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Qian MB, Keiser J, Utzinger J, Zhou XN. Clonorchiasis and opisthorchiasis: epidemiology, transmission, clinical features, morbidity, diagnosis, treatment, and control. Clin Microbiol Rev 2024; 37:e0000923. [PMID: 38169283 PMCID: PMC10938900 DOI: 10.1128/cmr.00009-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 07/18/2023] [Indexed: 01/05/2024] Open
Abstract
Clonorchis sinensis, Opisthorchis viverrini, and Opisthorchis felineus are important liver flukes that cause a considerable public health burden in eastern Asia, southeastern Asia, and eastern Europe, respectively. The life cycles are complex, involving humans, animal reservoirs, and two kinds of intermediate hosts. An interplay of biological, cultural, ecological, economic, and social factors drives transmission. Chronic infections are associated with liver and biliary complications, most importantly cholangiocarcinoma. With regard to diagnosis, stool microscopy is widely used in epidemiologic surveys and for individual diagnosis. Immunologic techniques are employed for screening purposes, and molecular techniques facilitate species differentiation in reference laboratories. The mainstay of control is preventive chemotherapy with praziquantel, usually combined with behavioral change through information, education and communication, and environmental control. Tribendimidine, a drug registered in the People's Republic of China for soil-transmitted helminth infections, shows potential against both C. sinensis and O. viverrini and, hence, warrants further clinical development. Novel control approaches include fish vaccine and biological control. Considerable advances have been made using multi-omics which may trigger the development of new interventions. Pressing research needs include mapping the current distribution, disentangling the transmission, accurately estimating the disease burden, and developing new diagnostic and treatment tools, which would aid to optimize control and elimination measures.
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Affiliation(s)
- Men-Bao Qian
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, People’s Republic of China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, People’s Republic of China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, People’s Republic of China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, People’s Republic of China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, People’s Republic of China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, People’s Republic of China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
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Saijuntha W, Sithithaworn P, Wangboon C, Andrews RH, Petney TN. Liver Flukes: Clonorchis and Opisthorchis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1454:239-284. [PMID: 39008268 DOI: 10.1007/978-3-031-60121-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Clonorchis sinensis, Opisthorchis viverrini and O. felineus are liver flukes of human and animal pathogens occurring across much of Europe and Asia. Nevertheless, they are often underestimated compared to other, better known neglected diseases in spite of the fact that many millions of people are infected and hundreds of millions are at risk. This is possibly because of the chronic nature of the infection and disease and that it takes several decades prior to a life-threatening pathology to develop. Several studies in the past decade have provided more information on the molecular biology of the liver flukes which clearly lead to better understanding of parasite biology, systematics and population genetics. Clonorchiasis and opisthorchiasis are characterized by a chronic infection that induces hepatobiliary inflammation, especially periductal fibrosis, which can be detected by ultrasonography. These chronic inflammations eventually lead to cholangiocarcinoma (CCA), a usually fatal bile duct cancer that develops in some infected individuals. In Thailand alone, opisthorchiasis-associated CCA kills up to 20,000 people every year and is therefore of substantial public health importance. Its socioeconomic impacts on impoverished families and communities are considerable. To reduce hepatobiliary morbidity and CCA, the primary intervention measures focus on control and elimination of the liver fluke. Accurate diagnosis of liver fluke infections in both human and other mammalian, snail and fish intermediate hosts is important for achieving these goals. While the short-term goal of liver fluke control can be achieved by praziquantel chemotherapy, a comprehensive health education package targeting school children is believed to be more beneficial for a long-term goal/solution. It is recommended that transdisciplinary research or multisectoral control approach including one health and/or eco health intervention strategy should be applied to combat the liver flukes and hence contribute to reduction of CCA in endemic areas.
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Affiliation(s)
| | - Paiboon Sithithaworn
- Department of Parasitology and Cholangiocarcinoma Research Institute, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
| | - Chompunoot Wangboon
- School of Preclinical Sciences, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Ross H Andrews
- CASCAP, Cholangiocarcinoma Research Institute, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Faculty of Medicine, St Mary's Campus, Imperial College London, London, UK
| | - Trevor N Petney
- CASCAP, Cholangiocarcinoma Research Institute, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Department of Paleontology and Evolution, State Museum of Natural History, Karlsruhe, Germany
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Namsanor J, Kiatsopit N, Laha T, Andrews RH, Petney TN, Sithithaworn P. Infection Dynamics of Opisthorchis viverrini Metacercariae in Cyprinid Fishes from Two Endemic Areas in Thailand and Lao PDR. Am J Trop Med Hyg 2020; 102:110-116. [PMID: 31701859 DOI: 10.4269/ajtmh.19-0432] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The infection dynamics of Opisthorchis viverrini metacercariae was analyzed in cyprinid fish from endemic areas in Mukdahan Province, Thailand, and Khammouane Province, Lao PDR. The fish were collected during the cool-dry (November-February), hot-dry (March-May), and rainy (June-October) seasons in 2017. They were examined by the digestion method, and the infection status was statistically analyzed by study area, season, and fish size. The prevalence (no. of fish positive/no. of fish examined × 100) and metacercarial intensities (no. of metacercariae detected/no. of fish positive) of O. viverrini in both study areas depended on season, being high in the cool-dry season and varying in the hot-dry and rainy seasons. In Mukdahan Province, the average prevalence was 18.3% (range 11.0-46.7%, n = 420) and the intensity was 4.07 ± 5.86 cysts/fish (mean ± SD), whereas in Khammouane Province, the prevalence was 51.9% (range 9.1-70.6%, n = 673) and the intensity was 6.67 ± 12.88 cysts/fish. Among the cyprinid fish species examined, the infection was associated with fish body size and predominantly found in Hampala dispar (86.5%), Cyclocheilichthys armatus (73.2%), and Puntius brevis (42.7%). The distribution of O. viverrini metacercariae in fish was skewed, with most of the fish having a low worm burden with an average of four to six cysts/fish. The findings that seasonality, sampling locality, fish size, and species of fish play roles in the risk of O. viverrini infection imply that these host and environmental factors are important for the transmission dynamics and control of O. viverrini.
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Affiliation(s)
- Jutamas Namsanor
- Faculty of Medicine, Cholangiocarcinoma Research Institute (CARI), Khon Kaen University, Khon Kaen, Thailand.,Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Nadda Kiatsopit
- Faculty of Medicine, Cholangiocarcinoma Research Institute (CARI), Khon Kaen University, Khon Kaen, Thailand.,Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Thewarach Laha
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Ross H Andrews
- Faculty of Medicine, Imperial College London, London, United Kingdom.,Faculty of Medicine, Cholangiocarcinoma Research Institute (CARI), Khon Kaen University, Khon Kaen, Thailand
| | - Trevor N Petney
- Evolution and Paleontology, State Museum of Natural History Karlsruhe, Karlsruhe, Germany.,Faculty of Medicine, Cholangiocarcinoma Research Institute (CARI), Khon Kaen University, Khon Kaen, Thailand
| | - Paiboon Sithithaworn
- Faculty of Medicine, Cholangiocarcinoma Research Institute (CARI), Khon Kaen University, Khon Kaen, Thailand.,Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
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Khieu V, Fürst T, Miyamoto K, Yong TS, Chai JY, Huy R, Muth S, Odermatt P. Is Opisthorchis viverrini Emerging in Cambodia? ADVANCES IN PARASITOLOGY 2019; 103:31-73. [PMID: 30878058 DOI: 10.1016/bs.apar.2019.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Opisthorchis viverrini infection is widely prevalent in Southeast Asia. In Cambodia information on this helminth infection is scare. Recent reports suggest that O. viverrini is an emerging public health problem. We aimed to synthesize all information in relation to the infection, epidemiology, and morbidity of O. viverrini in Cambodia; from published as well as thus far unpublished sources. First reports on O. viverrini date back to 1995. In 2006 an O. viverrini initiative was launched by the national helminth control program. Since then O. viverrini has been reported in all - except two - provinces. Villages with high prevalences (>20%) were found in provinces from Preah Vihear to Takeo. The infection has a highly focal distribution. In many villages no infections were detected. O. viverrini infection was also reported in cats, dogs and intermediate hosts. No report on morbidity associated with O. viverrini was found. The current evidence suggests that O. viverrini infection remains underreported in Cambodia. It is likely that the transmission will further increase in the future with potentially serious consequences for human health.
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Affiliation(s)
- Virak Khieu
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Thomas Fürst
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; School of Public Health, Imperial College London, London, United Kingdom
| | - Kazuko Miyamoto
- School of Nursing, Faculty of Medicine & Center for International Education and Exchange, Yamanashi University, Yamanashi, Japan
| | - Tai-Soon Yong
- Department of Environmental Biology, Institute of Tropical Medicine, and Arthropods of Medical Importance Resource Bank, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jong-Yil Chai
- Institute of Parasitic Diseases, Korea Association of Health Promotion, Seoul, Republic of Korea; Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Rekol Huy
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Sinuon Muth
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Peter Odermatt
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
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Saijuntha W, Sithithaworn P, Kiatsopit N, Andrews RH, Petney TN. Liver Flukes: Clonorchis and Opisthorchis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1154:139-180. [PMID: 31297762 DOI: 10.1007/978-3-030-18616-6_6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Clonorchis sinensis, Opisthorchis viverrini, and O. felineus are liver flukes of human and animal pathogens occurring across much of Europe and Asia. Nevertheless, they are often underestimated compared to other, better known neglected diseases in spite of the fact that many millions of people are infected and hundreds of millions are at risk. This is possibly because of the chronic nature of the infection and disease and that it takes several decades prior to a life-threatening pathology to develop. Several studies in the past decade have provided more information on the molecular biology of the liver flukes which clearly lead to better understanding of parasite biology, systematics, and population genetics. Clonorchiasis and opisthorchiasis are characterized by a chronic infection that induces hepatobiliary inflammation, especially periductal fibrosis, which can be detected by ultrasonography. These chronic inflammations eventually lead to cholangiocarcinoma (CCA), a usually fatal bile duct cancer that develops in some infected individuals. In Thailand alone, opisthorchiasis-associated CCA kills up to 20,000 people every year and is therefore of substantial public health importance. Its socioeconomic impacts on impoverished families and communities are considerable. To reduce hepatobiliary morbidity and CCA, the primary intervention measures focus on control and elimination of the liver fluke. Accurate diagnosis of liver fluke infections in both human and other mammalian, snail and fish intermediate hosts, are important for achieving these goals. While the short-term goal of liver fluke control can be achieved by praziquantel chemotherapy, a comprehensive health education package targeting school children is believed to be more beneficial for a long-term goal/solution. It is recommended that a transdisciplinary research or multisectoral control approach including one health and/or eco health intervention strategy should be applied to combat the liver flukes, and hence contribute to reduction of cholangiocarcinoma in endemic areas.
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Affiliation(s)
- Weerachai Saijuntha
- Walai Rukhavej Botanical Research Institute, Mahasarakham University, Maha Sarakham, Thailand
| | - Paiboon Sithithaworn
- Department of Parasitology, Faculty of Medicine, Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand.
| | - Nadda Kiatsopit
- Department of Parasitology, Faculty of Medicine, Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
| | - Ross H Andrews
- CASCAP, Faculty of Medicine, Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand.,Faculty of Medicine, St Mary's Campus, Imperial College London, London, UK
| | - Trevor N Petney
- CASCAP, Faculty of Medicine, Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand.,Department of Paleontology and Evolution, State Museum of Natural History, Karlsruhe, Germany
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Petney TN, Andrews RH, Saijuntha W, Tesana S, Prasopdee S, Kiatsopit N, Sithithaworn P. Taxonomy, Ecology and Population Genetics of Opisthorchis viverrini and Its Intermediate Hosts. ADVANCES IN PARASITOLOGY 2018; 101:1-39. [PMID: 29907251 DOI: 10.1016/bs.apar.2018.05.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
There have been considerable advances in our understanding of the systematics and ecology of Opisthorchis viverrini; however, this new knowledge has not only clarified but also complicated the situation. We now know that what was once considered to be a single species is, in fact, a species complex, with the individual species being confined to specific wetland areas. There is also a strong genetic association between the members of the O. viverrini species complex and their Bithynia snail intermediate hosts. Although this does not negate data collected before the recognition of this situation, it does lead to the caveat that regional and temporal variations in data collected may be related to the species examined. The advances in ecology have generally been spatially limited and have led, in part, to contradictory results that may well be related to nonrecognition of the species studied. It may also be related to natural temporal and spatial variation related, for example, to habitat characteristics. To understand the variation present, it will be necessary to conduct long-term (several years at least) sampling projects after defining the genetic characteristics of O. viverrini sensu lato and its Bithynia snail intermediate hosts.
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Affiliation(s)
- Trevor N Petney
- Cholangiocarcinoma Screening and Care Program (CASCAP), Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Institute of Zoology 1: Ecology and Parasitology, Karlsruhe Institute of Technology, Karlsruhe, Germany; State Museum of Natural History Karlsruhe, Karlsruhe, Germany
| | - Ross H Andrews
- Cholangiocarcinoma Screening and Care Program (CASCAP), Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Weerachai Saijuntha
- Walai Rukhavej Botanical Research Institute, Mahasarakham University, Maha Sarakham, Thailand
| | - Smarn Tesana
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Sattrachai Prasopdee
- Chulabhorn International College of Medicine, Thammasat University, Bangkok, Thailand
| | - Nadda Kiatsopit
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Paiboon Sithithaworn
- Cholangiocarcinoma Screening and Care Program (CASCAP), Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
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Hughes T, O’Connor T, Techasen A, Namwat N, Loilome W, Andrews RH, Khuntikeo N, Yongvanit P, Sithithaworn P, Taylor-Robinson SD. Opisthorchiasis and cholangiocarcinoma in Southeast Asia: an unresolved problem. Int J Gen Med 2017; 10:227-237. [PMID: 28848361 PMCID: PMC5557399 DOI: 10.2147/ijgm.s133292] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The prevalence of cholangiocarcinoma (CCA) in Southeast Asia is much higher than other areas of the world. Eating raw, fermented, or undercooked cyprinid fish, infected with the liver fluke, Opisthorchis viverrini sensu lato (sl), results in chronic biliary inflammation, periductal fibrosis, and increased cancer risk. There may be associated glomerulonephritis. The process of infection is difficult to disrupt because eating practices have proven extremely difficult to change, and the life cycle of the fluke cannot be broken due to high prevalence in canine and feline reservoir hosts. Fecal analysis and enzyme-linked immunosorbent assay tests can be used to diagnose opisthorchiasis. Diagnosis of CCA is complex, partly due to the lack of definitive imaging characteristics but also due to the difficulty of obtaining samples for cytology or histology. This cancer has proven to be resistant to common chemotherapy treatments and so the two avenues of treatment available are surgical resection and liver transplantation, both requiring early detection of the tumor for the best chances of success. Late presentation of symptoms reduces the chances of successful surgical intervention. While liver fluke infections can be treated with praziquantel, individuals will often become reinfected, and multiple reinfections can be more harmful than a singular, long-term infection. A key research on the detection and characterization of novel biomarkers in all parts of the carcinogenic pathway for early diagnosis is needed.
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Affiliation(s)
- Thomas Hughes
- Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Thomas O’Connor
- Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Anchalee Techasen
- Department of Biochemistry, Faculty of Medicine, Liver Fluke and Cholangiocarcinoma Centre
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
| | - Nisana Namwat
- Department of Biochemistry, Faculty of Medicine, Liver Fluke and Cholangiocarcinoma Centre
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
| | - Watcharin Loilome
- Department of Biochemistry, Faculty of Medicine, Liver Fluke and Cholangiocarcinoma Centre
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
| | - Ross H Andrews
- Department of Biochemistry, Faculty of Medicine, Liver Fluke and Cholangiocarcinoma Centre
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Faculty of Medicine, St Mary’s Campus, Imperial College, London, UK
| | - Narong Khuntikeo
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Department of Surgery
| | - Puangrat Yongvanit
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry
| | - Paiboon Sithithaworn
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Department of Parasitology, Faculty of Medicine, Liver Fluke and Cholangiocarcinoma Centre, Khon Kaen University, Khon Kaen, Thailand
| | - Simon D Taylor-Robinson
- Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, London, UK
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Pechdee P, Chaiyasaeng M, Sereewong C, Chaiyos J, Suwannatrai A, Wongmaneeprateep S, Tesana S. Effects of albendazole, artesunate, praziquantel and miltefosine, on Opisthorchis viverrini cercariae and mature metacercariae. ASIAN PAC J TROP MED 2017; 10:126-133. [PMID: 28237476 DOI: 10.1016/j.apjtm.2017.01.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 12/10/2016] [Accepted: 01/03/2017] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE To explore larvicidal effects of anthelmintic drugs on Opisthorchis viverrini (O. viverrini) for alternative approach to interrupting its cycle for developing a field-based control program. METHODS The larvicidal activities of albendazole (Al), artesunate (Ar), praziquantel (Pzq) and miltefosine (Mf) on O. viverrini cercariae and mature metacercariae were investigated. Lethal concentrations (LC50 and LC95) of these drugs were determined. Mature metacercariae previously exposed to various concentrations of the drugs were administered to hamsters. Worms were harvested 30 d post infection and worm recovery rates calculated. Al, Ar, Pzq and Mf produced morphological degeneration and induced shedding tails of cercariae after 24 h exposure. RESULTS The LC50 and LC95 of Al, Ar, Pzq and Mf on cercariae were 0.720 and 1.139, 0.350 and 0.861, 0.017 and 0.693, and 0.530 and 1.134 ppm, respectively. LC50 and LC95 of Ar on mature metacercariae were 303.643 and 446.237 ppm and of Mf were 289.711 and 631.781 ppm, respectively but no lethal effect in Pzq- and Al-treated groups (up to 1 ppt). No worms were found in hamsters administered Pzq-treated metacercariae. The adult worms from Al-treated metacercariae were significantly bigger in size compared to the control group (P < 0.05). Fecundity and body width were greater in adults from Mf-treated metacercariae compared to the control group (P < 0.05). CONCLUSIONS The larvicidal effects of these drugs were high efficacy to O. viverrini cercariae but lesser efficacy to metacercariae. It should be further studied with the eventual aim of developing a field-based control program.
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Affiliation(s)
- Phornphitcha Pechdee
- Food-Borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Monticha Chaiyasaeng
- Food-Borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Chanisala Sereewong
- Food-Borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Jukkrid Chaiyos
- Food-Borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Apiporn Suwannatrai
- Food-Borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Sutee Wongmaneeprateep
- Department of Fisheries, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand
| | - Smarn Tesana
- Food-Borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
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