title: Hyperendemicity of Haplorchis taichui infection among riparian people in Saravane and Champasak province, Lao PDR.
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.
authors.affiliation: Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, Seoul 110-799, Korea.
authors.forename: Jong-Yil
authors.initials: JY
authors.lastname: Chai
authors.forename: Tai-Soon
authors.initials: TS
authors.lastname: Yong
authors.forename: Keeseon S
authors.initials: KS
authors.lastname: Eom
authors.forename: Duk-Young
authors.initials: DY
authors.lastname: Min
authors.forename: Hyeong-Kyu
authors.initials: HK
authors.lastname: Jeon
authors.forename: Tae-Yun
authors.initials: TY
authors.lastname: Kim
authors.forename: Bong-Kwang
authors.initials: BK
authors.lastname: Jung
authors.forename: Lay
authors.initials: L
authors.lastname: Sisabath
authors.forename: Bounnaloth
authors.initials: B
authors.lastname: Insisiengmay
authors.forename: Bounlay
authors.initials: B
authors.lastname: Phommasack
authors.forename: Han-Jong
authors.initials: HJ
authors.lastname: Rim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002648:Child; D003710:Demography; D019353:Endemic Diseases / Q000706:statistics & numerical data*; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D007812:Laos / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010270:Parasite Egg Count; D045483:Rivers; D014200:Trematoda; D014201:Trematode Infections / Q000469:parasitology*; D055815:Young Adult
keywords: Centrocestus formosanus; Champasak province; Haplorchis pumilio; Haplorchis taichui; Lao PDR; Opisthorchis viverrini; Saravane province; hyperinfection; prevalence; riparian people