title: Distribution and abundance of Opisthorchis viverrini metacercariae in cyprinid fish in Northeastern Thailand.
abstract: To increase public health awareness for prevention of opisthorchiasis caused by eating raw freshwater fish, the distribution and abundance of Opisthorchis viverrini metacercariae (OV MC) was investigated in freshwater fish obtained from 20 provinces in northeastern Thailand between April 2011 and February 2012. A cross-sectional survey was conducted on 12,890 fish consisting of 13 species randomly caught from 26 rivers, 10 dams, and 38 ponds/lakes. Fish, were collected in each of the rainy and winter seasons from each province. Fish were identified, counted, weighed, and digested using pepsin-HCl. Samples were examined for OV MC by a sedimentation method, and metacercariae were identified under a stereomicroscope. OV MC were found in 6 species of fish; i.e., Cyclocheilichthys armatus, Puntius orphoides, Hampala dispar, Henicorhynchus siamensis, Osteochilus hasselti, and Puntioplites proctozysron from localities in 13 provinces. Among the sites where OV MC-infected fish were found, 70.0% were dams, 23.7% were ponds/lakes, and 7.7% were rivers. The mean intensity of OV MC ranged from 0.01 to 6.5 cysts per fish (or 1.3-287.5 cysts per kg of fish). A high mean intensity of OV MC per fish (>3 cysts) was found in 5 provinces: Amnat Charoen (6.5 cysts), Nakhon Phanom (4.3), Mukdahan (4.1), Khon Kaen, (3.5) and Si Sa Ket (3.4). In conclusion, OV MC are prevalent in natural cyprinid fish, with the infection rate varying according to fish species and habitats.
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Somchai
authors: S
authors: Pinlaor
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Sudarat
authors: S
authors: Onsurathum
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Thidarut
authors: T
authors: Boonmars
authors: Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Porntip
authors: P
authors: Pinlaor
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Nuttanan
authors: N
authors: Hongsrichan
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Apisit
authors: A
authors: Chaidee
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Ornuma
authors: O
authors: Haonon
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Wutipong
authors: W
authors: Limviroj
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Smarn
authors: S
authors: Tesana
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Sasithorn
authors: S
authors: Kaewkes
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Paiboon
authors: P
authors: Sithithaworn
mesh_terms: D000818:Animals; D003430:Cross-Sectional Studies; D003530:Cyprinidae / Q000469:parasitology*; D005393:Fish Diseases / Q000453:epidemiology* / Q000469:parasitology*; D058488:Metacercariae / Q000302:isolation & purification*; D008853:Microscopy; D009889:Opisthorchiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D009891:Opisthorchis / Q000302:isolation & purification*; D010274:Parasitology / Q000379:methods; D015995:Prevalence; D013785:Thailand
keywords: Opisthorchis viverrini; cyprinid fish; distribution; foodborne trematode; intensity; metacercaria