Updated molecular phylogenetic data for Opisthorchis spp. (Trematoda: Opisthorchioidea) from ducks in Vietnam.

While it is likely that Opisthorchis sp. BD2013 is distinct from O. viverrini, it is clearly a sister taxon of O. viverrini within the limited number of Opisthorchis species for which appropriate sequence data are available. The new sequences provided here will assist the diagnosis and the taxonomic clarification of the opisthorchiid species.