Haplorchis taichui

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Jong-yil Chai - One of the best experts on this subject based on the ideXlab platform.

  • Mixed infections with Opisthorchis viverrini and intestinal flukes in residents of Vientiane Municipality and Saravane Province in Laos.
    Journal of Helminthology, 2020
    Co-Authors: Jong-yil Chai, Eun Hee Shin, Woon-mok Sohn, J.-h. Park, Tai-soon Yong
    Abstract:

    Faecal examinations for helminth eggs were performed on 1869 people from two riverside localities, Vientiane Municipality and Saravane Province, along the Mekong River, Laos. To obtain adult flukes, 42 people positive for small trematode eggs (Opisthorchis viverrini, heterophyid, or lecithodendriid eggs) were treated with a 20‐ 30 mg kg 21 single dose of praziquantel and purged. Diarrhoeic stools were then collected from 36 people (18 in each area) and searched for helminth parasites using stereomicroscopes. Faecal examinations revealed positive rates for small trematode eggs of 53.3% and 70.8% (average 65.2%) in Vientiane and Saravane Province, respectively. Infections with O. viverrini and six species of intestinal flukes were found, namely, Haplorchis taichui, H. pumilio, H. yokogawai, Centrocestus caninus, Prosthodendrium molenkampi, and Phaneropsolus bonnei. The total number of flukes collected and the proportion of fluke species recovered were markedly different in the two localities; in Vientiane, 1041 O. viverrini (57.8 per person) and 615 others (34.2 per person), whereas in Saravane, 395 O. viverrini (21.9 per person) and 155207 others (8622.6 per person). Five people from Saravane harboured no O. viverrini but numerous heterophyid and/or lecithodendriid flukes. The results indicate that O. viverrini and several species of heterophyid and lecithodendriid flukes are endemic in these two riverside localities, and suggest that the intensity of

  • Dna quantities and qualities from various stages of some trematodes using optical and HAT-RAPD methods.
    The Southeast Asian journal of tropical medicine and public health, 2020
    Co-Authors: Chalobol Wongsawad, Pheravut Wongsawad, Jong-yil Chai, Thipmani Paratasilpin, S Anuntalabhochai
    Abstract:

    The aim of this experiment was to minimize DNA quantity and quality for detection by optical (spectrophotometer at 260 nm and 280 nm) and HAT-RAPD methods. Total DNA from different stages, adult, metacercaria and eggs of 6 trematode species were isolated for analysis. In this experiment, the adult trematodes were classified into 3 groups by size: small, Haplorchis taichui and Stellantchasmus falcatus; medium, Opisthorchis viverrini and Ganeo tigrinus; and large, Paramphistomum epiclitum and Fischoederius elongatus. The adult minimal DNA quantities and qualities of all specimen samples detected by optical method were 97.22,72.28, 3,167.00, 1,490.62, 21,382.66, and 27,321.77 ng; eggs were 3.92, 3.57, 3.72, 6.23, 17.53, and 14.01 ng, respectively; and metacercarial stages 50.70 and 40.98 ng in H. taichui and S. falcatus. In addition, the HAT-RAPD technique was chosen to amplify the minimal DNA qualities and quantities of all trematode specimens. Total DNA was 1-1 x 10(-12) ng; DNA templates in each dilution were used for amplification by primer OPA-09. DNA concentrations ranging between 1 x 10(-8) and 1 x 10(-11) ng were amplified with high polymorphism. Our experiment concluded that only a single specimen of each egg, metacercaria, or adult stage could be amplified with distinct bands.

  • THE OCCURRENCE OF HETEROPHYID METACERCARIAE IN CYPRINOID FISH IN CHIANG MAI PROVINCE
    Southeast Asian Journal of Tropical Medicine and Public Health, 2020
    Co-Authors: Supap Saenphet, A. Rojanapaibul, Chalobol Wongsawad, Pramote Vanittanakom, Kanokporn Saenphet, Jong-yil Chai
    Abstract:

    The occurrence of the heterophyid metacercariae in cyprinoid fish from 10 districts of Chiang Mai Province, Thailand, was investigated from November 2001 to October 2002. Seven hundred sixty-seven out of 849 (90.34%) cyprinoid fish were infected with heterophyid metacercariae, namely: Stellantchasmus falcatus, Haplorchis taichui, Centrocestus caninus and Haplorchoides sp. The highest prevalence of heterophyid metacercariae (95%) was observed during the winter November - January (95%) and the lowest (90%) was observed during the summer months February - April (90%). S. falcatus metacercariae were found in Dermogenus pusillus only. The highest numbers of H. taichui, C. caninus and Haplorchoides sp metacercariae were collected from Henicorrhyncus siamensis, Rasbora perviei and Mystacoleucus marginatus, respectively. The distributions in the fish hosts also varied. The most common site for 5. falcatus and H. taichui metacercarial infection was the muscle, whereas the greatest numbers of C. caninus and Haplorchoides sp metacercariae were found in the gills and scales, respectively. The high prevalence of heterophyid flukes observed in this survey suggests that people who live in this area are at high risk for heterophyid fluke infection.

  • Infection status with zoonotic trematode metacercariae in fish from Lao PDR
    Acta Tropica, 2019
    Co-Authors: Jong-yil Chai, Woon-mok Sohn, Bounlay Phommasack
    Abstract:

    Abstract Studies on the infection status with fishborne zoonotic trematode (FZT) metacercariae were reviewed with our data, which obtained from the fish survey in 8 administrative localities, i.e., Vientiane Municipality, Luang Prabang, Xieng Khouang, Vientiane, Khammuane, Savannakhet, Saravane and Champasak Provinces of Lao PDR (Laos) in 10 times. Total 1,046 freshwater fishes (69 species) were examined with the artificial digestion method from 2002 to 2011. Total 6 species of zoonotic trematode, i.e., Opisthorchis viverrini, Haplorchis taichui, Haplorchis yokogawai, Haplorchis pumilio, Centrocestus formosanus and Procerovum varium, metacercariae were detected in fishes from Laos. The metacercariae of O. viverrini were detected in 284 (37.9%) out of 749 fishes (26 spp.), and their average density was 297 per fish infected. The prevalences of 4 heterophyid species, i.e., H. taichui, H. yokogawai, H. pumilio and C. formosanus, metacercariae were 45.4% (out of 941 fishes in 46 spp. examined), 45.1% (811 fishes in 35 spp.), 8.8% (457 fishes in 11 spp.) and 18.1% (475 fishes in 13 spp.), their average densities were 291, 218, 4 and 15 per fish infected respectively. The endemicities of O. viverrini metacercariae were much higher in fishes from Savannakhet Province and Vientiane Municipality (2002). Those of H. taichui metacercariae were much higher in fishes from Khammuane and Luang Prabang (2011) Provinces. By the present study, it was confirmed that some species of FZT metacercariae are highly prevalent in fishes from Laos.

  • Echinostoma ilocanum Infection in Two Residents of Savannakhet Province, Lao PDR.
    Korean Journal of Parasitology, 2018
    Co-Authors: Jong-yil Chai, Tai-soon Yong, Eui Hyug Hoang, Bounlay Phommasack, Woon-mok Sohn, Bounnaloth Insisiengmay
    Abstract:

    : Adult specimens of Echinostoma ilocanum (Garrison, 1908) Odhner, 1911 (Trematoda: Echinostomatidae) were recovered from 2 riparian people who resided along the Mekong River in Savannakhet Province, Lao PDR. In fecal examinations done by the Kato-Katz technique, they revealed echinostome eggs together with eggs of Opisthorchis viverrini (and minute intestinal fluke eggs) and hookworms. To recover the adult flukes, they were treated with praziquantel 30-40 mg/kg in a single dose and purged with magnesium salts. A total of 658 adult fluke specimens were recovered from the 2 people; 456 from case 1 and 202 from case 2. Specimens from case 1 consisted of 335 echinostomes (301 E. ilocanum and 34 species undetermined), 120 O. viverrini, and 1 Haplorchis taichui, and those from case 2 consisted of 36 E. ilocanum, 134 O. viverrini, and 32 H. taichui. Thus, the number of E. ilocanum specimens was 337 in total (average per person, 168.5). From this study, it is suggested that foodborne intestinal flukes and liver flukes are highly prevalent along the Mekong River in Savannakhet Province. The present report describes for the first time human infections with E. ilocanum in Lao PDR.

Trevor N. Petney - One of the best experts on this subject based on the ideXlab platform.

  • Susceptibility, metacercarial burden, and mortality of juvenile silver barb, common carp, mrigal, and tilapia following exposure to Haplorchis taichui
    Parasitology Research, 2015
    Co-Authors: Kulthida Kopolrat, Smarn Tesana, Ross H Andrews, Paiboon Sithithaworn, Trevor N. Petney
    Abstract:

    Fish-borne zoonotic trematodes (FZT) including heterophyids and opisthorchiids are prevalent in native and aquaculture fish in Southeast Asia. FZT are reported highly prevalent in juvenile aquaculture fish that belonged to the family Heterophyidae, particularly Haplorchis taichui . Aquaculture fish are reported to have varying levels of natural infection with H. taichui , but data for their susceptibility as well as resistance to infection are not available. The aim of this study was to determine the susceptibility of five aquaculture fish to H. taichui . Experimental infections were performed by exposing fish individually to 0 (control), 50, 100, or 200 H. taichui cercariae for 12 h. Metacercarial burden was measured at 45 days postinfection. Three out of five fish species, silver barb ( Barbonymus gonionotus ), common carp ( Cyprinus carpio ), and mrigal ( Cirrhinus mrigala ), were highly susceptible to H. taichui infection with percentage ranging from 93.33 to 100 %. The Nile and red tilapia were not susceptible to infection. Among the susceptible fish species, silver barb had higher intensity of H. taichui metacercariae than common carp and mrigal ( P  

  • susceptibility metacercarial burden and mortality of juvenile silver barb common carp mrigal and tilapia following exposure to Haplorchis taichui
    Parasitology Research, 2015
    Co-Authors: Kulthida Kopolrat, Trevor N. Petney, Ross H Andrews, Smarn Tesana, Paiboon Sithithaworn
    Abstract:

    Fish-borne zoonotic trematodes (FZT) including heterophyids and opisthorchiids are prevalent in native and aquaculture fish in Southeast Asia. FZT are reported highly prevalent in juvenile aquaculture fish that belonged to the family Heterophyidae, particularly Haplorchis taichui. Aquaculture fish are reported to have varying levels of natural infection with H. taichui, but data for their susceptibility as well as resistance to infection are not available. The aim of this study was to determine the susceptibility of five aquaculture fish to H. taichui. Experimental infections were performed by exposing fish individually to 0 (control), 50, 100, or 200 H. taichui cercariae for 12 h. Metacercarial burden was measured at 45 days postinfection. Three out of five fish species, silver barb (Barbonymus gonionotus), common carp (Cyprinus carpio), and mrigal (Cirrhinus mrigala), were highly susceptible to H. taichui infection with percentage ranging from 93.33 to 100 %. The Nile and red tilapia were not susceptible to infection. Among the susceptible fish species, silver barb had higher intensity of H. taichui metacercariae than common carp and mrigal (P < 0.001). Metacercarial burden significantly correlated with the dose of cercarial infection (P < 0.001). Our findings that common aquaculture fish species have varying degrees of susceptibility to H. taichui infection provide important information to reduce parasite transmission in aquaculture fish.

  • A cross-sectional study on the potential transmission of the carcinogenic liver fluke Opisthorchis viverrini and other fishborne zoonotic trematodes by aquaculture fish.
    Foodborne Pathogens and Disease, 2013
    Co-Authors: Opal Pitaksakulrat, Trevor N. Petney, Paiboon Sithithaworn, Nonglak Laoprom, Thewarach Laha, Ross H Andrews
    Abstract:

    Abstract Throughout Southeast Asia and China, eating raw and or partially cooked cyprinid fish causes liver (hepatobiliary) disease and cancer (cholangiocarcinoma) due to fishborne zoonotic trematodes (FZT), in particular Clonorchis sinensis and Opisthorchis viverrini. The primary source of transmission is by native fish, but aquaculture fish are also reported to have high infective potential. Here, a cross-sectional survey of FZT in fish farms was conducted in an endemic area in Khon Kaen Province, Thailand. By using conventional and polymerase chain reaction (PCR) methods, we detected O. viverrini and FZT metacercariae (Centrocestus formosanus and Haplorchis taichui) in two popular fish species, Barbonymus gonionotus (silver barb) and Cirrhinus mrigala (mrigal), from aquaculture farms. Both species were infected in five of six farms examined by PCR but not by conventional methods, yet the prevalence of FZT metacercariae in aquaculture fish was high (46.9%). In addition to O. viverrini (17.1%), the nativ...

Jitra Waikagul - One of the best experts on this subject based on the ideXlab platform.

  • Zoonotic helminth contamination of the environment in rural villages of southern Lao PDR.
    2020
    Co-Authors: Wanna Maipanich, Megumi Sato, Tippayarat Yoonuan, Boungnong Boupha, Kazuhiko Moji, Tiengkham Pongvongsa, Kittipong Chaisiri, Marcello Otage Sato, Jitra Waikagul
    Abstract:

    Abstract Helminth infections are common among humans and animals in Savannakhet Province, LaoPDR. To assess the level of such environmental contamination, surface soil samples, houseflies,and vegetables, were collected from Ban Lahanam and Ban Thakhamlaine villages, in SongkhoneDistrict. Surface soil samples contained one ascarid egg, as well as free-living nematode larvae. Theexternal body surfaces of the houseflies carried adult Haplorchis taichui (otherwise known as minuteintestinal fluke), as well as opisthorchid and taeniid eggs, nematode larvae, and mites. Three thirdstageangiostrongylid larvae were found on pre-washed vegetables purchased at a local market.Taeniid, oxyurid, trichurid and strongylid helminths eggs were detected on other vegetable samples.Such findings indicate this environment was contaminated with several different helminth species atvarious stages of development, highlighting the risk of parasitic zoonotic infections for humans anddomestic animals. Communities should therefore be offered advice on how to improve standards ofsanitation. Keywords: zoonotic helminth infection, environmental contamination, Lao PDR

  • genetic differences among Haplorchis taichui populations in indochina revealed by mitochondrial cox1 sequences
    Journal of Helminthology, 2017
    Co-Authors: Urusa Thaenkham, Surapol Sanguankiat, Do Trung Dung, Supaporn Nuamtanong, Vicente Y Belizario, Tippayarat Yoonuan, Y Vonghachack, Orawan Phuphisut, Paron Dekumyoy, Jitra Waikagul
    Abstract:

    Haplorchis taichui is an intestinal heterophyid fluke that is pathogenic to humans. It is widely distributed in Asia, with a particularly high prevalence in Indochina. Previous work revealed that the lack of gene flow between three distinct populations of Vietnamese H. taichui can be attributed to their geographic isolation with no interconnected river basins. To test the hypothesis that interconnected river basins allow gene flow between otherwise isolated populations of H. taichui, as previously demonstrated for another trematode, Opisthorchis viverrini, we compared the genetic structures of seven populations of H. taichui from various localities in the lower Mekong Basin, in Thailand and Laos, with those in Vietnam, using the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene. To determine the gene flow between these H. taichui populations, we calculated their phylogenetic relationships, genetic distances and haplotype diversity. Each population showed very low nucleotide diversity at this locus. However, high levels of genetic differentiation between the populations indicated very little gene flow. A phylogenetic analysis divided the populations into four clusters that correlated with the country of origin. The negligible gene flow between the Thai and Laos populations, despite sharing the Mekong Basin, caused us to reject our hypothesis. Our data suggest that the distribution of H. taichui populations was incidentally associated with national borders.

  • patterns of trematode infections of opisthorchis viverrini opisthorchiidae and Haplorchis taichui heterophyidae in human populations from two villages in savannakhet province lao pdr
    Journal of Helminthology, 2015
    Co-Authors: Megumi Sato, Surapol Sanguankiat, Tippayarat Yoonuan, Boungnong Boupha, Kazuhiko Moji, Tiengkham Pongvongsa, Jun Kobayashi, Futoshi Nishimoto, Marcello Otake Sato, Jitra Waikagul
    Abstract:

    The liver fluke, Opisthorchis viverrini, and the minute intestinal fluke, Haplorchis taichui, are prevalent in many Asian countries. This study analysed the patterns of infections of O. viverrini and H. taichui in Lahanam and Thakhamlien villages (Savannakhet Province, Lao PDR), in two cross-sectional investigations. Out of a total of 207 human participants, post-anthelmintic treatment positivity rates for expelled worms were 170 (82.1%) for H. taichui and 65 (31.4%) for O. viverrini. Both these species co-exist in the study villages. When each parasite was analysed separately, H. taichui infections reached a plateau among people aged >20 years. Opisthorchis viverrini infection rates were highest in the age group 21–30 years, with decreasing infection rates after the age of 30. Our findings indicated that fish-borne trematode infections were more prevalent among adults. Fish, common intermediate hosts, were acquired in the study area for analysis. The examination of 35 species of fish as intermediate hosts found O. viverrini metacercariae in only six species, and these were found mostly during the month of November. Many farmers who live on the rice fields obtain their food from their immediate environment, including these intermediate-host fish, potentially putting them at greater risk of O. viverrini infection. By contrast, H. taichui metacercariae were found in three species of fish obtained from the market, meaning that anyone could consume them and become infected. If people who work in rice fields limit the species of fish they consume, or avoid consuming raw fish during the month of November, they may reduce their risk of O. viverrini infection.

  • genetic differences among vietnamese Haplorchis taichui populations using the coi genetic marker
    Journal of Helminthology, 2013
    Co-Authors: Do Trung Dung, Urusa Thaenkham, Jitra Waikagul
    Abstract:

    Adults of the fish-borne intestinal trematode species Haplorchis taichui were collected from humans in three provinces of Vietnam: Ha Giang, Thanh Hoa and Quang Tri. Genetic analysis revealed three groups of the parasite from clustering dendrograms, correlating with the localities in which they were collected. Measurements of evolutionary divergence over sequence pairs were greater between the different populations than within them, which indicated that the three populations were genetically different. The significance (Fst= 0.73; P value < 0.05) of the genetic variation of the three studied populations implied that genetic separation of the populations had already occurred, which may have been caused by a low gene flow among the different H. taichui populations. Factors contributing to the low gene flow may include isolation resulting from the intermediate-host fish rarely being sold outside of the rural commune where they are raised and the enclosed aquacultural areas themselves.

  • Rapid and simple identification of human pathogenic heterophyid intestinal fluke metacercariae by PCR-RFLP.
    Parasitology International, 2011
    Co-Authors: Urusa Thaenkham, Surapol Sanguankiat, Orawan Phuphisut, Jitra Waikagul, Yukifumi Nawa, Wallop Pakdee, Nirundorn Homsuwan, Trung Dung
    Abstract:

    Abstract Six species of heterophyid intestinal flukes (HIFs) constitute the major endemic zoonotic fish-borne pathogens in Asia: Haplorchis taichui, H. pumilio, H. yokogawai, Procerovum varium, Stellantchasmus falcatus , and Centrocestus formosanus . Several different species of these parasites are often found co-infecting the same second intermediate fish host. Because of their morphological similarities, differentiating between species of HIF metacercariae is difficult, time-consuming, and frequently results in misidentification. In this study, we aimed to develop an efficient and accurate method of identifying metacercariae of these 6 HIFs. Metacercariae were roughly grouped together, based on morphological characteristics seen under a stereomicroscope. Then, PCR-restriction fragment length polymorphism (PCR-RFLP) was used to identify the exact species of each metacercaria, using the 28S ribosomal RNA gene as the genetic marker and Mbo II as the restriction enzyme. Using a combination of morphological and molecular methods eliminates the need for DNA sequencing and infecting animal subjects to obtain adult worms, increases accuracy, and decreases the need for laborious morphological identification. Because the method is simple, rapid, and relatively cheap compared with PCR-sequencing, it may be an effective tool for epidemiological studies of HIFs in endemic areas.

Woon-mok Sohn - One of the best experts on this subject based on the ideXlab platform.

  • Mixed infections with Opisthorchis viverrini and intestinal flukes in residents of Vientiane Municipality and Saravane Province in Laos.
    Journal of Helminthology, 2020
    Co-Authors: Jong-yil Chai, Eun Hee Shin, Woon-mok Sohn, J.-h. Park, Tai-soon Yong
    Abstract:

    Faecal examinations for helminth eggs were performed on 1869 people from two riverside localities, Vientiane Municipality and Saravane Province, along the Mekong River, Laos. To obtain adult flukes, 42 people positive for small trematode eggs (Opisthorchis viverrini, heterophyid, or lecithodendriid eggs) were treated with a 20‐ 30 mg kg 21 single dose of praziquantel and purged. Diarrhoeic stools were then collected from 36 people (18 in each area) and searched for helminth parasites using stereomicroscopes. Faecal examinations revealed positive rates for small trematode eggs of 53.3% and 70.8% (average 65.2%) in Vientiane and Saravane Province, respectively. Infections with O. viverrini and six species of intestinal flukes were found, namely, Haplorchis taichui, H. pumilio, H. yokogawai, Centrocestus caninus, Prosthodendrium molenkampi, and Phaneropsolus bonnei. The total number of flukes collected and the proportion of fluke species recovered were markedly different in the two localities; in Vientiane, 1041 O. viverrini (57.8 per person) and 615 others (34.2 per person), whereas in Saravane, 395 O. viverrini (21.9 per person) and 155207 others (8622.6 per person). Five people from Saravane harboured no O. viverrini but numerous heterophyid and/or lecithodendriid flukes. The results indicate that O. viverrini and several species of heterophyid and lecithodendriid flukes are endemic in these two riverside localities, and suggest that the intensity of

  • Infection status with zoonotic trematode metacercariae in fish from Lao PDR
    Acta Tropica, 2019
    Co-Authors: Jong-yil Chai, Woon-mok Sohn, Bounlay Phommasack
    Abstract:

    Abstract Studies on the infection status with fishborne zoonotic trematode (FZT) metacercariae were reviewed with our data, which obtained from the fish survey in 8 administrative localities, i.e., Vientiane Municipality, Luang Prabang, Xieng Khouang, Vientiane, Khammuane, Savannakhet, Saravane and Champasak Provinces of Lao PDR (Laos) in 10 times. Total 1,046 freshwater fishes (69 species) were examined with the artificial digestion method from 2002 to 2011. Total 6 species of zoonotic trematode, i.e., Opisthorchis viverrini, Haplorchis taichui, Haplorchis yokogawai, Haplorchis pumilio, Centrocestus formosanus and Procerovum varium, metacercariae were detected in fishes from Laos. The metacercariae of O. viverrini were detected in 284 (37.9%) out of 749 fishes (26 spp.), and their average density was 297 per fish infected. The prevalences of 4 heterophyid species, i.e., H. taichui, H. yokogawai, H. pumilio and C. formosanus, metacercariae were 45.4% (out of 941 fishes in 46 spp. examined), 45.1% (811 fishes in 35 spp.), 8.8% (457 fishes in 11 spp.) and 18.1% (475 fishes in 13 spp.), their average densities were 291, 218, 4 and 15 per fish infected respectively. The endemicities of O. viverrini metacercariae were much higher in fishes from Savannakhet Province and Vientiane Municipality (2002). Those of H. taichui metacercariae were much higher in fishes from Khammuane and Luang Prabang (2011) Provinces. By the present study, it was confirmed that some species of FZT metacercariae are highly prevalent in fishes from Laos.

  • Echinostoma ilocanum Infection in Two Residents of Savannakhet Province, Lao PDR.
    Korean Journal of Parasitology, 2018
    Co-Authors: Jong-yil Chai, Tai-soon Yong, Eui Hyug Hoang, Bounlay Phommasack, Woon-mok Sohn, Bounnaloth Insisiengmay
    Abstract:

    : Adult specimens of Echinostoma ilocanum (Garrison, 1908) Odhner, 1911 (Trematoda: Echinostomatidae) were recovered from 2 riparian people who resided along the Mekong River in Savannakhet Province, Lao PDR. In fecal examinations done by the Kato-Katz technique, they revealed echinostome eggs together with eggs of Opisthorchis viverrini (and minute intestinal fluke eggs) and hookworms. To recover the adult flukes, they were treated with praziquantel 30-40 mg/kg in a single dose and purged with magnesium salts. A total of 658 adult fluke specimens were recovered from the 2 people; 456 from case 1 and 202 from case 2. Specimens from case 1 consisted of 335 echinostomes (301 E. ilocanum and 34 species undetermined), 120 O. viverrini, and 1 Haplorchis taichui, and those from case 2 consisted of 36 E. ilocanum, 134 O. viverrini, and 32 H. taichui. Thus, the number of E. ilocanum specimens was 337 in total (average per person, 168.5). From this study, it is suggested that foodborne intestinal flukes and liver flukes are highly prevalent along the Mekong River in Savannakhet Province. The present report describes for the first time human infections with E. ilocanum in Lao PDR.

  • Zoonotic Trematode Metacercariae in Fish from Yangon, Myanmar and Their Adults Recovered from Experimental Animals.
    Korean Journal of Parasitology, 2017
    Co-Authors: Jong-yil Chai, Eui Hyug Hoang, Woon-mok Sohn, Byoung-kuk Na, Jong-bok Park, Hoo-gn Jeoung, Thi Thi Htoon
    Abstract:

    : A survey was performed to investigate the infection status of zoonotic trematode (ZT) metacercariae in fish from a local market in Yangon City, Myanmar. A total of 264 fish (12 species) were collected through 4 times from December 2013 to June 2015. All collected fish were transferred to our laboratory on ice and examined by the artificial digestion method. More than 7 species of ZT metacercariae, i.e., Haplorchis taichui, H. pumilio, H. yokogawai, Centrocestus spp., Stellantchasmus falcatus, Pygidiopsis cambodiensis, and Procerovum sp. were detected. Metacercariae of H. taichui were collected in 58 (42.3%) out of 137 fish (5 species), and their average density was 42.9 per fish infected. Metacercariae of H. pumilio were detected in 96 (49.0%) out of 196 fish (9 species), and their average density was 23.6 per fish infected. H. yokogawai metacercariae were found in 40 (50.0%) out of 80 fish (5 species), and Centrocestus spp. metacercariae in 91 (50.8%) out of 179 fish (8 species), and their densities were 306 and 25.8 per fish infected, respectively. Metacercariae of S. falcatus and P. cambodiensis were detected only in mullets, Chelon macrolepis. A total of 280 Procerovum sp. metacercariae were found in 6 out of 12 climbing perch, Anabas testudineus. Morphological characteristics of adult flukes recovered from experimental animals were described. It has been first confirmed that fish from Yangon, Myanmar are commonly infected with various species of ZT metacercariae.

  • Infection Status of Zoonotic Trematode Metacercariae in Fishes from Vientiane Municipality and Champasak Province in Lao PDR.
    Korean Journal of Parasitology, 2015
    Co-Authors: Han Sol Park, Tai-soon Yong, Bounnaloth Insisiengmay, Jong-yil Chai, Woon-mok Sohn, Bounlay Phommasack
    Abstract:

    The infection status of fishborne zoonotic trematode (FZT) metacercariae was investigated in fishes from 2 localities of Lao PDR. Total 157 freshwater fishes (17 species) were collected in local markets of Vientiane Municipality and Champasak Province in December 2010 and July 2011, and each fish was examined by the artificial digestion method. Total 6 species of FZT metacercariae, i.e., Opisthorchis viverrini, Haplorchis taichui, Haplorchis yokogawai, Haplorchis pumilio, Centrocestus formosanus, and Procerovum varium, were detected in fishes from Vientiane Municipality. The metacercariae of O. viverrini were detected in 50 (49.5%) out of 101 fishes (6 species), and their average number was 154 per fish infected. The remaining 5 species of heterophyid metacercariae were detected in 36.8%, 65.8%, 9.4%, 23.9%, and 5.1% fishes examined, and their average densities were 12, 1,038, 4, 15, and 13 per infected fish, respectively. In fishes from Champasak Province, 3 species of FZT metacercariae, i.e., O. viverrini, H. taichui, and H. yokogawai, were detected. Only 2 O. viverrini metacercariae were found in only 1 Barbonymus schwanefeldi. The metacercariae of H. taichui and H. yokogawai were detected in 60.0% and 50.0% of fishes examined, and their average densities were 47 and 28 per fish infected. By the present study, it has been confirmed that several species of FZT metacercariae are prevalent in fishes from Vientiane Municipality, with P. varium being a new member of FZT in Lao PDR. In comparison, FZT metacercariae are less prevalent in fishes from Champasak Province.

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  • Infection status with zoonotic trematode metacercariae in fish from Lao PDR
    Acta Tropica, 2019
    Co-Authors: Jong-yil Chai, Woon-mok Sohn, Bounlay Phommasack
    Abstract:

    Abstract Studies on the infection status with fishborne zoonotic trematode (FZT) metacercariae were reviewed with our data, which obtained from the fish survey in 8 administrative localities, i.e., Vientiane Municipality, Luang Prabang, Xieng Khouang, Vientiane, Khammuane, Savannakhet, Saravane and Champasak Provinces of Lao PDR (Laos) in 10 times. Total 1,046 freshwater fishes (69 species) were examined with the artificial digestion method from 2002 to 2011. Total 6 species of zoonotic trematode, i.e., Opisthorchis viverrini, Haplorchis taichui, Haplorchis yokogawai, Haplorchis pumilio, Centrocestus formosanus and Procerovum varium, metacercariae were detected in fishes from Laos. The metacercariae of O. viverrini were detected in 284 (37.9%) out of 749 fishes (26 spp.), and their average density was 297 per fish infected. The prevalences of 4 heterophyid species, i.e., H. taichui, H. yokogawai, H. pumilio and C. formosanus, metacercariae were 45.4% (out of 941 fishes in 46 spp. examined), 45.1% (811 fishes in 35 spp.), 8.8% (457 fishes in 11 spp.) and 18.1% (475 fishes in 13 spp.), their average densities were 291, 218, 4 and 15 per fish infected respectively. The endemicities of O. viverrini metacercariae were much higher in fishes from Savannakhet Province and Vientiane Municipality (2002). Those of H. taichui metacercariae were much higher in fishes from Khammuane and Luang Prabang (2011) Provinces. By the present study, it was confirmed that some species of FZT metacercariae are highly prevalent in fishes from Laos.

  • Echinostoma ilocanum Infection in Two Residents of Savannakhet Province, Lao PDR.
    Korean Journal of Parasitology, 2018
    Co-Authors: Jong-yil Chai, Tai-soon Yong, Eui Hyug Hoang, Bounlay Phommasack, Woon-mok Sohn, Bounnaloth Insisiengmay
    Abstract:

    : Adult specimens of Echinostoma ilocanum (Garrison, 1908) Odhner, 1911 (Trematoda: Echinostomatidae) were recovered from 2 riparian people who resided along the Mekong River in Savannakhet Province, Lao PDR. In fecal examinations done by the Kato-Katz technique, they revealed echinostome eggs together with eggs of Opisthorchis viverrini (and minute intestinal fluke eggs) and hookworms. To recover the adult flukes, they were treated with praziquantel 30-40 mg/kg in a single dose and purged with magnesium salts. A total of 658 adult fluke specimens were recovered from the 2 people; 456 from case 1 and 202 from case 2. Specimens from case 1 consisted of 335 echinostomes (301 E. ilocanum and 34 species undetermined), 120 O. viverrini, and 1 Haplorchis taichui, and those from case 2 consisted of 36 E. ilocanum, 134 O. viverrini, and 32 H. taichui. Thus, the number of E. ilocanum specimens was 337 in total (average per person, 168.5). From this study, it is suggested that foodborne intestinal flukes and liver flukes are highly prevalent along the Mekong River in Savannakhet Province. The present report describes for the first time human infections with E. ilocanum in Lao PDR.

  • Infection Status of Zoonotic Trematode Metacercariae in Fishes from Vientiane Municipality and Champasak Province in Lao PDR.
    Korean Journal of Parasitology, 2015
    Co-Authors: Han Sol Park, Tai-soon Yong, Bounnaloth Insisiengmay, Jong-yil Chai, Woon-mok Sohn, Bounlay Phommasack
    Abstract:

    The infection status of fishborne zoonotic trematode (FZT) metacercariae was investigated in fishes from 2 localities of Lao PDR. Total 157 freshwater fishes (17 species) were collected in local markets of Vientiane Municipality and Champasak Province in December 2010 and July 2011, and each fish was examined by the artificial digestion method. Total 6 species of FZT metacercariae, i.e., Opisthorchis viverrini, Haplorchis taichui, Haplorchis yokogawai, Haplorchis pumilio, Centrocestus formosanus, and Procerovum varium, were detected in fishes from Vientiane Municipality. The metacercariae of O. viverrini were detected in 50 (49.5%) out of 101 fishes (6 species), and their average number was 154 per fish infected. The remaining 5 species of heterophyid metacercariae were detected in 36.8%, 65.8%, 9.4%, 23.9%, and 5.1% fishes examined, and their average densities were 12, 1,038, 4, 15, and 13 per infected fish, respectively. In fishes from Champasak Province, 3 species of FZT metacercariae, i.e., O. viverrini, H. taichui, and H. yokogawai, were detected. Only 2 O. viverrini metacercariae were found in only 1 Barbonymus schwanefeldi. The metacercariae of H. taichui and H. yokogawai were detected in 60.0% and 50.0% of fishes examined, and their average densities were 47 and 28 per fish infected. By the present study, it has been confirmed that several species of FZT metacercariae are prevalent in fishes from Vientiane Municipality, with P. varium being a new member of FZT in Lao PDR. In comparison, FZT metacercariae are less prevalent in fishes from Champasak Province.

  • prevalence of Haplorchis taichui among humans and fish in luang prabang province lao pdr
    Acta Tropica, 2014
    Co-Authors: Woon-mok Sohn, Tai-soon Yong, Bounlay Phommasack, Bounnaloth Insisiengmay, Bong Kwang Jung, Virasack Banouvong, Jong-yil Chai
    Abstract:

    Abstract This study confirmed the prevalence of the intestinal fluke Haplorchis taichui (Trematoda: Heterophyidae) among people and fish in Luang Prabang Province, Lao PDR. Fecal specimens were collected from 559 riparian people (229 males and 330 females), residing in 4 Districts (Luang Prabang, Xieng Ngeun, Pak Ou, and Nam Bak) and were examined by the Kato-Katz fecal smear technique. The overall helminth egg positive rate was 64.9%. The positive rate for small trematode eggs (STE), which may include H. taichui and other heterophyids, Opisthorchis viverrini, and lecithodendriids, was 15.2%. For recovery of adult helminths, 10 STE-positive people were treated with 40 mg/kg praziquantel and 15 mg/kg pyrantel pamoate, and then purged. Mixed infections with 3 Haplorchis species (H. taichui, H. pumilio, and H. yokogawai), a species of cestode (Taenia saginata), and several species of nematodes including Enterobius vermicularis and hookworms were found. The worm load for trematodes was exclusively high for H. taichui with an average of 7691 specimens per infected person, followed by H. yokogawai (8.3 specimens) and H. pumilio (4.1 specimens). Out of 207 freshwater fish (17 species) purchased in a market in Luang Prabang District, 138 (67%) harboured H. taichui metacercariae (metacercarial burden per fish; 520). Lower prevalence of fish and lower metacercarial density were observed for H. yokogawai (52% and 50 per fish, respectively) and H. pumilio (18% and 3 per fish, respectively). STE found in the surveyed population of Luang Prabang Province were verified to be those of intestinal fukes, particularly H. taichui.

  • hyperendemicity of Haplorchis taichui infection among riparian people in saravane and champasak province lao pdr
    Korean Journal of Parasitology, 2013
    Co-Authors: Jong-yil Chai, Tai-soon Yong, Bounnaloth Insisiengmay, Hyeongkyu Jeon, Bong Kwang Jung, Lay Sisabath, Bounlay Phommasack
    Abstract:

    In this study, we found that Haplorchis taichui, a heterophyid intestinal fluke, is highly prevalent, with heavy worm loads, among riparian people in Saravane and Champasak province, Lao PDR. Fecal specimens were collected from 1,460 people (717 men and 743 women) in 12 riparian (Mekong river) districts and were examined by the Kato-Katz fecal smear technique. The overall helminth egg positive rate was 78.8% and 66.4% in Saravane and Champasak province, respectively. The positive rate for small trematode eggs (STE), which included H. taichui and other heterophyids, Opisthorchis viverrini, and lecithodendriids, was 69.9% and 46.3% in Saravane and Champasak province, respectively. To obtain adult flukes, 30 STE-positive people were treated with 40 mg/kg praziquantel and then purged. Whole diarrheic stools were collected 4-5 times for each person and searched for fluke specimens using a stereomicroscope. Mixed infections with various species of trematodes (H. taichui, Haplorchis pumilio, O. viverrini, Prosthodendrium molenkampi, Centrocestus formosanus, and Echinochasmus japonicus) and a species of cestode (Taenia saginata) were found. However, the worm load was exceptionally high for H. taichui compared with other trematode species, with an average of 21,565 and 12,079 specimens per infected person in Saravane and Champasak province, respectively, followed by H. pumilio (41.9 and 22.5, respectively) and O. viverrini (9.4 and 1.5, respectively). These results show that diverse species of intestinal and liver flukes are prevalent among riparian people in Saravane and Champasak province, Lao PDR, with H. taichui being the exceptionally dominant species.