Gastrointestinal parasites of cats in Brazil: frequency and zoonotic risk

Feline strongyloidiasis: An insight into its global prevalence and transmission cycle

The potential cross-transmission of Strongyloides stercoralis between dogs and humans has become an increasing focus of strongyloidiasis research and control programs. However, the role of cats and wild felids in the maintenance and transmission cycles of human and canine strongyloidiasis has received sparse attention. Feline strongyloidiasis epidemiology remain enigmatic. We conducted a systematic review and meta-analysis to assess the global prevalence of Strongyloides spp. in felines and reviewed cross-species infection studies to elucidate the transmission cycle of some feline Strongyloides species. Literature searched from seven databases identified 42 eligible prevalence studies published between 1985 and 2024. Of these, 44 datasets from 40 studies were included in the meta-analysis. Using a random effect model combined with the Rogan-Gladen method, we estimated the pooled global prevalence of Strongyloides spp. in felines at 13.3% (95% CI: 8.3-18.3%), with rates of 12.2% (95% CI: 6.7-17.8%) in domestic cats (Felis catus) and 20.0% (95% CI: 14.9-25.2%) in wild felids. Feline strongyloidiasis was distributed across all six WHO regions, with Africa (49.7%; 95% CI: 40.0-59.3%) and the Western Pacific (46.9%; 95% CI: 42.6-51.1%) showing the highest pooled prevalence. Subgroup analysis revealed a significantly higher prevalence of Strongyloides infection in stray domestic cats (29.2%; 95% CI: 6.3-52.1%) compared to pet cats (9.3%; 95% CI: 3.7-14.9) and shelter cats (4.4; 95% CI: 0-9.0). Historical cross-species transmission studies demonstrated variable susceptibility of cats to human- or canine-derived S. stercoralis. It remains inconclusive whether cats act as a reservoir for S. stercoralis infection in humans or vice versa. Feline strongyloidiasis is a prevalent condition in wild, stray, pet and shelter cats. Much of the available prevalence data does not discriminate to species level, and the role of cross-species transmission in feline S. stercoralis infections remains obscure. Future studies would benefit from utilising molecular genotyping tools to enable species-level phylogenetic differentiation.

Toxocara cati Infection in Cats (Felis catus): A Systematic Review and Meta-Analysis

Introduction: Toxocariasis is an infection caused in canines, felines, humans, and other vertebrates by species of the genus Toxocara, such as T. canis and T. cati. The embryonated eggs of these parasites are the primary means of acquiring the infection for both definitive hosts, dogs and cats, respectively, and for intermediates, such as humans and other vertebrates. When deposited on park soils, environmental contamination becomes a risk to environmental, human, and animal health. Objective: To determine the global prevalence of Toxocara cati in cats (Felis catus). Methods: A systematic review of the literature was carried out in six databases (Scopus, PubMed, ScienceDirect, SciELO and Google Scholar) to evaluate the global prevalence of Toxocara cati in cats, defined by coproparasitological, histological, and molecular techniques. A meta-analysis was performed using a random effects model to calculate pooled prevalence and 95% confidence intervals (95% CI). A two-tailed 5% alpha level was used for hypothesis testing. Results: Two hundred and eighty-nine studies were included. The global pooled prevalence of Toxocara cati in cats using coproparasitological methods was 17.0% (95.0% CI: 16.2-17.8%). In the subgroup analysis according to country, Nepal had the highest prevalence of T. cati infection (94.4%; 95% CI 89.7-99.2%). The pooled prevalence of T. cati infection by PCR in four studies was 4.9% (95.0% CI: 1.9-7.9%). Conclusions: This systematic review underscores the need for preventive action against toxocariasis due to its widespread prevalence. The interplay between animal and human health should be emphasised, necessitating measures like deworming cats, hygiene practices, and public education to mitigate risks. Safeguarding feline health can also reduce human transmission, benefiting both species.

Endoparasites in domestic cats (Felis catus) in the semi-arid region of Northeast Brazil

The aim of this study was to evaluate the prevalence of endoparasites in domestic cats (Felis catus) in the city of Sousa, state of Paraíba, Northeast Brazil. A total of 207 samples of fresh feces were randomly collected from domestic and semi-domiciled cats. The samples were analyzed by simple centrifugation and centrifuge-flotation in sucrose solution for the diagnosis of helminth eggs and enteric protozoan oocysts and cysts. Epidemiological information was obtained to determine risk factors related to infections. Among the samples collected, 81.6% (169/207; 95% CI: 77.4-83.8) were positive for at least one parasite genus. Ancylostoma spp. was the most prevalent, at 67.1% (139/207), followed by Taenia spp. at 28.5% (59/207), and Spirometra spp. and Platynosomum sp., both at 17.3% (36/207). The variables associated with helminth infection were a historic lack of deworming (Odds ratio = 12.25) and the presence of dry fur (Odds ratio = 2.15). No risk factors were observed for enteric protozoa infection. This study demonstrated a high prevalence of endoparasites in domestic cats in the city of Sousa, state of Paraíba, and associated risk factors, thus establishing an overview of the main helminths and protozoa that affect cats in this region.

Prevalence of gastrointestinal parasites in domestic cats (Felis catus) diagnosed by different coproparasitological techniques in the municipality of Seropédica, Rio de Janeiro

The objectives of this work were to investigate the occurrence of parasites in feces of cats, compare different coproparasitological techniques for their diagnosis and determine associations with parasitism. The samples were processed using three different coproparasitological techniques: centrifugal flotation in sucrose, centrifugal flotation in ZnSO4 and simple sedimentation. The parasitic association between parasitism and variables such as age, sex and fecal consistency was performed using the chi-square test or the G test with a significance level of 5%. A total of 237 samples were analyzed, of which 93 (39.2%) were positive, being Ancylostoma spp. (17.3%), Giardia intestinalis (12.2%), Platynosomum illiciens (8.0%), Cystoisospora spp. (6.3%), Toxoplasma gondii/ Hammondia hammondi (3.4%), Diphyllobothriidae (2.1%), Toxocara spp. (1.7%), Dipylidium caninum (1.3%) and Mesocestoides spp. (0.8%). In the parasitism association analysis, it was possible to verify a statistical difference in the age category for Cystoisospora spp. (p=0.001) observing a strong relationship between parasitism and young animals, the association with sex proved to be important for P. illiciens (p<0.001) with a higher frequency of parasitized females and fecal consistency revealed to be related to the parasites G. intestinalis (p=0.007) and P. illiciens (p=0.033) showing a higher number of positive animals for these parasites with normal fecal consistency. In conclusion, we observed a higher occurrence of Ancylostoma spp. and G. intestinalis in fecal samples from domestic cats received in routine diagnoses and the presence of other parasites with zoonotic potential, as well as the relationship of these diagnosed parasites with the categories sex, age and fecal consistency.

Prevalence of Intestinal Parasites, Risk Factors and Zoonotic Aspects in Dog and Cat Populations from Goiás, Brazil

Gastrointestinal diseases caused by parasites are frequently diagnosed in the clinical routine of domestic animals, especially dogs and cats. In general, they trigger factors that can affect human health due to zoonoses. Therefore, this study aims to identify the main intestinal parasites obtained from the fecal samples of dogs and cats in the municipality of Jata, Brazil, and their associated risk factors. Between October 2020 and March 2022, fecal samples were collected from 359 dogs and 55 cats through spontaneous defecation and subsequently subjected to coproparasitological analyses using the Willis fluctuation and Hoffman spontaneous sedimentation techniques. The following parasitic species were identified: Ancylostoma spp., Toxocara spp., Trichuris vulpis, Dipylidium caninum; Giardia spp., Entamoeba spp., Cystoisospora spp., and Platynosomum fastosum. The risk factors associated with parasitism include age, average income of owners, access to garbage, sewage, waste, outdated deworming, and contact with animals. The results demonstrate the need to establish public policies and implement preventive and control measures to reduce the occurrence of parasites in animals and the exposure of humans to pathogenic agents.

Survey on the prevalence of intestinal parasites in domestic cats (Felis catus Linnaeus, 1758) in central Nepal

INTRODUCTION

Cats (Felis catus) are the only felines that live in close contact with humans. Since cats can act as vectors, carriers, reservoirs and definitive hosts of many gastrointestinal (GI) parasites, parasitic assessment could contribute to their survival and well-being.

AIMS

The current study aimed to assess the diversity and prevalence of GI parasites in domestic and feral cats from Ratnanagar in Chitwan in Central Nepal.

METHODS

A total of 107 fresh faecal samples of cats (90 household cats and 17 feral cats) of varied ages and sex were collected and transported to the laboratory. The copromicroscopic examination was carried out following direct wet mount, formalin-ethyl acetate sedimentation, saturated salt flotation, acid-fast staining and sporulation techniques. Furthermore, associated risk factors were evaluated to ascertain the predictor of risks for parasitic acquisition.

RESULTS

The current study revealed an overall 95.3% prevalence rate with a 100% rate in feral cats and 94.4% in household cats. Altogether, 18 (17 known and one unknown) different species of GI parasites were reported with the helminths (95.3%; 11 species) and the protozoa (55.1%; seven species). Besides age and sex, outdoor lifestyle, absence or unknown history of medication and hunting behaviour of the felines are the predictors of risk. Furthermore, mixed infection was comparatively higher than single infection in the faecal samples.

CONCLUSIONS

Cats harbour a higher prevalence and greater diversity of GI parasites, and parasitism varies with age and sex. This finding can be essential for veterinarians and public health authorities for strategic treatment and for assessing the zoonotic transmission of the parasites from these felines. Importantly, an effective medication strategy for cats and owners is recommended.

The diagnosis of human and companion animal Strongyloides stercoralis infection: Challenges and solutions. A scoping review

Strongyloidiasis is the infection caused by soil-transmitted nematodes of Strongyloides species, infecting humans and some animals. Strongyloides stercoralis is the species with most clinical and epidemiological relevance in humans and dogs, due to its high prevalence and its capacity of inducing a life-threatening hyperinfection. Diagnosis of strongyloidiasis is challenging, due to the absence of a single reference standard test with high sensitivity and specificity, which also hampers the estimation of the accuracy of other diagnostic tests. In this chapter, we review the deployment and performance of the parasitological, immunological, molecular tests for the diagnosis of strongyloidiasis in humans and in dogs. Further, we comment the available evidence from genotyping studies that have addressed the zoonotic potential of S. stercoralis. Finally, we discuss the use of different diagnostic methods in relation to the purpose (i.e., screening, individual diagnosis, inclusion in a clinical trial) and the setting (endemic/non-endemic areas) and report the accuracy figures reported by systematic reviews on either parasitological, serological or molecular techniques published in literature.

Gastrointestinal parasites in dogs and cats in line with the One Health' approach

ABSTRACT Dogs and cats are frequently affected by gastrointestinal parasites of medical and veterinary concern. The correct diagnosis is pivotal to the treatment outcome, reducing the risk of environmental contamination and spreading of these pathogens. The aim of this study was to determine the prevalence of gastrointestinal parasites of domiciled dogs and cats in an urban area of Northeastern Brazil, as well as to discuss the findings from a “One Health” perspective. Fecal samples (n = 231) of dogs (n = 126) and cats (n = 105) were obtained directly from the environment after spontaneous defecation, and subsequently analyzed through the Mini-FLOTAC and Baermann techniques. Of all samples, 28.14% (65/231) presented immature forms of gastrointestinal parasites, with 31.75% (40/126) and 23.81% (25/105) of dogs and cats positive, respectively (x 2 = 1.413; p = 0.2345). Two genera of helminths (Ancylostoma and Toxocara) and two genera of protozoa (Cystoisospora and Entamoeba) were identified. Additionally, co-infections were observed in 15% (6/40) of positive dogs and 28% (7/25) of positive cats (p = 0.2207). None metastrongyloid larvae were detected. In conclusion, animals herein assessed presented a high prevalence of zoonotic gastrointestinal nematodes. Therefore, preventive measures against these neglected parasites should be stimulated.

Automated Diagnostics: Advances in the Diagnosis of Intestinal Parasitic Infections in Humans and Animals

The increasingly close proximity between people and animals is of great concern for public health, given the risk of exposure to infectious diseases transmitted through animals, which are carriers of more than 60 zoonotic agents. These diseases, which are included in the list of Neglected Tropical Diseases, cause losses in countries with tropical and subtropical climates, and in regions with temperate climates. Indeed, they affect more than a billion people around the world, a large proportion of which are infected by one or more parasitic helminths, causing annual losses of billions of dollars. Several studies are being conducted in search for differentiated, more sensitive diagnostics with fewer errors. These studies, which involve the automated examination of intestinal parasites, still face challenges that must be overcome in order to ensure the proper identification of parasites. This includes a protocol that allows for elimination of most of the debris in samples, satisfactory staining of parasite structures, and a robust image database. Our objective here is therefore to offer a critical description of the techniques currently in use for the automated diagnosis of intestinal parasites in fecal samples, as well as advances in these techniques.

Intestinal parasites and risk factors in dogs and cats from Rio de Janeiro, Brazil

The urban populations of pets, mainly dogs and cats, have been growing in recent years and, consequently, human-animal relationships have become increasingly closer. However, pets are vulnerable to infection by various parasites, as well are their owners due to the zoonotic potential of these agents. This study aimed to assess the frequency and risk factors of intestinal parasites in dogs and cats attended at the Municipal Institute of Veterinary Medicine Jorge Vaitsman, Rio de Janeiro, Brazil, as well as georeferencing the parasitized animals. A total of 608 animals (400 dogs and 208 cats) were enrolled from August 2017 to November 2018. Fecal samples were obtained from the animal's rectum during clinical examination. In addition, the owners of the enrolled dogs and cats were asked to complete an epidemiological questionnaire with questions about the animals' general information, lifestyle, and handling. Fecal samples were subjected to sedimentation and centrifugal-flotation in sucrose solution techniques. The frequencies of intestinal parasites total in dogs and cats were 11.3% and 24.5%, respectively, with hookworms being the most detected parasites in dogs (8.3%) and Dipylidium caninum in cats (12.5%). Sex was the only variable that showed statistical differences in the canine population males being more often infected than female (p < 0.05), while street access was associated with parasitic infections in cats (p < 0.05). The results obtained in this study demonstrate the need to control parasitic infections in domiciled dogs and cats in different municipalities in the metropolitan region of the state of Rio de Janeiro, including residents in the northern, western and central areas.

Phylogenetic relationships of Strongyloides species in carnivore hosts

Strongyloides stercoralis is a parasitic nematode and a major pathogen responsible for human strongyloidiasis. The presence of this species in the dog population has led to an interest in studying the phylogenetic relationships among Strongyloides spp. in carnivore hosts. In the present study, Strongyloides spp. from various carnivore hosts (raccoon, Japanese badger, Siberian weasel, raccoon dog, masked palm civet, and domestic cat) were sought. Except for civets, Strongyloides spp. were identified in all host species. Based on 18S rDNA sequences, nine OTUs (operational taxonomy units) were identified. Molecular phylogenetic analyses using 18S28S rDNA and mitochondrial cox1 (cytochrome c oxidase subunit 1) sequences clustered them into two groups. The first group (named the stercoralis/procyonis group) was comprised of six OTUs and occurred in cats, raccoon dogs, raccoons (S. procyonis), Siberian weasels, and Japanese badgers and included S. stercoralis from humans and dogs. The second group (named the planiceps group) was made up of Strongyloides spp. from raccoon dogs (two OTUs) and one OTU from Siberian weasels. Subsequent analysis using almost the full-length nucleotide sequences of protein-coding genes in their mitochondrial genomes placed Strongyloides spp. of cats in a sister taxon position to S. stercoralis, whereas S. procyonis from raccoons was more distantly related to them. The presence of Strongyloides spp. from various carnivore hosts, which are close relatives of S. stercoralis, suggests this group of Strongyloides (the stercoralis/procyonis group) essentially evolved as parasites of carnivores, although more data on Strongyloides spp. from primate hosts are needed.

Endoparasites of household and shelter cats in the city of Rio de Janeiro, Brazil

Endoparasitic infections are associated with morbidity in cats. This study aimed to investigate the occurrence of endoparasites among cats of different life stages in the city of Rio de Janeiro, Brazil. The samples were analyzed individually by macroscopic exploration for proglottids and centrifugal-flotation. Stool samples were obtained from household cats (n = 57) and shelter cats (n = 336). Endoparasites were detected in 50.64% of the samples. Among household and shelter cats, 21.05% and 55.66% were infected with endoparasites, respectively. In household cats, the most prevalent endoparasites were Ancylostoma spp. (in 25.0%) and Strongyloides spp. (in 25.0%), followed by Toxocara spp. (in 16.67%), Dipylidium caninum (in 16.67%), Cystoisospora spp. (in 8.33%), and Uncinaria spp. + Ancylostoma spp. (in 8.33%). In shelter cats, the most prevalent endoparasite was Ancylostoma spp. (in 29.41%), followed by Cystoisospora spp. (in 26.20%) and Toxocara spp. (in 16.58%), as well as Cystoisospora spp. + Toxocara spp. (in 8.02%); Ancylostoma spp. + Toxocara spp. (in 11.76%); Cystoisospora spp. + Ancylostoma spp. (in 3.74%); Cystoisospora spp. + Toxocara spp. + Ancylostoma spp. (in 3.21%); and Dipylidium caninum + Ancylostoma spp. (in 0.53%). Endoparasitic infections in cats underscore the need for preventive veterinary care and routine coproparasitologic tests.

Toxocara prevalence in dogs and cats in Brazil

I herein review published studies reporting the prevalence of Toxocara infection in dogs and cats in Brazil. Based on data gathered from faecal examinations of approximately 38,940 dogs and 5600 cats from different Brazilian studies, the mean prevalence of Toxocara infection is 11.4% (range: 0.7-48.9%) in dogs and 16.7% (0.3-43.1%) in cats. These mean values based on faecal examinations should be interpreted with cautious, considering the obvious differences in terms of sample size, diagnostic tests and animal populations. Accordingly, necropsy investigations reveal higher mean prevalence values (21.9% for Toxocara canis and 27.6% Toxocara cati in dogs and cats, respectively). The contamination with Toxocara eggs in different environments and the significance of these parasites from a public health perspective in Brazil are briefly discussed.

Strongyloides spp. in cats: a review of the literature and the first report of zoonotic Strongyloides stercoralis in colonic epithelial nodular hyperplasia in cats

BACKGROUND

Four species of Strongyloides, Strongyloides felis, Strongyloides planiceps, Strongyloides stercoralis and Strongyloides tumefaciens, have been identified in cats based on morphology and location in the host with limited data on the prevalence and disease potential of these different species. Strongyloides tumefaciens adults are located in colonic nodules while the other three species are in the small intestine. The literature on Strongyloides in cats is scattered and has never been compiled. The aim of this article is to provide a short review of the existing literature on Strongyloides spp. in cats, to describe the pathology of colonic nodules containing Strongyloides sp. seen at necropsies of cats in St. Kitts, West Indies, and to provide the first unequivocal report of zoonotic S. stercoralis in cats based on sequencing analysis of a portion of the cytochrome c oxidase subunit 1 (cox1) gene, and supported by phylogenetic analysis.

RESULTS

Colonic nodules containing sections of nematodes, histologically compatible with Strongyloides sp. were seen during necropsy in six cats in St. Kitts, West Indies. Sequencing of the cox1 gene of the mitochondrial DNA extracted from colonic nodules from two of these cats matched sequences of the zoonotic strain of S. stercoralis.

CONCLUSIONS

The morphological similarities between S. stercoralis-associated colonic nodules and previous reports of S. tumefaciens, together with the insufficient defining criteria for S. tumefaciens raises questions about the validity of the species. Further sampling and genetic characterization of isolates is needed to understand the species in cats and their zoonotic potential.

A Review of Strongyloides spp. Environmental Sources Worldwide

Strongyloides spp. are parasitic nematodes that are transmitted through the environment and are capable of causing disease. These nematodes affect an estimated 3–300 million humans worldwide. Identifying the environmental reservoirs of Strongyloides spp. is essential for the development of appropriate control strategies. This systematic literature review examined all published studies that identified Strongyloidesstercoralis, Strongyloidesfuelleborni, Strongyloidesfuellebornikellyi, and Strongyloides spp. from an environmental source. Most studies detected the nematode from dog and primate fecal samples. Other environmental sources identified were ruminants, cats, rodents, insects, water, soil, as well as fruit and vegetables. Most studies used microscopy-based identification techniques; however, several employed molecular-based techniques, which have become increasingly popular for the detection of Strongyloides spp. A limitation identified was a lack of studies that comprehensively screened all potential environmental samples in a region. Future research should undertake this holistic screening process to identify which environmental reservoirs pose the greatest significance to human health. Potential controls can be identified through the identification of environmental sources. Understanding where Strongyloides spp. is commonly found within the environment of endemic areas will inform environmental control strategies to reduce this neglected disease.

Gastrointestinal parasites in feral cats and rodents from the Fernando de Noronha Archipelago, Brazil

Gastrointestinal parasites are important pathogens affecting animals, some of them are of medical and veterinary concern. Although the dynamic of parasitic infections is a complex phenomenon that has been studied under experimental conditions, it shows several gaps in knowledge, especially in insular regions where a confined population of animals and parasites co-exists. In this study was assessed the parasitism by endoparasite gastrointestinal in feral cats (n = 37) and rodents (n = 30) from the Fernando de Noronha Archipelago; in addition, the risk of human infection and ecological implications of these findings were discussed. Out of all samples analysed, 100% scored positive for the presence of gastrointestinal parasites in both feral cats and rodents. A total 17 genera and/or species of endoparasite gastrointestinal were identified, Ancylostoma sp., Strongyloides sp., Trichuris campanula and Toxocara cati were the parasites more frequently in feral cats. In rodents Eimeria sp., Strongyloides sp. and Trichuris muris were parasites more frequently herein detected. Human population living in this area are at risk of parasite infections due to the population of rodents and feral cats in the archipelago.

Frequency of gastrointestinal parasites in cats seen at the University of São Paulo Veterinary Hospital, Brazil

The frequency of gastrointestinal infections in 502 cats seen at the Veterinary Hospital of the University of São Paulo, SP, Brazil, between 2005 and 2014, was measured. The samples were analyzed using methods of flotation and sedimentation. The results were compared with those from studies published previously using fecal samples from the same hospital at different times. Associations between the frequency of positivity for each parasite and age, breed, sex, diarrhea and use of anthelmintic were investigated (chi-square or Fisher's exact tests). A partitioned chi-square test was used to compare different periods. Cryptosporidium spp., Giardia spp., Cystoisospora spp. and Sarcocystis spp. were the most common parasites, followed by Toxocara cati and Ancylostoma spp. Cryptosporidium spp. presented higher frequency in young cats and Sarcocystis spp. with the presence of diarrhea (p < 0.05). Results from this study with previous periods showed that the frequencies of Cryptosporidium spp., Cystoisospora spp. and T. cati were lower (p < 0.05) than those observed in previous periods. The frequencies of Giardia spp. and Ancylostoma spp. were similar to the results found in the preceding period and lower than the values found for the other periods (p < 0.05). The reasons for these changes should be investigated.