title: Risk factors for Clonorchis sinensis infection transmission in humans in northern Vietnam: A descriptive and social network analysis study.
abstract: Clonorchis sinensis is major fish-borne trematode, endemic in North Vietnam. Risk factors described so far include individual eating behaviors and environmental factors. Here, additional to conventional risk factors, we report on socially influenced liver fluke transmission in endemic communities. A cross-sectional study on risk factors and fish sharing networks was conducted in 4 villages of Gia Thinh Commune, Ninh Binh Province. A total of 510 residents in 272 households were recruited for risk factor analysis while 220 households, 28 fishermen and 10 fish-sellers were enrolled for social network study. Fecal examination for C. sinensis eggs was performed. Average C. sinensis infection rate at Gia Thinh commune was 16.5% (range 2% to 34.4%). Higher infection rates were significantly associated with males, lower educational levels, eating raw fish, and location of the villages. Social network analysis (SNA) showed a strong positive correlation between ego network size (number of households in fish sharing network) and quantity of raw fish consumed (r=0.603, P<0.05). The infection rate in people who ate raw-fish caught from a nearby river was significantly higher than those who consumed fish taken from farmed ponds (P<0.05). The amount of raw-fish meal consumed per resident/year was significantly higher in villages that had a strong network of sharing raw-fish food (P<0.001). This study reports for the first time on fish-food sharing among neighbors, proximity to water bodies, frequency of eating raw fish from natural water bodies and low education were key risk factors in C. sinensis infection transmission in northern Vietnam.
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Center, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; National Institute of Malariology, Parasitology and Entomology, Ministry of Health, BC 10200, Luong the Vinh Str., Hanoi, Vietnam.
authors.forename: Hoang Quang
authors.initials: HQ
authors.lastname: Vinh
authors.affiliation: Department of Veterinary Public Health, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand.
authors.forename: Waraphon
authors.initials: W
authors.lastname: Phimpraphai
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Center, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Sirikachorn
authors.initials: S
authors.lastname: Tangkawattana
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Center, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: John F
authors.initials: JF
authors.lastname: Smith
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Sasithorn
authors.initials: S
authors.lastname: Kaewkes
authors.affiliation: National Institute of Malariology, Parasitology and Entomology, Ministry of Health, BC 10200, Luong the Vinh Str., Hanoi, Vietnam.
authors.forename: Do Trung
authors.initials: DT
authors.lastname: Dung
authors.affiliation: National Institute of Malariology, Parasitology and Entomology, Ministry of Health, BC 10200, Luong the Vinh Str., Hanoi, Vietnam.
authors.forename: Tran Thanh
authors.initials: TT
authors.lastname: Duong
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Center, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: banchob@kku.ac.th.
authors.forename: Banchob
authors.initials: B
authors.lastname: Sripa
mesh_terms: D000818:Animals; D003003:Clonorchiasis / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission*; D003004:Clonorchis sinensis / Q000302:isolation & purification; D003430:Cross-Sectional Studies; D005191:Family Characteristics; D005243:Feces / Q000469:parasitology; D005247:Feeding Behavior; D005260:Female; D005399:Fishes / Q000469:parasitology; D016266:Food Parasitology; D006801:Humans; D008297:Male; D066256:Raw Foods / Q000469:parasitology*; D012307:Risk Factors; D017747:Seafood / Q000469:parasitology; D012931:Social Environment; D011795:Surveys and Questionnaires; D014744:Vietnam / Q000453:epidemiology
keywords: Clonorchiasis; Clonorchis sinensis; Risk factors; SNA; Social network analysis; Vietnam