The epidemiology of infections with Giardia species and genotypes in well cared for dogs and cats in Germany

Prevalence and molecular characterization of Giardia duodenalis in companion dogs, domestic livestock and wildlife in the Jordan Basin, Israel

Giardiasis is a small intestinal disease caused by the zoonotic parasite, Giardia duodenalis. This study presents the molecular findings of G. duodenalis infection in companion dogs, domestic livestock and wildlife in the Northern Jordan Basin, Israel. Identification of G. duodenalis was accomplished by nested PCR (nPCR) targeting the 18S rRNA gene. Samples were collected from water (five samples from four sources of which one was recycled water), as well as feces from wolves (Canis lupus) (n = 34), jackals (Canis aureus) (n = 24), wild boars (Sus scrofa) (n = 40), cattle (Bos taurus) (n = 40), dogs (Canis lupus familiaris) (n = 37) and nutria (Mayocastor coypus) (n = 100). All positive samples were sequenced and a phylogenetic tree was drawn using the Bayesian Inference (BI) algorithm. Differences in G. duodenalis prevalence between the different hosts were analyzed by Pearson's chi-square (p < 0.05). Of the total 275 fecal samples, 36 were positive for G. duodenalis (13%). Frequency rates among different animal species was highest in wolves (32.3%), whilst rates in wild boars (22.5%), dogs (16.2%), cattle (12.5%) and jackals (4.2%), were observed to be significantly lower (p < 0.001). Three out of 5 recycled water (RW) samples were G. duodenalis positive. Three clusters with high posterior probabilities (PP) were found in the BI: Cluster 1: samples from wolves, wild boars, water and cattle together with database sequences of assemblages A, B and F, Cluster 2: samples from dogs, nutria and a jackal with sequences from assemblage D and Cluster 3: samples from cattle, wild boars, wolves and dogs with sequences from assemblage C and D. We suggest that wolves serve as reservoirs of G. duodenalis in this region. The finding of Giardia in RW suggests that this vehicle may further contaminate crops intended for human consumption as this water source is used for agricultural irrigation.

Molecular characterization of Cryptosporidium spp. and Giardia duodenalis in pet cats in Henan Province, central China

Cryptosporidium spp. and G. duodenalis often infect humans, cats, and other mammals, causing diarrhea and being responsible for numerous outbreaks of waterborne and foodborne infections worldwide. The rapid increase in the number of pet cats poses a substantial public health risk. However, there were few reports about the infection of Cryptosporidium spp. and G. duodenalis infections in pet cats in Henan Province, central China. Thus, to understand the prevalence and genetic distribution of Cryptosporidium spp. and G. duodenalis in pet cats, and to evaluate the zoonotic potential, possible transmission routes and public health implications of isolates, fecal samples (n = 898) were randomly collected from pet cats in 11 cities in Henan Province, central China. Nested PCR based on the SSU rRNA gene and bg gene was used to the prevalence of Cryptosporidium spp. and G. duodenalis, respectively. The prevalence was 0.8 % (7/898) and 2.0 % (18/898) for Cryptosporidium spp. and G. duodenalis respectively. Additionally, the Cryptosporidium spp. positive isolates were identified as C. parvum subtype IIdA19G1 by gp60 gene. In the present study, the IIdA19G1 subtype was discovered in pet cats for the first time in China, enriching the information on the host type and geographical distribution of Cryptosporidium spp. in China. For G. duodenalis, a total of 18 G. duodenalis positive samples were identified, belonging to four assemblages: a zoonotic assemblage A1 (4/898), three host-specific assemblages C (8/898), D (5/898), and F (1/898). Interestingly, we found that pet cats infected with Cryptosporidium spp. and G. duodenalis are more likely to experience emaciation symptoms compared to the negative group. More importantly, the prevalence of Cryptosporidium spp. and G. duodenalis detected in the present study were low, but the subtype IIdA19G1 of Cryptosporidium spp. and the assemblages A1, C, D, and F of G. duodenalis have the potential for zoonotic transmission. Thus, we should focus on preventing and controlling the risk of cross-species transmission that may occur in pet cats in Henan Province.

The Influence of Giardia duodenalis on the Occurrence of Clinical Signs in Dogs

Giardia duodenalis infections are common in dogs and are mainly caused by assemblages C and D. The aim of this study was to investigate the correlation between the presence of Giardia duodenalis and different Giardia assemblages detected in symptomatic and asymptomatic dogs and the occurrence of certain clinical signs. All the dogs included (n = 82) were clinically examined, and fecal samples were examined for other parasites and Clostridium spp. Also, G. duodenalis assemblages were detected and the occurrence of certain clinical signs was assessed. A total of 42/82 (51.2%) dogs were symptomatic and had one or more gastrointestinal signs, and 40/82 (48.8%) dogs were asymptomatic. G. duodenalis was found in 25/82 (30.5%) dogs: assemblage C in 10/25 (40%) and assemblage D in 15/25 (60%). Only Cryptosporidium spp. showed a higher coinfection rate with G. duodenalis but that did not have an influence on clinical sign appearance. There was no correlation between the presence of different assemblages of G. duodenalis and the sex of the host or the duration and appearance of certain clinical signs, except the presence of mucus in feces, which was more frequent in dogs invaded with G. duodenalis assemblage C. Further research of other assemblages is needed.

[Feline and canine giardiosis: An Update]

Giardia duodenalis is a facultative pathogenic intestinal parasite. Giardiosis in dogs and cats may appear with or without clinical signs. Typical signs include diarrhea with or without vomiting. The prevalence in young animals is high and may amount to up to 50%. There are 8 different genotypes (A - H), which are called assemblages. Assemblages C and D are most common in dogs and assemblage F most frequent in cats. However, animals may also be infected with the zoonotically effective assemblages A and B or exhibit mixed infections. The immunofluorescence test (IFA), the enzyme-linked immunosorbent assay (ELISA) and fecal centrifugation using zinc sulphate solution are currently recommended as diagnostic methods. Polymerase chain reaction (PCR) may be used to determine the corresponding assemblage. Approved treatments for giardiosis include fenbendazole and metronidazole. In addition, undertaking specific hygiene measures is warranted. Only animals showing clinical signs or those living in the same household with high-risk patients (e. g. immunosuppressed humans) are recommended to receive medication. The aim of treatment is clinical improvement of the diseased dogs and cats. Frequently, complete elimination of Giardia is not attained.

The detection and phylogenetic characterization of Cryptosporidium, Cystoisospora, and Giardia duodenalis of cats in South Korea

Introduction

Cryptosporidium, Cystoisospora, and Giardia duodenalis are gastrointestinal protozoa parasites that cause diarrhea in various animals. However, information regarding the detection and phylogenetic characterization of gastrointestinal protozoa parasites in cats is limited throughout South Korea. Therefore, this study aimed to determine the detection and identify subspecies of gastrointestinal protozoa parasites in cats from South Korea.

Methods

A total of 290 fecal samples were collected from stray, companion, and shelter cats in six provinces. Cryptosporidium, Cystoisospora, and G. duodenalis were identified by PCR. All positive samples were subtyped by PCR and sequencing of gp60, ITS-1, tpi, bg, and gdh.

Results

The overall detection of gastrointestinal protozoan parasitic infection was 17.93%. G. duodenalis was the most prevalent, with 7.93%, followed by Cystoisospora spp. (7.24%) and Cryptosporidium spp. (4.48%). In addition, C. felis (n=10), C. parvum (n=2), C. ryanae (n=1), Cystoisospora felis (n=14), Cystoisospora suis (n=5), Cystoisospora ohioensis (n=1), Cystoisospora spp. were identified in subspecies analysis of positive samples. C. felis showed a significant association with diarrhea (7.81%) and living condition (6.04%), and Cystoisospora felis in diarreha (9.38%) according to detection. Through phylogenetic analysis of the tpi, bg, and gdh genes from 23 G. duodenalispositive samples, it was confirmed that the samples of present study belonged to assemblage A, B, C, and D.

Discussion

South Korean cats have a high rate of gastrointestinal protozoan parasites infection with cat-specific Cryptosporidium and Cystoisospora, which are associated with living conditions and diarrhea symptoms. Moreover, zoonotic and other animal-specific subtype of protozoan parasites have been detected in cat feces.

Epizootiology and biological characteristics of echinococcosis in agricultural animals, dogs, wild carnivores, and rodents in the Western region of the Republic of Kazakhstan

Background and Aim

Echinococcosis is one of the most dangerous parasitic diseases common to humans and animals. In Kazakhstan, echinococcosis is widespread in animals. This study aimed to estimate the prevalence and biological characteristics of echinococcosis in agricultural animals, dogs, wild carnivores, and rodents in the Western region of the Republic of Kazakhstan.

Materials and Methods

The study analyzed slaughtered carcasses of cattle (2500), sheep (4200), pigs (250), horses (91), and camels (45). Furthermore, the study analyzed 144 dogs (herding, rural, and urban), 41 wild carnivores (wolves, red foxes, and corsac foxes), and 339 wild rodents (great gerbils, tamarisk jirds, little ground squirrels, yellow ground squirrels, and muskrats). Postmortem and vital examination methods were used in the helminthological studies of dogs, wild carnivores, and rodents. In agricultural animals, localization and intensity were determined by counting echinococcal cysts in parenchymatous organs.

Results

Extensiveness of invasion (EI) averaged 19.2% in cattle, 27.5% in sheep, 5.6% in pigs, and 13.3% in camels. Echinococcal cysts mainly affected the liver in sheep (45.4%) and the lungs in cattle (35.5%). The fertility of echinococcal cysts decreased with age in animals. Acephalocysts were registered mainly in cattle. The highest invasiveness of Echinococcus granulosus was found in herding dogs with an EI of 12.5%. Experimental infestations of dogs showed that maturation of echinococcal eggs occurred by days 36-40 and maturation of segments by day 50. Studies of wild carnivores and rodents showed the presence of E. granulosus (imago stage) in wolves, Alveococcus multilocularis (imago stage) in red foxes and corsac foxes, and A. multilocularis (larval stage) in great gerbils and muskrats.

Conclusion

Our data provide evidence of high epizootiological danger for the population and significant damage caused by E. granulosus to animal husbandry in the region. Studies on the spread of echinococcosis suggest the possibility of controlling the situation with human and animal diseases and show the importance of this issue.

Microscopic and molecular diagnoses of Giardia duodenalis in pet animals in Babylon Province, Iraq

Background and Aim

The breeding of pet animals, especially dogs and cats, in Iraq has increased recently. However, no epidemiological or molecular data exist regarding Giardia duodenalis infection in pet animals, particularly in Babylon Province. Therefore, this study aimed to detect G. duodenalis and its genotypes in pets using microscopic and molecular techniques.

Materials and Methods

For microscopic examination, 150 pet fecal samples (dogs = 75, cats = 75) were examined from October 1, 2022, to March 30, 2023. Fourteen isolates of G. duodenalis (7 per host) were genetically characterized using SSUrDNA gene sequencing.

Results

Microscopic examination revealed that the rates of G. duodenalis infection was 14.67% (11/75) and 12% (9/75) in dogs and cats, respectively. According to sex, the infection rate in dogs was 22.22% (8/36) for males and 7.69% (3/39) for females. Conversely, the infection rate in cats was 5.56% (2/36) for males and 17.95% (7/39) for females. The highest infection rates were recorded for animals under 6 months of age, with 16.67% (3/18) for dogs and 27.27% (3/11) for cats. In rural areas, the infection rate was higher than that in urban areas, with 17.65% (6/34) in dogs and 13.89% (5/36) in cats. For the molecular diagnosis, 14 isolates of G. duodenalis (7 per host) were genetically characterized using SSUrDNA gene sequencing. In dogs, the findings revealed specific genotypes, with D at 3/7 (42.86%) and C at 2/7 (28.57%). In addition, zoonotic genotype A was found in 2/7 (28.57%) of dogs. In cats, the specific assemblage F was present in 4/7 (57.14%), while zoonotic genotype A was found in 3/7 (42.86%).

Conclusion

This study is considered the first in Babylon Province to detect G. duodenalis genotypes in pet animals (dogs and cats), as some have zoonotic genotypes that could transmit infections to humans. The results of this study illustrate the epidemiological importance of this parasite in this region.

Parasites and zoonotic bacteria in the feces of cats and dogs from animal shelters in Carinthia, Austria

Due to their close associations with humans, dogs and cats can be important reservoirs for zoonotic pathogens. In the current study 200 fecal samples of dogs (n = 70 samples) and cats (n = 130 samples) from animal shelters in Carinthia, southern Austria, were examined for the presence of parasites (fecal flotation and larval migration assay) and selected bacteria. Overall, 17.1% of the canine and 38.5% of the feline samples were positive for parasites (p < 0.001), most commonly Giardia duodenalis (dogs and cats), including potentially zoonotic genotypes revealed by multilocus genotyping, and Toxocara cati (cats). Cryptosporidium (C. felis), Cystoisospora spp. (dogs and cats), hookworms (dog), Trichuris (dog) Capillaria hepatica (cats), taeniids (cat), and Aelurostrongylus abstrusus (cat) were also found. Zoonotic bacteria were detected in 10.5% of the samples, Salmonella enterica (dogs), Campylobacter jejuni (dogs and cats) and Yersinia enterocolitica (cat) and were significantly associated with parasite infections in cats but not in dogs. Samples that were positive for several pathogens were common; especially G. duodenalis and T. cati were frequently found in association with each other, other parasites or bacteria. The spectrum of detected pathogens is comparable to that of other dog and cat populations in central Europe. However, since animals from shelters are frequently rehomed, diagnostic measures, appropriate hygiene and therapy as well as training of shelter staff are recommended to prevent zoonotic transmission of enteropathogens to staff or new owners. The presence of heteroxenic parasites, i.e. Aelurostrongylus abstrusus and Taenia taeniaeformis, and spurious excretion of Ca. hepatica in cats, indicates that these animals preyed on intermediate hosts, and that biosafety measures in pet shelters need to be evaluated for their efficacy in the prevention of pathogen transmission.

What is the role of Swiss domestic cats in environmental contamination with Echinococcus multilocularis eggs?

BACKGROUND

The role of the domestic cat as definitive host for Echinococcus multilocularis and thus in environmental contamination with eggs has not yet been entirely resolved. This study aimed to assess the prevalence of E. multilocularis and other gastrointestinal parasites in Swiss domestic cats and to compare the diagnostic sensitivity of different methods for the detection of intestinal taeniid infection.

METHODS

Faecal samples from 146 cats were included in the study. Faecal samples only were available from 55 cats; for the other 91 cats, necropsy was performed in addition to faecal sample testing. All (n = 146) faecal samples were analysed by a combined sedimentation/flotation technique (44% ZnCl2) and by the sodium acetate-acetic acid-formalin (SAF) sedimentation technique; when sufficient material was available (n = 121 samples) the Baermann-Wetzel technique was also used. Additionally, all samples were analysed by two coproantigen (copro)-quantitative PCRs (qPCR): (i) a multiplex qPCR able to detect and differentiate between E. multilocularis, Echinococcus granulosus sensu lato and Taenia spp./other cestodes (CEST-qPCR) and (ii) an E. multilocularis-specific qPCR (EM-qPCR). Finally, the intestines were examined macroscopically and microscopically for parasite stages at necropsy (n = 91) and using an intestinal scraping technique (IST) (n = 64).

RESULTS

Of the 146 cats examined, 24 (17.1%) were infected by intestinal parasites, namely Hydatigera (syn. Taenia) taeniaeformis (8.9%), Toxocara cati (6.1%), Capillaria sp. (3.4%), hookworms (3.4%), Mesocestoides litteratus (1.4%), Giardia sp. (1.4%), Cystoisospora rivolta (1.4%), Cystoisospora felis (0.7%), Toxoplasma gondii (0.7%), Hammondia hammondi (0.7%) and Strongyloides sp. (0.7%). Necropsy and the IST revealed adult H. taeniaeformis in 12 animals, of which eight faecal samples were positive by the CEST-qPCR (sensitivity = 67%) and six samples by the sedimentation/flotation technique (sensitivity = 50%). No E. multilocularis infection was detected in the sampled cats. Using Bayesian latent class analysis, the mean posterior prevalence probability was 0.0% (95% confidence interval 0-0.83%) for E. multilocularis.

CONCLUSIONS

There was no evidence of E. multilocularis infection among the 146 cats examined, suggesting that the prevalence of this parasite is low (< 1%) in the Swiss domestic cat population. Nonetheless, some of the sampled cats were infected by parasites that have rodents as intermediate hosts, demonstrating successful predation by these cats, and some were infected with zoonotic parasites. Cats therefore should not be disregarded as potential hosts for E. multilocularis and other zoonotic parasites.

Gastrointestinal parasites in young dogs and risk factors associated with infection

Young dogs are particularly susceptible to infections with endoparasites. The occurrence of endoparasites was investigated in young dogs from Central Germany between July 2020 and July 2022. In total, 386 fecal samples originating from 171 dogs were examined for the prevalence of endoparasites using a combined flotation- and sedimentation technique and conventional PCR. Overall, in 41.2% (159/386) of the examined samples, endoparasites were detected. The most frequently occurring endoparasites were Giardia duodenalis (29%), Cryptosporidium spp. (9.1%), Cystoisospora spp. (7.3%), and Toxocara canis (6%). Sequencing of G. duodenalis positive samples showed that most infections belonged to the host-specific assemblages C (38.4% (43/112)) and D (35.7% (40/112)). The zoonotic assemblage A was identified in 8% (9/112) of the samples. Moreover, mixed infections were observed as follows: C/D in 5 (4.5%), D/A in 4 (3.6%), and C/A in 3 (2.7%) samples. All assemblage A infections were assigned to the potentially zoonotic subassemblage AI. Co-infections of G. duodenalis and Cryptosporidium spp. were observed in 3.1% (12/386) of the samples. Analyzing several host factors for their potential association with endoparasitic infection, the origin of dogs, as well as the living environment were identified as the main risk factors for infection with endoparasites. Overall, this study shows a high infection rate with endoparasites, especially G. duodenalis, in young dogs from Germany. The results of this study contribute to further insight into the distribution and potential risk factors associated with endoparasitic infections, as well as the zoonotic potential these parasites may present.

Is there any change in the prevalence of intestinal or cardiopulmonary parasite infections in companion animals (dogs and cats) in Germany between 2004-2006 and 2015-2017? An assessment of the impact of the first ESCCAP guidelines

Main objective of the present nationwide study was to assess the impact of the ESCCAP guideline for the control of worm infections in dogs and cats 8-10 years after its first publication in Germany. A secondary aim was to determine the prevalence of canine and feline cardiopulmonary nematodes and intestinal protozoa. Faecal samples of 53,693 dogs and 26,491 cats in 2004-2006 as well as of 129,578 dogs and 45,709 cats in 2015-2017 routinely submitted by veterinarians to a private veterinary laboratory were examined using appropriate parasitological methods. In dogs, the prevalence of Toxocara and taeniid egg shedding was significantly lower in 2015-2017 (3.8 % and 0.16 %, respectively) than in 2004-2006 (4.6 % and 0.27 %, respectively). The prevalence of hookworm and Capillaria eggs was higher in the second study period (2.3 % and 0.77 %, respectively) than in the first (1.3 % and 0.6 %, respectively). For Toxascaris leonina (0.55-0.6 %) and Trichuris (0.8-0.9 %), the difference was not significant between the study periods. Dogs shed more often Angiostrongylus vasorum larvae in the second study (3.1 %) than in the first (1.0 %), whereas the prevalence of Crenosoma vulpis did not change significantly (2.2-2.6 %). Cystoisospora canis and C. ohioensis-like infections were less detected in the second study period (1.0 % and 2.1 %, respectively) than in the first (1.8 % and 2.7 %, respectively). Neospora-like oocysts and Sarcocystis sporocysts were more prevalent in the second study period (0.19 % and 0.13 %, respectively) than in the first (0.13 % and 0.06 %, respectively). The percentage of Giardia or Cryptosporidium coproantigen-positive samples was lower in the second study period (18.9 % and 6.7 %, respectively) than in the first (22.8 % and 10.0 %, respectively). In cats, the prevalence of egg shedding of T. cati, Capillaria and taeniids was significantly lower in 2015-2017 (3.5 %, 0.25 % and 0.1 %, respectively) than in 2004-2006 (4.8 %, 0.54 % and 0.22 %, respectively). No difference was recorded for hookworms (0.12-0.13 %) and Ts. leonina (0.04-0.05 %). Aelurostrongylus-like larvae were detected more often in the second study period (6.5 %) than in the first (2.6 %). Infections with Cystoisospora felis, C. rivolta, Toxoplasma-like coccids and Sarcocystis were less prevalent in the second study period (1.9 %, 0.7 %, 0.24 % and 0.02 %, respectively) than in the first (2.7 %, 1.1 %, 0.36 % and 0.1 %, respectively). The percentage of Giardia or Cryptosporidium coproantigen-positive samples was significantly lower in the second study period (10.6 % and 4.8 %, respectively) than in the first (15.4 % and 8.3 %, respectively). Although these results indicate a decline of the occurrence of most canine and feline intestinal parasites in Germany over the years, a transmission risk of zoonotic parasites remains. Therefore, the control of helminth infections in domestic dogs and cats continues to be a challenge for veterinarians and pet owners.

Lack of efficacy of fenbendazole against Giardia duodenalis in a naturally infected population of dogs in France

Giardiosis is a worldwide intestinal parasitosis, affecting both humans and animals. Treatment in dogs remains limited and the lack of efficacy of the few approved medications is a rising concern. In this study, 23 dogs raised by veterinary students and naturally infected with Giardia duodenalis were treated in home conditions with fenbendazole (50 mg/kg orally for 5 consecutive days). Fecal samples were collected immediately before treatment (FS1), 2-4 days after treatment (FS2) and 8-10 days after treatment (FS3). Giardia duodenalis cyst excretion was measured quantitatively by direct immunofluorescence assay (DFA) at FS1, FS2 and FS3. Molecular typing with a nested PCR targeting the SSU _rDNA locus was also performed at FS1 and FS2. Fecal consistency improved in 16/21 dogs (76%) and mean cyst shedding was reduced by 84% after treatment. However, only 8/23 dogs (35%) achieved therapeutic success (≥90% reduction of cysts) and only 4/23 dogs (17%) had complete elimination of G. duodenalis. Molecular typing showed that dogs harbored only canine-specific assemblages, with a high prevalence of assemblage C in analyzed samples (30/39). We also detected different assemblages after treatment and nucleotide substitutions in assemblage C sequences that have not been described previously. Eight to ten days after treatment, high Giardia cyst excretion was measured, suggesting possible reinfection despite hygiene measures and/or multiplication. These data suggest that fenbendazole treatment may improve fecal consistency but has limited therapeutic efficacy against giardiosis in this population of dogs. Further research is still needed to assess the efficacy of fenbendazole against canine giardiosis.

Prevalence, risk factors and zoonotic potential of intestinal parasites in dogs from four locations in Morocco

Dogs can harbor various intestinal parasites that have serious clinical, economic, and zoonotic impact. In Morocco, the epidemiological status of those parasites is largely unknown. This study aimed to obtain data on the prevalence of intestinal parasites in various Moroccan dog populations, to identify associated risk factors, to evaluate people's knowledge regarding zoonotic parasites and to estimate the risk of human infection. A total of 291 fecal samples were analyzed using a 33% Zinc Sulphate (ZnSO4) centrifugal flotation and a sheather's sugar simple flotation techniques. In addition, 100 dog owners were asked to fill out a questionnaire about their knowledge regarding canine zoonotic intestinal parasites. Overall, 58% of sampled dogs were positive for at least one parasite species. Ancylostoma/Uncinaria spp. (31.9%), Toxascaris leonina (27.4%), Toxocara canis (27.1%), Cystoisospora spp. (13.4%) and Giardia spp. (7.2%) were the most frequently isolated parasites. The overall prevalence was associated with the dogs' activity, and feces consistency. More specifically, the prevalence of Ancylostoma/Uncinaria spp., Toxascaris leonina and Cystoisospora spp. was associated with dogs' activity and feces consistency and, additionally with age for Cystoisosporaspp.Toxocara canis prevalence was associated with age and feces consistency, while Giardia spp. prevalence was associated with dogs' activity. A weak awareness among dog owners regarding the zoonotic potential of canine intestinal parasites was noticed (33%) especially when their knowledge was compared to another endemic zoonotic disease, i.e. rabies (85%). Furthermore, the rate of respecting the vaccination protocol (82%) was significantly higher than the rate of respecting the deworming protocol (47%). We conclude that intestinal parasites, including the zoonotic ones, were highly prevalent in the dogs sampled in this study whereas people's knowledge about those parasites was very limited. These findings suggest that the risk of human infection is very likely, which highlights the need for effective control programs and health education.

Evaluation for associations amongst Giardia duodenalis assemblages and diarrhea in dogs

Giardia duodenalis is a species complex comprising at least eight assemblages. Most dogs harbor the host-adapted assemblages C and D and approximately 30 % harbor the zoonotic assemblages. Humans and dogs with giardiosis can exhibit a variety of clinical manifestations ranging from the absence of clinical signs to acute or chronic diarrhea. Human studies report conflicting results concerning associations between clinical signs and assemblage type. The objective of this study was to use results of molecular and phylogenetic analyses to evaluate associations between G. duodenalis assemblages and diarrhea in client-owned dogs from the United States. Fecal samples that were positive for Giardia cysts were classified as normal or diarrheal. Samples were analyzed by PCR assays of the beta-giardin (bg), glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) genes. Sequences of the three genes were analyzed by BLAST analysis and phylogenetic analysis was performed by Neighbor-Joining analysis. Two hundred and eighty-eight Giardia-positive fecal samples were evaluated by the three PCRs. One or more genes were amplified from 95 normal samples and 93 diarrheal samples, 27 samples were positive for one or more genes but could not be sequenced due to low quality DNA, and 73 samples tested negative. Ninety seven percent of the samples (182/188) in both the diarrheal and normal groups typed as dog-specific assemblages (D or C) by at least one gene. Phylogenetic analysis of the three genes placed the isolates from assemblages A, B, C and D separated from each other with strong bootstrap support. Diarrhea was not associated with the Giardia assemblage or other parasitic co-infection in this sample set. Other factors, such as the role of gut microbiota in giardiosis should be considered in future studies.

Giardia duodenalis in colony stray cats from Italy

Giardia duodenalis is the most common intestinal protozoan in humans and animals worldwide, including eight morphologically identical assemblages, infecting pets, livestock, wildlife and human beings. Assemblages A and B are those with the higher zoonotic potential, and they have been detected in several mammals other than humans; the others (C to H) show a higher host specificity. Cats can harbour both the specific Assemblage F and the zoonotic ones A and B. Several studies have been carried out on G. duodenalis genotypes in cats; however, the role of this species in the epidemiology of giardiasis is still poorly understood. In this scenario, the present study carried out the detection and genetic characterization at sub‐assemblage level of G. duodenalis from colony stray cats in central Italy. In the period 2018–2019, 133 cat faecal samples were analysed for the presence of G. duodenalis cysts by a direct immunofluorescence assay. Positive samples were subsequently subjected to molecular analyses for assemblage/sub‐assemblage identification. Forty‐seven samples (35.3%) were positive for G. duodenalis cysts by immunofluorescence. G. duodenalis DNA was amplified at SSU‐rDNA locus from 39 isolates: 37 were positive for zoonotic Assemblage A and 2 showed a mixed infection (A + B). Positive results for the β‐giardin gene were achieved for 25 isolates. Sequence analysis revealed 16 isolates belonging to Sub‐assemblage AII and 8 to Sub‐assemblage AIII. One isolate resulted as ambiguous AI/AIII. Large sequence variability at the sub‐assemblage level was detected, with several double peaks and mutations, making complex a proper isolate allocation. When compared with previous studies, the 35.3% prevalence of G. duodenalis in cats reported in the present article was surprisingly high. Moreover, all positive cats resulted to be infected with zoonotic assemblages/sub‐assemblages, thus indicating stray cats as a possible source of human giardiasis and highlighting the sanitary relevance of cat colonies in the study area.

Detection and identification of Giardia species using real-time PCR and sequencing

We report a specific region of Giardia spp. 18S ribosomal RNA (18S rDNA) that serves as an ideal target for quantitative PCR (qPCR) detection and sequencing to identify Giardia species, including the clinically-relevant G. duodenalis, in clinical and environmental samples. The presence of multiple copies of the 18S rDNA gene and variations in the selected 18S genomic region enabled the development of a rapid, sensitive qPCR screening method for the detection of Giardia spp. The analytical sensitivity of the Giardia qPCR assay was determined to be a cyst equivalent of 0.4 G. duodenalis cysts per PCR reaction. Amplicon sequencing of the PCR product confirmed Giardia spp. detection and among the 35 sequences obtained, 31, 3 and 1 isolates were classified as belonging to G. duodenalis, G. microti and G. muris, respectively. The TaqMan assay reported here may be useful for the detection of low levels of Giardia in clinical and environmental samples, and further enables the effective use of direct sequencing of the PCR product for Giardia confirmation and to identify major species of Giardia, including G. duodenalis.

The occurence of endoparasites in Slovakian household dogs and cats

Pets play a pivotal role as definitive or reservoir hosts for many zoonotic parasites. Dogs and cats without any clinical signs may be a carrier for the infection. In a one-year study, collected fecal samples of 257 dogs and 50 cats were examined coproscopically for endoparasite infections. Out of 307 investigated fecal samples, 107 (34.9%) were positive for the presence of the propagative stages of endoparasites In 257 dogs fecal samples, following 12 different species of endoparasites were detected: Giardia duodenalis, Cystoisospora spp., Sarcocystis spp., Hammondia/Neospora-like eggs, Angiostrongylus vasorum larvae, Capillaria aerophila, Crenosoma vulpis, Toxocara spp., Toxascaris leonina, Trichuris vulpis, Strongyloides stercoralis, and eggs from the family Ancylostomatidae. Only 4 different parasitic species were found in 50 domestic cat fecal samples - G. duodenalis cysts Cystoisospora spp., T. cati, and larvae of Aelurostrongylus abstrusus. It was confirmed that significant differences were found concerning age for G. duodenalis, T. canis, S. stercoralis, and family Ancylostomatidae. Close and frequent contact between pets and people increases the risks for the transmission of zoonotic diseases.

Molecular detection of Giardia duodenalis and Cryptosporidium spp. from stray dogs residing in monasteries in Bangkok, Thailand

Both Cryptosporidium spp. and Giardia duodenalis are enteric protozoan parasites that infect a wide variety of domestic animals as well as humans worldwide, causing diarrheal diseases. Giardia duodenalis assemblages C and D are specific to canine hosts and zoonotic assemblages A and B are also found in dogs as a reservoir host. In dogs, Cryptosporidium canis is the host-specific species while humans are infected by C. hominis and C. parvum and at least another 16 zoonotic Cryptosporidium species have been reported causing human infections, with C. meleagridis, C. viatorum, and C. ubiquitum being the most frequent. The objective of this study was to determine the prevalence of Cryptosporidium spp. and G. duodenalis from stray dogs in areas of Bangkok and to identify the species and assemblages. Fecal samples (540) were collected from dogs residing in 95 monasteries in 48 districts in the Bangkok metropolitan area. Nested Polymerase Chain Reaction (PCR) was performed using the ssu-rRNA gene for both parasites. In total, 3.0% (16/540) samples were positive for G. duodenalis, with most being G. duodenalis assemblage D (7/16) followed by assemblage C (7/16) and zoonotic assemblage A (2/16). The prevalence of Cryptosporidium spp. was 0.7% (4/540) based on the PCR results and all were the dog genotype C. canis. These results indicated that dogs residing in Bangkok monasteries poses a limited role as source of human giardiosis and cryptosporidiosis.

Infection rate and genetic diversity of Giardia duodenalis assemblage C in Iranian stray dogs, targeting the glutamate dehydrogenase gene

Background and Aim

Giardia duodenalis is one of the most common enteric protozoan parasites in vertebrates, such as humans, domestic and wild animals, causing giardiasis. To the best of our knowledge, little is known about the genetic diversity of G. duodenalis assemblages. This study aimed to identify genetic diversity of G. duodenalis assemblages in Iranian stray dogs.

Materials and Methods

A total of 450 fecal samples were collected from 2015 to 2016 from stray dogs of Northwest Iran. All specimens were observed microscopically following concentration and flotation techniques. Subsequently, DNA samples were extracted, amplified, and sequenced targeting the glutamate dehydrogenase gene.

Results

The overall prevalence of G. duodenalis in infected dogs was estimated at 1.6%, based on microscopic and molecular diagnoses. Sequencing and phylogenetic analyses indicated a high level of genetic diversity of assemblage C (haplotype diversity; 0.802).

Conclusion

The pairwise sequence distances between the identified isolates of assemblage C showed an intradiversity of 0.3%-1.3% and identity of 98.7%-100%. Current findings indicate that a significant genetic diversity of G. duodenalis assemblage C haplotypes is unequivocally circulates among stray dogs in Northwest Iran.

FELINE GIARDIASIS IN TURKEY: PREVALENCE AND GENETIC AND HAPLOTYPE DIVERSITY OF GIARDIA DUODENALIS BASED ON THE β-GIARDIN GENE SEQUENCE IN SYMPTOMATIC CATS

Giardia duodenalis is a common zoonotic protozoan parasite with a broad host distribution. The main objectives of the present study were to determine the prevalence of giardiasis and to reveal the genetic and haplotype diversity of G. duodenalis in symptomatic cats in Turkey. Fecal samples were collected from cats (n = 102) with diarrhea that were admitted to different pet clinics in the Central Anatolia region of Turkey. All samples were analyzed by microscopic examination (ME), rapid immunochromatographic test (ICT), and PCR targeting the β-giardin (bg) loci of the parasite. Phylogenetic, haplotype, and network analyses of G. duodenalis based on the bg gene were carried out. Overall, G. duodenalis was detected in 70/102 (68.6%) of the cats with diarrhea by ME (38/102, 37.3%), ICT (51/102, 50%), and PCR (30/102, 29.4%). According to sequence analyses of the bg gene region, all isolates were identified as G. duodenalis assemblage B. Haplotype analyses revealed 2 known and 8 novel haplotypes for G. duodenalis assemblage B. This study provides first prevalence and genetic and haplotype diversity data on G. duodenalis assemblage B from cats in Turkey.

Anti-Giardia Drug Discovery: Current Status and Gut Feelings

Giardia parasites are ubiquitous protozoans of global importance that impact a wide range of animals including humans. They are the most common enteric pathogen of cats and dogs in developed countries and infect ∼1 billion people worldwide. While Giardia infections can be asymptomatic, they often result in severe and chronic diseases. There is also mounting evidence that they are linked to postinfection disorders. Despite growing evidence of the widespread morbidity associated with Giardia infections, current treatment options are limited to compound classes with broad antimicrobial activity. Frontline anti-Giardia drugs are also associated with increasing drug resistance and treatment failures. To improve the health and well-being of millions, new selective anti-Giardia drugs are needed alongside improved health education initiatives. Here we discuss current treatment options together with recent advances and gaps in drug discovery. We also propose criteria to guide the discovery of new anti-Giardia compounds.

Demystifying and Demonstrating the Value of a One Health Approach to Parasitological Challenges

The One Health approach recognizes the interconnectedness of human, animal, and ecosystem health and encourages collaboration between diverse disciplines to address complex health problems. In this paper, 3 academics, with diverse training, experience and backgrounds who each work on different pathogenic parasites, will share their stories of tackling parasitic challenges by applying a One Health approach. The pathogenic parasites to be discussed include the helminth Taenia solium and protozoans Giardia, Theileria, Babesia, Neospora and Toxoplasma species. The 3 narratives focus on research and clinical case-based challenges and illustrate where collaboration between human, animal, and environmental health scientists either has or could lead to improved control of human and animal health as well as important research discoveries. The need for better evaluation of interventions and scientific evidence to support changes in clinical practice and encourage enhanced collaboration between human and veterinary clinicians, as well as new governmental policies to improve public and wildlife health, are described. The need for a range of evidence-based metrics to monitor the success and impact of the One Health approach to veterinary parasitology is also discussed.

Prevalence and molecular characterization of Giardia duodenalis in dogs in Israel

Three hundred and two stool samples were collected from municipal shelters and owned dogs in different geographical locations in Israel from December 2016 to September 2017 and examined for Giardia and assemblage type by PCR targeting the 18S rRNA and β-giardin genes. Overall Giardia prevalence was 24.5 % (74/30). Giardia prevalence was 1.9-fold higher in dogs ≤ 6 months old compared to > 6 ≤ 12 months old and older dogs [25/61 (41 %), 18/73 (24.6 %) and 31/166 (18.7 %), respectively, (p = 0.001)], 2.3-fold higher in winter [32/90 (35.5 %)] compared to its prevalence during autumn [15/60 (25 %)], spring [10/62 (16.1 %)] and summer [17/89 (19.1 %), p = 0.003)], and 2.7-fold more frequent among diarrheic dogs [23/43 (53.4 %)] compared to those with formed stools [51/253 (20.1 %)], (p = 0.001)]. The Giardia sp. assemblages detected were C and D. Higher infection rates in young, diarrheic dogs, sampled during winter, and housed in municipal shelters, indicates the need for targeted preventive measures.

Companion animals as a potential source of Giardia intestinalis infection in humans in the Czech Republic - A pilot study

Giardia intestinalis is a common enteric single-celled parasite infecting both humans and animals. Its eight morphologically identical but genetically distinct groups called assemblages differ from each other in host range. While assemblages A and B infect a wide range of hosts, including humans, the other assemblages (C to H) limit their host preferences to particular animal groups only. In companion animals as Giardia hosts, genotyping data have previously shown various results depending on pet species, location, environmental or breeding conditions, and the study design. To strengthen available epidemiological data from developed countries and to evaluate the role of pets in Giardia zoonotic transmission, we investigated Giardia-positive stool samples of three pet species (54 dogs, 18 cats, and 18 chinchillas) by a sequence-based analysis of three Giardia genes (β-giardin, glutamate dehydrogenase and triose phosphate isomerase). In dog samples, we confirmed assemblage C (21/54), assemblage D (32/54), and one case of a mixed infection C + D (1/54). In cats, we found assemblage F (16/18) and assemblage A, specifically sub-assemblage AI (2/18). All Giardia samples from chinchillas were characterised as assemblage B, specifically sub-assemblage BIV (18/18). These results indicate that in the Czech Republic, pet dogs may not represent a source of Giardia infection for humans because of the presence of only canid-specific genotypes C and D. In contrast, other pets, namely, chinchillas and, to a lesser extent, cats, may pose a potential risk of Giardia transmission to owners or breeders because they can host zoonotic Giardia genotypes.

Whole-genome sequencing of dog-specific assemblages C and D of Giardia duodenalis from single and pooled cysts indicates host-associated genes

Giardia duodenalis (syn. Giardia intestinalis or Giardia lamblia) infSAects over 280 million people each year and numerous animals. G. duodenalis can be subdivided into eight assemblages with different host specificity. Unculturable assemblages have so far resisted genome sequencing efforts. In this study, we isolated single and pooled cysts of assemblages C and D from dog faeces by FACS, and sequenced them using multiple displacement amplification and Illumina paired-end sequencing. The genomes of assemblages C and D were compared with genomes of assemblages A and B from humans and assemblage E from ruminants and pigs. The genomes obtained from the pooled cysts and from the single cysts were considered complete (>99 % marker genes observed) and the allelic sequence heterozygosity (ASH) values of assemblages C and D were 0.89 and 0.74 %, respectively. These ASH values were slightly higher than for assemblage B (>0.43 %) and much higher than for assemblages A and E, which ranged from 0.002 to 0.037 %. The flavohaemoglobin and 4Fe-4S binding domain family encoding genes involved in O₂ and NO detoxification were only present in assemblages A, B and E. Cathepsin B orthologs were found in all genomes. Six clades of cathepsin B orthologs contained one gene of each genome, while in three clades not all assemblages were represented. We conclude that whole-genome sequencing from a single Giardia cyst results in complete draft genomes, making the genomes of unculturable Giardia assemblages accessible. Observed differences between the genomes of assemblages C and D on one hand and the assemblages A, B and E on the other hand are possibly associated with host specificity.

Identifying human enteric parasitic infections in Greece, with focus on Giardia and Cryptosporidium

A study was conducted in two different areas in Greece to investigate the presence of intestinal human parasitic infections (targeting healthy and individuals with diarrhoea). In total, 876 stool samples were collected from 822 adults and 54 children. Both sedimentation (acid/ether) and concentration/flotation techniques were performed in all samples to detect intestinal parasites. Additionally, a quantitative direct immunofluorescence assay was used specifically for the detection of Giardia and Cryptosporidium. PCR followed by sequencing was applied to genotype Giardia and Cryptosporidium positive samples. Thirty-five (4%) of the individuals examined harboured at least one species of intestinal parasite, the majority of which were protozoa (3.8%). The species found were Blastocystis hominis (1.8%), Giardia duodenalis (1.3%), Cryptosporidium spp. (0.6%), Entamoeba coli (0.2%) and E. histolytica/E. dispar (0.1%). Two persons were positive for Enterobius vermicularis. Genotyping results revealed the presence of G. duodenalis sub-assemblage AII, whereas sequencing was not successful for Cryptosporidium positive samples. A novel multi-locus genotype of G. duodenalis was identified, which has not been described in humans or animals previously. Overall, in the studied population, infection rates with intestinal parasites were low and similar to previous published data. As infection levels were low, no associations could be made between infection status and clinical relevance, risk factors or indication of potential sources of infection, apart from the fact that infections with Giardia were positively correlated to diarrhoea. Based on the parasite species and genotypes detected, there was no indication that animals were an important source of infection. Thus, it is suggested that Giardia infections were more likely to be acquired via human-to-human transmission, either involving indirect pathways such as contaminated food or water, or via direct contact.

The Prevalence and Assemblages of Giardia Duodenalis in Dogs: A Systematic Review in Europe

Giardiasis is one of the most frequent causes of diarrhoeic diseases in the world. Giardia cysts are most commonly transferred via ingestion of contaminated water or food. On the basis of genetic characteristics Giardia duodenalis is classified in eight assemblages A—H. Zoonotic assemblages A and B are increasingly found in isolates from dogs which may constitute the reservoir of human giardiasis. This article presents a brief review of G. duodenalis assemblages detected in dogs that were documented in European countries.

Molecular epidemiology of giardiasis from a veterinary perspective

A total of eight Giardia species are accepted. These include: Giardia duodenalis (syn. Giardia intestinalis and Giardia lamblia), which infects humans and animals, Giardia agilis, Giardia ardeae, Giardia psittaci, Giardia muris, Giardia microti, Giardia peramelis and G. cricetidarum, which infect non-human hosts including amphibians, birds, rodents and marsupials. Giardia duodenalis is a species complex consisting of eight assemblages (A-H), with assemblages A and B the dominant assemblages in humans. Molecular studies to date on the zoonotic potential of Giardia in animals are problematic and are hampered by lack of concordance between loci. Livestock (cattle, sheep, goats and pigs) are predominantly infected with G. duodenalis assemblage E, which has recently been shown to be zoonotic, followed by assemblage A. In cats and dogs, assemblages A, B, C, D and F are commonly reported but relatively few studies have conducted molecular typing of humans and their pets and the results are contradictory with some studies support zoonotic transmission but the majority of studies suggesting separate transmission cycles. Giardia also infects a broad range of wildlife hosts and although much less well studied, host-adapted species as well as G. duodenalis assemblages (A-H) have been identified. Fish and other aquatic wildlife represent a source of infection for humans with Giardia via water contamination and/or consumption of undercooked fish and interestingly, assemblage B and A predominated in the two molecular studies conducted to date. Our current knowledge of the transmission dynamics of Giardia is still poor and the development of more discriminatory typing tools such as whole genome sequencing (WGS) of Giardia isolates is therefore essential.

Prevalence and genetic characterization of Giardia spp. and Cryptosporidium spp. in dogs in Iqaluit, Nunavut, Canada

There are few epidemiologic studies on the role of dogs in zoonotic parasitic transmission in the Circumpolar North. The objectives of this study were to: (a) estimate the faecal prevalence of Giardia spp. and Cryptosporidium spp. in dogs; (b) investigate potential associations between the type of dog population and the faecal presence of Giardia spp. and Cryptosporidium spp.; and (c) describe the molecular characteristics of Giardia spp. and Cryptosporidium spp. in dogs in Iqaluit, Nunavut. We conducted two cross-sectional studies in July and September 2016. In July, the team collected daily faecal samples for 3 days from each of 20 sled dogs. In September, the team collected three faecal samples from each of 59 sled dogs, 111 samples from shelter dogs and 104 from community dogs. We analysed faecal samples for the presence of Giardia spp. and Cryptosporidium spp. using rapid immunoassay and flotation techniques. Polymerase chain reaction (PCR) and sequencing of target genes were performed on positive faecal samples. Overall, the faecal prevalence of at least one of the target parasites, when one faecal sample was chosen at random for all dogs, was 8.16% (CI: 5.52-11.92), and for Giardia spp. and Cryptosporidium spp., prevalence was 4.42% (CI: 2.58-7.49) and 6.12% (CI: 3.88-9.53), respectively. The odds of faecal Giardia spp. in sled dogs were significantly higher than those in shelter and community dogs (OR 10.19 [CI: 1.16-89.35]). Sequence analysis revealed that 6 faecal samples were Giardia intestinalis, zoonotic assemblage B (n = 2) and species-specific assemblages D (n = 3) and E (n = 1), and five faecal samples were Cryptosporidium canis. Giardia intestinalis is zoonotic; however, Cryptosporidium canis is rare in humans and, when present, usually occurs in immunosuppressed individuals. Dogs may be a potential source of zoonotic Giardia intestinalis assemblage B infections in residents in Iqaluit, Nunavut, Canada; however, the direction of transmission is unclear.

One-year parasitological screening of stray dogs and cats in County Dublin, Ireland

To date, there are no recent studies identifying the prevalence of parasites of human and veterinary importance in dogs and cats in Ireland. The interaction between pets and wildlife species in the environment is an important source of parasite exposure to canids and felines, and one likely to be heightened in the stray animal population. This study aimed to establish the prevalence of endoparasites in unowned dogs and cats in County Dublin, Ireland. Feces from stray dogs (n= 627) and cats (n= 289) entering a rehoming centre were collected immediately after defecation. The main parasitic agents detected were ascarids (15.52 and 30.26%),Cystoisospora(3.27 and 3.69%),Giardiaspp. (6.02 and 1.84%) and lungworms (0.64 and 2.08%), in dogs and cats respectively. Animals younger than 3 months of age were more likely to be infected with ascarids (P< 0.001) andCystoisosporaspp. (P= 0.008 andP= 0.014) than older animals. All lungworms were morphologically identified and dogs were infected withAngiostrongylus vasorum(0.48%) andCrenosoma vulpis(0.16%) whereas cats were only infected withAelurostrongylus abstrusus(2.08%). This represents the first prevalence study of stray animals in Ireland. Data collected will inform the treatment and in addition, the future monitoring and control studies of parasite populations.

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

Giardia lamblia is a worldwide zoonotic intestinal parasite that infects humans and a wide range of mammals including dogs and cats, causing giardiasis with diarrhea. To investigate the infection and distribution of G. lamblia genotypes from stray dogs and cats in Guangdong, China according to different districts, gender and ages, fecal samples were collected and examined by microscopy, and all isolates were genotyped by PCR amplification using beta-giardin (bg) and triose phosphate isomerase (tpi) genes as molecular markers. The results showed that the prevalence of dogs and cats was 10.8% (57/527) and 5.8% (6/104), respectively. Sixty-one samples were detected by microscopy and 63 were amplified and successfully sequenced by the PCR. Based on the phylogenetic analysis, 25 canine isolates (24 assemblages AI and 1 assemblage D) were genotyped by tpi gene and 57 canine isolates (26 assemblages AI, 18 assemblages C and 13 assemblages D) genotyped by bg gene; 6 feline isolates were identified as assemblage AI by tpi gene, and as 3 assemblages AI and 3 assemblages F by bg gene. The dominant genotypes were assemblage AI in younger dogs (assemblage C in adult dogs) and assemblage C in male dogs (assemblage AI in female dogs). Mixed genotype infections were found in different age and gender groups. The results indicated that G. lamblia from stray dogs and cats in Guangdong province had a zoonotic potential with assemblage AI as the prevalent genotype. The different risk factors (age and sex) may have an impact on the infection of different genotypes.

Occurrence and molecular epidemiology of Giardia duodenalis infection in dog populations in eastern Spain

Background

Giardia duodenalis is one of the most common enteric parasites in domestic animals including dogs. Young animals are more prone to the infection, with clinical manifestations ranging from asymptomatic to acute or chronic diarrhoea. Dogs are primarily infected by canine-specific (C-D) assemblages of G. duodenalis. However, zoonotic assemblages A and B have been increasingly documented in canine isolates, raising the question of whether and to which extent dogs can act as natural reservoirs of human giardiosis.

Methods

In this cross-sectional epidemiological survey we assessed the molecular diversity of G. duodenalis in dogs in the province of Castellón, Eastern Spain. A total of 348 individual faecal samples from sheltered (n = 218), breeding (n = 24), hunting (n = 68), shepherd (n = 24), and pet (n = 14) dogs were collected between 2014 and 2016. Detection of G. duodenalis cysts in faecal material was carried out by direct fluorescence microscopy as a screening test, whereas a qPCR targeting the small subunit ribosomal RNA gene of the parasite was subsequently used as a confirmatory method.

Results

Giardia duodenalis was detected in 36.5% (95% CI: 31.6–41.7%) of dogs. No significant differences in prevalence rates could be demonstrated among dogs according to their sex and geographical origin, but breeding (45.8%; 95% CI: 27.9–64.9%) and sheltered (40.4%; 95% CI: 34.1–47.0%) dogs harboured significantly higher proportions of G. duodenalis. Multi-locus sequence-based genotyping of the glutamate dehydrogenase and β-giardin genes of G. duodenalis allowed the characterization of 35 canine isolates that were unambiguously assigned to assemblages A (14.3%), B (22.9%), C (5.7%), and D (37.1%). A number of inter-assemblage mixed infections including A + B (11.4%), A + D (2.9%), and A + B + D (5.7%) were also identified.

Conclusions

Data presented here are strongly indicative of high infection pressures in kennelled animals. Zoonotic sub-assemblages AII, BIII, and BIV were responsible for a considerable proportion of the G. duodenalis infections detected, but very few of the genotypes identified have been previously documented in Spanish human populations. Although possible, zoonotic transmission between dogs and humans seems an infrequent event in this Spanish region.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1353-z) contains supplementary material, which is available to authorized users.

Survey of intestinal parasitism in dogs in the Phoenix metropolitan area

OBJECTIVE To determine the prevalence of selected intestinal parasites in pet dogs and recently apprehended free-roaming (AFR) shelter dogs in the Phoenix metropolitan area and compare those prevalences between the 2 groups. DESIGN Cross-sectional study. SAMPLE Convenience samples of fecal specimens from owned pet dogs from the Phoenix metropolitan area (n = 175) and free-roaming dogs apprehended and admitted to Maricopa County Animal Care and Control and Arizona Humane Society facilities from November 2014 through March 2015 (188). PROCEDURES Fresh fecal specimens were collected from all dogs; for AFR shelter dogs, specimens were collected within 72 hours after facility admission. Standard centrifugal flotation tests and an ELISA were performed to detect 5 common intestinal parasites (roundworms, hookworms, whipworms, Giardia spp, and Cystoisospora spp). Group comparisons were performed by means of the χ² test and Rogan-Gladen prevalence estimate. RESULTS At least 1 of the 5 evaluated parasites was detected in 85 (45.2%) fecal specimens from AFR shelter dogs and 24 (13.7%) specimens from owned pet dogs. This prevalence differed significantly between the groups. Notably, the prevalence of Giardia spp in AFR shelter dogs (n = 76 [40.4%]) was higher than previously reported in the United States. CONCLUSIONS AND CLINICAL RELEVANCE The prevalence of the evaluated intestinal parasites, particularly of Giardia spp, in AFR shelter dogs was higher than expected. This information is important for veterinarians, animal shelter personnel, pet owners, human health-care providers, and public health officials to consider when devising effective interventions and risk communication efforts against potential zoonotic threats, particularly those relevant to the Phoenix metropolitan area.

Multilocus genotyping of Giardia duodenalis isolates from breeding cattery cats in Japan

Objectives

The present study reports the multilocus genotyping of Giardia duodenalis isolates from cats maintained in breeding catteries in Japan and discusses their potential for zoonotic transmission.

Methods

A total of 41 faecal samples positive for Giardia-specific antigen were procured from cats maintained in five breeding catteries and subjected to PCR to amplify four gene loci, namely small subunit ribosomal RNA (SSU rRNA), glutamate dehydrogenase (gdh), beta-giardin (bg) and triose phosphate isomerase (tpi ). The PCR-amplified DNA fragments were sequenced to determine the G duodenalis genotypes (synonym for assemblages).

Results

The most commonly occurring single assemblage was assemblage F (68.3%; n = 28/41), followed by assemblage A (12.2%; n = 5/41) and assemblage C (2.4%; n = 1/41). The mixed assemblages were identified as follows: assemblages F and A (9.8%; n = 4/41), assemblages F and C (4.9%; n = 2/41) and assemblages C and D (2.4%; n = 1/41). Additional sub-genotyping of assemblage A isolates based on three of the sequenced loci (gdh, bg and tpi ) revealed that all eight isolates were identified as sub-assemblage AI and/or AII.

Conclusions and relevance

The present study is the first to report the detection of dog-adapted assemblages C and D in feline isolates from Japan. In addition, zoonotic sub-assemblage AI and human-adapted sub-assemblage AII were also identified. Thus, we concluded that the risk of transmission of G duodenalis from breeding cattery cats to humans is considerable and cannot be ignored.

Prevalence, genotyping and risk factors of Giardia duodenalis from dogs in Vietnam

This study was carried out to determine the prevalence, genotypes/assemblages and possible risk factors associated with Giardia duodenalis infection in dogs in central Vietnam. A total of 209 dog fecal samples, randomly collected from private owned dogs (n=105) and dogs from stores (n=104), were examined for Giardia cysts by microscopy. Positive samples were genotyped by PCR-sequence analysis of β-giardin and triosephosphate isomerase genes markers. Risk factors were studied using a structured questionnaire and collected data were analyzed by univariate and multivariate logistic regression analyses. Results indicated that the overall infection rate was 8.6% (18/209) with the detected parasites were belonging to the non-zoonotic assemblages C and D. Age, gender and origin of animals were the main risk factors associated with G. duodenalis infection in dogs under study. Occurrence of infection was more likely in young animals compared to old ones and in females compared to males. Dogs originated from stores were more prone to Giardia infection compared to private owned counterparts.

Prevalence of Selected Zoonotic and Vector-Borne Agents in Dogs and Cats on the Pine Ridge Reservation

The prevalence of intestinal parasites and vector-borne agents of dogs and cats in the Pine Ridge Reservation, South Dakota were determined. Fecal samples (84 dogs, 9 cats) were examined by centrifugal floatation and by immunofluorescence assay (FA) for Giardia and Cryptosporidium. PCR was performed on Giardia [beta-giardin (bg), triose phosphate isomerase (tpi), glutamate dehydrogenase genes (gdh)] and Cryptosporidium [heat shock protein-70 gene (hsp)] FA positive samples. Cat sera (n = 32) were tested for antibodies against Bartonella spp., Toxoplasma gondii, and FIV, and antigens of FeLV and Dirofilaria immitis. Dog sera (n = 82) were tested for antibodies against T. gondii, Borrelia burgdorferi, Ehrlichia canis, and Anaplasma phagocytophilum and D. immitis antigen. Blood samples (92 dogs, 39 cats) were assessed by PCR for amplification of DNA of Bartonella spp., Ehrlichia spp., Anaplasma spp., haemoplasmas, and Babesia spp. (dogs only). The most significant results were Giardia spp. (32% by FA), Taenia spp. (17.8%) and Cryptosporidium spp. (7.1%). The Giardia isolates typed as the dog-specific assemblages C or D and four Cryptosporidium isolates typed as C. canis. Antibodies against T. gondii were detected in 15% of the dogs. Antibodies against Bartonella spp. and against T. gondii were detected in 37.5% and 6% of the cats respectively. FeLV antigen was detected in 10% of the cats.

No molecular epidemiological evidence supporting household transmission of zoonotic Giardia duodenalis and Cryptosporidium spp. from pet dogs and cats in the province of Álava, Northern Spain

The role of pet dogs and cats as suitable source of human infections by the diarrheagenic protozoan parasites Giardia duodenalis and Cryptosporidium spp. has been a topic of intense debate for long time and still remains a largely unsolved problem. In this cross-sectional molecular epidemiological survey we attempted to investigate whether zoonotic (or zooanthroponotic) disease transmission was occurring among humans and domestic dogs and cats sharing the same spatial and temporal setting in both rural and urban areas of the province of Álava, Northern Spain. A total of 268 (including 179 human, 55 canine, and 34 feline) individual faecal specimens were obtained from 63 family households during February-March and November-December 2014. Detection of G. duodenalis cysts and Cryptosporidium spp. oocysts was achieved by direct fluorescence microscopy (DFAT) and PCR-based methods targeting the small subunit (SSU) ribosomal RNA gene of the parasites. Giardia-positive isolates were subsequently sub-genotyped at the glutamate dehydrogenase (GDH) and β-giardin (BG) genes. Overall, G. duodenalis infections were identified in 3.4% (6/179) of humans, 29% (16/55) of dogs, and 5.9% (2/34) of cats, respectively. Cryptosporidium spp. infections were detected in 1.1% (2/179) of humans, 5.5% (3/55) of dogs, and 8.8% (3/34) of cats, respectively. Simultaneous infections in human and canine/feline hosts by G. duodenalis or Cryptosporidium spp. were only demonstrated in a single household in which a cat and its owner tested positive for Cryptosporidium by DFAT, but this result could not be confirmed by SSU-PCR. Infections were homogeneously distributed among the studied human or animal populations irrespectively of their sex, age group, or geographical region of origin. Inadequate washing of raw vegetables and fruits was the only risk factor significantly associated to a higher likelihood of having human giardiosis/cryptosporidiosis. Molecular characterization of G. duodenalis isolates revealed the presence of sub-assemblage BIV in a single human isolate. All dog (n=3) and cat (n=2) isolates successfully genotyped were assigned to canine- and feline-specific assemblages C and F, respectively. No mixed assemblage or sub-assemblage infections could be demonstrated. Regarding Cryptosporidium, C. canis was found infecting dogs (n=2), and C. felis a single cat. Attempts to amplify and characterize Cryptosporidium human isolates failed repeatedly. Our results suggest that pet dogs and cats do not seem to play a significant role as suitable reservoirs of human giardiosis or cryptosporidiosis in the province of Álava. We conclude, therefore, that zoonotic transmission of giardiosis or cryptosporidiosis among pet dogs and cats and their owners in this geographical region is very likely a rare event.

Abundance, zoonotic potential and risk factors of intestinal parasitism amongst dog and cat populations: The scenario of Crete, Greece

Background

The objectives of this study were to evaluate the prevalence and infection intensity of intestinal parasites in different dog and cat populations in Crete, Greece, estimate the zoonotic risk and identify risk factors.

Methods

Faecal samples from shelter, household and shepherd dogs and shelter and household cats were analyzed using sedimentation/flotation techniques. Giardia and Cryptosporidium were detected by a quantitative direct immunofluorescence assay (IFA). PCR and sequencing was performed to evaluate the zoonotic potential of Giardia and Cryptosporidium positive samples.

Results

Totals of 879 dog and 264 cat faecal samples were examined. In dogs, the overall prevalence was 25.2% (CI: 22.4–28.1) for Giardia spp.; 9.2% (CI: 7.3–11.1) for Ancylostoma/Uncinaria spp.; 7.6% (CI: 5.9–9.4) for Toxocara spp.; 5.9% (CI: 4.4–7.5) for Cryptosporidium spp.; 4.6% (CI: 3.2–5.9) for Cystoisospora spp.; 2.7% (CI: 1.7–3.8) for Toxascaris leonina; 1.7% (CI: 0.9–2.6) for Capillaria spp.; 0.8% (CI: 0.2–1.4) for taeniid eggs; 0.2% (CI: 0–0.5) for Dipylidium caninum; and 0.1% (CI: 0–0.3) for Strongyloides stercoralis. In cats, the prevalence was 20.5% (CI: 15.6–25.3) for Giardia spp.; 9.5% (CI: 5.9–13.0) for Cystoisospora spp.; 8.3% (CI: 5.0–11.7) for Toxocara spp.; 7.6% (CI: 4.4–10.8) for Ancylostoma/Uncinaria spp.; 6.8% (CI: 3.8–9.9) for Cryptosporidium spp.; 4.2% (CI: 1.8–6.6) for Capillaria spp.; 0.8% (CI: 0–1.8) for taeniid eggs; and 0.4% (CI: 0–1.1) for Hammondia/Toxoplasma. Concerning the risk factors evaluated, there was a negative association between age and Giardia infection and between age and T. leonina infection intensity for dogs. Sequencing results revealed the presence of mainly animal-specific G. duodenalis assemblages C and D in dogs and assemblages F, C and BIV-like in cats, with only a limited number of (co-)infections with assemblage A. As for Cryptosporidium, the dog-specific C. canis and the pig-specific C. scrofarum were detected in dogs and the cat-specific C. felis was detected in cats.

Conclusions

High levels of parasitism in both dogs and cats were recorded. Giardia was the most prevalent parasite in all dog and cat populations except for shepherd dogs. Genotyping results suggest a limited zoonotic risk of Giardia and Cryptosporidium infections from dogs and cats in Crete. Taeniid eggs were more prevalent in shepherd dogs suggesting access to carcasses and posing a threat for cystic echinococcosis transmission. Infection rates of Toxocara spp. in both dogs and cats show that companion animals could be a significant source of infection to humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-1989-8) contains supplementary material, which is available to authorized users.

Population genetic analysis of Giardia duodenalis: genetic diversity and haplotype sharing between clinical and environmental sources

Giardia duodenalis is a flagellated intestinal protozoan responsible for infections in various hosts including humans and several wild and domestic animals. Few studies have correlated environmental contamination and clinical infections in the same region. The aim of this study was to compare groups of Giardia duodenalis from clinical and environmental sources through population genetic analyses to verify haplotype sharing and the degree of genetic similarity among populations from clinical and environmental sources in the metropolitan region of Campinas. The results showed high diversity of haplotypes and substantial genetic similarity between clinical and environmental groups of G. duodenalis. We demonstrated sharing of Giardia genotypes among the different populations studied. The comparison between veterinary and human sequences led us to identify new zoonotic genotypes, including human isolates from genetic assemblage C. The application of a population genetic analysis in epidemiological studies allows quantification of the degree of genetic similarity among populations of Giardia duodenalis from different sources of contamination. The genetic similarity of Giardia isolates among human, veterinary, and environmental groups reinforced the correlation between clinical and environmental isolates in this region, which is of great importance for public health.

Validation of various parasite detection tests for use in the Australian marsupials quenda ( Isoodon obesulus) and brushtail possums ( Trichosurus vulpecula)

We aimed to validate the use of 1) the modified agglutination test and a polymerase chain reaction (PCR) protocol in detecting Toxoplasma gondii infection in quenda ( Isoodon obesulus) and brushtail possums ( Trichosurus vulpecula); 2) immunofluorescence microscopy of feces and a PCR and sequencing protocol in detecting Giardia spp. infection in quenda; and 3) a fecal flotation protocol in detecting gastrointestinal helminth infections of quenda. Quenda and brushtail possum carcasses, and samples from trapped quenda, were tested with 2 parasite detection tests per parasite, and results were modeled using Bayesian latent class analysis to estimate test sensitivity and specificity. The modified agglutination test and the PCR protocol were highly specific at detecting T. gondii infections in quenda and brushtail possums (≥93%); however, data were insufficient to assess sensitivity with adequate precision. Immunofluorescence microscopy and the PCR and sequencing protocol were both highly specific at detecting Giardia spp. in quenda (≥96%), but the PCR and sequencing protocol was relatively insensitive (69%, 95% credible interval [CrI]: 60-77%) compared to the highly sensitive immunofluorescence microscopy (98%, 95% CrI: 93-99%). The fecal flotation protocol was generally highly specific in the detection of gastrointestinal helminth infections (≥94%, with the exception of Trichuris spp. (88%, 95% CrI: 71-99%). The fecal flotation protocol was moderately to highly sensitive (≥74%) in the detection of strongyles, Labiobulura spp., Linstowinema spp., and Trichuris spp. Sensitivity was poor for detection of the cestode genus Potorolepis (36%, 95% CrI: 14-67%).

Evaluation of three enzyme-linked immunosorbent assays for sarcoptic mange diagnosis and assessment in the Iberian ibex, Capra pyrenaica

BACKGROUND

Sarcoptic mange is a contagious skin disease caused by the mite Sarcoptes scabiei, affecting different mammalian species worldwide including the Iberian ibex (Capra pyrenaica), in which mortalities over 90 % of the population have been reported. No efficient diagnostic methods are available for this disease, particularly when there are low mite numbers and mild or no clinical signs. In this study, three enzyme-linked immunosorbent assays (ELISA) developed for dog (ELISA A), Cantabrian chamois (Rupicapra pyrenaica parva) (ELISA B) and Alpine chamois (Rupicapra rupicapra) (ELISA C), were evaluated to detect specific antibodies (IgG) to sarcoptic mange in Iberian ibex sera.

METHODS

Serum samples from 131 Iberian ibexes (86 healthy and 45 scabietic) were collected from 2005 to 2012 in the Sierra Nevada Natural and National Parks (southern Spain). Based on visual inspection, ibexes were classified into one of three categories, namely healthy (without scabietic compatible lesions), mildly affected (skin lesions over less than 50 % of the body surface) and severely affected (skin lesions over more than 50 % of the body surface). The optimal cut-off point, specificity, sensitivity and the area under the curve (AUC) were calculated, and the agreement between tests was determined. Moreover, differences in the optical density (OD) related to scabies severity have been evaluated for the best test.

RESULTS

ELISA C showed better performance than the two other tests, reaching higher values of sensitivity (93.0 %) and specificity (93.5 %) against the visual estimation of the percentage of affected skin, chosen as the gold standard. Significantly higher concentrations of specific antibodies were observed with this test in the mildly and severely infested ibexes than in healthy ones.

CONCLUSIONS

Our results revealed that ELISA C was an optimal test to diagnose sarcoptic mange in the Iberian ibex. Further studies characterizing immune response during the course of the disease, including spontaneous or drug induced recovery, should follow in order to better understand sarcoptic mange in Iberian ibex populations.

Occurrence and multilocus genotyping of Giardia intestinalis assemblage C and D in farmed raccoon dogs, Nyctereutes procyonoides, in China

Background

Giardia intestinalis, the only causative agent of human giardiasis, can infect a wide range of animals. As no information concerning the prevalence and genotyping of G. intestinalis in raccoon dogs in China is available, examination of 305 faecal samples from raccoon dogs in Jilin Province (n = 110), Heilongjiang Province (n = 40), Liaoning Province (n = 72), Hebei Province (n = 54) and Shandong Province (n = 29) was conducted to estimate the prevalence of G. intestinalis in raccoon dogs in northern China and identify their genotypes using a genetic approach.

Findings

Of 305 faecal samples from farmed raccoon dogs, 22 (7.21 %) were detected G. intestinalis-positive by nested PCR amplification of the triosephosphate isomerase (tpi) gene. The prevalence of G. intestinalis was strongly related to the region and season of sampling. All 22 samples were analysed at the tpi, the glutamate dehydrogenase (gdh) and the beta giardin (bg) gene loci, showing 13, 3, 2 subtypes, respectively. The results also demonstrated that two raccoon dogs harboured mixed infections of assemblage C and assemblage D (or mixed C/D), whereas only assemblage C was detected in the remaining 20 samples. Moreover, five new multilocus genotypes, named as MLGs C1-C5, were observed in the assemblage C in the present study.

Conclusions

This is the first report of G. intestinalis infection in raccoon dogs in China. DNA sequence analysis of the tpi, gdh and bg gene indicated that 13, 3, 2 subtypes were found at these loci, respectively. Furthermore, this is also the first report of five new multilocus genotypes (MLGs C1-C5) in farmed raccoon dogs, which provides baseline data for further studies of the distribution of G. duodenalis in different hosts.

An Improved PCR-RFLP Assay for Detection and Genotyping of Asymptomatic Giardia lamblia Infection in a Resource-Poor Setting

Laboratory workers, in resource-poor countries, still consider PCR detection of Giardia lamblia more costly and more time-consuming than the classical parasitological techniques. Based on 2 published primers, an in-house one-round touchdown PCR-RFLP assay was developed. The assay was validated with an internal amplification control included in reactions. Performance of the assay was assessed with DNA samples of various purities, 91 control fecal samples with various parasite load, and 472 samples of unknown results. Two cysts per reaction were enough for PCR detection by the assay with exhibited specificity (Sp) and sensitivity (Se) of 100% and 93%, respectively. Taking a published small subunit rRNA reference PCR test results (6%; 29/472) as a nominated gold standard, G. lamblia was identified in 5.9% (28/472), 5.2%, (25/472), and 3.6% (17/472) by PCR assay, RIDA^® Quick Giardia antigen detection test (R-Biopharm, Darmstadt, Germany), and iodine-stained smear microscopy, respectively. The percent agreements (kappa values) of 99.7% (0.745), 98.9% (0.900), and 97.7% (0.981) were exhibited between the assay results and that of the reference PCR, immunoassay, and microscopy, respectively. Restriction digestion of the 28 Giardia-positive samples revealed genotype A pattern in 12 and genotype B profile in 16 samples. The PCR assay with the described format and exhibited performance has a great potential to be adopted in basic clinical laboratories as a detection tool for G. lamblia especially in asymptomatic infections. This potential is increased more in particular situations where identification of the parasite genotype represents a major requirement as in epidemiological studies and infection outbreaks.