title: New locality record for Haplorchoides mehrai and possible interactions with Opisthorchis viverrini metacercariae in cyprinid fishes in Northeast Thailand.
abstract: Metacercariae of Opisthorchis viverrini, a carcinogenic liver fluke, and Haplorchoides sp., a trematode maturing in catfish, are commonly found in cyprinid fish, the second intermediate hosts of both flukes. However, the specific identity of Haplorchoides sp. in Thailand and a precise assessment of the effects of co-infections with O. viverrini have never been clarified. Therefore, we aimed to identify the species of Haplorchoides and to investigate possible interactions of the two trematode species in cyprinid fishes. Based on the morphology and morphometry of the cercaria, metacercaria, and adult stages, the Haplorchoides species found was identified as Haplorchoides mehrai Pande and Shukla 1976. Thailand is formally recorded as a new locality for H. mehrai, where naturally infected hosts include the snail Melanoides tuberculata (first intermediate host), the cyprinid fishes Hampala dispar, Cyclocheilichthys apogon, Puntius leiacanthus, Labiobarbus burmanicus, and Cirrhina jullieni (second intermediate hosts), and a catfish, Mystus nemurus (definitive host). The co-infection rates of O. viverrini and H. mehrai were significantly associated with fish species and fish body region (P < 0.001), with an overall significantly higher average intensity of H. mehrai (126.26 metacercariae/fish) than that of O. viverrini (18.02 metacercariae/fish). Further work is required to demonstrate the extent and mechanisms of possible interactions between these trematode species in the fish host. These data may provide a better understanding of O. viverrini transmission dynamics, and help design integrated control interventions.
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
authors.forename: Yupin
authors.initials: Y
authors.lastname: Manpratum
authors.affiliation: Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Wanlop
authors.initials: W
authors.lastname: Kaewkes
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Laboratory, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.|Global Health Asia, Integrative Research and Education Programme, Faculty of Public Health, Mahidol University, Bangkok, Thailand.
authors.forename: Pierre
authors.initials: P
authors.lastname: Echaubard
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Laboratory, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Banchob
authors.initials: B
authors.lastname: Sripa
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand. sasithrn@kku.ac.th.
authors.forename: Sasithorn
authors.initials: S
authors.lastname: Kaewkes
mesh_terms: D000818:Animals; D002397:Catfishes / Q000469:parasitology; D060085:Coinfection / Q000469:parasitology; D003530:Cyprinidae / Q000469:parasitology; D005393:Fish Diseases / Q000469:parasitology*; D006578:Heterophyidae / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D009889:Opisthorchiasis / Q000469:parasitology / Q000662:veterinary*; D009891:Opisthorchis / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D013785:Thailand; D014201:Trematode Infections / Q000469:parasitology / Q000662:veterinary*
keywords: Co-infections; Haplorchoides mehrai; Metacercaria; Opisthorchis viverrini