1.Echinostome Flukes Receovered from Humans in Khammouane Province, Lao PDR.
Jong Yil CHAI ; Woon Mok SOHN ; Tai Soon YONG ; Keeseon S EOM ; Duk Young MIN ; Eui Hyug HOANG ; Bounlay PHAMMASACK ; Bounnaloth INSISIENGMAY ; Han Jong RIM
The Korean Journal of Parasitology 2012;50(3):269-272
Echinostome eggs were detected in 22 (1.1%) of 2,074 people residing in riparian villages along the Mekong River in Khammouane Province, Lao PDR. In order to recover the adult flukes, 9 persons were treated with praziquantel and purged with magnesium salts. A total of 55 echinostome specimens (4 species) were recovered from the 9 persons. Echinostoma revolutum (8 specimens) was recovered from 3 persons, Artyfechinostomum malayanum (8 specimens) was from 2 persons, Echinochasmus japonicus (33 specimens) was from 7 persons, and Euparyphium sp. (6 specimens) was from 1 person. In Lao PDR, only human infections with E. japonicus were previously known. Therefore, the present study describes human infections with E. revolutum, A. malayanum, and Euparyphium sp. for the first time in Lao PDR. These results indicate that the surveyed villages of Khammouane Province, Lao PDR are low-grade endemic foci of echinostomiasis.
Adult
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Animals
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Anthelmintics/administration & dosage
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Echinostomatidae/*classification/*isolation & purification
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Female
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Humans
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Laos
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Magnesium/administration & dosage
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Male
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Praziquantel/administration & dosage
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Trematode Infections/*parasitology
2.Human Neurocysticercosis Case and an Endemic Focus of Taenia solium in Lao PDR.
Hyeong Kyu JEON ; Tai Soon YONG ; Woon Mok SOHN ; Jong Yil CHAI ; Duk Young MIN ; Han Jong RIM ; Bounnaloth INSISIENGMAY ; Keeseon S EOM
The Korean Journal of Parasitology 2013;51(5):599-602
A male patient with neurocysticercosis was identified in Montai Village, Xay District, Oudomxay Province, Lao PDR in February 2004. He had a history of diagnosis for neurocysticercosis by a CT scan in Thailand after an onset of epileptic seizure in 1993. A pig in the same district was found to contain Taenia solium metacestodes (=cysticerci); the slaughtered pig body contained more than 2,000 cysticerci. In addition to morphological identification, molecular identification was also performed on the cysticerci by DNA sequencing analysis of the mitochondrial cox1 gene; they were confirmed as T. solium metacestodes. The patient is regarded as an indigenous case of neurocysticercosis infected in an endemic focus of T. solium taeniasis/cysticercosis in Oudomxay Province, Lao PDR.
Animals
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Cysticercus
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Electron Transport Complex IV/genetics
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Humans
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Laos/epidemiology
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Male
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Mitochondria/genetics
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Neurocysticercosis/*epidemiology/parasitology/radiography
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Risk Factors
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Sequence Analysis, DNA
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Swine
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Swine Diseases/*epidemiology/parasitology/radiography
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Taenia solium/classification/genetics/*isolation & purification
3.Echinostoma ilocanum Infection in Two Residents of Savannakhet Province, Lao PDR
Jong Yil CHAI ; Woon Mok SOHN ; Jaeeun CHO ; Keeseon S EOM ; Tai Soon YONG ; Duk Young MIN ; Eui Hyug HOANG ; Bounlay PHOMMASACK ; Bounnaloth INSISIENGMAY ; Han Jong RIM
The Korean Journal of Parasitology 2018;56(1):75-79
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.
Adult
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Ancylostomatoidea
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Echinostoma
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Echinostomiasis
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Eggs
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Fasciola hepatica
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Humans
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Magnesium
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Opisthorchis
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Ovum
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Praziquantel
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Rivers
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Salts
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Trematoda
4.Echinostoma aegyptica (Trematoda: Echinostomatidae) Infection in Five Riparian People in Savannakhet Province, Lao PDR
Jong-Yil CHAI ; Bong-Kwang JUNG ; Taehee CHANG ; Hyejoo SHIN ; Woon-Mok SOHN ; Keeseon S. EOM ; Tai-Soon YONG ; Duk-Young MIN ; Bounlay PHAMMASACK ; Bounnaloth INSISIENGMAY ; Han-Jong RIM
The Korean Journal of Parasitology 2020;58(1):67-72
Human infection with Echinostoma aegyptica Khalil and Abaza, 1924 (Trematoda: Echinostomatidae) is extremely rare. In this study, we confirmed E. aegyptica infection in 5 riparian residents living along the Mekong River in Savannakhet Province, Lao PDR. The patients revealed eggs of Opisthorchis viverrini/minute intestinal flukes, echinostomes, and other parasites in fecal examinations using the Kato-Katz technique. Following treatment with praziquantel 30-40 mg/kg and pyrantel pamoate 10-15 mg/kg in a single dose and purging with magnesium salts, adult specimens of various helminth species were collected. Among the trematodes, echinostome flukes of 4.5-7.6 mm in length (n = 134; av. 22.3 specimens per case) were of taxonomic interest and subjected in this study. The flukes were morphologically characterized by having total 43-45 collar spines arranged in 2 alternating rows (corner spines usually 5 on each side) and compatible with previous descriptions of E. aegyptica. The patients were mixed-infected with other helminths, so specific clinical manifestations due to this echinostome fluke were difficult to determine. The present paper describes for the first time human E. aegyptica infections in Lao PDR. This is the second report of human infection (2nd-6th cases) with E. aegyptica in the world following the first one from China.
5.Prevalence of the Intestinal Flukes Haplorchis taichui and H. yokogawai in a Mountainous Area of Phongsaly Province, Lao PDR.
Jong Yil CHAI ; Tai Soon YONG ; Keeseon S EOM ; Duk Young MIN ; Eun Hee SHIN ; Virasack BANOUVONG ; Bounnaloth INSISIENGMAY ; Sithat INSISIENGMAY ; Bounlay PHOMMASACK ; Han Jong RIM
The Korean Journal of Parasitology 2010;48(4):339-342
Phongsaly Province, located in the northernmost area of Lao PDR, was previously suggested to be endemic for the liver fluke Opisthorchis viverrini infection. To confirm, or rule out, this suggestion, the Phonxay village in the Khoua District, Phongsaly Province, was selected for a survey. Ten volunteers (8 men and 2 women aged 31-57 years) who consumed raw freshwater fish and had gastrointestinal troubles were treated with a single dose of praziquantel (40 mg/kg) and pyrantel pamoate (10 mg/kg) and purged with magnesium sulfate to recover any worm parasites. Eight of the 10 volunteers expelled 1 or more species of trematodes, nematodes, or cestodes (worm positive rate; 80%). The worms were morphologically identified as H. taichui (861 worms from 8 people), H. yokogawai (59 from 6 people), Phaneropsolus bonnei (1 from 1 person), Trichostrongylus sp. (2 from 2 people), Ascaris lumbricoides (2 from 1 person), Enterobius vermicularis (11 from 3 people), and Taenia saginata (1 strobila with scolex from 1 person). The results indicate that the mountainous area of Phongsaly Province, Lao PDR, is not endemic for the liver fluke but endemic for intestinal flukes, in particular, Haplorchis taichui and H. yokogawai.
Adult
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Animals
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Antiparasitic Agents/administration & dosage
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Feces/parasitology
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Female
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Heterophyidae/anatomy & histology/classification/*isolation & purification
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Humans
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Laos/epidemiology
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Male
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Middle Aged
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Praziquantel/administration & dosage
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Prevalence
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Pyrantel Pamoate/administration & dosage
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Trematode Infections/drug therapy/*epidemiology/*parasitology
6.Intestinal Helminths Recovered from Humans in Xieng Khouang Province, Lao PDR with a Particular Note on Haplorchis pumilio Infection.
Jong Yil CHAI ; Woon Mok SOHN ; Bong Kwang JUNG ; Tai Soon YONG ; Keeseon S EOM ; Duk Young MIN ; Bounnaloth INSISIENGMAY ; Sithat INSISIENGMAY ; Bounlay PHOMMASACK ; Han Jong RIM
The Korean Journal of Parasitology 2015;53(4):439-445
A survey of intestinal helminths was undertaken in riparian people in Xieng Khouang Province, Lao PDR. Fecal specimens were collected from 643 people (289 males and 354 females) residing in 4 districts (Nonghet, Kham, Phoukout, and Pek) and were examined by the Kato-Katz technique. The overall helminth egg positive rate was 41.2%, and hookworms revealed the highest prevalence (32.7%) followed by Trichuris trichiura (7.3%) and Ascaris lumbricoides (5.6%). The positive rate for small trematode eggs (STE), which may include Opisthorchis viverrini, heterophyids, and lecithodendriids, was 4.4%. For recovery of adult helminths, 12 STE or nematode/cestode egg-positive people were treated with 40 mg/kg praziquantel and 15 mg/kg pyrantel pamoate, and then purged. Mixed infections with 2 Haplorchis species (H. pumilio and H. taichui), Centrocestus formosanus, Opisthorchis viverrini, a species of cestode (Taenia saginata), and several species of nematodes including hookworms and Enterobius vermicularis were detected. The worm load for trematodes was the highest for H. pumilio with an average of 283.5 specimens per infected person followed by C. formosanus, H. taichui, and O. viverrini. The worm load for nematodes was the highest for hookworms (21.5/infected case) followed by E. vermicularis (3.2/infected case). The results revealed that the surveyed areas of Xieng Khouang Province, Lao PDR are endemic areas of various species of intestinal helminths. The STE found in the surveyed population were verified to be those of heterophyids, particularly H. pumilio.
Adolescent
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Adult
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Aged
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Aged, 80 and over
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Animals
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Cestode Infections/epidemiology/parasitology
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Female
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Helminthiasis/epidemiology/*parasitology
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Helminths/classification/genetics/*isolation & purification
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Humans
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Intestines/*parasitology
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Laos/epidemiology
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Male
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Middle Aged
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Platyhelminths/classification/genetics/*isolation & purification
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Young Adult
7.High Prevalence of Haplorchis taichui, Phaneropsolus molenkampi, and Other Helminth Infections among People in Khammouane Province, Lao PDR.
Jong Yil CHAI ; Eun Taek HAN ; Eun Hee SHIN ; Woon Mok SOHN ; Tai Soon YONG ; Keeseon S EOM ; Duk Young MIN ; Jin Young UM ; Min Sung PARK ; Eui Hyug HOANG ; Bounlay PHOMMASACK ; Bounnaloth INSISIENGMAY ; Soon Hyung LEE ; Han Jong RIM
The Korean Journal of Parasitology 2009;47(3):243-247
The prevalence of liver and intestinal helminth infections, including Opisthorchis, Haplorchis, Phaneropsolus, hookworms, Enterobius, and Taenia, was surveyed in Khammouane province, Lao PDR. Fecal specimens were collected from 1,242 people (590 men and 652 women) in 3 Mekong riverside villages and were examined by the Kato-Katz thick smear technique. The overall helminth egg positive rate was 81.1%. The positive rate for small trematode eggs, including Opisthorchis viverrini, heterophyids, and lecithodendriids, was 81.1% and the positive rate for hookworms was 6.7%. To obtain adult worms, 35 people who were positive for small trematode eggs were treated with 20-30 mg/kg praziquantel and 10-15 mg/kg pyrantel pamoate, and then purged. Diarrheic stools were collected from 33 of these people and searched for helminth parasites using a stereomicroscope. Mixed infections with various helminths (Haplorchis taichui, Haplorchis yokogawai, Prosthodendrium molenkampi, Phaneropsolus bonnei, echinostomes, hookworms, Trichostrongylus spp., Trichuris trichiura, Enterobius vermicularis, and/or Taenia saginata) were found. The total number of helminth specimens collected was 20,907 (approximately 634 per person). The most common species was H. taichui, followed by P. molenkampi, O. viverrini, P. bonnei, E. vermicularis, hookworms, and Trichostrongylus spp. These results show that diverse species of intestinal nematodes, trematodes, and cestodes are infecting humans in Khammouane province, Lao PDR.
Adolescent
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Adult
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Aged
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Aged, 80 and over
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Animals
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Child
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Feces/parasitology
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Female
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Helminthiasis/*epidemiology/*parasitology
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Helminths/*isolation & purification
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Humans
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Laos/epidemiology
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Male
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Middle Aged
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Prevalence
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Young Adult
8.ERRATUM: High Prevalence of Haplorchis taichui, Phaneropsolus molenkampi, and Other Helminth Infections among People in Khammouane Province, Lao PDR.
Jong Yil CHAI ; Eun Taek HAN ; Eun Hee SHIN ; Woon Mok SOHN ; Tai Soon YONG ; Keeseon S EOM ; Duk Young MIN ; Jin Young UM ; Min Sung PARK ; Eui Hyug HOANG ; Bounlay PHOMMASACK ; Bounnaloth INSISIENGMAY ; Soon Hyung LEE ; Han Jong RIM
The Korean Journal of Parasitology 2010;48(1):93-93
The article 'High Prevalence of Haplorchis taichui, Phaneropsolus molenkampi, and Other Helminth Infections among People in Khammouane Province, Lao PDR' authored by Jong-Yil Chai, Eun-Taek Han, Eun-Hee Shin, Woon-Mok Sohn, Tai-Soon Yong, Keeseon S. Eom, Duk-Young Min, Jin-Young Um, Min-Sung Park, Eui-Hyug Hoang, Bounlay Phommasack, Bounnaloth Insisiengmay, Soon-Hyung Lee and Han-Jong Rim, published in the September issue (Vol. 47, No. 3) of The Korean Journal of Parasitology (2009), has an erratum. The genus name of a parasite in the title was mistakenly given as Phaneropsolus. It should be corrected as Prosthodendrium. The Korean Journal of Parasitology apologizes to the readers for this error.
9.Hyperendemicity of Haplorchis taichui Infection among Riparian People in Saravane and Champasak Province, Lao PDR.
Jong Yil CHAI ; Tai Soon YONG ; Keeseon S EOM ; Duk Young MIN ; Hyeong Kyu JEON ; Tae Yun KIM ; Bong Kwang JUNG ; Lay SISABATH ; Bounnaloth INSISIENGMAY ; Bounlay PHOMMASACK ; Han Jong RIM
The Korean Journal of Parasitology 2013;51(3):305-311
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.
Adolescent
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Adult
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Aged
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Aged, 80 and over
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Animals
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Child
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Demography
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Endemic Diseases/*statistics & numerical data
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Feces/parasitology
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Female
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Humans
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Laos/epidemiology
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Male
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Middle Aged
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Parasite Egg Count
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Rivers
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*Trematoda
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Trematode Infections/*parasitology
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Young Adult
10.Current Status of Human Taeniasis in Lao People's Democratic Republic.
Hyeong Kyu JEON ; Tai Soon YONG ; Woon Mok SOHN ; Jong Yil CHAI ; Duk Young MIN ; Cheong Ha YUN ; Han Jong RIM ; Tiengkham PONGVONGSA ; Virasack BANOUVONG ; Bounnaloth INSISIENGMAY ; Bounlay PHOMMASACK ; Keeseon S EOM
The Korean Journal of Parasitology 2013;51(2):259-263
Human taeniasis was investigated in Lao People's Democratic Republic (Lao PDR) between 2000 and 2011 as part of the nation's helminthiasis survey. A total of 55,038 inhabitants, including 29,846 school children, were examined using the Kato-Katz and scotch-tape anal swab method, and morphological observation of adult worms. Molecular identification of Taenia tapeworms was performed by multiplex PCR or DNA sequence analysis of the mitochondrial cox1 gene. Taenia eggs were present at a rate of 1.5% (845/55,038) in the subject population. Adult tapeworms were identified as T. solium or T. saginata by analyzing the collectable stool specimens (n=126). Three specimens identified as T. solium were found in Luang Prabang, while the remaining 123 specimens, which were T. saginata, were found in Bokeo, Bolikhamxay, Champasak, Houaphan, Khammouane, Luang Namta, Luang Prabang, Oudomxay, Phongsaly, Saysomboune, Saravane, Savannakhet, Xayaboury, Xekong, Xieng Khouang Province, and Vientiane Municipality.
Adolescent
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Adult
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Aged
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Anal Canal/parasitology
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Animals
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Child
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Female
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Humans
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Laos/epidemiology
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Male
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Microscopy
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Middle Aged
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Polymerase Chain Reaction
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Prevalence
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Taenia saginata/isolation & purification
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Taenia solium/isolation & purification
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Taeniasis/*epidemiology/parasitology