Prevalence of Toxoplasma gondii and Other Gastrointestinal Parasites in Domestic Cats from Households in Thika Region, Kenya

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.

Molecular characterization of Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp. infecting domestic and feral/stray cats in Jordan

This study aimed to carry out a molecular screening for the presence of Giardia, Cryptosporidium, and/or Entamoeba in the feces of pet and stray/feral cats in Jordan. G. duodenalis was found in 27.9% (95% CI, 23.2-32.9) of the 348 sampled cats overall; E. histolytica was found in only 0.6% (95% CI, 0.1-2.1) of the cats, while none of the sampled cats had Cryptosporidium infections. The infection rate of G. duodenalis among indoor cats (32.3%) did not differ significantly from that among outdoor cats (24.1%). There were significantly more infections (p = 0.0004) geographically in the cold semiarid areas (67%) than in the cold desert areas (24%). Multilocus sequence typing analysis of amplicons based on the bg, tpi, and gdh genes revealed that the majority of G. duodenalis infections were zoonotic assemblage B (65.9%; 64 of 97 positive samples); followed by feline-specific assemblage F (18.5%, 18/97); cattle-specific assemblage E (5.2%, 5/97); and then assemblage C that was shared with canids (1.0%; 1/97). Within Giardia isolates, a substitution mutation (A/G) was found at position 297 of the complete protein coding sequence (cds) of tpi-assemblage B, which may represent a new spreading mutation within this gene among the cat population in Jordan. The results of the present study suggest that close human-cat interactions could play a role in zoonotic transmission of Giardia, but further research is needed to determine the possible contribution of cats to the transmission of other protozoa to humans.

Microscopic and molecular prevalence and associated risk factors with Toxocara and Blastocystis infection in dogs and cats in Mitidja, Algeria

Domestic dogs and cats can serve as a source of environmental contamination with Toxocara spp. and Blastocystis spp., and this represents a neglected public and veterinary health problem. We assessed the microscopic and molecular prevalence of these species in a locality in Algeria and identified the associated risk factors. The faeces of 225 dogs and 78 cats were collected in Mitidja between March and July 2022. The samples were analysed by coproscopy and by polymerase chain reaction (PCR) targeting the Internal Transcribed Spacer 2 (ITS2) and Small Subunit Ribosomal (SSU-RNA) of T. canis and Blastocystis spp. respectively. The overall microscopic prevalence of Toxocara spp. in dogs and cats was 9.78 ± 1.98% and 12.82 ± 7.42%, respectively. The rate of Blastocystis spp. was 15.11 ± 2.39% and 15.38 ± 4.08% in dogs and cats, respectively while the molecular prevalence of T. canis in dogs was 4.89 ± 1.44% and in cats 1.28 ± 1.27%; the prevalence of Blastocystis spp. was 41.78 ± 3.29% and 34.62 ± 5.39% in dogs and cats, respectively. Phylogenetic and phylogeographic analyses identified the presence of the H1 subtype of T. canis in dogs, and the ST1 subtype of Blastocystis in dogs and cats. Dogs with clinical signs were more likely to be infected with T. canis (OR 6.039, P < 0.05) than healthy dogs. This study demonstrates that dogs and cats are carriers of Toxocara spp. and Blastocystis spp. and are therefore a source of environmental contamination. Veterinarians and human health professionals should work together to implement control strategies as part of a "One Health" approach to improving animal health and reducing the risk of transmission to humans.

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.

Gastrointestinal parasites of cats in Egypt: high prevalence high zoonotic risk

BACKGROUND

Several gastrointestinal parasites that infect cats pose potential health threats for humans and animals. The present study is the first to report gastrointestinal (GIT) parasites in feces of stray cats from Gharbia governorate, Egypt. Findings were combined with those published in the earlier surveys from various Egyptian governorates, and various meta-analyses were conducted to underline the parasitic zoonoses from cats in Egypt.

RESULTS

Out of 143 samples tested in Gharbia, 75 (52.4%) were found infected with 13 different parasites. Co-infections were observed in 49.3% of positives. Several parasites were detected, e.g., Toxocara cati (30.0%), Toxascaris leonina (22.4%), hookworms (8.4%), taeniids (4.2%), Strongyloides spp. (2.1%), Physaloptera spp. (2.1%), Alaria spp. (1.4%) and Dipylidium caninum (0.7%). Opisthorchis-like eggs were found in a single sample being the first report from cats in Africa. Oocysts of 4 coccidian parasites were identified, and a few Toxoplasma gondii-like oocysts were detected in 2 samples (1.4%). Results of the meta-analysis illustrated that occurrence of T. gondii oocysts in feces of cats from Egypt may have been overestimated in earlier studies; 1432 cats have been tested and displayed a 5 times higher pooled prevalence (11.9%) than the published global pooled prevalence for T. gondii oocysts in cats. This overestimation might have occurred because some small-sized oocysts that belong to other coccidian parasites were mis-identified as T. gondii. Toxocara cati had a high pooled prevalence (22.5%) in cats from Egypt, which is even greater than the published pooled prevalence in cats globally; however, several reports from Egypt have neglected the role of T. cati in human toxocarosis. Dipylidium caninum displayed also a high prevalence (26.7%).

CONCLUSION

Several zoonotic parasite species have been found in stray cats from Egypt, raising concerns about the risks to the Egyptian human population as well as environmental contamination. Prompt surveillance supervised by the government and accompanied by data dissemination will be helpful for developing effective control strategies.

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.

Prevalence and Molecular Characterization of Toxoplasma gondii and Toxocara cati Among Stray and Household Cats and Cat Owners in Tehran, Iran

Toxoplasma gondii and Toxocara spp. are the most critical parasites common between humans and cats. The close association of cats with humans in urban areas persuaded us to investigate the prevalence of these parasites in stray and household cats and their possible role in the owners' infection. Herein, 132 and 33 fecal samples of stray and household cats, respectively, and 33 blood samples of their owners were collected in Tehran, Iran. The prevalence of T. gondii was determined by targeting the B1 gene in the feces of stray and household cats and the blood of cat owners. Furthermore, genotypes of T. gondii were identified based on the multilocus genotyping of BTUB, GRA6, SAG3, and APICO loci. Toxocara spp. were detected by targeting the second internal transcribed spacer (ITS-2) of the ribosomal DNA of these parasites in the cats' feces and the humans' blood. Also, Toxocara IgG was assessed in the human serum samples. The B1 gene amplification showed that 15.2% of stray cats, 18.2% of household cats, and 51.5% of cat owners were infected with T. gondii. The multilocus sequence analysis revealed the predominance of genotype I of T. gondii in stray cats and genotype II of T. gondii in household cats and cat owners. The amplifying of ITS-2 revealed a high prevalence of T. cati infection (47.0%) in stray cats, whereas no infection was found in the feces of household cats or the serum of cat owners. Likewise, Toxocara IgG was not detected in the serum of humans. The lower prevalence of T. gondii in stray/household cats than in the cat owners indicates the limited impact of close contact with infected cats in human toxoplasmosis. However, the high prevalence of T. cati infection in stray cats can cause contamination of the environment by excreting eggs that may lead to infecting humans through soil or water. Therefore, public health education in urban management planning is necessary for routine urban cat deworming programs and for training the healthcare workers to prevent, control, and treat these infections.

Occurrence of serum antibodies to Toxoplasma gondii and associated risk factors in donkeys from central Kenya

Toxoplasma gondii is an intracellular parasite of zoonotic concern and economic importance in humans and animals, respectively. This study was conducted to determine the occurrence of T. gondii and associated risk factors in domestic donkeys from Kirinyaga and Meru counties in Kenya. Blood samples were collected from 363 randomly selected donkeys for detection of antibodies to T. gondii using a commercial kit ID Screen® Toxoplasmosis Multi-species indirect enzyme-linked immunosorbent assay (ELISA). The data on risk factors were collected by interviewing donkey owners using epidemiological questionnaire. Serum antibodies to T. gondii were detected in 26.4% (95% CI: 22.2-31.3) of the donkeys. The analysis showed that age of donkeys (OR = 2.484, 95% CI: 1.315-4.693; p = 0.005) was associated with increased risk for T. gondii seroprevalence while county of origin of donkeys (OR = 0.182, 95% CI: 0.083-0.400; p = 0.000), residential place of donkeys (OR = 0.301, 95% CI: 0.136-0.665; p = 0.003), rearing chicken (OR = 0.203, 95% CI: 0.064-0.644; p = 0.007), and donkey production system (OR = 0.644, 95% CI: 0.456-0.909; p = 0.012) were associated with reduced risk of T. gondii seroprevalence. This is the first report to provide epidemiological information on T. gondii infection among donkeys in Kenya. The presence of antibodies to T. gondii in donkeys suggests the high potential of transmission to other animals and humans. Regular monitoring and control of T. gondii infection in donkeys were recommended in the study area.

A survey of intestinal helminths in domestic dogs in a human-animal-environmental interface: the Oloisukut Conservancy, Narok County, Kenya

Dogs living in a domestic-wildlife interface can serve as reservoirs and sentinels of parasites shared among humans, domestic animals and wildlife. In Kenya, the epidemiology of intestinal parasites of dogs and their role as reservoirs of zoonoses is poorly understood, especially in domestic-wildlife interfaces. This study aimed to determine the occurrence of intestinal helminths in domestic dogs in the Oloisukut Conservancy. One hundred dog faecal samples were collected per rectum and examined microscopically following zinc chloride flotation and formal-ether concentration techniques. Genotyping of helminths was achieved by nested polymerase chain reaction of NADH dehydrogenase subunit 1, cytochrome oxidase 1 and partial sequencing. Nine genera were detected by microscopy in 65 (65%) dog faecal samples from 54/76 (71.05%) households. The most frequent helminths were hookworm (39%), Spirometra spp. (17%), taeniids (13%), Toxocara spp. (10%), Trichuris spp. (10%), Spirocerca lupi (5%), Physaloptera spp. (2%), Dipylidium caninum (1%) and Strongyloides spp. (1%). Ancylostoma caninum was the only hookworm species detected in dogs, while Taenia serialis and Taenia madoquae were detected in four and one faecal samples, respectively. This study reports for the first time the molecular detection of the cestodes Spirometra theileri, D. caninum and Mesocestoides sp. in dogs in Kenya. The presence of zoonotic helminths in dogs indicates that the residents of this conservancy are exposed to public health risks. The helminths reported here confirm the interaction of domestic dogs with wildlife. An integrated control programme involving the medical, veterinary and wildlife conservation professionals is needed to avert transmission of infectious diseases to humans, domestic animals and wildlife.

The global prevalence and risk factors of Cryptosporidium infection among cats during 1988-2021: A systematic review and meta-analysis

Cryptosporidiosis is an important zoonosis caused by Cryptosporidium. This disease causes a global public health problem. The cat is considered to be one of the potential hosts for transmitting Cryptosporidium to humans. In this study, a global meta-analysis for Cryptosporidium infection in cats was performed. The articles related to Cryptosporidium infection in cats were systematically searched in databases China National Knowledge Infrastructure (CNKI), Wanfang data, VIP Chinese Journal Database, PubMed, and ScienceDirect. Finally, 92 articles published from 1988 to 2021, which met the criteria of systematic review and meta-analysis, were collected. During the selected period, the overall prevalence of Cryptosporidium among cats was identified to be 6.0%. The prevalence of Cryptosporidium detected by microscopy, coproantigens, and molecular biology methods were 4.2%, 8.2%, and 5.0%, respectively. Among 9 species/genotypes (C. felis, C. parvum, C. muris, Cryptosporidium rat genotype IV, C. baileyi, C. ryanae, C. hominis, Cryptosporidium sp. rat genotype III and most closely related to Cryptosporidium sp. rat genotype III), the prevalence of C. parvum (4.2%) was significantly higher than that of other species/genotypes. Among five continents, the prevalence of Cryptosporidium in Africa (30.5%) was significantly higher than in other continents. We also analyzed the effects of different geographical factors (longitude, latitude, altitude, mean temperature, precipitation, and humidity) on Cryptosporidium infection among cats. The results showed that cryptosporidiosis was common in cats all over the world. This systematic review and meta-analysis has systematically introduced the global epidemiology of Cryptosporidium in cats and correlated risk factors. Health authorities, doctors, veterinarians and cat owners' awareness of the prevalence, risk factors and complications of Cryptosporidium are important for the development of effective prevention strategies for cryptosporidiosis.

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.

A Review on the Present Advances on Studies of Toxoplasmosis in Eastern Africa

Toxoplasmosis is a zoonotic infection caused by the protozoan parasite, Toxoplasma gondii. It was discovered over 100 years ago and is credited as the most successful parasitic organism worldwide, able to infect and multiply in all warm blooded animals including an estimated 2.3 billion people. Toxoplasmosis is asymptomatic in immunocompetent individuals. Infection in the developing fetus and immunocompromised individuals can cause severe clinical disease. Toxoplasmosis is also a major cause of reproductive failure in livestock. The economic impact of toxoplasmosis is believed to be substantial. Factors associated with toxoplasmosis infection have been defined. Eastern Africa region is a high-risk area mainly due to the close association of humans and livestock as well as sociocultural practices, poor environmental hygiene, and poverty. The present paper provides a narrative review of published data on toxoplasmosis in Eastern Africa.

High-throughput multiplex qPCRs for the surveillance of zoonotic species of canine hookworms

The canine hookworms Ancylostoma braziliense, Ancylostoma ceylanicum, Ancylostoma caninum and Uncinaria stenocephala are not only capable of producing morbidity and mortality in dogs but are also neglected tropical zoonoses. Each hookworm species differs considerably in its geographical distribution, life cycle, biology, pathogenic impacts on both canine and human hosts, zoonotic potential, and response to treatment with anthelminthics. Here we describe the development and validation of two Taq-Man based multiplex PCR assays capable of detecting and differentiating all four canine hookworm species in faeces of naturally infected dogs. The analytical sensitivity of both assays was assessed using 10-fold serial dilutions of synthetic gene block fragments containing individual sequence targets of each hookworm species. The sensitivity of the assays and ability to detect mixed species infections were compared to a conventional PCR-Restriction Fragment Length Polymorphism based-approach when applied to laboratory and field samples from endemic areas. The qPCRs detected at least one species of hookworms in 82.4% of PCR-RFLP-negative but microscopy-positive samples. The qPCRs detected an additional 68% mixed infections with different species of canine hookworms, and additional single species infection with A. caninum (47%), U. stenocephala (33%) and A. ceylanicum (0.02%) that were missed by PCR-RFLP. These multiplex qPCR assays will assist field based epidemiological surveillance studies towards an accurate and sensitive monitoring of canine hookworm infections in dogs, to inform their species-specific zoonotic risks to populations living in endemic areas, globally.

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.

The Prevalence of Endoparasites of Free Ranging Cats (Felis catus) from Urban Habitats in Southern Poland

Simple Summary

Free ranging domestic cats are common in urban and suburban habitats and may cause a threat of disease transmission to other pets, wildlife and humans. We investigated the occurrence of endoparasites in cats in Kraków city, Southern Poland, based on examination of road-killed individuals. More than half of the cats were infected with at least one of seven identified parasites. Cats from suburban areas were more likely to be infected than cats from the city core. Our study supports the results from other studies, showing that cats may serve as a significant source of zoonotic transmission.

Abstract

Growing urbanization leads to an increased risk of parasite spread in densely inhabited areas. Free-ranging cats can be locally numerous and come into frequent contact with both wildlife and humans. Cats are thus expected to contribute to parasitic disease transmission. In our study, we investigated the prevalence of endoparasites in free ranging cats in urban areas of Kraków city, based on necropsy of road-killed cats in relation to sex and diet of cat, season and habitat type. We found that 62% of 81 cats were infected with endoparasites with Toxocara cati being the most prevalent. In total, we identified seven parasite species. The number of parasite species was higher in suburban habitats and aside from Eucoleus aerophilus the prevalence of all parasites was higher in cats from suburban areas than in the individuals living in the city urban core. The prey of examined cats included mostly rodents, followed by soricomorphs and birds, which can all serve as paratenic hosts. Based on our results, we suggest that cats in urban areas should be considered as a serious potential zoonotic threat. Implementation of proper veterinary control and wider education on the topic is recommended.

Prevalence of Toxocara in dogs and cats in Africa

Dogs and cats have a close association with humans providing companionship; however, pets are reservoirs of zoonotic pathogens such as Toxocara. Toxocara canis and Toxocara cati are small intestinal nematodes found in canids and felids, respectively. Infected pets shed thousands of eggs resulting in environmental contamination. Toxocara can infect a wide variety of paratenic hosts including humans, rodents, pigs and chickens. Paratenic hosts become infected by ingestion of the infective eggs containing the third stage larvae or ingestion of dormant larvae in animal tissues. Infected humans may develop visceral larval migrans or ocular toxocariasis. Regular anthelmintic treatment and restricted movement of dogs and cats are recommended to control Toxocara environmental contamination. This paper reviews the prevalence and risk factors of Toxocara in dogs and cats in Africa; and pet owners' awareness of canine zoonotic helminths.

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.

Toxoplasma gondii Infection in Dustmen in Northeastern China: A Case-Control Seroprevalence Study

Background

Toxoplasmosis is caused by an intracellular parasite Toxoplasma gondii, which can infect many hosts including humans.

Methods

In order to estimate whether dustmen are more susceptible to T. gondii, a case-control study was conducted containing 332 dustmen from Jilin and Heilongjiang in Northeastern China, as well as 332 general populations from the same regions as control subjects. Serum samples were tested IgG and IgM antibodies to T. gondii using the enzyme-linked immunosorbent assay (ELISA).

Results

The overall anti-T. gondii IgG was 15.06% (50/332) in dustmen compared with 9.64% (32/332) in the controls (P = 0.0337). Also, 5 (1.51%) dustmen had anti-T. gondii IgM antibodies compared with 2 (0.60%) control individuals (P = 0.2543). A significant association was only found between dustmen and level of T. gondii IgG in comparison with the control subjects. Seroprevalence of T. gondii IgG antibodies in male dustmen was significant higher than male control subjects (P = 0.0399). Dustmen from Jilin had the significant higher T. gondii IgG rate (P = 0.0143), in comparison with the control subjects from Jilin. Moreover, dustmen raising cat at home had the significant higher T. gondii IgG rate (P = 0.0097), in comparison with the control subjects. Risk factor analysis suggested that raising cat at home and not having habits of washing hand before eating were mainly related to the T. gondii infection in dustmen.

Conclusions

This is the first record of seroprevalence of T. gondii infection in dustmen in Jilin and Heilongjiang provinces in Northeastern China. These findings also suggest that the government departments should pay close attention to the toxoplasmosis in dustmen in Northeastern China.