Prevalence and genotypes of Giardia lamblia from stray dogs and cats in Guangdong, China

Prevalence of Intestinal Parasites in Dog Faecal Samples from Public Environments in Qinghai Province, China

Dogs are popular companions in our daily lives for company, hunting, protection or shepherding, but they also serve as reservoirs for zoonotic parasites. We analysed faecal samples from urban and rural environments in Qinghai Province on the Qinghai-Tibet Plateau of China to determine the prevalence of intestinal parasites. A total of 682 faecal samples were collected from four urban and two rural environments from October 2019 to December 2020. The samples were analysed for common intestinal parasites using a species-specific PCR approach. The total number of samples with parasites was 40 (5.87%): 23 (3.37%) were positive for helminths, and 17 (2.49%) were positive for protozoa. The following parasites were identified, and their respective prevalence rates were calculated: Cryptosporidium canis (1.32%), Giardia duodenalis (1.17%, assemblages D (n = 6) and C (n = 2)), Taenia hydatigena (1.03%), Taenia multiceps (0.59%), Toxocara canis (0.59%), Echinococcus shiquicus (0.29%), Dipylidium caninum (0.29%), Taenia pisiformis (0.15%), Mesocestoides lineatus (0.15%), Trichuris vulpis (0.15%), and Ancylostoma spp. (0.15%). The overall prevalence was significantly higher in dog faecal samples from rural environments than in those from urban environments (16.19% vs. 3.99%). E. shiquicus, T. pisiformis, M. lineatus, T. vulpis, and Ancylostoma spp. were only found in dog faecal samples from rural environments. The results of the present study indicate that intestinal parasite-positive dogs are important sources of environmental contamination, suggesting a significant zoonotic infection risk in humans and other animals. This has implications for the ongoing control of intestinal parasite infections in dogs in Qinghai Province, China.

Molecular characterization of Cryptosporidium spp. and Giardia duodenalis in pet dogs in Xinjiang, China

Cryptosporidium spp. and Giardia duodenalis are opportunistic zoonotic protozoa transmitted through several routes. In this study, a total of 604 fecal samples were collected from pet dogs in Xinjiang, China to detect the presence of Cryptosporidium spp. and G. duodenalis by PCR amplification of the small subunit (SSU) rRNA gene. The incidence rate of Cryptosporidium spp. or G. duodenalis was 5.3% (32/604). Among the collection sites, a higher number of Cryptosporidium spp. or G. duodenalis positive dogs were detected in Hotan (9.9%, 21/213) and Shihezi (9.8%, 4/41) were higher than those in Aksu (4.5%, 1/22), Urumqi (2.1%, 4/191), and Korla (1.5%, 2/137). Among the sources, dogs in pet shops (7.4%, 19/256) showed a significantly higher incidence rate than those in pet hospitals (3.0%, 4/134) and pet kennels (2.3%, 5/214). When the data were examined by age, dogs < 1 year of age (6.1%, 28/459) were more likely to be infected by Cryptosporidium spp. or G. duodenalis than older (≥ 1 year) dogs (2.8%, 4/145). No significant differences were observed when animals were grouped by sex (5.0%, 14/278 for males; 5.5%, 18/326 for females). Sequence analysis revealed that the Cryptosporidium spp. (n = 10) in dogs were identified as C. canis. The G. duodenalis detected belonged to assemblages A (n = 1), C (n = 14), and D (n = 7). Among the identified 22 G. duodenalis isolates, eight samples were subtyped according to β-giardin (bg) and the results were consistent with the identified assemblages. To our knowledge, this is the first report of Cryptosporidium spp. and G. duodenalis infections in domesticated canines in Xinjiang, China. The C. canis and G. duodenalis assemblage A identified in pet dogs in the present study were previously associated with infections in humans, indicating the potential for zoonotic transmission.

Zoonotic giardiasis: an update

Giardia duodenalis is a common intestinal parasite in various hosts, with the disease giardiasis being a zoonosis. The use of molecular typing tools has improved our understanding of the distribution and zoonotic potential of G. duodenalis genotypes in different animals. The present review summarizes recent data on the distribution of G. duodenalis genotypes in humans and animals in different areas. The dominance of G. duodenalis assemblages A and B in humans and common occurrence of host-adapted assemblages in most domesticated animals suggests that zoonotic giardiasis is probably less common than believed and could be attributed mainly to contact with or contamination from just a few species of animals such as nonhuman primates, equines, rabbits, guinea pigs, chinchillas, and beavers. Future studies should be directed to advanced genetic characterization of isolates from well-designed epidemiological investigations, especially comparative analyses of isolates from humans and animals living in the same household or community. This will likely lead to better understanding of zoonotic transmission of G. duodenalis in different environmental and socioeconomic settings.

Molecular Investigation of Zoonotic Intestinal Protozoa in Pet Dogs and Cats in Yunnan Province, Southwestern China

Giardia duodenalis, Enterocytozoon bieneusi and Cryptosporidium spp. are common enteric pathogens that reside in the intestines of humans and animals. These pathogens have a broad host range and worldwide distribution, but are mostly known for their ability to cause diarrhea. However, very limited information on prevalence and genotypes of G. duodenalis, E. bieneusi and Cryptosporidium spp. in pet dogs and cats are available in China. In the present study, a total of 433 fecal samples were collected from 262 pet dogs and 171 pet cats in Yunnan province, southwestern China, and the prevalence and the genotypes of G. duodenalis, E. bieneusi and Cryptosporidium spp. were investigated by nested PCR amplification and DNA sequencing. The prevalence of G. duodenalis, E. bieneusi and Cryptosporidium spp. was 13.7% (36/262), 8.0% (21/262), and 4.6% (12/262) in dogs, and 1.2% (2/171), 2.3% (4/171) and 0.6% (1/171) in cats, respectively. The different living conditions of dogs is a risk factor that is related with the prevalence of G. duodenalis and E. bieneusi (p < 0.05). However, there were no statistically significant difference in prevalence of three pathogens in cats. DNA sequencing and analyses showed that four E. bieneusi genotypes (PtEb IX, CD9, DgEb I and DgEb II), one Cryptosporidium spp. (C. canis) and two G. duodenalis assemblages (C and D) were identified in dogs; two E. bieneusi genotypes (Type IV and CtEb I), one Cryptosporidium spp. (C. felis) and one G. duodenalis assemblage (F) were identified in cats. Three novel E. bieneusi genotypes (DgEb I, DgEb II and CtEb I) were identified, and the human-pathogenic genotypes/species Type IV C. canis and C. felis were also observed in this study, indicating a potential zoonotic threat of pet dogs and cats. Our results revealed the prevalence and genetic diversity of G. duodenalis, E. bieneusi and Cryptosporidium spp. infection in pet dogs and cats in Yunnan province, southwestern China, and suggested the potential threat of pet dogs and cats to public health.

Genotypes of Giardia duodenalis in Household Dogs and Cats from Poland

BACKGROUND

Giardia duodenalis is a widespread protozoan parasite affecting humans and many species of animals, including dogs and cats. Due to its zoonotic potential, it is important to know the frequency of this parasite in companion animals. The aim of this study was to determine current epidemiological status of G. duodenalis in household dogs and cats.

METHODS

In this study, 293 fecal samples from pet dogs and cats were collected from January 2017 to July 2019 and tested for G. duodenalis by PCR (using β-giardin gene). The animals were divided into groups depending on their age, breed and fecal consistency.

RESULTS

The examination allowed for detection of G. duodenalis in 6.0% of canine and 3.9% of feline fecal samples. The highest frequency was revealed in young (under one-year old) dogs. Sequencing confirmed the presence of assemblages C and D in dogs and A and F in cats.

CONCLUSION

The study showed current frequency of G. duodenalis in dogs and cats and also revealed the occurrence of host-specific assemblages as well as zoonotic assemblage A.

Occurrence and genotypes of Cryptosporidium spp., Giardia duodenalis, and Blastocystis sp. in household, shelter, breeding, and pet market dogs in Guangzhou, southern China

Cryptosporidium spp., Giardia duodenalis, and Blastocystis sp. are common intestinal protozoans that infect humans and animals worldwide. A survey that assessed the prevalence, molecular characteristics, and zoonotic potential of these pathogens was conducted on a variety of dogs in Guangzhou, southern China. A total of 651 canine stool samples from household (n = 199), shelter (n = 149), breeding (n = 237), and pet market dogs (n = 66) were collected from eight districts in Guangzhou. Cryptosporidium spp., Giardia duodenalis, and Blastocystis sp. were detected by PCR amplification of the SSU rRNA gene. Giardia duodenalis-positive specimens were further assigned into assemblages using the glutamate dehydrogenase gene. Cryptosporidium spp., G. duodenalis, and Blastocystis sp. were found in 21 (3.2%), 20 (3.1%), and 35 (5.4%) samples, respectively. The overall prevalence of shelter dogs (40.28%, 60/149) was significantly higher than that of household (3.0%, 6/199), breeding (2.1%, 5/237), and pet market dogs (7.5%, 5/66) (χ² = 154.72, df = 3, P < 0.001). Deworming in the past 12 months had a strong protective effect on the risk of contracting parasite infections (P < 0.001). No significant differences were detected between age or sex groups (P > 0.05). Dog-specific C. canis (n = 19) and zoonotic C. parvum (n = 2) were the only two Cryptosporidium species. Sequence analysis revealed the presence of three G. duodenalis assemblages: dog-specific assemblages D (n = 14) and C (n = 5), and cat-specific F (n = 1). Zoonotic Blastocystis ST3 (n = 28) was the dominant subtype, followed by ST1 (n = 6) and ST10 (n = 1). To our knowledge, this is the first large-scale investigation on the occurrence and molecular characteristics of Blastocystis sp. in dogs in China. Our results indicated that the dogs seemed to play a negligible role as reservoirs for Cryptosporidium spp. and G. duodenalis transmission to humans, but they are potential novel suitable hosts of Blastocystis sp. A strict sentinel surveillance system of dogs should be established to minimise the zoonotic risk of spreading blastocystosis among humans and dogs.

Epidemiological study of Giardia duodenalis infection in companion dogs from the metropolitan area of São Paulo Brazil

Giardia duodenalis is a zoonotic pathogen associated with gastrointestinal disease that has a direct life cycle, with cysts eliminated in the faeces of an infected host being ingested by a susceptible host. In Brazil, studies of chronically infected adult dogs estimated a prevalence of 10%-20%. Diagnosis of giardiasis, as a cause of diarrhoea is important for the global One-Health guidelines when controlling cyst dissemination in the environment. We investigated the prevalence of G. duodenalis in the pet dog population of the metropolitan area of Sao Paulo, compared the efficacy of direct tests available to the veterinary clinical practice and attempted to identify possible risk factors associated with the parasite. Ten veterinary practices distributed throughout the municipality randomly performed the rapid SNAP ELISA test on canine faecal samples, and dog owners provided information specific to the animal via a questionnaire. The samples were also analysed using sucrose and zinc sulphate flotation techniques. Sensitivity and specificity of the tests were used to calculate required number of samples and true prevalence. Significance, agreement among tests, and odds ratio (OR) were assessed with a confidence interval (CI) of 95%. The prevalence of G. duodenalis in dogs (n = 265) was 6.9% (CI 3.47-11.21). Positive tests were significantly more frequent in animals younger than 1 year, with an OR for G. duodenalis occurrence nearly 7-fold that of older dogs. Direct diagnosis tests showed high agreement (96.1%, κ = 0.729; p < .0001) showing that the combined techniques provide a highly accurate diagnosis. Results indicated that the control of the pathogen has been improving in the pet dog population in metropolitan Sao Paulo, but management tools including diagnosis, immunization, and treatment, especially in puppies, must be continued in order to advance towards continuous decrease of the disease.