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Nguyen HM, Do DT, Greiman SE, Nguyen HV, Hoang HV, Phan TQ, Pham-Duc P, Madsen H. An overview of human helminthioses in Vietnam: Their prevention, control and lessons learnt. Acta Trop 2023; 238:106753. [PMID: 36375522 DOI: 10.1016/j.actatropica.2022.106753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/31/2022] [Accepted: 11/10/2022] [Indexed: 11/13/2022]
Abstract
In Vietnam, helminthioses remain a major threat to public health and contribute to the maintenance of poverty in highly endemic regions. Through increased awareness of the damaging effects caused by helminthioses, the Vietnamese government has implemented many national programs over the past 30 years for the prevention and control of the most important helminthioses, such as, lymphatic filariasis, soil transmitted helminths, food borne zoonotic helminths, and others. Various control strategies have been applied to reduce or eliminate these worms, e.g. mass drug administration, economic development, control of vectors or intermediate hosts, public health interventions through education, proper composting procedures for excreta potentially containing helminth eggs, and the expansion of food supply chains and improved technologies for the production and inspection of food products. These control measures have resulted in a significant reduction in the distribution and transmission of helminth infections and have improved the overall living conditions and health outcomes of the Vietnamese citizens. However, the persistence of several helminth diseases continues in some endemic areas, especially where poverty is widespread and local traditions include the consumption of raw foods, especially fish and meats. This manuscript provides an overview of the helminth infection prevention and control programs conducted in Vietnam, their achieved results, learned lessons, and future works.
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Affiliation(s)
- Hung Manh Nguyen
- Institute of Ecology and Biological Resources, Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Street, Hanoi, Viet Nam.
| | - Dung Trung Do
- National Institute of Malariology, Parasitology and Entomology, 34 Trung Van Street, Hanoi, Viet Nam
| | - Stephen E Greiman
- Georgia Southern University, 4324 Old Register Road, Statesboro, GA 30460, USA
| | - Ha Van Nguyen
- Institute of Ecology and Biological Resources, Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Street, Hanoi, Viet Nam
| | - Hien Van Hoang
- Institute of Ecology and Biological Resources, Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Street, Hanoi, Viet Nam
| | - Toan Quoc Phan
- The Center for Entomology and Parasitology Research, College of Medicine and Pharmacy, Duy Tan University, 3 Quang Trung Street, Da Nang, Viet Nam
| | - Phuc Pham-Duc
- Institute of Environmental Health and Sustainable Development, 32/12/3A To Ngoc Van Street, Hanoi, Viet Nam
| | - Henry Madsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej 100, Frederiksberg C 1870, Denmark
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Le TTH, Vu-Thi N, Dang-Xuan S, Nguyen-Viet H, Pham-Duc P, Nguyen-Thanh L, Pham-Thi N, Noh J, Mayer-Scholl A, Baumann M, Meemken D, Unger F. Seroprevalence and Associated Risk Factors of Trichinellosis and T. Solium Cysticercosis in Indigenous Pigs in Hoa Binh Province, Vietnam. Trop Med Infect Dis 2022; 7:tropicalmed7040057. [PMID: 35448832 PMCID: PMC9026120 DOI: 10.3390/tropicalmed7040057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/22/2022] [Accepted: 03/29/2022] [Indexed: 12/10/2022] Open
Abstract
Trichinellosis and cysticercosis remain challenges to human health and animal productivity worldwide, especially in developing countries. While information on the occurrence of both diseases is infrequent, they are endemic in parts of Vietnam and mainly related to indigenous pigs kept by ethnic minorities. This study aimed to determine the seroprevalence and risk factors of both diseases in indigenous pigs and explore the perception and awareness of both human and pig trichinellosis and cysticercosis of pig farmers. A total of 352 pig sera samples from 131 holdings were collected and analyzed using ELISA antibody tests in six communes in the Da Bac districts of Hoa Binh province, Vietnam. A survey was conducted with representatives from these households to understand the knowledge and perspective on food-borne parasitic diseases. Overall, the seroprevalence of trichinellosis and T. solium cysticercosis was 13.6% (95% CI 10.2–17.7) and 1.7% (95% CI 0.6–3.7), respectively. The seroprevalence of trichinellosis was significantly higher in female and older pigs. Risk perception and knowledge of interviewed people on both human and pig trichinellosis and cysticercosis of pig farmers was poor. Risky practices, including free roaming of pigs and eating undercooked or fermented pork, were observed. Educational and awareness campaigns aligned with further research on feasible practice changes are critical to addressing these issues.
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Affiliation(s)
- Trang Thi-Huyen Le
- International Livestock Research Institute, Hanoi 100000, Vietnam; (T.T.-H.L.); (H.N.-V.); (F.U.)
| | - Nga Vu-Thi
- National Institute of Veterinary Research, Hanoi 100000, Vietnam; (N.V.-T.); (N.P.-T.)
| | - Sinh Dang-Xuan
- International Livestock Research Institute, Hanoi 100000, Vietnam; (T.T.-H.L.); (H.N.-V.); (F.U.)
- Center for Public Health and Ecosystem Research, Hanoi University of Public Health, Hanoi 10000, Vietnam; (P.P.-D.); (L.N.-T.)
- Correspondence: ; Tel.: +84-09-6981-3048
| | - Hung Nguyen-Viet
- International Livestock Research Institute, Hanoi 100000, Vietnam; (T.T.-H.L.); (H.N.-V.); (F.U.)
| | - Phuc Pham-Duc
- Center for Public Health and Ecosystem Research, Hanoi University of Public Health, Hanoi 10000, Vietnam; (P.P.-D.); (L.N.-T.)
| | - Luong Nguyen-Thanh
- Center for Public Health and Ecosystem Research, Hanoi University of Public Health, Hanoi 10000, Vietnam; (P.P.-D.); (L.N.-T.)
| | - Ngoc Pham-Thi
- National Institute of Veterinary Research, Hanoi 100000, Vietnam; (N.V.-T.); (N.P.-T.)
| | - John Noh
- Centers for Disease Control and Prevention, Atlanta, GA 30333, USA;
| | - Anne Mayer-Scholl
- Federal Institute for Risk Assessment, National Laboratory for Trichinella, 10589 Berlin, Germany;
| | - Maximilian Baumann
- Working Group Meat Hygiene, Institute of Food Safety and Food Hygiene, Freie Universität Berlin, 14163 Berlin, Germany; (M.B.); (D.M.)
| | - Diana Meemken
- Working Group Meat Hygiene, Institute of Food Safety and Food Hygiene, Freie Universität Berlin, 14163 Berlin, Germany; (M.B.); (D.M.)
| | - Fred Unger
- International Livestock Research Institute, Hanoi 100000, Vietnam; (T.T.-H.L.); (H.N.-V.); (F.U.)
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Tran Thi G, Azzena I, Scarpa F, Cossu P, Danh Le C, Ton Nu PA, Chau Ngo TM, Sanna D, Casu M. Molecular Identification and Appraisal of the Genetic Variation of Taenia saginata in Central Regions of Vietnam. Life (Basel) 2022; 12:70. [PMID: 35054461 PMCID: PMC8781798 DOI: 10.3390/life12010070] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/29/2021] [Accepted: 01/01/2022] [Indexed: 06/14/2023] Open
Abstract
Taenia saginata is a globally distributed tapeworm responsible for human taeniasis due to the ingestion of raw or undercooked beef. T. saginata is present in several Asian countries, including China, Thailand, Lao PDR, Cambodia, and Vietnam, but little is known about its genetic variation. Studying the tapeworm's phylogeographic patterns is crucial to better understanding their association with the geographic distribution of taeniasis/cysticercosis in human populations. In the present study, 38 specimens of this putative species were collected in central regions of Vietnam and analysed using the mitochondrial gene Cytochrome c Oxidase subunit I (COI) as a molecular marker to assess the correct species identification and investigate the level of genetic variation at different geographic scales. Phylogenetic and phylogeographic analyses were carried out on a dataset that included COI sequences from Vietnamese specimens and from all conspecifics available in GenBank to date. The results showed that the collected Vietnamese specimens belonged to the species T. saginata. In Southeast Asia, signs of a possible founder effect were discovered, with the most common haplotypes frequent and present in many countries, except Lao PDR, which shares its most common haplotype only with individuals from Thailand. Remarkably, a unique taxonomic entity was found worldwide, even though the available COI sequences of T. saginata belonging to non-Asiatic countries are, at present, limited. Therefore, future studies including more COI sequences from a higher number of countries and the use of a combined molecular approach with multiple genetic markers would be useful to provide deeper insight into the global genetic variation of this species.
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Affiliation(s)
- Giang Tran Thi
- Department of Parasitology, Hue University of Medicine and Pharmacy, Hue University, 06 Ngo Quyen Street, Hue City 4200, Vietnam; (G.T.T.); (P.A.T.N.); (T.M.C.N.)
| | - Ilenia Azzena
- Dipartimento di Medicina Veterinaria, Università di Sassari, Via Vienna 2, 07100 Sassari, Italy; (I.A.); (F.S.); (P.C.); (M.C.)
- Dipartimento di Scienze Biomediche, Università di Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy
| | - Fabio Scarpa
- Dipartimento di Medicina Veterinaria, Università di Sassari, Via Vienna 2, 07100 Sassari, Italy; (I.A.); (F.S.); (P.C.); (M.C.)
| | - Piero Cossu
- Dipartimento di Medicina Veterinaria, Università di Sassari, Via Vienna 2, 07100 Sassari, Italy; (I.A.); (F.S.); (P.C.); (M.C.)
| | - Cong Danh Le
- Traditional Medicine Hospital of Thua Thien Hue Province, Hue City 4200, Vietnam;
| | - Phuong Anh Ton Nu
- Department of Parasitology, Hue University of Medicine and Pharmacy, Hue University, 06 Ngo Quyen Street, Hue City 4200, Vietnam; (G.T.T.); (P.A.T.N.); (T.M.C.N.)
| | - Thi Minh Chau Ngo
- Department of Parasitology, Hue University of Medicine and Pharmacy, Hue University, 06 Ngo Quyen Street, Hue City 4200, Vietnam; (G.T.T.); (P.A.T.N.); (T.M.C.N.)
| | - Daria Sanna
- Dipartimento di Scienze Biomediche, Università di Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy
| | - Marco Casu
- Dipartimento di Medicina Veterinaria, Università di Sassari, Via Vienna 2, 07100 Sassari, Italy; (I.A.); (F.S.); (P.C.); (M.C.)
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Binh VTL, Dung DT, Vinh HQ, Anke VH, Nicolas P, Pierre D, Veronique D. Human Taeniasis and Cysticercosis and Related Factors in Phu Tho Province, Northern Vietnam. THE KOREAN JOURNAL OF PARASITOLOGY 2021; 59:369-376. [PMID: 34470088 PMCID: PMC8413854 DOI: 10.3347/kjp.2021.59.4.369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 07/19/2021] [Indexed: 11/23/2022]
Abstract
Several factors presumed to facilitate the transmission of Taenia spp. were reported in Vietnam. We conducted a cross-sectional study taking questionnaires from 1,185 participants, and collecting 1,151 sera and 1,036 stool samples in northern Vietnam. Sera were examined for circulating antigens of Taenia solium cysticerci using ELISA, stools for Taenia eggs by Kato-Katz smear, and copro-antigens by ELISA. Ag-ELISA revealed 4.6% antigen positivity, indicating infection with viable cysticerci. Taenia eggs were detected in 1.5% of participants. Copro-antigens were found in 2.8% of participants. Eating raw meat and/or vegetables was significantly associated with the presence of copro-antigen (OR=8.6, 95% CI: 1.16–63.9, P=0.01). Considering the high taeniasis prevalence and the associated threat, public health attention should be given to treat the tapeworm carriers in the projected areas.
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Affiliation(s)
- Vu Thi Lam Binh
- National Institute of Malariology, Parasitology and Entomology (NIMPE), No 34 Trung Van, Nam Tu Liem, Ha Noi, Vietnam
| | - Do Trung Dung
- National Institute of Malariology, Parasitology and Entomology (NIMPE), No 34 Trung Van, Nam Tu Liem, Ha Noi, Vietnam
| | - Hoang Quang Vinh
- National Institute of Malariology, Parasitology and Entomology (NIMPE), No 34 Trung Van, Nam Tu Liem, Ha Noi, Vietnam
| | - Van Hul Anke
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerpen, Belgium
| | - Praet Nicolas
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerpen, Belgium.,The Janssen Pharmaceutical Companies of Johnson & Johnson, Beerse, Belgium
| | - Dorny Pierre
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerpen, Belgium.,Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Dermauw Veronique
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerpen, Belgium
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Liu Y, Dong Z, Pang J, Liu M, Jin X. Prevalence of meat-transmitted Taenia and Trichinella parasites in the Far East countries. Parasitol Res 2021; 120:4145-4151. [PMID: 33768333 DOI: 10.1007/s00436-021-07124-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/14/2021] [Indexed: 12/21/2022]
Abstract
Taenia and Trichinella parasites are globally distributed foodborne zoonotic pathogens transmitted from animal to humans via consumption of raw or undercooked meats. This short review is intended to provide the parasites community a snapshot of the literature on the current and recent prevalence of taeniasis and trichinellosis in humans and animals in the Far East countries. Prevalence rates in these countries are highly diverse due to differences in development, culture, ethnic and religious background, animal forming practices, and eating habits. Taenia and Trichinella remain as important meat-transmitted pathogens in the Far East. A One Health approach is needed to eliminate or continuously reduce the foodborne zoonotic taeniasis and trichinellosis in the Far East.
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Affiliation(s)
- Yi Liu
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Zijian Dong
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Jianda Pang
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Mingyuan Liu
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225000, Jiangsu, China.
| | - Xuemin Jin
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
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6
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Abstract
Pigs act as the intermediate hosts of the zoonotic tapeworms Taenia solium and Taenia asiatica, as well as of the non-zoonotic Taenia hydatigena. In Vietnam, human taeniasis and cysticercosis have been reported throughout the country; however, data on porcine cysticercosis are scarce. Our study aimed to estimate the prevalence of Taenia spp. in slaughtered pigs in two districts in Phu Tho, a mountainous province in northern Vietnam from where neurocysticercosis patients commonly originate. The carcasses of 399 pigs from 51 small-scale abattoirs were checked for cysticerci, while tongue, liver, masseter muscles, diaphragm and heart were sliced and examined. Retrieved cysticerci underwent polymerase chain reaction-restriction fragment length polymorphism and sequencing for species confirmation. Blood was also collected to detect antibodies by lentil lectin-purified glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP-EITB) and recombinant T24H antigen (rT24H)-EITB and circulating antigens by B158/B60 Ag-ELISA. In two pigs, T. asiatica cysticerci were found, confirming the presence of the parasite in pigs in Vietnam at a low prevalence (0.5%; 95% exact confidence interval (CI): 0-1.19%). Cysticerci of T. solium were found in none of the pigs, although one serum sample was positive for antibodies in both LLGP-EITB and rT24H-EITB. Furthermore, a high prevalence of T. hydatigena cysticercosis was observed (18.0%; 95% Wilson score CI: 14.6-22.1%). In more than half of the T. hydatigena-positive pigs, circulating antigens were detected by Ag-ELISA, confirming that this test cannot be used to diagnose T. solium cysticercosis in this region. Finally, Spirometra erinaceieuropaei was found in one pig liver. It is the first record of this zoonotic cestode species in pigs in Vietnam. Overall, the findings confirmed the complex epidemiology of Taenia spp. in pigs in Vietnam.
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Eichenberger RM, Thomas LF, Gabriël S, Bobić B, Devleesschauwer B, Robertson LJ, Saratsis A, Torgerson PR, Braae UC, Dermauw V, Dorny P. Epidemiology of Taenia saginata taeniosis/cysticercosis: a systematic review of the distribution in East, Southeast and South Asia. Parasit Vectors 2020; 13:234. [PMID: 32381027 PMCID: PMC7206752 DOI: 10.1186/s13071-020-04095-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/24/2020] [Indexed: 02/14/2023] Open
Abstract
BACKGROUND Taenia saginata is an important zoonotic parasite, causing taeniosis in humans and cysticercosis in bovines, the latter being a significant concern for the global beef industry. Many countries in East, Southeast and South Asia are experiencing rapid economic growth, and an increasing number of people in these countries are dependent on the livestock industry. Currently, however, an overview of the prevalence of T. saginata in this region is lacking. In this review, we analysed the available literature on T. saginata taeniosis and bovine cysticercosis for East, Southeast and South Asia. METHODS A systematic review was conducted, based on both published and grey literature. Articles published between 1990 and 2017 were mined for information on the occurrence, prevalence, and geographical distribution of T. saginata taeniosis and bovine cysticercosis in East, Southeast and South Asia. RESULTS The presence of T. saginata was described in 15 of 27 countries of the region, including Afghanistan, Cambodia, China, India, Indonesia, Japan, Lao PDR, Malaysia, Mongolia, Nepal, Pakistan, Philippines, South Korea, Thailand and Vietnam. The only country that reported an absence of T. saginata is Japan, although sporadic reports of imported cases and unconfirmed reports of autochthonous infections were identified. Nationwide surveys of taeniosis with systematic sample collection and high sample numbers were available for Cambodia, China, Lao PDR, and South Korea, although speciation of Taenia was not always performed. Regional prevalence of taeniosis and bovine cysticercosis in endemic regions ranged between 0.02-42.6%, and 0.76-46.7%, respectively. However, data for bovine cysticercosis were only available for five countries (Japan, Lao PDR, Mongolia, Pakistan and Vietnam). CONCLUSIONS The data indicate a widespread occurrence of T. saginata throughout East, Southeast and South Asia. Identification of Taenia spp. in human infections was frequently not performed, leading to gaps in knowledge about the distribution of human tapeworm infections, mainly in regions where different human Taenia species co-occur. A high prevalence of T. saginata taeniosis and bovine cysticercosis may reflect insufficiencies in sanitation, limited health education standards, and insufficient food safety measures. Therefore, there is a need to improve local surveillance, notification, and overall control systems.
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Affiliation(s)
- Ramon M. Eichenberger
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Lian F. Thomas
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
- International Livestock Research Institute, Nairobi, Kenya
| | - Sarah Gabriël
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Branco Bobić
- Centre of Excellence for Food– and Vector–borne Zoonoses, Institute for Medical Research, University of Belgrade, Belgrade, Serbia
| | - Brecht Devleesschauwer
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
- Department of Epidemiology and Public Health, Sciensano, Brussels, Belgium
| | - Lucy J. Robertson
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Anastasios Saratsis
- Veterinary Research Institute, Hellenic Agricultural Organization Demeter, Thermi, Greece
| | - Paul R. Torgerson
- Section of Veterinary Epidemiology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
| | - Uffe C. Braae
- One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis
- Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institute, Copenhagen, Denmark
| | - Veronique Dermauw
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Pierre Dorny
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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Eom KS, Rim HJ, Jeon HK. Taenia asiatica: Historical overview of taeniasis and cysticercosis with molecular characterization. ADVANCES IN PARASITOLOGY 2020; 108:133-173. [PMID: 32291084 DOI: 10.1016/bs.apar.2019.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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).
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Affiliation(s)
- Keeseon S Eom
- Department of Parasitology, Parasite Research Center and Parasite Resource Bank, Chungbuk National University School of Medicine, Cheongju, South Korea.
| | - Han-Jong Rim
- Department of Parasitology, Korea University College of Medicine, Seoul, South Korea
| | - Hyeong-Kyu Jeon
- Department of Parasitology, Parasite Research Center and Parasite Resource Bank, Chungbuk National University School of Medicine, Cheongju, South Korea
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9
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Betson M, Alonte AJI, Ancog RC, Aquino AMO, Belizario VY, Bordado AMD, Clark J, Corales MCG, Dacuma MG, Divina BP, Dixon MA, Gourley SA, Jimenez JRD, Jones BP, Manalo SMP, Prada JM, van Vliet AHM, Whatley KCL, Paller VGV. Zoonotic transmission of intestinal helminths in southeast Asia: Implications for control and elimination. ADVANCES IN PARASITOLOGY 2020; 108:47-131. [PMID: 32291086 DOI: 10.1016/bs.apar.2020.01.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intestinal helminths are extremely widespread and highly prevalent infections of humans, particularly in rural and poor urban areas of low and middle-income countries. These parasites have chronic and often insidious effects on human health and child development including abdominal problems, anaemia, stunting and wasting. Certain animals play a fundamental role in the transmission of many intestinal helminths to humans. However, the contribution of zoonotic transmission to the overall burden of human intestinal helminth infection and the relative importance of different animal reservoirs remains incomplete. Moreover, control programmes and transmission models for intestinal helminths often do not consider the role of zoonotic reservoirs of infection. Such reservoirs will become increasingly important as control is scaled up and there is a move towards interruption and even elimination of parasite transmission. With a focus on southeast Asia, and the Philippines in particular, this review summarises the major zoonotic intestinal helminths, risk factors for infection and highlights knowledge gaps related to their epidemiology and transmission. Various methodologies are discussed, including parasite genomics, mathematical modelling and socio-economic analysis, that could be employed to improve understanding of intestinal helminth spread, reservoir attribution and the burden associated with infection, as well as assess effectiveness of interventions. For sustainable control and ultimately elimination of intestinal helminths, there is a need to move beyond scheduled mass deworming and to consider animal and environmental reservoirs. A One Health approach to control of intestinal helminths is proposed, integrating interventions targeting humans, animals and the environment, including improved access to water, hygiene and sanitation. This will require coordination and collaboration across different sectors to achieve best health outcomes for all.
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Affiliation(s)
- Martha Betson
- University of Surrey, Guildford, Surrey, United Kingdom.
| | | | - Rico C Ancog
- University of the Philippines Los Baños, Laguna, Philippines
| | | | | | | | - Jessica Clark
- University of Surrey, Guildford, Surrey, United Kingdom
| | | | | | - Billy P Divina
- University of the Philippines Los Baños, Laguna, Philippines
| | | | | | | | - Ben P Jones
- University of Surrey, Guildford, Surrey, United Kingdom
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10
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Accurate diagnosis of lesions suspected of being caused by Taenia solium in body organs of pigs with naturally acquired porcine cysticercosis. PLoS Negl Trop Dis 2019; 13:e0007408. [PMID: 31237878 PMCID: PMC6592510 DOI: 10.1371/journal.pntd.0007408] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 04/24/2019] [Indexed: 11/19/2022] Open
Abstract
The definitive method for diagnosis of porcine cysticercosis is the detection of cysticerci at necropsy. Cysts are typically located in the striated muscle and brain. Until recently Taenia solium cysticerci have not been definitively identified in other tissue locations, despite several comprehensive investigations having been undertaken which included investigation of body organs other than muscle and brain. Recently a study conducted in Zambia reported 27% infection with T. solium in the liver of pigs with naturally acquired porcine cysticercosis, as well as some T. solium infection in the lungs and spleen of some animals. We investigated the cause of lesions in sites other than the muscle or brain in a total of 157 pigs from T. solium endemic regions of Uganda and Nepal which were subjected to extensive investigations at necropsy. Lesions which had the potential to be caused by T. solium were characterised by macroscopic and microscopic examination, histology as well as DNA characterisation by PCR-RFLP and sequencing. Lesions were confirmed as being caused by Taenia hydatigena (both viable and non-viable), by T. asiatica and Echinococcus granulosus (in Nepal) and nematode infections. No T. solium-related lesions or cysticerci were identified in any tissue other than muscle and brain. It is recommended that future evaluations of porcine cysticercosis in aberrant tissue locations include DNA analyses that take appropriate care to avoid the possibility of contamination of tissue specimens with DNA from a different tissue location or a different animal. The use of appropriate control samples to confirm the absence of cross-sample contamination is also recommended.
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Taenia solium, Taenia saginata, Taenia asiatica, their hybrids and other helminthic infections occurring in a neglected tropical diseases' highly endemic area in Lao PDR. PLoS Negl Trop Dis 2018; 12:e0006260. [PMID: 29420601 PMCID: PMC5821399 DOI: 10.1371/journal.pntd.0006260] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/21/2018] [Accepted: 01/22/2018] [Indexed: 12/19/2022] Open
Abstract
Most part of Southeast Asia is considered endemic for human-infecting Taenia tapeworms; Taenia solium, T. saginata, and T. asiatica. However, until now there was no report of the occurrence of human cases of T. asiatica in Lao PDR. This study, conducted in Savannakhet Province, Lao PDR, microscopically examined a total of 470 fecal samples by Kato Katz method and found 86% of people harboring at least one helminth. Hookworms were detected in 56% of the samples besides Opisthorchis like eggs (42%), Trichuris trichiura (27%), Ascaris spp. (14%), and Taenia spp. (4%) eggs. Serology for cysticercosis showed 6.8% positives with results varying from 3% to 14.3% in Ethnic School students and Kalouk Kao village respectively. Species-specific PCR targeting mitochondrial DNA (mtDNA) of 28 tapeworms, recovered from 16 patients, revealed T. solium (n = 2), T. saginata (n = 21), and T. asiatica (n = 5). Two patients were confirmed to be coinfected with T. saginata and T. asiatica, indicating the endemicity of the 3 human Taenia in Lao PDR. However, nucleotide sequencing of a nuclear DNA gene, DNA polymerase delta (pold) revealed that all the tapeworms identified as T. asiatica using mtDNA had T. saginata type allele at pold locus, demonstrating that they are not "pure T. asiatica" but the hybrid descendants between the two species, confirming the wide distribution of hybrids of T. saginata/ T. asiatica in Southeast Asia. The high prevalence of several helminthic NTDs in east Savannakhet area even with conventional control measures indicates the importance to establish wide and multifaceted health programs to sustainably improve the quality of life of the populations living in these communities.
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Dorny P, Dermauw V, Van Hul A, Trevisan C, Gabriël S. Serological diagnosis of Taenia solium in pigs: No measurable circulating antigens and antibody response following exposure to Taenia saginata oncospheres. Vet Parasitol 2017; 245:39-41. [PMID: 28969835 DOI: 10.1016/j.vetpar.2017.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 08/11/2017] [Accepted: 08/13/2017] [Indexed: 11/29/2022]
Abstract
Taenia solium taeniasis/cysticercosis is a zoonosis included in the WHO's list of neglected tropical diseases. Accurate diagnostic tools for humans and pigs are needed to monitor intervention outcomes. Currently used diagnostic tools for porcine cysticercosis all have drawbacks. Serological tests are mainly confronted with problems of specificity. More specifically, circulating antigen detecting tests cross-react with Taenia hydatigena and the possibility of transient antigens as a result of aborted infections is suspected. Furthermore, the hypothesis has been raised that hatched ingested eggs of other Taenia species may lead to a transient antibody response or to the presence of circulating antigen detectable by serological tests used for porcine cysticercosis. Here we describe the results of a study that consisted of oral administration of Taenia saginata eggs to five piglets followed by serological testing during five weeks and necropsy aiming at studying possible cross reactions in serological tests used for porcine cysticercosis. The infectivity of the eggs was verified by in vitro hatching and by experimental infection of a calf. One piglet developed acute respiratory disease and died on day 6 post infection. The remaining four piglets did not show any clinical signs until euthanasia. None of the serum samples from four piglets collected between days 0 and 35 post infection gave a positive reaction in the B158/B60 Ag-ELISA and in a commercial Western blot for antibody detection. In conclusion, this study showed that experimental exposure of four pigs to T. saginata eggs did not result in positive serologies for T. solium. These results may help interpreting serological results in monitoring of T. solium control programmes.
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Affiliation(s)
- P Dorny
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium; Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - V Dermauw
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - A Van Hul
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - C Trevisan
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - S Gabriël
- Department of Veterinary Public Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Ng-Nguyen D, Stevenson MA, Dorny P, Gabriël S, Vo TV, Nguyen VAT, Phan TV, Hii SF, Traub RJ. Comparison of a new multiplex real-time PCR with the Kato Katz thick smear and copro-antigen ELISA for the detection and differentiation of Taenia spp. in human stools. PLoS Negl Trop Dis 2017; 11:e0005743. [PMID: 28686662 PMCID: PMC5517074 DOI: 10.1371/journal.pntd.0005743] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 07/19/2017] [Accepted: 06/23/2017] [Indexed: 11/19/2022] Open
Abstract
Background Taenia solium, the cause of neurocysticercosis (NCC), has significant socioeconomic impacts on communities in developing countries. This disease, along with taeniasis is estimated to infect 2.5 to 5 million people globally. Control of T. solium NCC necessitates accurate diagnosis and treatment of T. solium taeniasis carriers. In areas where all three species of Taenia tapeworms (T. solium, Taenia saginata and Taenia asiatica) occur sympatrically, conventional microscope- and copro-antigen based diagnostic methods are unable to distinguish between these three Taenia species. Molecular diagnostic tools have been developed to overcome this limitation; however, conventional PCR-based techniques remain unsuitable for large-scale deployment in community-based surveys. Moreover, a real-time PCR (qPCR) for the discrimination of all three species of Taenia in human stool does not exist. This study describes the development and validation of a new triplex Taq-Man probe-based qPCR for the detection and discrimination of all three Taenia human tapeworms in human stools collected from communities in the Central Highlands of Vietnam. The diagnostic characteristics of the test are compared with conventional Kato Katz (KK) thick smear and copro-antigen ELISA (cAgELISA) method utilizing fecal samples from a community based cross-sectional study. Using this new multiplex real-time PCR we provide an estimate of the true prevalence of taeniasis in the source population for the community based cross-sectional study. Methodology/Principal findings Primers and TaqMan probes for the specific amplification of T. solium, T. saginata and T. asiatica were designed and successfully optimized to target the internal transcribed spacer I (ITS-1) gene of T. solium and the cytochrome oxidase subunit I (COX-1) gene of T. saginata and T. asiatica. The newly designed triplex qPCR (T3qPCR) was compared to KK and cAgELISA for the detection of Taenia eggs in stool samples collected from 342 individuals in Dak Lak province, Central Highlands of Vietnam. The overall apparent prevalence of taeniasis in Dak Lak province was 6.72% (95% confidence interval (CI) [3.94–9.50]) in which T. solium accounted for 1.17% (95% CI [0.37–3.17]), according to the T3qPCR. There was sympatric presence of T. solium, T. saginata and T. asiatica. The T3qPCR proved superior to KK and cAgELISA for the detection and differentiation of Taenia species in human feces. Diagnostic sensitivities of 0.94 (95% credible interval (CrI) [0.88–0.98]), 0.82 (95% CrI [0.58–0.95]) and 0.52 (95% CrI [0.07–0.94]), and diagnostic specificities of 0.98 (95% CrI [0.94–1.00]), 0.91 (95% CrI [0.85–0.96]) and 0.99 (95% CrI [0.96–1.00]) were estimated for the diagnosis of taeniasis for the T3qPCR, cAgELISA and KK thick smear in this study, respectively. Conclusions T3qPCR is not only superior to the KK thick smear and cAgELISA in terms of diagnostic sensitivity and specificity, but it also has the advantage of discriminating between species of Taenia eggs in stools. Application of this newly developed T3qPCR has identified the existence of all three human Taenia tapeworms in Dak Lak province and proves for the first time, the existence of T. asiatica in the Central Highlands and the south of Vietnam. Human taeniid tapeworms comprise three species, Taenia solium, Taenia saginata and Taenia asiatica. Taeniasis is a meat-borne zoonosis transmitted by the consumption of cysticerci in raw or undercooked pork for T. solium and T. asiatica (liver) and in beef for T. saginata. Accidental ingestion of T. solium eggs by humans also results in the formation of cysticerci, often in the brain, referred to as neurocysticercosis (NCC). T. solium NCC is a significant cause of morbidity and mortality owing to epilepsy in many resource-poor communities. In animals, ingestion of eggs passed by humans results in organ and/or carcass condemnation and suboptimal economic outcomes for farmers. The accurate diagnosis of T. solium tapeworm carriers is essential to monitor the success of control programs. In areas where all three species of Taenia tapeworms occur together, conventional diagnostic methods are unable to distinguish between the different species of Taenia. In this study, we develop and apply a T3qPCR capable of detecting and discriminating all three-tapeworm species in stools in a rapid and high-throughput fashion, suitable for large-scale community surveys. The newly developed T3qPCR proved superior to previously developed immunodiagnostic and conventional microscopic-based tests in terms of diagnostic sensitivity, specificity and the ability to identify and distinguish human Taenia species. This qPCR assay facilitated the identification of T. asiatica tapeworms in the Central Highlands of Vietnam, for the first time.
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Affiliation(s)
- Dinh Ng-Nguyen
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Dak Lak, Vietnam
- * E-mail: ,
| | - Mark A. Stevenson
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Pierre Dorny
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Sarah Gabriël
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Tinh Van Vo
- Department of Physiology, Pathology and Immunology, Pham Ngoc Thach University of Medicine, Ho Chi Minh, Vietnam
| | - Van-Anh Thi Nguyen
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Dak Lak, Vietnam
| | - Trong Van Phan
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Dak Lak, Vietnam
| | - Sze Fui Hii
- Barwon Health, University Hospital Geelong, Victoria, Australia
| | - Rebecca J. Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
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Sahu PS, Lim YAL, Mahmud R, Somanath SD, Tan CT, Ramachandran CP. Needs of exploring the burden of recent onset seizures due to neurocysticercosis and challenges in southeast Asia focusing on scenario in Malaysia. ASIAN PAC J TROP MED 2017; 10:332-340. [PMID: 28552103 DOI: 10.1016/j.apjtm.2017.03.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/10/2017] [Accepted: 03/15/2017] [Indexed: 10/19/2022] Open
Abstract
Seizures due to neurocysticercosis (NCC) is a neglected human-to-human transmitted disorder and an emerging problem worldwide. A substantial portion of recent onset seizures is known to be attributed to NCC in Taenia solium (T. solium) endemic areas where populations which neither raise pigs nor eat pig meat are also at risk. High prevalence of NCC causing epilepsy has been reported in the underdeveloped areas of Southeast Asia (SEA) however, only fragmentary information on its incidence is available in countries like Malaysia. In Malaysia T. solium infection was previously thought to be infrequent due to Muslim population majority and the religious prohibition of consuming pork, but it is not totally absent. There is an evident lack of knowledge and awareness of the actual burden, routes of transmission, and the impact of NCC in this region. The problem is assumed to be more prevalent particularly in cities because of the frequent inflow of possibly T. solium infected individuals or carriers among those who migrate from neighboring endemic countries to Malaysia. The issue of imported cases that are likely to be emerging in Malaysia is highlighted here. An accurate quantification of regional burdens of epilepsy due to NCC in Malaysia is warranted considering the disease emergence in its neighboring countries. It is suggested that the importance of NCC be recognized through quantification of its burden, and also to collect epidemiological data for its subsequent elimination in line of World Health Organization's mission for control of cysticercosis as a neglected tropical disease. In this review the need as well as a strategy for neuro-care center screening of epilepsy cases, and various issues with possible explanations are discussed. It is also proposed that NCC be declared as a reportable disease which is one of the eradicable public health problems in SEA.
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Affiliation(s)
- Priyadarshi S Sahu
- Division of Pathology, School of Medicine, International Medical University, 57000 Kuala Lumpur, Malaysia.
| | - Yvonne A L Lim
- Department of Parasitology, Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Rohela Mahmud
- Department of Parasitology, Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Sushela D Somanath
- Division of Pathology, School of Medicine, International Medical University, 57000 Kuala Lumpur, Malaysia
| | - Chong T Tan
- Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - C P Ramachandran
- Programme Review Group, Neglected Tropical Diseases-WHO-Western Pacific Region, Kuala Lumpur, Malaysia
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15
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Ng-Nguyen D, Stevenson MA, Traub RJ. A systematic review of taeniasis, cysticercosis and trichinellosis in Vietnam. Parasit Vectors 2017; 10:150. [PMID: 28320455 PMCID: PMC5359969 DOI: 10.1186/s13071-017-2085-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 03/10/2017] [Indexed: 11/10/2022] Open
Abstract
Taeniasis, cysticercosis and trichinellosis have been ranked as the most important food-borne parasites of humans in terms of public health, socioeconomic and trade impact. Despite this, information on these food-borne zoonoses in Vietnam is scarce and fragmented, and many local reports remain inaccessible to the international research community. This study aims to conduct comprehensive literature searches to report on the incidence and estimate the true prevalence of taeniasis in humans and T. solium cysticercosis in humans and pigs in Vietnam utilizing Bayesian models; in addition, to report the incidence and the distribution of trichinellosis. A Bayesian approach was used to estimate the true prevalence of taeniasis and cysticercosis based on published diagnostic test characteristics used in each published cross-sectional survey. The utilization of coproscopic-based examination of Taenia eggs in stool, although highly specific for genus-level detection, has poor sensitivity and led to an underestimation of the prevalence of human taeniasis. Similarly, post-mortem-based surveys of T. solium cysticercosis in pigs also led to the underestimation of prevalence of porcine cysticercosis. On the other hand, the low specificity of immunodiagnostic methods, in particular Ab-ELISA, led to a likely overestimation of T. solium cysticercosis in humans. Due to the use of imperfect diagnosis tests combined with poor descriptions of sampling methods, our ability to draw solid conclusions from these data is limited. We estimate that the true prevalence of taeniasis and T. solium cysticercosis in rural ‘hotspots’, is as high as 13% for each, in humans. Taeniasis and T. solium cysticercosis occurs in 60 of the 63 provinces of Vietnam. Most of the information relating to the distribution and prevalence of porcine cysticercosis is limited to commercial abattoir surveys. In Vietnam, Taenia asiatica appears to be confined to the north where it occurs sympatrically with T. solium and Taenia saginata. The status of T. asiatica in Central and South Vietnam remains unascertained. To date, five outbreaks of trichinellosis have been reported in the north and northwest of Vietnam, affecting a total of 114 people and responsible for eight fatalities. In the same region, studies of free-roaming pigs showed evidence of high levels of exposure to Trichinella and, in cases where larvae were recovered, the species present were identified as Trichinella spiralis. Based on five studies, the main risk factors for pork-borne zoonoses in Vietnam include the consumption of undercooked/raw meat and vegetables and the use of night-soil for fertilization of local produce. This systematic review draws attention to the importance of these pork-borne zoonoses.
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Affiliation(s)
- Dinh Ng-Nguyen
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, 3052, Australia. .,Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Dak Lak province, Vietnam.
| | - Mark A Stevenson
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, 3052, Australia
| | - Rebecca J Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, 3052, Australia
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Aung AK, Spelman DW. Taenia solium Taeniasis and Cysticercosis in Southeast Asia. Am J Trop Med Hyg 2016; 94:947-54. [PMID: 26834197 PMCID: PMC4856625 DOI: 10.4269/ajtmh.15-0684] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/15/2015] [Indexed: 12/12/2022] Open
Abstract
Human taeniasis/cysticercosis caused by the pork tapeworm Taenia solium has been identified as a potentially eradicable disease by the International Task Force for Disease Eradication of the World Health Organization. In southeast Asia, T. solium taeniasis/cysticercosis is considered one of the major neglected tropical diseases afflicting the region. In the last few decades, a considerable effort has been invested toward establishing the epidemiology and burden of disease in several southeast Asian countries. Moreover, further evidence is emerging as to understanding the dynamics of disease transmission and cultural, political, and socioeconomic factors influencing the success of control and eradication efforts within the region. However, despite major collaborations by several champion groups, advances have been slow and little remains known about the complete epidemiology of taeniasis/cysticercosis and the barriers to programmatic success. This review article aims to address the above issues with a further focus on the challenges to control and eradicate taeniasis/cysticercosis within the southeast Asia region.
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Affiliation(s)
- Ar Kar Aung
- Department of General Medicine, The Alfred Hospital, Victoria, Australia; Department of Infectious Diseases, The Alfred Hospital, Victoria, Australia; Monash University, Victoria, Australia; Department of Microbiology, The Alfred Hospital, Victoria, Australia
| | - Denis W Spelman
- Department of General Medicine, The Alfred Hospital, Victoria, Australia; Department of Infectious Diseases, The Alfred Hospital, Victoria, Australia; Monash University, Victoria, Australia; Department of Microbiology, The Alfred Hospital, Victoria, Australia
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Van De N, Le TH, Lien PTH, Eom KS. Current status of taeniasis and cysticercosis in Vietnam. THE KOREAN JOURNAL OF PARASITOLOGY 2014; 52:125-9. [PMID: 24850954 PMCID: PMC4028448 DOI: 10.3347/kjp.2014.52.2.125] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 09/27/2013] [Accepted: 10/27/2013] [Indexed: 11/23/2022]
Abstract
Several reports on taeniasis and cysticercosis in Vietnam show that they are distributed in over 50 of 63 provinces. In some endemic areas, the prevalence of taeniasis was 0.2-12.0% and that of cysticercosis was 1.0-7.2%. The major symptoms of taeniasis included fidgeted anus, proglottids moving out of the anus, and proglottids in the feces. Clinical manifestations of cysticercosis in humans included subcutaneous nodules, epileptic seizures, severe headach, impaired vision, and memory loss. The species identification of Taenia in Vietnam included Taenia asiatica, Taenia saginata, and Taenia solium based on combined morphology and molecular methods. Only T. solium caused cysticercosis in humans. Praziquantel was chosen for treatment of taeniasis and albendazole for treatment of cysticercosis. The infection rate of cysticercus cellulosae in pigs was 0.04% at Hanoi slaughterhouses, 0.03-0.31% at provincial slaughterhouses in the north, and 0.9% in provincial slaughterhouses in the southern region of Vietnam. The infection rate of cysticercus bovis in cattle was 0.03-2.17% at Hanoi slaughterhouses. Risk factors investigated with regard to transmission of Taenia suggested that consumption of raw meat (eating raw meat 4.5-74.3%), inadequate or absent meat inspection and control, poor sanitation in some endemic areas, and use of untreated human waste as a fertilizer for crops may play important roles in Vietnam, although this remains to be validated.
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Affiliation(s)
- Nguyen Van De
- Department of Parasitology, Hanoi Medical University, Vietnam
| | - Thanh Hoa Le
- Department of Immunology, Institute of Bio-Technology, Vietnam
| | | | - Keeseon S Eom
- Department of Immunology, Institute of Bio-Technology, Vietnam
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18
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Galán-Puchades MT, Fuentes MV. Lights and shadows of the Taenia asiatica life cycle and pathogenicity. Trop Parasitol 2014; 3:114-9. [PMID: 24470994 PMCID: PMC3889087 DOI: 10.4103/2229-5070.122114] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/26/2013] [Indexed: 11/04/2022] Open
Abstract
Humans are definitive hosts of two well-known species of the Taenia genus, Taenia solium (the pig tapeworm) and Taenia saginata (the cattle tapeworm). In the 1990s, a third species, Taenia asiatica, was discovered, sharing features with the other two since the adult morphology is similar to that of T. saginata, but its life cycle is like that of T. solium. Human taeniasis usually is asymptomatic or displays mild symptoms, and only T. solium can cause other sometimes serious disorders when humans accidentally ingest the eggs and develop the larval stage in different organs (cysticercosis). In this review, we expose what we currently know (lights) and what we do not yet know (shadows) about the life cycle and pathogenicity of T. asiatica. Concerning its life cycle, the main uncertainty is whether humans can act as intermediate hosts of this species. We also suggest that due to its small size and location in pigs, the cysticerci probably escape veterinary inspection becoming a silent parasite. Concerning pathogenicity, it is still not known if T. asiatica can cause human liver cysticercosis, taking into account its principal hepatic tropism in pigs. To answer all these questions it would be essential to perform sensitive as well as specific diagnostic techniques for T. asiatica in humans and pigs. Currently, only molecular methods are able to determine the Taenia species, since morphology and immunology are useless, but unfortunately although largely used in research those methods are not employed in routine diagnosis.
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Affiliation(s)
| | - Màrius Vicent Fuentes
- Department of Parasitology, Faculty of Pharmacy, University of Valencia, Valencia, Spain
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Ale A, Victor B, Praet N, Gabriël S, Speybroeck N, Dorny P, Devleesschauwer B. Epidemiology and genetic diversity of Taenia asiatica: a systematic review. Parasit Vectors 2014; 7:45. [PMID: 24450957 PMCID: PMC3900737 DOI: 10.1186/1756-3305-7-45] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 01/08/2014] [Indexed: 11/10/2022] Open
Abstract
Taenia asiatica has made a remarkable journey through the scientific literature of the past 50 years, starting with the paradoxical observation of high prevalences of T. saginata-like tapeworms in non-beef consuming populations, to the full description of its mitochondrial genome. Experimental studies conducted in the 1980s and 1990s have made it clear that the life cycle of T. asiatica is comparable to that of T. saginata, except for pigs being the preferential intermediate host and liver the preferential location of the cysts. Whether or not T. asiatica can cause human cysticercosis, as is the case for Taenia solium, remains unclear. Given the specific conditions needed to complete its life cycle, in particular the consumption of raw or poorly cooked pig liver, the transmission of T. asiatica shows an important ethno-geographical association. So far, T. asiatica has been identified in Taiwan, South Korea, Indonesia, the Philippines, Thailand, south-central China, Vietnam, Japan and Nepal. Especially this last observation indicates that its distribution is not restricted to South-East-Asia, as was thought so far. Indeed, the molecular tools developed over the last 20 years have made it increasingly possible to differentiate T. asiatica from other taeniids. Such tools also indicated that T. asiatica is related more closely to T. saginata than to T. solium, feeding the debate on its taxonomic status as a separate species versus a subspecies of T. saginata. Furthermore, the genetic diversity within T. asiatica appears to be very minimal, indicating that this parasite may be on the verge of extinction. However, recent studies have identified potential hybrids between T. asiatica and T. saginata, reopening the debate on the genetic diversity of T. asiatica and its status as a separate species.
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Affiliation(s)
| | | | | | | | | | | | - Brecht Devleesschauwer
- Institute of Health and Society (IRSS), Université catholique de Louvain, Brussels, Belgium.
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Galán-Puchades MT, Fuentes MV. Taenia asiatica: left out by globalisation? Trends Parasitol 2013; 30:54-5. [PMID: 24380665 DOI: 10.1016/j.pt.2013.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 12/02/2013] [Indexed: 11/16/2022]
Affiliation(s)
- María Teresa Galán-Puchades
- Department of Parasitology, Faculty of Pharmacy, University of Valencia, Av Vicent Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain.
| | - Màrius V Fuentes
- Department of Parasitology, Faculty of Pharmacy, University of Valencia, Av Vicent Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain
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Carrique-Mas JJ, Bryant JE. A review of foodborne bacterial and parasitic zoonoses in Vietnam. ECOHEALTH 2013; 10:465-89. [PMID: 24162798 PMCID: PMC3938847 DOI: 10.1007/s10393-013-0884-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 06/10/2013] [Accepted: 09/24/2013] [Indexed: 06/02/2023]
Abstract
Vietnam has experienced unprecedented economic and social development in recent years, and the livestock sector is undergoing significant transformations. Although food animal production is still dominated by small-scale 'backyard' enterprises with mixed crop-livestock or livestock-aquatic systems, there is a trend towards more intensive and vertically integrated operations. Changes in animal production, processing and distribution networks for meat and animal products, and the shift from wet markets to supermarkets will undoubtedly impact food safety risks in Vietnam in unforeseen and complex ways. Here, we review the available published literature on bacterial and parasitic foodborne zoonoses (FBZ) in Vietnam. We report on clinical disease burden and pathogen prevalence in animal reservoirs for a number of important FBZ, and outline opportunities for future research.
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Affiliation(s)
- Juan J Carrique-Mas
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, W.1, Dist.5, Ho Chi Minh City, Vietnam,
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Devleesschauwer B, Aryal A, Tharmalingam J, Joshi DD, Rijal S, Speybroeck N, Gabriël S, Victor B, Dorny P. Complexities in using sentinel pigs to study Taenia solium transmission dynamics under field conditions. Vet Parasitol 2013; 193:172-8. [DOI: 10.1016/j.vetpar.2012.12.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 11/30/2012] [Accepted: 12/05/2012] [Indexed: 10/27/2022]
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Galán-Puchades MT, Fuentes MV. Taenia asiatica: the most neglected human Taenia and the possibility of cysticercosis. THE KOREAN JOURNAL OF PARASITOLOGY 2013; 51:51-4. [PMID: 23467406 PMCID: PMC3587749 DOI: 10.3347/kjp.2013.51.1.51] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 12/18/2012] [Accepted: 12/18/2012] [Indexed: 11/23/2022]
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.
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Affiliation(s)
- M Teresa Galán-Puchades
- Department of Parasitology, Faculty of Pharmacy, University of Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjasssot, Valencia, Spain.
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Conlan JV, Vongxay K, Khamlome B, Dorny P, Sripa B, Elliot A, Blacksell SD, Fenwick S, Thompson RCA. A cross-sectional study of Taenia solium in a multiple taeniid-endemic region reveals competition may be protective. Am J Trop Med Hyg 2012; 87:281-91. [PMID: 22855759 DOI: 10.4269/ajtmh.2012.11-0106] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We conducted cross-sectional surveys for taeniasis and cysticercosis in humans, pigs, and dogs in four northern provinces of Laos. Human cysticercosis and taeniasis prevalence was 2.2% (95% confidence interval [CI] = 1.4-3.0%) and 8.4% (95% CI = 6.9-9.9%), respectively. Eating uncooked beef, being male, province of residence, age, and ethnicity were significant risk factors for taeniasis and only province of residence was a significant risk factor for cystiercosis. Thirty-five human tapeworms were recovered during the survey and 33 (94.3%) and 2 (5.7%) were identified as Taenia saginata and T. solium, respectively. Maximum-likelihood adjusted prevalence of T. solium and T. hydatigena in pigs was 4.2% (95% CI = 0.5-7.9%) and 55.9% (95% CI = 47.5-64.3%), respectively, and T. hydatigena taeniasis in dogs was 4.8% (95% CI = 0.0-11.3%). Taenia hydatigena and T. saginata were the most prevalent taeniids in the respective pig and human populations and together may suppress T. solium transmission.
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Affiliation(s)
- James V Conlan
- School of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, Western Australia, Australia.
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Trung DD, Praet N, Cam TDT, Lam BVT, Manh HN, Gabriël S, Dorny P. Assessing the burden of human cysticercosis in Vietnam. Trop Med Int Health 2012; 18:352-6. [PMID: 23279716 DOI: 10.1111/tmi.12043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To describe the occurrence of cysticercosis in patients living in rural areas of Northern Vietnam presenting clinical signs of neurocysticercosis. METHODS Serological antigen detection, reflecting current infection with viable larval stages of Taenia solium, was used to estimate the prevalence of active cysticercosis in this patient population. RESULTS The seroprevalence in epileptic patient population was <10%. However, antigen detection cannot detect dead cysticerci, which may also cause clinical signs. Therefore, the seroprevalence figures shown here may underestimate the role of neurocysticercosis as a causal agent of epilepsy and headaches in this population. CONCLUSIONS Human and porcine cysticercosis remain public and veterinary public health problems in Northern Vietnam and probably in other parts of the country.
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Affiliation(s)
- Dung Do Trung
- National Institute of Malariology, Parasitology and Entomology, Hanoi, Vietnam
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Devleesschauwer B, Aryal A, Joshi DD, Rijal S, Sherchand JB, Praet N, Speybroeck N, Duchateau L, Vercruysse J, Dorny P. Epidemiology of Taenia solium in Nepal: is it influenced by the social characteristics of the population and the presence of Taenia asiatica? Trop Med Int Health 2012; 17:1019-22. [PMID: 22643112 DOI: 10.1111/j.1365-3156.2012.03017.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The transmission of the zoonotic pork tapeworms Taenia solium and T. asiatica depends on a combination of specific risk factors, such as open defecation, backyard pig raising and the consumption of raw or undercooked pork and viscera. A community-based survey was conducted among 289 households in south-eastern Nepal to study the heterogeneity of these risk factor frequencies as a function of the social composition of the population. The frequency of open defecation, backyard pig raising and pork consumption differed significantly (P < 0.005) among the different coexisting caste and ethnic groups. In the same survey, the taeniosis prevalence was examined among the different groups. Tapeworm carriers were identified at a high prevalence among the Dum, one of the most disadvantaged communities of Nepal. A PCR-RFLP assay revealed that all collected tapeworm specimens were T. asiatica, a species thus far not known to occur in South Asia. These results can help to understand the epidemiology of T. solium in Nepal, which appears to be more complex than thought so far.
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Affiliation(s)
- Brecht Devleesschauwer
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
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Galán-Puchades MT, Fuentes MV. Human taeniasis diagnosed by radiography/endoscopy and morphology. Gastrointest Endosc 2012; 75:927. [PMID: 22440208 DOI: 10.1016/j.gie.2011.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 12/01/2011] [Indexed: 12/11/2022]
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Yanagida T, Sako Y, Nakao M, Nakaya K, Ito A. Taeniasis and cysticercosis due to Taenia solium in Japan. Parasit Vectors 2012; 5:18. [PMID: 22248435 PMCID: PMC3398336 DOI: 10.1186/1756-3305-5-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Accepted: 01/17/2012] [Indexed: 11/10/2022] Open
Abstract
Taenia solium is a zoonotic cestode that causes taeniasis and cysticercosis in humans. The parasite is traditionally found in developing countries where undercooked pork is consumed under poor sanitary conditions and/or as part of traditional food cultures. However, the recent increase in international tourism and immigration is spreading the disease into non-endemic developed countries such as the United States. Although there has been concern that the number of cysticercosis cases is increasing in Japan, the current situation is not clear. This is largely because taeniasis and cysticercosis are not notifiable conditions in Japan and because there have been no comprehensive reviews of T. solium infections in Japan conducted in the last 15 years. Herein, we provide an overview of the status of T. solium infection in Japan over the past 35 years and point out the potential risks to Japanese society.
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Affiliation(s)
- Tetsuya Yanagida
- Asahikawa Medical University, Asahikawa, Hokkaido, 078-8510, Japan.
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Conlan JV, Sripa B, Attwood S, Newton PN. A review of parasitic zoonoses in a changing Southeast Asia. Vet Parasitol 2011; 182:22-40. [PMID: 21846580 DOI: 10.1016/j.vetpar.2011.07.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Parasitic zoonoses are common and widely distributed in the Southeast Asian region. However, the interactions between parasites, hosts and vectors are influenced by environmental, socio-cultural and livestock production changes that impact on the distribution, prevalence and severity of disease. In this review we provide an update on new knowledge in the context of ongoing changes for the food-borne pig associated zoonoses Taenia solium and Trichinella spp., the food-borne trematodes Opisthorchis viverrini and Clonorchis sinensis, the water-borne trematodes Schistosoma spp., the vector-borne zoonotic protozoa Plasmodium knowlesi and Leishmania spp. and the soil-borne zoonotic hookworm Ancylostoma ceylanicum. These various changes need to be considered when assessing or developing regional control programs or devising new research initiatives in a changing SE Asia.
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Affiliation(s)
- James V Conlan
- School of Veterinary and Biomedical Sciences, Murdoch University, WA, Australia.
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Eom KS, Jeon HK, Rim HJ. Geographical distribution of Taenia asiatica and related species. THE KOREAN JOURNAL OF PARASITOLOGY 2010; 47 Suppl:S115-24. [PMID: 19885327 DOI: 10.3347/kjp.2009.47.s.s115] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 10/13/2009] [Accepted: 10/13/2009] [Indexed: 11/23/2022]
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.
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Affiliation(s)
- Keeseon S Eom
- Department of Parasitology and Medical Research Institute, Chungbuk National University College of Medicine, Chongju, Chungbuk 361-763, Korea.
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Willingham AL, Wu HW, Conlan J, Satrija F. Combating Taenia solium Cysticercosis in Southeast Asia. ADVANCES IN PARASITOLOGY 2010; 72:235-66. [DOI: 10.1016/s0065-308x(10)72009-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Conlan JV, Vongxay K, Fenwick S, Blacksell SD, Thompson RA. Does interspecific competition have a moderating effect on Taenia solium transmission dynamics in Southeast Asia? Trends Parasitol 2009; 25:398-403. [DOI: 10.1016/j.pt.2009.06.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 06/02/2009] [Accepted: 06/05/2009] [Indexed: 11/26/2022]
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Abstract
Parasitic food-borne diseases are generally underrecognised, however they are becoming more common. Globalization of the food supply, increased international travel, increase of the population of highly susceptible persons, change in culinary habits, but also improved diagnostic tools and communication are some factors associated with the increased diagnosis of food-borne parasitic diseases worldwide. This paper reviews the most important emerging food-borne parasites, with emphasis on transmission routes. In a first part, waterborne parasites transmitted by contaminated food such as Cyclospora cayetanensis, Cryptosporidium and Giardia are discussed. Also human fasciolosis, of which the importance has only been recognised in the last decades, with total numbers of reported cases increasing from less than 3000 to 17 million, is looked at. Furthermore, fasciolopsiosis, an intestinal trematode of humans and pigs belongs to the waterborne parasites as well. A few parasites that may be transmitted through faecal contamination of foods and that have received renewed attention, such as Toxoplasma gondii, or that are (re-)emerging, such as Trypanosoma cruzi and Echinococcus spp., are briefly reviewed. In a second part, meat-borne parasite infections are reviewed. Humans get infected by eating raw or undercooked meat infected with cyst stages of these parasites. Meat inspection is the principal method applied in the control of Taenia spp. and Trichinella spp. However, it is often not very sensitive, frequently not practised, and not done for T. gondii and Sarcocystis spp. Meat of reptiles, amphibians and fish can be infected with a variety of parasites, including trematodes (Opisthorchis spp., Clonorchis sinensis, minute intestinal flukes), cestodes (Diphyllobothrium spp., Spirometra), nematodes (Gnathostoma, spp., anisakine parasites), and pentastomids that can cause zoonotic infections in humans when consumed raw or not properly cooked. Another important zoonotic food-borne trematode is the lungfluke (Paragonimus spp.). Traditionally, these parasitic zoonoses are most common in Asia because of the particular food practices and the importance of aquaculture. However, some of these parasites may emerge in other continents through aquaculture and improved transportation and distribution systems. Because of inadequate systems for routine diagnosis and monitoring or reporting for many of the zoonotic parasites, the incidence of human disease and parasite occurrence in food is underestimated. Of particular concern in industrialised countries are the highly resistant waterborne protozoal infections as well as the increased travel and immigration, which increase the exposure to exotic diseases. The increased demand for animal proteins in developing countries will lead to an intensification of the production systems in which the risk of zoonotic infections needs to be assessed. Overall, there is an urgent need for better monitoring and control of food-borne parasites using new technologies.
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Affiliation(s)
- P Dorny
- Department of Animal Health, Institute of Tropical Medicine, B-2000 Antwerp, Belgium.
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Galán-Puchades M, Fuentes M. Taenia asiatica and pig cysticercosis. Vet Parasitol 2008; 157:160-1. [DOI: 10.1016/j.vetpar.2008.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 07/01/2008] [Accepted: 07/07/2008] [Indexed: 10/21/2022]
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Abstract
PURPOSE OF REVIEW This review summarizes the biology, clinical aspects, diagnosis, treatment and epidemiology for the common and rarer (zoonotic) intestinal cestodes of humans. RECENT FINDINGS Mass drug application to eliminate Taenia solium carriers may have only temporary effects on cysticercosis transmission. At least two major world genotypes of T. solium have been identified and greater genetic heterogeneity may occur at the regional level. A new human taeniid T. asiatica has been confirmed which occurs sympatrically with T. saginata and T. solium in Southeast Asia. Coproantigen and PCR tests for Taenia spp. have greatly improved diagnostic efficacy and epidemiological studies. There appears to be an increase in human diphyllobothriasis in Europe, Japan and the Americas. SUMMARY Human intestinal cestode infections are globally primarily caused by species in three genera: Taenia, Hymenolepis or Diphyllobothrium. Sporadic zoonotic infections caused by nontaeniids are usually food-borne or due to accidental ingestion of invertebrate hosts. Intestinal cestode infections generally result in only mild symptoms characterized chiefly by abdominal discomfort and diarrhoea. Most human intestinal cestode infections can be treated with a single oral dose of praziquantel or niclosamide.
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Affiliation(s)
- Philip Craig
- Cestode Zoonoses Research Group, Biomedical Sciences Research Institute and School of Environment and Life Sciences, University of Salford, Greater Manchester, UK.
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Galán-Puchades MT, Fuentes MV. Comment on: Human tapeworms in north Vietnam. Trans R Soc Trop Med Hyg 2007; 101:628-9; author reply 629-30. [PMID: 17257633 DOI: 10.1016/j.trstmh.2006.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Accepted: 12/05/2006] [Indexed: 11/20/2022] Open
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Yamasaki H, Nakaya K, Nakao M, Sako Y, Ito A. Significance of Molecular Diagnosis using Histopathological Specimens in Cestode Zoonoses. Trop Med Health 2007. [DOI: 10.2149/tmh.35.307] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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