title: Re-evaluation of the species of hookworms infecting dogs in Central Vietnam.
abstract: BACKGROUND
  Differentiation of canine hookworm species is crucial from both a veterinary and public health standpoint. In Vietnam, three hookworm species, namely Ancylostoma caninum, Ancylostoma braziliense and Uncinaria stenocephala are reported to infect dogs. In light of the emerging distribution of A. ceylanicum in Asia, this study aims to re-evaluate the status of Ancylostoma in dogs in Vietnam.
  
  
  METHODS
  Faecal samples collected from 200 community dogs in Dak Lak province were subjected to faecal floatation for the detection of hookworm eggs. Hookworm-positive samples were subjected to a PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) assay targeting the internal transcribed spacer (ITS) region of rDNA for hookworm species identification. A subset of hookworm-positive samples was also subject to haplotype characterisation at the cytochrome oxidase-1 (COX-1) gene. Detailed morphological criteria were utilised in addition to molecular markers, to identify adult hookworms recovered from necropsied dogs.
  
  
  RESULTS
  Of 200 canine faecal samples, 111 (55.5 %) were positive for hookworm eggs on faecal flotation. Of these, 94/111 (84.7 %) were successfully amplified and assigned species status by PCR-RFLP targeting the ITS region. In total, 54.3 % (51/94) dogs harboured single infections with A. ceylanicum, 33.0 % (31/94) with A. caninum, and 12.7 % (12/94) harboured mixed infections with both A. ceylanicum and A. caninum. Adult worms recovered from necropsied dogs matched morphological description provided for A. ceylanicum, Looss (1911) for which the mediolateral and posteriolateral rays are parallel. Characterisation of the COX-1 gene placed all Vietnamese canine isolates of A. ceylanicum within the 'zoonotic' haplotype.
  
  
  CONCLUSIONS
  Based on this information, it is apparent that the hookworms present in dogs in Vietnam are those of A. ceylanicum and not A. braziliense. Owing to the endemic nature of this significant zoonosis in dogs, the study strongly advocates for specific identification of this hookworm in human hookworm surveys.
authors.affiliation: Faculty of Animal Science and Veterinary Medicine, Tay Nguyen University, Buon Ma Thuot, Dak Lak, Vietnam. ngocn4@student.unimelb.edu.au.|Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, 3052, Australia. ngocn4@student.unimelb.edu.au.
authors.forename: Dinh
authors.initials: D
authors.lastname: Ng-Nguyen
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, 3052, Australia. sze.hii@unimelb.edu.au.|School of Veterinary Science, The University of Queensland, Gatton, 4343, Australia. sze.hii@unimelb.edu.au.
authors.forename: Sze Fui
authors.initials: SF
authors.lastname: Hii
authors.affiliation: Faculty of Animal Science and Veterinary Medicine, Tay Nguyen University, Buon Ma Thuot, Dak Lak, Vietnam. vananhknts@gmail.com.
authors.forename: Van-Anh T
authors.initials: VA
authors.lastname: Nguyen
authors.affiliation: Faculty of Animal Science and Veterinary Medicine, Tay Nguyen University, Buon Ma Thuot, Dak Lak, Vietnam. nvtrongdhtn@gmail.com.
authors.forename: Trong
authors.initials: T
authors.lastname: Van Nguyen
authors.affiliation: Faculty of Animal Science and Veterinary Medicine, Tay Nguyen University, Buon Ma Thuot, Dak Lak, Vietnam. dienparasite@yahoo.com.
authors.forename: Dien
authors.initials: D
authors.lastname: Van Nguyen
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, 3052, Australia. rebecca.traub@unimelb.edu.au.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Traub
mesh_terms: D000723:Ancylostomatoidea / Q000145:classification* / Q000235:genetics; D000818:Animals; D018509:DNA, Helminth / Q000235:genetics; D004283:Dog Diseases / Q000453:epidemiology / Q000469:parasitology*; D004285:Dogs; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D006239:Haplotypes; D006725:Hookworm Infections / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D010802:Phylogeny; D014744:Vietnam / Q000453:epidemiology
chemical_list: D018509:DNA, Helminth; D003576:Electron Transport Complex IV