Re-evaluation of the species of hookworms infecting dogs in Central Vietnam

Abstract

BackgroundDifferentiation 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.MethodsFaecal 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.ResultsOf 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.ConclusionBased 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.

Molecular Identification of Hookworm Isolates in Humans, Dogs and Soil in a Tribal Area in Tamil Nadu, India

“…For this, molecular tools are more appropriate [ 20 ]. Second, various studies have identified hookworm species separately across humans [ 19 , 21 , 22 ], dogs [ 23 , 24 , 25 ] or soil [ 26 ], but to our knowledge there are no studies which have identified hookworm species using molecular techniques within both hosts and environment in the same geographical region. The present study aims at molecular identification of hookworms isolates from humans, dogs and soil from a tribal area in Tamil Nadu, India.…”

Prevalence of gastrointestinal helminth parasites of zoonotic significance in dogs and cats in lower Northern Thailand

“…Humans can be infected via contact with a dog or cat or via contamination of infective stages in food or water [20, 35]. Worldwide, there is a significant variation in the prevalence of gastrointestinal zoonotic helminths in dogs and cats [19, 24]. High infection rates of zoonotic parasites including hookworms, Trichuris spp., Spirometra spp., Taenia spp., Toxocara spp.…”

Ancylostoma ceylanicum, novel etiological agent for traveler’s diarrhea—report of four Japanese patients who returned from Southeast Asia and Papua New Guinea

“…A . ceylanicum is commonly found in dogs and cats in Asia, and high rates of infection with that species in domestic, stray, and community-raised dogs and cats have been reported in Malaysia [ 3 ], Laos [ 5 ], India [ 15 , 16 ], Thailand [ 6 , 7 , 17 ], Cambodia [ 8 ], Vietnam [ 18 ], Indonesia [ 19 ], and southern China [ 20 ]. In addition, infections in dogs as well as humans have also been reported in the Solomon Islands [ 21 , 22 ] and northern Australia [ 23 – 27 ].…”