title: First molecular identification and report of genetic diversity of Strongyloides stercoralis, a current major soil-transmitted helminth in humans from Lao People's Democratic Republic.
abstract: Strongyloidiasis is a major soil-transmitted helminth (STH) disease that affects people worldwide. We present updated data on prevalence in the Lao People's Democratic Republic (Lao PDR) in 2015, arising from a community cross-sectional helminthiasis survey. Fecal samples were collected from 327 individuals across three provinces in Lao PDR (Luang Prabang in the north, Khammouane in the center, and Champasack in the south). Agar plate culture and Kato-Katz methods were used to examine duplicate stool samples from each participant to detect Strongyloides stercoralis and co-infecting helminths. Overall prevalences of S. strercoralis human hookworm, Taenia spp., Trichuris trichiura, Ascaris lumbricoides, and Enterobius vermicularis were 41.0, 28.1, 4.9, 4.0, 1.5, and 0.9 %, respectively. The prevalence of miscellaneous trematodiases (including opisthorchiasis) was 37.9 % and of Schistosoma mekongi infection was 0.3 %. Strongyloidiasis is a current major STH disease in Lao PDR. We also report the molecular-phylogenetic identification of S. stercoralis adult males collected from 40 representative human strongyliodiasis fecal samples. DNA was extracted, amplified, and sequenced from a portion of the mitochondrial cox1 gene and the nuclear 18S ribosomal DNA. Phylogenetic analyses indicated that all specimens sequenced belonged to S. stercoralis (Bavay, 1876) Stiles and Hassall, 1902. The cox1 sequences exhibited great diversity (24 haplotypes) in Lao PDR. This is the first molecular identification and report of genetic diversity of S. stercoralis in humans from Lao PDR. An effective parasite control program is needed to reduce the serious health impacts.
authors.affiliation: Department of Parasitology and Research and Diagnostic Center for Infectious Disease, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.|Centre of Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Lao PDR.
authors.forename: Sakhone
authors.initials: S
authors.lastname: Laymanivong
authors.affiliation: Centre of Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Lao PDR.
authors.forename: Bouasy
authors.initials: B
authors.lastname: Hangvanthong
authors.affiliation: Department of Communicable Diseases Control, Ministry of Health, Vientiane, Lao PDR.
authors.forename: Bounnaloth
authors.initials: B
authors.lastname: Insisiengmay
authors.affiliation: Centre of Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Lao PDR.
authors.forename: Viengxay
authors.initials: V
authors.lastname: Vanisaveth
authors.affiliation: Centre of Malariology, Parasitology and Entomology, Ministry of Health, Vientiane, Lao PDR.
authors.forename: Pinnakhone
authors.initials: P
authors.lastname: Laxachack
authors.affiliation: Department of Parasitology and Research and Diagnostic Center for Infectious Disease, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Jurairat
authors.initials: J
authors.lastname: Jongthawin
authors.affiliation: Department of Parasitology and Research and Diagnostic Center for Infectious Disease, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.|Faculty of Medicine, Maha Sarakram University, Maha Sarakram, Thailand.
authors.forename: Oranuch
authors.initials: O
authors.lastname: Sanpool
authors.affiliation: Faculty of Medicine, Maha Sarakram University, Maha Sarakram, Thailand.
authors.forename: Tongjit
authors.initials: T
authors.lastname: Thanchomnang
authors.affiliation: Department of Parasitology and Research and Diagnostic Center for Infectious Disease, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Lakkhana
authors.initials: L
authors.lastname: Sadaow
authors.affiliation: Department of Parasitology and Research and Diagnostic Center for Infectious Disease, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Issarapong
authors.initials: I
authors.lastname: Phosuk
authors.affiliation: Department of Parasitology and Research and Diagnostic Center for Infectious Disease, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Rutchanee
authors.initials: R
authors.lastname: Rodpai
authors.affiliation: Department of Parasitology and Research and Diagnostic Center for Infectious Disease, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Wanchai
authors.initials: W
authors.lastname: Maleewong
authors.affiliation: Department of Parasitology and Research and Diagnostic Center for Infectious Disease, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand. pewpan@kku.ac.th.
authors.forename: Pewpan M
authors.initials: PM
authors.lastname: Intapan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005243:Feces / Q000469:parasitology; D005260:Female; D014644:Genetic Variation; D006373:Helminthiasis / Q000453:epidemiology; D006376:Helminths / Q000302:isolation & purification; D006801:Humans; D007812:Laos / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D015995:Prevalence; D012987:Soil / Q000469:parasitology*; D017171:Strongyloides stercoralis / Q000235:genetics* / Q000302:isolation & purification; D013322:Strongyloidiasis / Q000453:epidemiology* / Q000635:transmission; D055815:Young Adult
chemical_list: D012987:Soil
keywords: Genetic diversity; Lao PDR; Molecular identification; Soil-transmitted helminth; Strongyloides stercoralis; Strongyloidiasis