans (as in the case of T. solium and the larvae of Echinococcus granulosus or E. multilocularis) or develop aberrant forms as in the case of T. solium (the racemose cysticercus). At the experimental level, larvae of T. Asiatica have been successfully developed in nonhepatic regions12xExperimental infections of pigs and cattle with eggs of Asian Taenia saginata with special reference to its extrahepatic viscerotropism. Eom, K.S. et al. Korean J. Parasitol. 1992; 30: 269–275CrossrefSee all References12 and can develop larger body sizes in hosts other than pigs13xHuman Taenia eggs develop into cysticerci in SCID mice. Ito, A. et al. Parasitology. 1997; 114: 85–88Crossref | PubMed | Scopus (24)See all References13.Evidence for the infection of humans by eggs of T. Asiatica therefore remains contradictory. However, we are of the opinion that C. viscerotropica should be included in the evaluation of liver lesions compatible with the larval development of cestodes, particularly in those Asian countries where the parasite is already known to occur.

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  • Taeniasis and cysticercosis in Asia: A review with emphasis on molecular approaches and local lifestyles.
    Acta Tropica, 2019
    Co-Authors: Akira Ito, Tetsuya Yanagida, Paron Dekumyoy, Munehiro Okamoto, Toni Wandra, Christine M. Budke
    Abstract:

    Abstract Taeniasis is an important parasitic condition in Asia, especially since all three human-infecting Taenia spp., Taenia solium, Taenia saginata, and Taenia Asiatica are found in this region. These three species are believed to be sympatrically distributed, with the largest disease burden found in remote and rural areas where people raise pigs and cattle in a traditional manner. Recent studies revealed that T. Asiatica and T. saginata are genetically-related sister species that are not completely reproductively isolated from each other. Current evidence indicates that most T. Asiatica adult worms are hybrid-derived descendants. Moving forward, nuclear DNA analysis will be critical in further assessing the species circulating locally. Lifestyle choices, such as the consumption of undercooked meat, are important in maintaining the life cycles of these parasites. In addition, poor hygiene and sanitation, in highly endemic areas, make disease control difficult, resulting in the need for sustainable education programs. An overview of the present situation of Taeniasis and cysticercosis in Asia is provided, followed by a discussion of molecular approaches to species assessment and the impact of human lifestyles on parasite transmission.

  • The present situation of human Taeniases and cysticercosis in Asia.
    Recent Patents on Anti-Infective Drug Discovery, 2015
    Co-Authors: Akira Ito, Agathe Nkouawa, Paron Dekumyoy, Munehiro Okamoto, Toni Wandra, Christine M. Budke
    Abstract:

    Three human Taenia species, Taenia solium, Taenia saginata, and Taenia Asiatica, are endemic in rural regions of Asia, with these species sympatrically distributed in parts of Thailand and China. The pork tapeworm, T. solium, is the most pathogenic to humans, causing cysticercosis and neurocysticercosis (NCC). Due to its public health impact, T. solium Taeniasis/cysticercosis is one of 17 neglected tropical diseases (NTDs) prioritized by the World Health Organization. In this review, the current status of Taeniasis and NCC in several Asian countries will be presented as will possible prevention and control strategies. Among the known T. solium endemic areas in Asia, Bali, Indonesia is of high importance due to the risk of tourists becoming infected. Therefore, special attention will be given to ongoing control initiatives in Bali.

  • REVIEW TaeniaSIS AND CYSTICERCOSIS IN ASIA AND THE PACIFIC: PRESENT STATE OF KNOWLEDGE AND PERSPECTIVES
    2015
    Co-Authors: Akira Ito, Minoru Nakao, Yasuhito Sako, Munehiro Okamoto, Hiroshi Yamasaki, Thomas Suroso, Toni W, Kazuhiro Nakaya
    Abstract:

    Abstract. Several topics on Taeniasis and cysticercosis in Asia and the Pacific are overviewed. In Asia and the Pacific, three human taeniid species have been recognized: Taenia solium, Taenia saginata and Taenia Asiatica. The first topic is on evolution of T. solium. Mitochondrial DNA polymorphisms of T. solium worldwide are discussed with emphasis of two specific genotypes: American-African and Asian. The second topic is recent major advances in sero- and molecular-diagnosis of T. solium cysticercosis in humans, pigs and dogs. The third is the present situation of T. solium Taeniasis/cysticercosis in Papua (Irian Jaya), Indonesia. The forth is the present situation of T. solium cysticercosis and T. saginata Taeniasis in Bali, Indonesia. The fifth is the present situation of T. Asiatica Taeniasis in Asia and the Pacific and in North Sumatra, Indonesia. The sixth is on the debate of the exact definition of T. Asiatica. Because T. Asiatica can not be differentiated from T. saginata morphologically, it is time to re-evaluate T. saginata in Asia and the Pacific. New and broad-based surveys across this region are necessary from epidemiological and public health perspectives, based on evidence

  • Taeniases and cysticercosis in Indonesia: past and present situations.
    Parasitology, 2013
    Co-Authors: Toni Wandra, Yasuhito Sako, Akira Ito, Nyoman Sadra Dharmawan, Kadek Swastika, Munehiro Okamoto
    Abstract:

    The main aim of this study is to overview the past and present situations of human Taeniases and cysticercosis in Indonesia and including future perspectives. Through joint projects from 1996, we have confirmed the occurrence of Taenia saginata (beef tapeworm) in Bali, of Taenia solium (pork tapeworm) mainly in Papua and sporadically in Bali, and of Taenia Asiatica in North Sumatra. These Taeniases were caused through eating uncooked pork and pig viscera for T. solium and T. Asiatica , respectively, and beef for T. saginata . The distribution of these tapeworms in Indonesia is basically highly restricted by the traditional cultural and religious backgrounds in each island. T. saginata is relatively common in Bali although people consume pork ‘ lawar’ more than beef ‘ lawar’ . Taeniases due to T. saginata or T. Asiatica and T. solium and cysticercosis due to T. solium have also been sporadically reported in some other islands. Among these species, T. solium is exceptional since humans can be infected not only by larval stages (cysticerci) in pork but also by eggs released from human tapeworm carriers. Cysticercosis has been confirmed in Indonesia in humans, pigs and even dogs.

  • a loop mediated isothermal amplification method for a differential identification of Taenia tapeworms from human application to a field survey
    Parasitology International, 2012
    Co-Authors: Agathe Nkouawa, Xingwang Chen, Minoru Nakao, Yasuhito Sako, Tetsuya Yanagida, Munehiro Okamoto, Tiaoying Li, Patrick Giraudoux, Francis Raoul, Kazuhiro Nakaya
    Abstract:

    In this study, we applied a loop-mediated isothermal amplification method for identification of human Taenia tapeworms in Tibetan communities in Sichuan, China. Out of 51 proglottids recovered from 35 carriers, 9, 1, and 41 samples were identified as Taenia solium, Taenia Asiatica and Taenia saginata, respectively. Same results were obtained afterwards in the laboratory, except one sample. These results demonstrated that the LAMP method enabled rapid identification of parasites in the field surveys, which suggested that this method would contribute to the control of Taenia infections in endemic areas.

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