Prevalence, molecular typing and risk factor analysis for Giardia duodenalis infections in dogs in a central London rescue shelter

Department of Veterinary Clinical Sciences, Royal Veterinary College, Hawkshead Lane, Hertfordshire AL9 7TA, UK.
Veterinary Parasitology (Impact Factor: 2.46). 09/2010; 172(3-4):341-6. DOI: 10.1016/j.vetpar.2010.05.010
Source: PubMed


A cross-sectional survey to investigate canine infections with Giardia duodenalis was undertaken at a central London rescue shelter between October 2006 and March 2007. The objectives of the study were to (i) estimate the prevalence of infection in dogs admitted to a London dog shelter using a commercially available ELISA-based test kit; (ii) identify the relative importance of potential dog level risk factors for infection; and (iii) identify the occurrence of different G. duodenalis assemblages present in this population in order to identify presence of any potentially zoonotic assemblages. A faecal sample was collected from each dog entering the shelter within 1 day of arrival. Each sample was tested for the presence of parasite cyst wall protein using the Giardia SNAP test kit (Idexx Laboratories). Samples were graded for faecal consistency on a standard scale and data on age, breed, categorized breed group, sex and neutered status were collected for each dog. Associations between infection status and each dog level variable were investigated using univariable and multivariable logistic regression. Selected G. duodenalis-positive samples were genotyped using previously described primers targeting the 18S rDNA gene and the beta-giardin gene. Samples from a total of 878 dogs were collected and the true prevalence found to be 21.0% (95% CI 16.7-25.4%). In the present study, the odds of infection decreased with increasing age (adjusted odds ratio 0.66, 95% CI 0.54-0.80, p<0.0001) and was increased for Rottweilers (adjusted odds ratio 2.12, 95% CI 1.03-4.34, p=0.04). Of the 51 samples selected for genotyping, 41 samples yielded a good amplification at one or both of the targeted genes, demonstrating the occurrence of mainly dog-specific assemblages C and D. The potentially zoonotic assemblage A and a mixed template C/D were found in two individual dogs. The results of the present study illustrate the high prevalence of G. duodenalis in shelter dogs. Although predominantly infected with dog-specific assemblages, the identification of assemblage A suggests that appropriate precautions should be taken to minimize the risk of transmission to staff.

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Available from: Melissa M Upjohn, Nov 06, 2014
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    • "The predominance of dog-specific assemblages C and D over zoonotic assemblages A and B in canine Giardia isolates exists not only in South Eastern Europe but also in other countries worldwide. The occurrence of non-zoonotic assemblages C or D was 100 % at the SSU rRNA and 93.3 % at the bg locus in England (Upjohn et al. 2010), 98.7 % at the SSU rRNA, 97.3 % at the bg and 100 % at the gdh and tpi loci in Canada (McDowall et al. 2011), 88.6 % at the SSU rRNA locus in the USA (Johansen 2013) and 96.2 % at the SSU rRNA locus in Trinidad and Tobago (Mark-Carew et al. 2013). In general, assemblage D outweighed assemblage C in most studies on canine Giardia assemblages including the present study. "
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    ABSTRACT: Giardia duodenalis is a worldwide occurring protozoan that can infect various mammalian hosts. While living conditions are getting closer between pet animals and owners, there is discussion whether dogs may contribute to the transmission of these pathogens to humans. The present study was conducted in order to identify the Giardia assemblages in dogs from South Eastern Europe. For this purpose, 1645 faecal samples of household and shelter dogs from Albania, Bulgaria, Hungary, Macedonia, Romania and Serbia were tested for Giardia coproantigen by enzyme-linked immunosorbent assay (ELISA). A subset of 107 faecal samples demonstrating Giardia cysts by direct immunofluorescence assay (IFA) or microscopy (15-22 per country) plus 26 IFA-positive canine faecal samples from Croatia were used for DNA extraction and multilocus sequence typing with nested PCRs targeting five different gene loci: SSU rRNA, ITS1-5.8S-ITS2, beta giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi). One third (33.7 %) of the samples tested positive for Giardia antigen in the coproantigen ELISA. Shelter dogs were infected more frequently than household dogs (57.2 vs. 29.7 %, p < 0.01). Amplification was obtained in 82.0, 12.8, 11.3, 1.5, and 31.6 %, of the investigated samples at the SSU rRNA, bg, gdh and tpi loci and the ITS1-5.8S-ITS2 region, respectively. The dog-specific assemblages C and D were identified in 50 and 68 samples, respectively. The results demonstrate that G. duodenalis should be considered as a common parasite in dogs from South Eastern Europe. However, there was no evidence for zoonotic Giardia assemblages in the investigated canine subpopulation.
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    • "Puppies, one year of age or less, were reported to be at a higher risk compared to older dogs (Little et al., 2009). In countries other than the United States, higher prevalence has been associated with dogs from breeding kennels (Mundim et al., 2007), purebred dogs (Fontanarrosa et al., 2006), and selected breeds (Rottweiler) (Upjohn et al., 2010). "
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    ABSTRACT: Estimates of the prevalence of intestinal infection of dogs with Giardia spp. in the United States vary widely. Risk factors for infection in a large sample of dogs over an extended period of time have not been well characterized. A national, electronic database of medical records was used to estimate the prevalence and identify risk factors for Giardia spp. infection among dogs visiting Banfield Pet Hospital™ located in 43 states in the United States. The overall prevalence of Giardia spp. Infection was 0.44% (95% CI: 0.43-0.45%) in approximately 2.5 million owned dogs who had a fecal flotation test performed from January 2003 to December 2009. A steady decrease in annual prevalence was observed, from a high of 0.61% in 2003 to 0.27% in 2009. Seasonal increases in prevalence were noted during the winter and summer months. Giardia spp. prevalence was highest in the Mountain region, especially Colorado (2.63%; 95% CI: 2.53-2.73%), and in puppies ≤0.5 year of age (0.63%; 95% CI: 0.61-0.64%). It was lowest for dogs of mixed breeding compared with pure breeds. Infection risk was 25-30% greater in sexually intact dogs compared to spayed and neutered dogs.
    No preview · Article · Jan 2013 · Veterinary Parasitology
    • "The prevalence of zoonotic assemblages in dogs was recently shown to be subjected to high variations, depending on the analyzed countries and dog populations (Leonhard et al., 2007; Upjohn et al., 2010) and it was therefore suggested to not draw conclusions from one geographical region to another in terms of the prevalence or assemblage composition of Giardia infections in dogs (Covacin et al., 2011). In any case, the awareness about this potential zoonotic risk was recommended to be maintained for all people involved (Upjohn et al., 2010). "
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