title: Human fascioliasis and the presence of hybrid/introgressed forms of Fasciola hepatica and Fasciola gigantica in Vietnam.
abstract: The two species common of liver fluke, Fasciola hepatica and Fasciola gigantica, cause human fascioliasis. Hybrids between these species, and introgressed forms of Fasciola, are known from temperate and subtropical regions of eastern Asia. Here, we report the presence of hybrid and/or introgressed liver flukes in Vietnam where it has recently been recognised that human fascioliasis is an important zoonotic disease. Specimens examined came from domestic stock (cattle and buffalo) at slaughter and also from human patients. DNA sequences were obtained from the nuclear ribosomal second internal transcribed spacer (ITS-2) and from portions of two mitochondrial protein-coding genes. Mitochondrial sequences in every case were similar to those of Fasciola gigantica. Nuclear ITS-2 sequences belonged to one or other of the Fasciola species, or, sequences from both were found in the same individual worm. This study extends the known range of hybrids or introgressed forms of Fasciola into tropical regions of Asia.
authors.affiliation: Department of Immunology, Institute of Biotechnology, Hanoi, Viet Nam.
authors.forename: Thanh Hoa
authors.initials: TH
authors.lastname: Le
authors.forename: Nguyen Van
authors.initials: NV
authors.lastname: De
authors.forename: Takeshi
authors.initials: T
authors.lastname: Agatsuma
authors.forename: Thanh Giang
authors.initials: TG
authors.lastname: Thi Nguyen
authors.forename: Quoc Doanh
authors.initials: QD
authors.lastname: Nguyen
authors.forename: Donald P
authors.initials: DP
authors.lastname: McManus
authors.forename: David
authors.initials: D
authors.lastname: Blair
mesh_terms: D000818:Animals; D002020:Buffaloes; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology*; D018509:DNA, Helminth / Q000032:analysis; D021903:DNA, Ribosomal Spacer / Q000032:analysis*; D005209:Fasciola / Q000145:classification* / Q000235:genetics; D005211:Fascioliasis / Q000469:parasitology / Q000662:veterinary*; D006801:Humans; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014744:Vietnam / Q000453:epidemiology
chemical_list: D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer