The epidemiology and public health importance of toxocariasis: A zoonosis of global importance

Gastrointestinal parasites of owned cats in three districts of Central Ethiopia: Prevalence and risk factors

This present, cross-sectional study investigated gastrointestinal parasites in owned cats was carried out across Bishoftu, Dukem, and Addis Ababa city and towns in Central Ethiopia from February 2022 to April 2023. The primary objectives were to estimate the prevalence and assess the risk factors associated with these parasites. A total of 213 faecal samples were collected and processed using flotation and McMaster techniques. An overall prevalence of 34.7% (74/213) of gastrointestinal parasites was recorded in the examined cats. The cats harboured nematode (14.6%), cestode (12.7%), and protozoan (5.6%) parasites in single (32.9%) and mixed (1.9%) species. Specifically, Toxocara cati, Dipylidium caninum, Taenia spp., Giardia spp., and Physaloptera spp. were the more frequently identified parasites, with prevalences of 9.4%, 8.9%, 3.8%, 2.8%, and 2.8%, respectively. Statistically significant differences (P < 0.05) were observed in the prevalence of gastrointestinal parasites among cats of different sexes, ages, and feeding conditions. Thus, higher prevalence rates were observed in females (49.1%, OR = 2.3), young cats (70%, OR = 4.7), and those consuming uncooked food (40.5%, OR = 3.6). Faecal consistency also showed a statistically significant association (P < 0.05) with the presence of gastrointestinal parasites. However, no significant differences were noted in the prevalence among cats of different housing conditions, seasons, or agro-ecological zones. Cats sharing shelter with families had the highest prevalence of gastrointestinal parasites (52.2%). In conclusion, this study uncovered a notably high occurrence of gastrointestinal parasites in cats in the surveyed regions, emphasizing the imperative of adopting a One Health strategy to address the zoonotic parasites found in cats, which pose significant public health risks.

Alterations of plasma circulating microRNAs in BALB/c mice with Toxocara canis visceral and cerebral larva migrans

BACKGROUND

Human toxocariasis is a neglected parasitic disease characterised by the syndromes visceral, cerebral, and ocular larva migrans. This disease is caused by the migrating larvae of Toxocara roundworms from dogs and cats, affecting 1.4 billion people globally. Via extracellular vesicles (EVs), microRNAs have been demonstrated to play roles in host-parasite interactions and proposed as circulating biomarkers for the diagnosis and follow-up of parasitic diseases.

METHODS

Small RNA-seq was conducted to identify miRNAs in the infective larvae of T. canis and plasma EV-containing preparations of infected BALB/c mice. Differential expression analysis and target prediction were performed to indicate miRNAs involved in host-parasite interactions and miRNAs associated with visceral and/or cerebral larva migrans in the infected mice. Quantitative real-time polymerase chain reaction (PCR) was used to amplify circulating miRNAs from the infected mice.

RESULTS

This study reports host and parasite miRNAs in the plasma of BALB/c mice with visceral and cerebral larva migrans and demonstrates the alterations of these miRNAs during the migration of larvae from the livers through the lungs and to the brains of infected mice. After filtering unspecific changes in an irrelevant control, T. canis-derived miRNAs and T. canis infection-induced differential miRNAs are predicted to modulate genes consistently involved in mitogen-activated protein kinase (MAPK) signalling and pathways regulating axon guidance and pluripotency of stem in the infected mice with visceral and cerebral larva migrans. For these plasma circulating miRNAs predicted to be involved in host-parasite crosstalk, two murine miRNAs (miR-26b-5p and miR-122-5p) are experimentally verified to be responsive to larva migrans and represent circulating biomarker candidates for visceral and cerebral toxocariasis in BALB/c mice.

CONCLUSIONS

Our findings provide novel insights into the crosstalk of T. canis and the mammalian host via plasma circulating miRNAs, and prime agents and indicators for visceral and cerebral larva migrans. A deep understanding of these aspects will underpin the diagnosis and control of toxocariasis in humans and animals.

The seroprevalence of toxocariasis and related risk factors in children in Ho Chi Minh City, Vietnam: results from a school-based cross-sectional study

BACKGROUND

Children are especially vulnerable to Toxocara infection and its severe complications; however, there have not been any published data on the disease prevalence and treatment effectiveness in the population of Vietnamese children. This study was conducted to determine the prevalence of toxocariasis and explore factors associated with Toxocara infection in children aged 3-15 y in Ho Chi Minh City, Vietnam.

METHODS

We conducted a cross-sectional study using a multistage cluster sampling approach in public schools. Blood samples were collected, and toxocariasis cases were confirmed, based on a history of contact with dogs/cats and positive anti-Toxocara antibody detection via ELISA. We calculated the percentage of seropositive children across gender, grade levels, districts and caregiver education. Multiple regression models were employed to identify potential risk factors.

RESULTS

Anti-Toxocara antibodies were found in 14.2% of the 986 children studied. Significant variations in seropositivity were observed across grade levels, districts and caregiver education levels. Multivariable analysis identified caregiver education, contact with dogs/cats and improper handling of pet feces as seropositivity risk factors.

CONCLUSION

This was the first community-based prevalence study of toxocariasis in a pediatric population in Vietnam. Implementation of preventive measures such as public education, routine fecal examinations and chemotherapeutic treatment of animals is highly recommended.

Understanding the research and practical needs required to control toxocariasis in Iran

Human toxocariasis (HT) is a widespread zoonotic infection globally, notably prevalent in tropical areas. Enhancing our understanding of toxocariasis can lead to increased attention towards the socioeconomic impact and control of this neglected zoonosis. We conducted a comprehensive review of all available articles and official documents on toxocariasis in Iran to identify research gaps and critical needs for its control. This review highlights that despite numerous studies exploring various aspects of toxocariasis in definitive and paratenic hosts, as well as humans and environmental contamination, significant data deficiencies and gaps persist across different regions in the country. These gaps involve investigating the worm burden and reinfection rates in definitive hosts, developing more sensitive methods to detect and differentiate of Toxocara species, and understanding the behavior of definitive host animals. Additionally, identifying potential paratenic hosts for HT and exploring the organ-specific affinity and survival duration of Toxocara larvae within these hosts are essential areas for exploration. It's also imperative to comprehend the sylvatic and domestic cycles of the parasite in paratenic hosts. Furthermore, assessing egg density in the environment, exploring potential new sources such as water, and identifying regions with optimal climatic conditions for the survival and development of Toxocara eggs are crucial for the formulation of effective prevention and control strategies. Identifying at-risk groups, developing early diagnosis techniques, employing imaging methods, and identifying long-term complications in humans are also crucial. Community health organizations should prioritize health education for the public and professionals. Furthermore, accurately estimating definitive host populations, monitoring and preventing their movements in public places, implementing regular deworming practices for pets and stray hosts, and recognizing the infection's significance as a health priority are critical. This comprehensive understanding advocates for a holistic "one health" approach to control of HT.

Influence of environmental factors on the occurrence of gastrointestinal and cardiopulmonary nematodes in the red fox in the semi-arid Mediterranean areas of the Iberian Peninsula

Human-induced ecosystem fragmentation is one of the drivers causing wildlife migration from their natural habitats to urban areas, among other reasons. The red fox (Vulpes vulpes) is the most abundant wild canid in the semi-arid Mediterranean areas of the Iberian Peninsula. Water scarcity may result in areas shared by synanthropic fox populations and domestic animals becoming hotspots for parasite transmission. This study describes the gastrointestinal and cardiopulmonary nematode species affecting fox populations in these semi-arid areas and the influence of environmental variables on parasite abundance. A total of 167 foxes collected from 2015 to 2021 in the Region of Murcia (SE Spain) were analysed. Parasite abundance and spatial distribution were evaluated using environmental variables and host characteristics with a Generalised Linear Model and the Moran index. Eleven species (seven from the gastrointestinal tract and four from the cardiopulmonary tract) were described. The influence of biotic and abiotic variables was studied for Angiostrongylus vasorum, Crenosoma vulpis, Uncinaria stenocephala, Toxocara canis and Toxascaris leonina. Temperature, humidity and areas of forest or agricultural land influenced the abundance of these parasites, providing optimal conditions for free-living stages of the direct life cycle nematodes and intermediate hosts. Absolute abundance distribution maps showed defined locations for C. vulpis, T. canis and T. leonina. The results for U. stenocephala, T. canis and T. leonina were particularly important as their higher abundance levels were found close to anthropized areas, which need to be carefully evaluated to prevent transmission of these nematodes between domestic and wild canids and human health.

Intestine proteomic and metabolomic alterations in dogs infected with Toxocara canis

Toxocariasis is an important zoonotic parasitic disease. Toxocaris canis adults live and reproduce in the intestinal tract of dogs and other canine hosts, and the infectious eggs are continuously excreted in feces, which causes environmental contamination and has an important public health significance. In this study, TMT proteomic and untargeted metabolomic methods were used to explore the physiological and pathological effects on the intestinal tract of dogs which infected with T. canis, and a series of bioinformatics analyses were conducted to identify differentially expressed proteins (DEPs) and differentially expressed metabolites (DEMs). The proteomics results showed that 198 DEPs were mainly enriched in the immune system and signal transduction pathway, and involved in the regulation of the occurrence and development of cancer and infectious diseases. T. canis could disrupt intestinal permeability by increasing the expression of proteins such as zinc finger protein DZIP1L and myosin heavy chain 10. Additionally, T. canis infection could also inhibit the host immune response by decreasing the expression of MHC-II, NF-κB, DLA and other immune-related molecules. While, the metabolomics results revealed that the expression of oxoglutaric acid, glutamate, d-aspartate, arginine, taurochenodeoxycholic acid and taurocholic acid which participated in tricarboxylic acid (TCA) cycle, glycolysis/gluconeogenesis, bile secretion, biosynthesis of amino acids pathway were significantly decreased. The correlation results of proteomics and metabolomics showed that DEPs and DEMs were mainly co-enriched in bile secretion pathway to regulate intestinal peristalsis. Analyzing DEPs and DEMs will not only provide insights into the mechanisms of host parasite interaction, but also aid in identifying potential targets for therapy and diagnosis, thus setting the groundwork for effectively preventing and managing toxocariasis.

Global Seroprevalence of Toxocara spp. in Children: A Systematic Review and Meta-analysis

BACKGROUND

In the present study, we performed a systematic review and meta-analysis to assess the global and regional seroprevalence of Toxocara spp. and associated risk factors among children.

METHODS

The present systematic review and meta-analysis was followed based on the Preferred Reporting. Items for Systematic Reviews and Meta-analyses (PRISMA) protocol. We searched the online databases (PubMed, Scopus, and Web of Science) and Google Scholar search engine for studies that measured seroprevalence of Toxocara spp. among children, published between 1 January 2000 and 15 January 2022. Accordingly, the pooled seroprevalence and 95% confidence intervals (CI) were estimated using a random-effects meta-analysis model.

RESULTS

A total of 65 articles from 22 countries met the inclusion criteria. The global seroprevalence of Toxocara spp. infection among children was estimated as 25% (95% CI 22-29). Meta-regression analysis showed that the type of population studied (p = 0.002) and year of publication (p = 0.044) it may be the source of heterogeneity. The highest and lowest pooled seroprevalence of Toxocara spp. infection were estimated in Thailand and Colombia as 58.2% (95% CI 50.9-65.5) and 7.04% (95% CI 3.05-11.3), respectively. Male gender was associated with a higher risk of Toxocara spp. compared to females, and this association was statistically significant (OR = 1.24; 95% CI 1.09-1.41, p = 0.001). However, residing in rural areas did not show a statistically significant increase in risk compared to living in urban areas (OR = 1.39; 95% CI 0.88-2.21, p = 0.143).

CONCLUSION

Toxocariasis is common among children, hence, prevention and control scheme of this helminth in children should be considered by health officials and health policymakers, especially in developing countries, where seroprevalence is highest.

A cross-sectional study to quantify the prevalence of Toxocara canis in dogs in the Central Highlands of Vietnam

Toxocara canis is a globally distributed zoonotic parasite. The parasite has recently become a concern for public health in Vietnam. This cross-sectional study aimed to identify and quantify the risk factors associated with T. canis infection in dogs in Dak Lak province in the Central Highlands of Vietnam. The risk factors were identified using a mixed-effects logistic regression model and quantified using population attributable fractions. Examination of fecal samples collected from 1455 dogs using the sodium nitrate flotation technique showed 37.32% (95% CI: 34.83-39.86) of dogs infected with T. canis. The factors, including study location, multiple dogs living in a household, dog age, dog breed, and places keeping dogs were associated with a dog's likelihood of being T. canis infection. The household and individual dog levels contributed 17% and 82%, respectively, to the prevalence of T. canis in dogs. The adjusted population attributable fraction for confining dogs and raising an individual dog per household was 52% and 27%, respectively. The result of this study indicated that to minimize the burden of T. canis, intervention measures should target individual dogs and household levels.

Seroprevalence and Potential Risk Factors of Toxocariasis among General Population in Southwest Iran: Implications on the One Health Approach

Toxocariasis is one of the most common zoonotic diseases distributed worldwide. This study aimed to estimate the seroprevalence of anti-Toxocara immunoglobulin G (IgG) antibodies and the associated risk factors among general populations living in urban and rural areas of Abadan and Khorramshahr cities in Khuzestan Province, Southwest Iran. This cross-sectional study was conducted between March and September 2022. There were 363 participants (190 females and 173 males) aged from <20 to ≥60 years old. Anti-Toxocara IgG antibodies in serum samples were measured using a commercially available enzyme-linked immunosorbent assay (ELISA). A structured questionnaire was employed to collect information regarding sociodemographic status and probable risk factors associated with toxocariasis. It was found that the seroprevalence rate in males (15.0%, 95% CI = 10.47-21.11) was higher than in females (10.5%, 95% CI = 6.92-15.70). Moreover, we observed that the seroprevalence was higher in participants at younger ages compared to other age ranges (COR = 2.55, 95% CI = 0.92-7.12, p =0.073). The findings of the univariate analysis revealed that residency in rural areas (p  < 0.001), using unpurified water (p  < 0.001), contact with dog (p =0.002), contact with soil (p  < 0.001), consumption of improperly washed vegetables (p  < 0.001), and history of drinking untreated water (p  < 0.001) were risk factors associated with toxocariasis. Further comprehensive studies with a focus on humans and animals should be designed in different areas of the Province. The data represented by the current study are useful to health policymakers to consider precise surveillance and effective prevention measures to control this zoonotic infection among general populations.

Prevalence, Infection, and Risk to Human Beings of Toxocara canis in Domestic Food-Producing Animals

Toxocariasis is a significant food-borne zoonotic parasitic disease, and a range of birds and mammals are the paratenic hosts of Toxocara canis. The consumption of raw or undercooked meat and viscera of these paratenic hosts frequently leads to T. canis infection and the development of human toxocariasis. In this review, we will perform an analysis of relevant papers published in the National Center for Biotechnology Infrastructure database on the parasitism, migration, and infection of T. canis in chickens, pigeons, quail, pigs, cattle, sheep, and other food-producing animals, so as to make the public aware of the risk factors of human toxocariasis, improve the public's understanding of T. canis infection, and provide evidence for targeted prevention and control measures.

Prevalence of Gastrointestinal Parasites in Zoo Animals and Phylogenetic Characterization of Toxascaris leonina (Linstow, 1902) and Baylisascaris transfuga (Rudolphi, 1819) in Jiangsu Province, Eastern China

The burden of gastrointestinal parasites in zoo animals has serious implications for their welfare and the health of veterinarians and visitors. Zhuyuwan Zoo is located in the eastern suburb of Yangzhou city in eastern China, in which over 40 species of zoo animals are kept. In order to understand the infection status of GI parasites in Zhuyuwan Zoo, a total of 104 fresh fecal samples collected randomly from birds (n = 19), primates (n = 19), and non-primate mammals (n = 66) were analyzed using the saturated saline flotation technique and nylon sifter elutriation and sieving method for eggs/oocysts, respectively. Two Ascaris species were molecularly characterized. The results showed that the overall prevalence of parasitic infection was 42.3% (44/104). The parasitic infection rate in birds, primates, and non-primate mammals were 26.3% (5/19), 31.6% (6/19), and 50.0% (33/66), respectively. A total of 11 species of parasites were identified, namely, Trichostrongylidae, Capillaria sp., Trichuris spp., Strongyloides spp., Amidostomum sp., Toxascaris leonina, Baylisascaris transfuga, Parascaris equorum, Paramphistomum spp., Fasciola spp., and Eimeria spp. Paramphistomum spp. eggs were first detected from the captive Père David's deer, and Fasciola spp. eggs were first reported from sika deer in zoo in China. A sequence analysis of ITS-2 and cox1 showed that the eggs isolated from the African lion (Panthera leo Linnaeus, 1758) were T. leonina, and the eggs from the brown bear (Ursus arctos Linnaeus, 1758) were B. transfuga. The public health threat posed by these potential zoonotic parasitic agents requires attention. These results lay a theoretical foundation for prevention and control of wild animal parasitic diseases at zoos in China.

Prevalence of intestinal parasites in street dogs (Canis lupus familiaris) with highlights on zoonosis in Lalitpur, Nepal

BACKGROUND

The presence of intestinal parasites influences the growth and well-being of canids. Additionally, infected dogs and their faeces with considerably higher eggs/oocysts released per gram (epg/opg) of zoonotic parasites contribute to parasitic spillover to humans, domestic animals and sympatric wildlife.

OBJECTIVES

The current study aimed to reveal the prevalence of intestinal parasites (protozoa and helminths) and to list the zoonotically significant parasites in free-roaming street dogs in Lalitpur Metropolitan City, Nepal.

METHODS

Fresh faecal samples (n = 332) were collected from feral dogs of varying ages and sexes and transported to the research laboratory. The copro microscopic examination was carried out via direct wet mount, formalin ethyl acetate sedimentation, saturated salt flotation, acid-fast staining and sporulation techniques.

RESULTS

Coproscopy revealed an overall 95.7% (318/332) prevalence rate with 23 diverse species of intestinal parasites (10 protozoa and 13 helminths). Among them, 5 protozoa and 11 helminths possessed zoonotic potential, and their overall prevalence was 92.5%. Helminth's overall prevalence was double that of the protozoa (87.7% vs. 43%). Polyparasitism was dominant over mono parasitism (79.5% vs. 16.3%), and co-infection of up to seven species of parasites at a time was recorded.

CONCLUSIONS

Urban street dogs harboured a higher prevalence of intestinal parasites that varied with age and sex. Since most of the reported parasites are zoonotic, dog density and parasitic richness indicate a greater spillover risk to humans and domestic animals. Furthermore, this study also provides appropriate 'baseline' data for assessing effective control measures against parasitic infestations among street dogs and controlling their transmission to humans.

Who Let the Dogs Out? Unmasking the Neglected: A Semi-Systematic Review on the Enduring Impact of Toxocariasis, a Prevalent Zoonotic Infection

Toxocariasis remains an important neglected parasitic infection representing one of the most common zoonotic infections caused by the parasite Toxocara canis or, less frequently, by Toxocara cati. The epidemiology of the disease is complex due to its transmission route by accidental ingestion of embryonated Toxocara eggs or larvae from tissues from domestic or wild paratenic hosts. Even though the World Health Organization and Centers for Disease Control classified toxocariasis amongst the top six parasitic infections of priority to public health, global epidemiological data regarding the relationship between seropositivity and toxocariasis is limited. Although the vast majority of the infected individuals remain asymptomatic or experience a mild disease, the infection is associated with important health and socioeconomic consequences, particularly in underprivileged, tropical, and subtropical areas. Toxocariasis is a disease with multiple clinical presentations, which are classified into five distinct forms: the classical visceral larva migrans, ocular toxocariasis, common toxocariasis, covert toxocariasis, and cerebral toxocariasis or neurotoxocariasis. Anthelmintic agents, for example, albendazole or mebendazole, are the recommended treatment, whereas a combination with topical or systemic corticosteroids for specific forms is suggested. Prevention strategies include educational programs, behavioral and hygienic changes, enhancement of the role of veterinarians, and anthelmintic regimens to control active infections.

Endoparasites in dogs diagnosed at the Veterinary Teaching Hospital (VTH)-University of Bologna, combined with clinicopathological results. A long-term retrospective secondary data study

Humans and dogs commonly share the same domestic environment. Europe, and Italy specifically, have a substantial and growing dog population. Potentially zoonotic parasites may be harbored even by dogs receiving regular veterinary care. Thus, transmission of zoonotic or potentially zoonotic parasites to owners and their families should not be underestimated. Frequently, endoparasite infections occur as a subclinical infection and clinicopathological alterations have been documented including anemia, hypoalbuminemia, and eosinophilia. The aim of this large retrospective secondary data study was to analyze coprological endoparasite results and putative risk factors obtained from owned dogs, through a 9-year-period (2011-2019). Possible associations between diagnosed endoparasites and sex, age, seasonality, and year of examination were evaluated. Additionally, parasitological diagnoses were combined to complete blood count parameters and biochemical profiles, when available, to check for any possible hematological alteration from parasitism. A total of 1,972 dogs were evaluated for endoparasites using common fecal diagnostic tests over a 9-year period. The overall proportion of endoparasite-positive animals was 10%. The most common endoparasites detected were Cystoisospora spp. (3%), Toxocara canis (2.8%), Giardia duodenalis (1.6%), and Trichuris vulpis (1.2%). Of these parasites detected, Toxocara poses the greatest zoonotic risk, while Giardia species are considered to have a low potential to be zoonotic. There was no significant diagnostic trend across the years through the study period. Dogs were more frequently diagnosed endoparasite-positive when young and during cold seasons compared to the baselines of mature dogs and warm seasons. The clinicopathological profiles indicated that parasitized dogs had mild hematological alterations. The frequency of detected potentially zoonotic endoparasites in this study highlights that the risk should not be underestimated. Parasitic infection was found to be mostly dependent on age and season. Having this information may help clinicians to develop anthelmintic protocols to reduce the risk of transmission.

Mitogenomic phylogenies suggest the resurrection of the subfamily Porrocaecinae and provide insights into the systematics of the superfamily Ascaridoidea (Nematoda: Ascaridomorpha), with the description of a new species of Porrocaecum

BACKGROUND

The family Toxocaridae is a group of zooparasitic nematodes of veterinary, medical and economic significance. However, the evolutionary relationship of Porrocaecum and Toxocara, both genera currently classified in Toxocaridae, and the monophyly of the Toxocaridae remain under debate. Moreover, the validity of the subgenus Laymanicaecum in the genus Porrocaecum is open to question. Due to the scarcity of an available genetic database, molecular identification of Porrocaecum nematodes is still in its infancy.

METHODS

A number of Porrocaecum nematodes collected from the Eurasian marsh harrier Circus aeruginosus (Linnaeus) (Falconiformes: Accipitridae) in the Czech Republic were identified using integrated morphological methods (light and scanning electron microscopy) and molecular techniques (sequencing and analyzing the nuclear 18S, 28S and ITS regions). The complete mitochondrial genomes of the collected nematode specimens and of Porrocaecum (Laymanicaecum) reticulatum (Linstow, 1899) were sequenced and annotated for the first time. Phylogenetic analyses of ascaridoid nematodes based on the amino acid sequences of 12 protein-coding genes of mitochondrial genomes were performed using maximum likelihood and Bayesian inference.

RESULTS

A new species of Porrocaecum, named P. moraveci n. sp., is described based on the morphological and genetic evidence. The mitogenomes of P. moraveci n. sp. and P. reticulatum both contain 36 genes and are 14,517 and 14,210 bp in length, respectively. Comparative mitogenomics revealed that P. moraveci n. sp. represents the first known species with three non-coding regions and that P. reticulatum has the lowest overall A + T content in the mitogenomes of ascaridoid nematodes tested to date. Phylogenetic analyses showed the representatives of Toxocara clustered together with species of the family Ascarididae rather than with Porrocaecum and that P. moraveci n. sp. is a sister to P. reticulatum.

CONCLUSIONS

The characterization of the complete mitochondrial genomes of P. moraveci n. sp. and P. reticulatum is reported for the first time. Mitogenomic phylogeny analyses indicated that the family Toxocaridae is non-monophyletic and that the genera Porrocaecum and Toxocara do not have an affinity. The validity of the subgenus Laymanicaecum in Porrocaecum was also rejected. Our results suggest that: (i) Toxocaridae should be degraded to a subfamily of the Ascarididae that includes only the genus Toxocara; and (ii) the subfamily Porrocaecinae should be resurrected to include only the genus Porrocaecum. The present study enriches the database of ascaridoid mitogenomes and provides a new insight into the systematics of the superfamily Ascaridoidea.

Toxocara Infection in Dogs and Cats in Isfahan Province of Iran in 2021

Background

Toxocariasis is an acute or chronic disease caused by parasites of the Ascaridae family, especially Toxocara of dogs and cats. Eggs are excreted out by feces of these animals on soil. Infective eggs develop on soil which can be infective to human. In this study, infection rate of Toxocara spp. in dogs and cats of urban and rural areas of Isfahan province of Iran has been investigated.

Materials and Methods

Three hundred and seventy-five stray dog feces and 230 stray cat feces were collected from the public environment (slaughterhouses, parks, children's playgrounds, student dormitories, university environment, streets and squares) in Isfahan province of Iran. At first, dogs' and cats' feces were examined for the presence of Toxocara spp. eggs using formalin ether method. In the second stage, by using molecular methods, Toxocara eggs spp. (Toxocara canis or Toxocara cati) were identified.

Results

From 375 dog fecal samples, 39 (10.40%) and from 230 cat fecal samples, 38 (16.52%) were positive for presence of the Toxocara eggs.

Conclusion

Dogs and cats in Isfahan province of Iran were infected with Toxocara parasite. These infections can be potential risk for human toxocariasis.

Public perspectives on strays and companion animal management in Malaysia

Strays and companion animal management is a sensitive issue in Malaysia that incites solid and conflicting views. Through structured questionnaires administered to a random sample of 704 respondents, this study explored public opinion on a) causes of the stray animal population, b) the management of the stray animal population, and c) the national strategy on strays and companion Animal Management. The results show that 70.3% of respondents agreed that a lack of public awareness regarding animal care was the major contributor to the stray animal population. In addition, 58.1% of respondents felt that treating and vaccinating animals exposed to zoonotic diseases is a viable approach that could be instituted as a reasonable measure in stray animal population management. Finally, developing animal protection areas through a multi-stakeholder partnership strategy initiative recorded the highest support (48.4%) for intervention planning for stray animal management at a national level. Notably, a significant percentage of public responses were implicitly influenced by demographic variables. These findings provide valuable insights into public opinion regarding stray and companion animal management in Malaysia. These findings could inform the development of future legislation aimed at reducing the unfavorable effects of stray animal populations on humans and the ecology of MalaysiaPlease check if affiliations [is/are] captured correctly.

Zoonotic helminths of dogs and risk factors associated with polyparasitism in Grenada, West Indies

Canine soil-transmitted helminths (STHs) cause important zoonoses in the tropics, with varying degrees of intensity of infection in humans and dogs. This study aimed to investigate the prevalence and associated risk factors for STHs in community dogs residing in Grenada, West Indies. In May 2021, 232 canine fecal samples were examined for zoonotic helminths by microscopy (following flotation), and genomic DNA from a subset of 211 of these samples were subjected to multiplex qPCR for the detection and specific identification of hookworms, Toxocara spp. and Strongyloides. Microscopic examination revealed that 46.5% (108/232, 95% CI 40–52.9), 9% (21/232, 95% CI 5.35–12.7) and 5.2% (12/232, 95% CI 2.3–8) of the samples contained eggs of Ancylostoma spp., Toxocara spp. and Trichuris vulpis, respectively. Multiplex qPCR revealed that, 42.2% (89/211, 95% CI 35.5–48.8) were positive for at least 1 zoonotic parasite. Of these, 40.8% (86/211, 95% CI 34.1–47.3) of samples tested positive for Ancylostoma spp., 36% (76/211, 95% CI 29.5–42.9) were positive for A. caninum, 13.3% (28/211, 95% CI 9–18.6) for A. ceylanicum, 5.7% for T. canis (12/211, 95% CI 2.97–8.81) and 1% (2/211, 95% CI 0–2.26) for Strongyloides spp. (identified as S. stercoralis and S. papillosus by conventional PCR-based Sanger sequencing). Using a multiple logistic regression model, a low body score and free-roaming behaviour were significant predictors of test-positivity for these parasitic nematodes in dogs (P < 0.05). Further studies of zoonotic STHs in humans should help elucidate the public health relevance of these parasites in Grenada.

Seroprevalence of human toxocariasis in Latin America and the Caribbean: a systematic review and meta-analysis

Introduction

The current study aimed to quantitatively synthesize available evidence regarding the seroprevalence of human toxocariasis in Latin America and the Caribbean.

Methods

A systematic research involving six electronic databases was conducted using a research strategy that combined MeSH terms with free terms. Article selection and information extraction were performed using a double and independent approach. The Newcastle-Ottawa tool was used to assess the risk of bias in the included articles. The meta-analysis used the random-effects approach, with subgroup analysis and sensitivity analysis for risk of bias also being performed.

Results

We included 101 articles with a total of 31,123 participants. The studies were conducted between 1990 and 2022, with Brazil accounting for the largest number of studies (n = 37). The overall seroprevalence of human toxocariasis was 31.0% (95% CI: 27.0-35.0%, I2 = 99%). The prevalence of the main characteristics observed in seropositive patients were as follows: ocular toxocariasis (30.0%), asymptomatic (26.0%), and presence of dogs at home (68.0%). In addition, the seroprevalence was lower in studies including only adults than in those including children or both. In contrast, no differences in seroprevalences were found between studies conducted in the community and hospital.

Conclusion

The overall seroprevalence of human toxocariasis in Latin America and the Caribbean was high. Notably, our findings showed that the seroprevalence was increased among populations who kept a dog at home but was decreased in populations comprising only adults. Our findings can be used to establish epidemiological surveillance strategies for the prevention and early identification of toxocariasis.

Toxoplasma and Toxocara seropositivity in juvenile idiopathic arthritis and its relation to disease activity and type of therapies

Juvenile idiopathic arthritis (JIA) is the most frequently encountered autoimmune rheumatic disease in children. To our knowledge, this is the first study aimed to estimate the frequency of Toxoplasma gondii (T. gondii) and Toxocara seropositivity in JIA and assess its relation to the disease activity, IL-10 levels, and type of the received therapies. This study was conducted on 43 JIA patients and 50 cases as a control group. All participants were evaluated by disease activity score (JADAS-27), and the presence of specific IgG and IgM antibodies against T. gondii and IgG against Toxocara species using an enzyme-linked immunosorbent assay. IL-10 serum levels were measured using an ELISA kit. The results show that JIA patients have significantly higher seropositivity for anti-T. gondii IgG compared to control subjects (p = 0.02) and a non-significant difference for Toxocara seropositivity (p = 0.41). All participants were negative for IgM anti-Toxoplasma gondii. Demographic parameters did not significantly affect these seroprevalence frequencies (p > 0.05). IL-10 was significantly higher among JIA patients compared to controls (p = 0.007) and seropositive anti-T. gondii JIA exhibited significantly higher IL-10 levels compared to seronegative ones (p = 0.03). Seropositive anti-T. gondii IgG JIA patients had a significantly higher disease activity score (JADAS-27) than seronegative anti-T. gondii IgG cases (p = 0.02). There was a significant positive correlation between anti-T. gondii IgG and JADAS-27 score (p = 0.009). A significant association was detected between T. gondii infection and DMARDs including the biological therapies (p < 0.05). Overall, this study supports a possible association between T. gondii infection and JIA, IL-10, disease activity score, and DMARDs therapies. It is possible that IL-10 plays a role in the development of JIA and contributes to persistent asymptomatic infection with T. gondii in JIA patients. As a result, a recommendation for screening tests for T. gondii infection among JIA patients is crucial before and during commencing DMARDs therapies and closely monitoring early signs of infection.

Toxocara canis seropositivity in different exposure groups in the Khyber Pakhtunkhwa province of Northwest Pakistan

Human toxocariasis is a highly prevalent zoonosis worldwide but is underreported in most countries. This study was conducted to evaluate Toxocara canis seropositivity in different exposure sub-groups located in the Mardan, Swabi, and Nowshera districts of the Khyber Pakhtunkhwa province of Northwest Pakistan. A total of 400 blood samples were collected from males 15 years of age and older with no animals, with livestock, with dogs and/or cats living in the house, and from butchers and veterinarians or para-veterinarians. Serum was tested using a commercial ELISA kit for detection of IgG antibodies against T. canis. Proportion seropositive was presented for each group and differences between groups were evaluated using the chi-square or Fisher's exact test as appropriate. Possible risk factors obtained through administration of a questionnaire were also evaluated for each sub-population. Overall T. canis seroprevalence was 14.2%, with a significant difference found between the seroprevalence of individuals with no animals (5.0%; 5/100), individuals with dogs and/or cats living in the household (8.0%; 8/100), individuals with livestock (18.0%; 18/100), veterinarians or para-veterinarians (24.0%; 12/50), and butchers (28.0%; 14/50) (p < 0.001). Significant differences in seropositivity by income bracket, education level, and working in the fields were found for some sub-groups. Study findings demonstrate that certain sub-populations, in Northwest Pakistan, may be at greater risk of T. canis infection. Development and implementation of targeted preventive strategies may, therefore, be needed.

Toward anthelmintic drug candidates for toxocariasis: Challenges and recent developments

Infections caused by parasitic helminths rank among the most prevalent infections of humans and animals. Toxocariasis, caused by nematodes of the genus Toxocara, is one of the most widespread and economically important zoonotic parasitic infections that humans share with dogs and cats. Despite the completion of the Toxocara canis draft genome project, which has been an important step towards advancing the understanding of this parasite and the search for drug targets, the treatment of toxocariasis has been dependent on a limited set of drugs, necessitating the search for novel anthelmintic agents, specially against Toxocara larvae in tissues. Given that research, development, and innovation are crucial to finding appropriate solutions in the fight against helminthiasis, this paper reviews the progress made in the discovery of anthelmintic drug candidates for toxocariasis. The main compounds reported in the recent years regards on analogues of albendazole, reactive quinone derivatives and natural produts and its analogues. Nanoparticles and formulations were also reviewed. The in vitro and/or in vivo anthelmintic properties of such alternatives are herein discussed as well as the opportunities and challenges for treatment of human toxocariasis. The performed review clarify that the scarcity of validated molecular targets and limited chemical space explored are the main bottlenecks for advancing in the field of anti-Toxocara agents.

A case report of spinal toxocariasis with extensive tumor-like involvement

BACKGROUND

Toxocariasis is a common parasitic infection worldwide. Although it can present as several clinical syndromes, neurological manifestation is rare. Only a few reports are available on spinal cord involvement of toxocariasis. We report a case that presented with gait disturbance due to progressive lower limb spasticity. The patient had had visceral toxocariasis infection 8 years before. A spine magnetic resonance image (MRI) showed syringomyelia along the entire thoracic cord with small nodular enhancing lesions in the mid-portion of the syrinx, which led to the suspicion of ependymoma. Surgical mass removal was performed. However, histopathological examination of the mass did not show any malignant cells; instead, there were numerous axonal retraction balls with an eosinophilic granular body-like appearance. The serum antibody titer against toxocariasis was borderline high. Taken together, these observations led to a diagnosis of Toxocara infection, and the patient was treated with albendazole.

CONCLUSION

To the best of our knowledge, this is the first case report of tumor-like spinal toxocariasis involving extensive lesions. A solid enhancing mass with accompanied syrinx and hemorrhage might be a Toxocara infection. It can easily be diagnosed with serologic tests and simply be treated with oral albendazole if suspected.

LARVICIDE ACTIVITY OF LACTOBACILLUS SPP. AND SACCHAROMYCES BOULARDII SUPERNATANTS ON TOXOCARA CANIS

Experimental studies have demonstrated the potential of probiotics to control visceral toxocariasis, which is a tissue parasitosis that is difficult to treat. This study evaluated the in vitro activity of probiotics and their supernatants on Toxocara canis larvae. The probiotics Lactobacillus rhamnosus (ATCC 7469), Lactobacillus paracasei (ATCC 335), Saccharomyces boulardii, Saccharomyces cerevisiae, and Bacillus cereus var. toyoi were tested in the following preparations: probiotic (P) 1 × 102 to 1 × 109 colony-forming units (CFUs), inactivated probiotic (IP) 1 × 102 to 1 × 109 CFUs, supernatant probiotic (SUpP), and inactivated probiotic supernatant (SupIP). The probiotics and their respective supernatants were separately incubated with 100 T. canis larvae per well using microculture plates with RPMI-1640 medium for 48 hr at 37 C and 5% CO2. The evaluation of the in vitro tests was based on the viability of T. canis larvae, through morphologic integrity, positive motility, and the absence of trypan blue stain. Only culture supernatants (SUpP and SUpIP) of Lactobacillus spp. resulted in 100% dead larvae, whereas S. boulardii showed larvicidal activity in T. canis >70%. The rest of the tests did not show larvicide activity. Therefore, it is important to investigate the supernatant effects of Lactobacillus spp. and S. boulardii in vivo on T. canis visceral infections, their mechanisms of action, and major metabolites involved.

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.

Prevalence of intestinal parasites in animal hosts and potential implications to animal and human health in Edo, Nigeria

BACKGROUND

Intestinal parasites in livestock cause huge economic setbacks. Moreover, these parasites can threaten human health when also present in companion animals.

OBJECTIVES

The study examined the prevalence and burden of intestinal parasites among roaming/migrating animals (goats, sheep, cattle, and dogs) to provide insights into the risk of potential human parasitic infections.

METHODS

A total of 1,741 fecal samples from goats (n = 920), sheep (n = 335), cattle (n = 230) and dogs (n = 256) were obtained randomly across 18 local government areas in Edo State, Nigeria. The parasite samples were recovered and identified under a microscope. Molecular tools were used to identify Toxocara spp.

RESULTS

Eighteen different parasites were isolated. Among the different groups of parasites observed, nematodes occurred the most, followed by protozoans. Among nematodes, Haemonchus was most prevalent in goats (28.04%) and sheep (29.85%), while Strongyloides (10.86%) and Bunostomum (8.69%) were relatively high in cattle. Strongyloides (3.9%), hookworm (3.9%), and Toxocara (3.12%) were the predominant parasites in dogs. For protozoan parasites, Eimeria was most common in all 4 animal hosts. Several goats (2.39%) and sheep (2.38%) tested positive for Fasciola spp. Molecular analysis confirmed Toxocara canis in dogs for the first time in Nigeria.

CONCLUSIONS

The major parasites recovered from these roaming/migrating animals have zoonotic potentials that can threaten human health.

Retrospective Survey of Dog and Cat Endoparasites in Ireland: Antigen Detection

Endoparasites of dogs and cats, play an important role in both veterinary medicine and public health. Untreated and stray dogs and cats, in particular, play an important role in contaminating the environment with important zoonotic parasites. Thus, the aim of this study was to estimate the prevalence of intestinal parasites in stray dogs and cats using highly sensitive and specific copro-antigen tests. Archive faecal samples from previous surveys conducted between 2016−2019 from dogs (n = 789) and cats (n = 241) were included in this study. The IDEXX Fecal Dx™ antigen panel was used for the detection of Toxocara, hookworms, Trichuris and the SNAP™ Giardia antigen assay was used for the detection of Giardia infection. Giardia duodenalis was the most common parasite (26%, n = 205) detected in the dogs, followed by ascarids (17.6%, n = 139) and hookworms (5.3%, n = 42). Trichuris vulpis was only detected in 1 dog. Ascarids (23.2%, n = 56) was the most common parasite detected in the cats, followed by Giardia (12.9%, n = 31) and hookworms (n = 7, 2.9%). No whipworms were detected in cats. Overall, there was little difference in the positivity between sexes in both dogs and cats. However, in terms of age, adolescent dogs (<3 years) and kittens (<1 year) had the highest parasite prevalence overall, with G. duodenalis and ascarids being the most prevalent. This study shows a high prevalence of parasite infection in untreated and stray dogs and cats in the greater Dublin area in Ireland. Since they live in synanthropic conditions and can roam over vast distances they can contaminate public areas and pose a risk to both humans and owned pets that utilise these spaces. It is therefore important to raise public awareness and increase the knowledge on zoonotic parasites.

Investigating the free-roaming dog population and gastrointestinal parasite diversity in Tulúm, México

Free-roaming domestic dogs (Canis lupus familiaris) pose major conservation and public health risks worldwide. To better understand the threat of domestic dogs to wildlife and people and add to the growing literature on free-roaming dog ecology, a study was conducted to estimate the dog population in Tulúm, México. A modified mark-recapture technique and program MARK were used to obtain dog population estimates along six different transects dividing the city. Population estimates ranged from 19.75 dogs in one transect to 101.841 dogs in another, with 150 total dogs identified throughout the study and an estimated minimum population density of 48.57 dogs/km2. Fecal samples were also opportunistically collected for parasite identification through fecal flotation analysis using the McMaster technique. Out of 25 samples collected, 19 tested positive for gastrointestinal parasites with the most common species found being Ancylostoma caninum, followed by Toxocara canis, Dipylidium caninum, and Cystoisospora spp. Parasite loads ranged from 50 to 10,700 ova per gram of feces. The large population of free-roaming dogs and the prevalence of three zoonotic parasites highlight the importance of understanding free-roaming dog ecology and educating the public on the health risks free-roaming dogs pose. Los perros callejeros (Canis lupus familiaris) representan un gran riesgo para la conservación de animales y la salud pública mundialmente. Para comprender mejor la amenaza que significan los perros domésticos para la fauna silvestre y los humanos y aportar a la creciente bibliografía sobre la ecología de los perros callejeros, se realizó una investigación para estimar la población de los perros en Tulúm, México. Se utilizó una técnica modificada de marcado y recaptura junto con el programa MARK para estimar la población canina en seis transectos de la ciudad. Los estimados varían desde 19.75 perros en un transecto hasta 101,841 en otro, con un total de 150 perros identificados en el transcurso de la investigación y una densidad mínima estimada de 48,57 perros/km2. Además, se hizo una recolección oportunista de muestras de heces para la identificación de parásitos por medio del análisis de flotacíon fecal, con el método McMaster. De las 25 muestras recolectadas, 19 resultaron positivas para parásitos gastrointestinales, de las cuales las especies más comunes fueron Ancylostomoa caninum, seguida por Toxocara canis, Dipylidium caninum, y Cystoisospora spp. Las cargas parasitarias variaron desde 50 hasta 10.700 óvulos por gramo de heces. La alta población de perros callejeros y la prevalencia de tres enfermedades zoonóticas resaltan la importancia de entender la ecología de los perros callejeros y educar al público sobre los riesgos que significan los perros callejeros para la salud.

Isolation and Production of Human Monoclonal Antibody Proteins against a Toxocara canis Excretory-Secretory Recombinant Antigen

Toxocariasis is a widespread zoonotic parasitic disease with a significant socioeconomic impact, particularly on underprivileged communities. Limitations of existing diagnostic tools and vague presenting symptoms may lead to misdiagnosis, thus underestimating the actual global impact of the disease. The present study describes the isolation and production of novel recombinant monoclonal antibodies against Toxocara canis recombinant TES-26 antigen (rTES-26) utilizing a human helminth scFv phage display library. The isolated antibody clones were characterized based on their gene sequences and binding characteristics. Three clones representing unique gene families (clone 48: IgHV3-LV1; clone 49: IgHV3-LV3; clone 50: IgHV6-LV3) were isolated, but only clones 48 and 49 showed successful insertion of the full-length scFv antibody sequence after sub-cloning. Both clones produced antibody proteins of good solubility and satisfactory yield and purity. Binding assays via Western blot and ELISA using rTES-26 and Toxocara canis native protein showed that both monoclonal antibodies were highly specific and sensitive to the target antigen. A preliminary antigen detection ELISA showed the diagnostic potential of the monoclonal antibody proteins. The proteins can also be useful in studying host−parasite interactions and therapeutic applications.

Evaluation of new Toxocara canis chimeric antigens as an alternative to conventional TES-Ag for anti-Toxocara antibodies detection

Human toxocariasis is one of the neglected helminthiases and it is caused by the zoonotic roundworm species Toxocara canis and Toxocara cati. Diagnosis of human toxocariasis is based on the combination of clinical, parasitological, and epidemiological criteria, as well as serology tests that detect anti-Toxocara antibodies. Notwithstanding, due to the absence of pathognomonic symptoms and signs of the disease, serology is the key evidence to support a conclusive diagnosis. TES-ELISA is the most widely used serological test for diagnosis. However, cross-reaction of TES antigens with antibodies produced to other helminth antigens is a major drawback for its application in countries with high parasitic prevalence. T. canis recombinant antigens have been described as an alternative to native TES for diagnosis. Nevertheless, the selection of antigenic proteins is a complex process that requires validation. In this paper, we developed an eGFP carrier-based system to express and purify blocks of recombinant polypeptides of T. canis antigenic proteins. Intense cross-reaction polypeptides were detected by Immunoblot and avoided to finally produce a chimeric prototype protein. Additionally, a control chimeric protein that harbors the complete tested proteins was produced. Purified chimeric antigens were tested in ELISA and Immunoblot assays with 310 sera samples of negative and positive control individuals. Our results showed that chimeric rCHITC0 and rCHITC1 antigens (with sensitivities of 62% 58%, 38% and 16% in IB-rCHITC0, ELISA-rCHITC0, ELISA-rCHITC1 and IB-rCHITC1 respectively for OLMS) can perform better in terms of specificity (being 91%, 89%, 87% and 76% for ELISA-rCHITC1, IB-rCHITC1, ELISA-rCHITC0 and IB-rCHITC0 respectively for OLMS) than T. canis TES-ELISA (with 61% specificity), giving a higher signal with serum samples of infected individuals as well the possibility to discriminate false positive cases with other parasitic infections. Our data suggest that T. canis chimeric proteins, represent candidate antigens for phase II studies.

Gastrointestinal helminths of stray dogs in Erzurum province: prevalence and risk to public health

Dogs have an important role in public health due to their close contact with humans and living in common areas. This study was aimed to investigate the presence and prevalence of gastrointestinal system helminths in stray dogs in Erzurum province. Gastrointestinal helminth eggs were detected in a total of 190 out of 446 (42.6%) in stray dogs in Erzurum province. In the study, taeniid eggs (17.71%, 79/446), T. canis (16.82%, 75/446), T. leonina (12.78%, 57/446), Linguatula spp. (4.48%, 20/446), spiny-headed worms (2.91%, 13/446), hookworms (2.69%, 12/446), Alaria spp. (1.12%, 5/446) and Trichuris spp. (0.22%, 1/446) eggs were observed. In addition, proglottid structures of Mesocestoides spp. (3.14%), Taenia spp. (2.69%), and D. caninum (1.12%), adults of Alaria spp. (0.22%), T. canis (0.22%), and T. leonina (0.22%) were detected. According to the results of the study, zoonotic parasites including taeniid cestodes, T. canis, Linguatula spp., spiny-headed worm, hookworm, Alaria spp., and Trichuris spp. were common in stray dogs in the province. Public health risks can be reduced by regular deworming of dogs, proper management of the process, prevention of environmental contamination with dog feces, and proper enforcement of sanitation protocols.

A Survey of Helminths of Dogs in Rural and Urban Areas of Uzbekistan and the Zoonotic Risk to Human Population

Dogs are very popular pets that can be infected with a wide diversity of endo- and ectoparasites, some of which have zoonotic potential. The aim of the present study was to determine the diversity and prevalence of helminths in rural and urban dogs in Tashkent, Samarkand and Karakalpakstan regions of Uzbekistan. A total of 399 dogs from rural and urban areas were examined by necropsy between November 2016 and March 2022. All helminth species were morphologically identified. A total of 31 species belonging to the classes Trematoda (3), Cestoda (9), Nematoda (18) and Acanthocephala (1) were identified in 378 dogs (94.7%). Twenty-one species are indicated for the helminth fauna of urban dogs and 31 species for rural dog populations. From the 31 species of helminths identified 18 species are zoonotic and four of them (Echinicoccus granulosus, Dipylidium cani-num, Toxocara canis, Dirofilaria repens) have a significant epidemiological importance. The study showed that the prevalence and diversity of helminths in dogs in rural areas of Uzbekistan is higher than in urban dogs.

Prevalence of major digestive and respiratory helminths in dogs and cats in France: results of a multicenter study

Background

The local distribution of helminths in dogs and cats and the evaluation of risk of contamination represent an important challenge for veterinarians due to their effects on animal health and their potential zoonotic risk. The overall goal of this study was to estimate the prevalence of the digestive and respiratory helminths infecting client-owned dogs and cats in France.

Methods

Faecal samples were collected from 414 pet dogs and 425 pet cats at 20 study sites during 2017–2018 and analysed by coproscopy. The samples included specimens collected from animals of both genders and various breeds and ages from a variety of living environments, and with different lifestyles and feeding regimes. Associations between parasitic infection and qualitative factors were explored.

Results

Overall, 125 (14.9%) samples (15.2% in dogs and 14.6% in cats) were positive for at least one of the species of helminths identified. Infection rates were highest for Toxocara canis and Toxocara cati (8.5% and 11.3%, respectively), while Toxascaris leonina was found only in one cat (0.2%). The apparent prevalence of Ancylostoma caninum and Uncinaria stenocephala in dogs was 1.7% and 4.3%, respectively. No hookworms were found in cats. Whipworms (Trichuris vulpis) were identified in 2.7% of the dogs. Tapeworms (Dipylidium caninum and Taeniidae) were rarely found (< 1% in dogs and < 3% in cats). The prevalence of Angiostrongylus vasorum Crenosoma vulpis, and Strongyloides stercoralis in dogs, Aelurostrongylus abstrusus in cats and Eucoleus spp. / Capillaria spp. in both dogs and cats was < 1%. Significantly higher fecal parasite emission rates were identified in young individuals, in animals with outdoor access, in animals living in the countryside and in intact animals (especially in cats). In addition, cats not fed exclusively with commercial diets and living with other animals (dogs and/or cats) were at higher risk for parasites. For dogs, hunting/herding and walking off-leash were found to be additional risk factors. Furthermore, pets with no reported history of deworming or dewormed > 1 year before the study were positive for parasites significantly more often than pets dewormed < 1 year before study participation.

Conclusions

The overall prevalence of helminths (some of which are zoonotic), the risk factors and the reportedly low deworming frequencies identified in this study (20.5% animals having never been dewormed and only 26.4% dewormed ≥ 3 times/year) illustrate the need for improving pet owners’ adherence to anthelmintic guidelines in France.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05368-7.

Evaluation of the cytokines response in buffaloes focused on its milk as a newly emerging indicator tracing for toxocariasis

This study aimed to evaluate the immune responses and oxidative stress provoked by Toxocara vitulorum infection in buffaloes with special reference to milk parameters as an emerging tool. The use of the milk tool was reported for the first time in tracing T. vitulorum infection in Egyptian buffaloes. Intestine, milk, serum, and liver samples were gathered from flocks in Cairo and Giza districts to evaluate buffalo immune responses provoked by T. vitulorum. The compositional items and somatic cells of milk were monitored. The intestine and milk were evaluated for interleukin IL-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) by quantitative real-time polymerase chain reaction protocol and the analysis of malondialdehyde (MDA) as an oxidative stress marker. The mean percentages for the total solids, fats, proteins, lactose, salts, pH, and somatic cell count/ml in positive samples were 11.23 ± 0.37, 5.1 ± 0.17, 4.44 ± 0.14, 3.9 ± 0.14, 0.81 ± 0.02, 6.8 ± 0.22, and 4.23 × 10⁶± 1.41 × 10⁵ cells/ml, respectively. A significant difference (p < 0.05) was observed in the mean values of compositional items except for the total protein %, salts %, and pH. For T. vitulorum-contaminated samples, the milk IL-1β, IL-6, TNF-α, and MDA (nmol/ml) were 7 ± 0.23, 18 ± 0.6, 17 ± 0.56, and 3.7 ± 0.12, respectively (which were less than the values for intestinal cytokines). There is a statistical difference (p < 0.05) between positive and negative samples in the intestinal, milk cytokines, and MDA. This study is an initial investigation of the utilization of intestine and milk cytokines in the evaluation of buffalo toxocariasis.

Seroprevalence of toxocariasis among allergic patients in Kuwait and its association with eosinophilia

Toxocariasis is a worldwide helminthic infection which is transmitted from infected dogs and cats and has been associated with peripheral blood eosinophilia. The Centers for Disease Control and Prevention (CDC) placed toxocariasis among the top 6 parasitic diseases in the USA which are prioritized for public health action. To our knowledge, there are no reports on human toxocariasis in Kuwait or in the other Gulf Cooperation Council (GCC) countries. This study aims at investigating the seroprevalence of toxocariasis among allergic patients in Kuwait and its association with eosinophilia, age, gender, nationality, and history of direct contact with dogs or cats. From September to December 2021, the laboratory records of allergic patients referred to Al-Rashed Allergy Hospital, Kuwait were reviewed and a total of 400 serum samples were selected: 200 samples from patients with normal eosinophil count (< 500 cells/μl) and 200 samples from patients with eosinophilia (> 500 cells/μl). The sera were screened for anti-Toxocara canis IgG antibodies via antibody enzyme-linked immunosorbent assay (Ab-ELISA). The seropositive patients were asked about their history of direct contact with dogs or cats. Statistical analyses were performed using Microsoft Excel® Analysis ToolPak software. Toxocariasis seropositivity was detected in 10 out of 400 (2.5%) allergic patients. Five patients had eosinophilia while 5 had normal eosinophil count. There was no difference in mean age or gender between Toxocara-seropositive and seronegative patients (p > 0.05). The seroprevalence rate was lower-than-expected among Kuwaiti patients (2/307, 0.7%) in comparison with non-Kuwaiti patients (8/57, 14.0%) (χ2 = 33.603, df = 1, p < 0.001) who originated from endemic South/Southeast Asian countries. Seven out of 8 (87.5%) seropositive patients had a history of direct contact with cats, dogs, or both. The seroprevalence rate of toxocariasis among allergic patients in Kuwait was 2.5%. Raising awareness and early deworming treatment/prophylaxis for juvenile dogs and cats remain crucial for toxocariasis prevention.

Dog and Cat Contact as Risk Factor for Human Toxocariasis: Systematic Review and Meta-Analysis

Toxocariasis, a neglected parasitic zoonosis with worldwide distribution, has been reportedly associated to different risk factors in several epidemiological and meta-analysis studies. However, dog and cat contact (environmental and animal exposure) as isolated associated risk factor for children and adults remains to be fully established. Accordingly, the present meta-analysis has aimed to directly assess dog and cat contact for toxocariasis seropositivity in under-18 and adult persons, using a survey strategy of PubMed/Medline, Embase, Scopus and Scielo Databases, from January 2009 to December 2021. A meta-analysis model of random effects was applied to estimate odds ratio (OR) with 95% Confidence Interval (CI). The statistical heterogeneity was evaluated by the Cochran Q-Test and I² values. A total of 41 transversal studies (n = 20.515 individuals) from different geographic regions (classified by the World Health Organization) were included herein. In overall, 1,882/13,496 (13.95%; 95% IC = 13.4–14.5) youngers and 513/7.019 (7.3%; 95% CI = 6.7–7.9) adults in contact with dogs or cats were serologically reagent for anti-Toxocara antibodies. Association of dog and cat contact was observed only in youngers, with both dogs (OR = 1.53; p < 0.0001) and cats (OR = 1.64; p = 0.0001). In addition, association of dog and contact and serology was statistically significant in populations of Americas (OR = 1.37; 95% CI = 1.1–1.7), Middle East (OR = 2.9; 95% CI = 1.6–5.1) and West Pacific (OR = 1.6; 95% IC = 1.3–1.9). In conclusion, contact with dogs and cats, particularly by younger individuals and in regions such as Americas, Middle East, and West Pacific, should be always a public health concern for toxocariasis. Moreover, dogs and cats should be periodically dewormed, washed and hair cleaned prior to contact with youngers. Finally, robust statistical results herein may serve as basis for future strategies and preventive measures for safer dog and cat contact.

Cytokine Profile in Aqueous Humor of Patients With Ocular Toxocariasis

Purpose

Ocular toxocariasis (OT) is a vision-threatening disease with a largely unknown intraocular pathogenesis. Herein, we determined the cytokine expression profile in aqueous humor (AH) of patients with OT.

Methods

This is a retrospective case-control study of cytokine levels in AH of patients with OT and uveitis and control subjects. Thirty samples from eyes with OT, 23 from eyes with non-OT uveitis, and 25 from eyes with age-related cataract were analyzed using a multiplexed magnetic bead immunoassay. Thirty-one cytokines were detected and classified into 5 categories: T-helper type 1 (Th1) -associated cytokines, Th2-associated cytokines, Th17 cytokine, proinflammatory mediators, and growth factors.

Results

In the 31 cytokines, 9 cytokines were undetectable, including IL-1a, IL-1b, IL-2, IL-3, IL-12p70, IL-17A, TGF-a, TNF-β, and IFN-g. From the 22 cytokines, 13 exhibited significantly increased expression in the OT group than in the control group, including TNF-a, IFN-a2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, sCD40L, PDGF-AA, PDGF-AB/BB, FLT3l, and EGF. There were 5 cytokines exhibited significantly increased expression in the OT group than in non-OT group, including IL-5, IL-9, IL-10, IL-13, and PDGF-AA. There was no significantly decreased expression in any cytokines in the OT group when compared with control or non-OT groups. To the 5 cytokines that showed significant difference in OT group alone, IL-10 and IL-13 exhibited more than 13-fold increase, and IL-5 showed the most obvious as 27-fold increase in OT patients, when compared with that in control group.

Conclusion

The cytokine profile expression in aqueous humor from patients with ocular toxocariasis was investigated, and our findings suggest that Th1 and Th17 cytokine responses are not enhanced, whereas the cytokine status was polarized toward a Th2 response. Our findings also suggest the involvement of IL-5, IL-10, and IL-13 in the immunopathogenesis of ocular toxocariasis.

The Value of the Antibody Detection in the Diagnosis of Ocular Toxocariasis and the Aqueous Cytokine Profile Associated With the Condition

Introduction

To evaluate and compare the specificity of Toxocara canis-specific antibody detection in the serum and aqueous samples for the diagnosis of ocular toxocariasis (OT) and explore the cytokine profiles associated with the condition in children.

Materials and Methods

This is a prospective cohort study. The inclusion criteria were the clinical presentations of OT, which included unilateral vision reduction, typical peripheral or posterior pole granuloma with variable degrees of vitritis, and exclusion of other diagnoses. The titer of antibody against the excretory-secretory antigen of Toxocara canis [T-immunoglobulin G (IgG)] was measured in serum and aqueous samples that were taken from the affected eyes. The diagnosis of OT was made upon positive detection of T-IgG either in the serum or aqueous. The rest with typical clinical presentations as described above but a positive serum or aqueous T-IgG could not be confirmed were diagnosed as suspected OT. Cytokines were measured using multiplexed cytometric bead array system.

Results

Two hundred and eleven eyes of 211 patients had participated in the study. One hundred and twenty-eight eyes were diagnosed as OT. The median age of the cohort was 7.7 years with a male to female ratio of 2.5:1. Major initial symptoms were decreased vision (74%) and strabismus (22%). The percentages of eyes with peripheral granuloma, posterior granuloma, and endophthalmitis were 40, 18, and 41%, respectively. Vitritis (100%), vitreous strands (64%), retinal fibrotic bands (57%), and retinal detachment (42%) were the most common signs. T-IgG was positive in 66.7% of the aqueous and 57.2% of the serum samples. Forty-four patients were diagnosed T-IgG negative in both serum and aqueous of the affected eyes. Interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, IL-8, eosinophil chemotactic protein (Eotaxin), MCP-1β, and vascular endothelial growth factor (VEGF) were higher in T-IgG negative eyes when compared to controls and further increased in T-IgG positive eyes. However, only T-IgG positive eyes showed increased IL-5, IL-13, and IL-10. IL-1β, tumor necrosis factor-alpha (TNF-α), IL-12, IL-2, interferon-gamma (IFN-γ), and IL-4 were undetectable in all eyes.

Conclusions

Pediatric OT is often present with severe retinal complications. Polarized intraocular Th2 response was only found in aqueous T-IgG positive eyes. Our results supported an aqueous sample-based antibody test for the more specific diagnosis of OT.

Prevalence of Anti-Toxocara canis Antibodies in Dogs Detected with Recombinant Cathepsin L-1 and TES-26 Antigens in Three States of India

PURPOSE

Toxocara canis is a common intestinal nematode parasite of dogs with recognized zoonotic potential in tropical countries. The purpose of this study was to determine the seroprevalence of anti-T. canis antibodies in two target dog populations: household and community-owned, distributed over three distinct geographical regions of India.

METHODS

Two recombinant proteins of T. canis, cathepsin L-1 (CL-1) and Toxocara excretory-secretory-26 (TES-26), expressed in Escherichia coli, were used for studying the prevalence of anti-T. canis antibodies in dog populations in three distinct geographical regions of the country using an IgG-enzyme-linked immunosorbent assay. A total of 615 sera, 507 from household and 108 from community owned dogs were screened for IgG antibodies.

RESULTS

ELISA with recombinant (r) CL-1 showed 37.7% and 53.7% seroreactivity in household and community owned dogs, respectively. However, the rTES-26 antigen showed higher seroreactivity of 39.6% and 87.9% in the corresponding groups of household and community owned dogs, respectively. Chi-squared analysis of the data indicated that there was not any association in the prevalence of anti-T. canis antibodies between the samples analyzed from the three regions and the two cohorts of dog groups. However, the seroprevalence was higher in community owned dogs compared to household owned dogs.

CONCLUSION

The results of the serological evaluation suggest that both the groups of dogs show high seroreactivity rates and are likely to harbor T. canis infections of tissue dwelling dormant larvae.

Toxocara canis- and Toxocara cati-Induced Neurotoxocarosis Is Associated with Comprehensive Brain Transcriptomic Alterations

Toxocara canis and Toxocara cati are globally occurring zoonotic roundworms of dogs and cats. Migration and persistence of Toxocara larvae in the central nervous system of paratenic hosts including humans may cause clinical signs of neurotoxocarosis (NT). As pathomechanisms of NT and host responses against Toxocara larvae are mostly unknown, whole-genome microarray transcription analysis was performed in cerebra and cerebella of experimentally infected C57Bl/6J mice as paratenic host model at days 14, 28, 70, 98, and 120 post-infection. Neuroinvasion of T. cati evoked 220 cerebral and 215 cerebellar differentially transcribed genes (DTGs), but no particular PANTHER (Protein ANalysis THrough Evolutionary Relationships) pathway was affected. In T. canis-infected mice, 1039 cerebral and 2073 cerebellar DTGs were identified. Statistically significant dysregulations occurred in various pathways, including cholesterol biosynthesis, apoptosis signaling, and the Slit/Robo mediated axon guidance as well as different pathways associated with the immune and defense response. Observed dysregulations of the cholesterol biosynthesis, as well as the Alzheimer disease-amyloid secretase pathway in conjunction with previous histopathological neurodegenerative findings, may promote the discussion of T. canis as a causative agent for dementia and/or Alzheimer’s disease. Furthermore, results contribute to a deeper understanding of the largely unknown pathogenesis and host-parasite interactions during NT, and may provide the basis for prospective investigations evaluating pathogenic mechanisms or designing novel diagnostic and therapeutic approaches.

Two trichinellosis outbreaks in Serbia – challenging diagnosis due to a potential co-infection with Toxocara spp

In Serbia, in most cases, small family outbreaks of trichinellosis occur due to the consumption of untested infected meat from domestic pigs that are raised and slaughtered in the backyards of small individual farms. The aim of this study is to present data regarding 24 patients involved in two outbreaks that occurred in two neighbouring districts in Serbia during a closely related period of time in August 2014. The source of infection in the first outbreak was undercooked pork, while raw pork sausages caused the second outbreak. Meat samples and sausages were Trichinella spp. positive by artificial digestion. With the aim to obtain a second opinion and validate the serological findings discovered at the Public Health Institute Nis, all samples were sent to the National Reference Laboratory for Trichinellosis, INEP. Serodiagnosis showed that 21 persons were positive (87.5%) and three (12.5%) were negative for anti-Trichinella antibodies, while 15 patients fulfilled the trichinellosis case definition. Western blot analysis (using an epitope unique for the muscle larvae stage of the Trichinella genus) confirmed the diagnosis of trichinellosis in five patients. Six patients also had specific antibodies against Toxocara canis (T. canis). Due to the fact that in endemic foci in Serbia there is the presence of Trichinella spiralis and T. canis and that these two infections could be asymptomatic, we consider that trichinellosis cases were irrefutably proven. The dilemma about the existence of co-infection with T. canis remained open due to the lack of clinical findings.

Soil contamination by Ancylostoma spp. and Toxocara spp. eggs in elementary school playgrounds in the extreme south of Brazil

Millions of people worldwide, and especially schoolchildren, may be infected by geohelminths due to their exposure to a contaminated environment. The aim of this study was to evaluate soil contamination by Ancylostoma spp. and Toxocara spp. eggs in recreation areas at elementary schools in Pelotas, state of Rio Grande do Sul, Brazil. Sand samples were collected from 22 schools and were processed using the centrifugal flotation method. Helminth eggs with zoonotic potential were found in 12 out of the 22 schools (54.5%). Contamination by Ancylostoma spp. and Toxocara spp. was observed in 36.4% (8/22) and 27.3% (6/22) of the soil samples collected at these schools, respectively. These findings of eggs show that the school communities are exposed to risks of zoonotic transmission.

Toxocara canis 30-35 kDa excretory-secretory antigen is an important marker in mice challenged by inocula containing different parasite load levels

The Western-blotting technique was applied to identify antigenic fractions of excretory-secretory Toxocara canis antigen recognized by IgG antibodies throughout an experimental infection in mice challenged by different inocula. Mice were inoculated with 5, 50 and 500 embryonated eggs and serum samples were collected 15, 30, 60, 90 and 120 days post-infection. Serum samples were analyzed using an excretory-secretory Toxocara antigen. Antibodies recognized antigenic fractions from 30 to 90 kDa. The protein fraction of 30-35 kDa was the most frequently recognized regardless of the size of inoculum and the stage of infection represented by the different collection times, but the antigenic recognition was more evident in groups infected with 50 and 500 eggs. This study presents an antigenic panel of the excretory-secretory antigen of T. canis and suggests that the 30-35 kDa antigenic fraction is a promising marker of the infection and should be further explored in future studies on experimental toxocariasis.

The epidemiology and control of Toxocara canis in puppies

Toxocara canis is a helminth zoonosis that is estimated to infect more than 100 million dogs and 1 billion people, mostly in the tropics. Humans can be infected by accidentally ingesting embryonated T. canis eggs from the environment or occasionally after ingesting L₃ larvae from paratenic hosts. This study investigated the importance of vertical transmission and the role of puppies in the epidemiology of T. canis through the examination of fecal samples from dogs less than one year of age in Grenada, West Indies, a small island tropical developing country. Samples were stored at 4 °C or in 10% formalin until microscopic examination for helminth eggs or using a rapid antigen test for the presence of protozoan species. A knowledge, attitudes and practices study was completed among dog owners, physicians and veterinary students. Of 306 dogs less than one year of age, 147 (48%) were found to have T. canis eggs. Vertical transmission was indicated by the proportion of infected dogs increasing from 50% at two weeks of age (from in utero transmission) to 70% by 12 weeks (in utero and lactogenic transmission). After 12 weeks the positivity rate dropped rapidly with no dogs over 40 weeks of age being infected. As T. canis eggs were found in puppy feces at two weeks of age, initial treatment of puppies should begin earlier, at twelve days post-partum, than currently recommended to prevent shedding of eggs. Perhaps even more importantly, treatment of pregnant dogs, preventing vertical transmission, would have a major impact on the control of T. canis infection. Knowledge of T. canis and other zoonotic helminths such as Ancylostoma caninum was found to be low among dog owners, physicians and veterinary students. None of the dog owners treated their dogs for helminths, all were unaware of the risk of zoonoses, and only 9% picked up dog feces. Efforts to prevent vertical transmission and to increase awareness and knowledge of these zoonoses could result in reducing their public health impact.

Factors associated with endoparasites and ectoparasites in domiciled dogs in the metropolitan area of Toluca, México

Introducción.

Los endoparásitos y ectoparásitos en perros son de distribución mundial. La estrecha relación entre los perros y el hombre implica un riesgo de transmisión de parasitosis zoonóticas, por lo cual es necesario conocer las especies que parasitan a los perros de esta zona y determinar los factores asociados.

Objetivos.

Estimar la prevalencia de endoparásitos y ectoparásitos, identificarlos en perros domiciliados de la zona metropolitana de Toluca, México, y determinar la prevalencia de Dipyilidium caninum en pulgas del género Ctenocephalides spp.

Materiales y métodos.

Se recolectaron muestras de 402 perros que fueron llevados a consulta en cuatro hospitales de referencia de Toluca. En el diagnóstico de endoparásitos, se utilizaron las técnicas coproparasitoscópicas de frotis directo, flotación y sedimentación; además, se recolectaron ectoparásitos para su identificación taxonómica. Por último, la detección de D. caninum en pulgas se hizo mediante la reacción en cadena de la polimerasa (PCR).

Resultados.

El 37,2 % de los perros resultó positivo para endoparásitos. Los géneros o especies identificados fueron Toxocara spp., Giardia spp., Ancylostoma spp., Cystoisospora spp., D. caninum, Taenia spp. y Trichuris vulpis. Se determinó una prevalencia de ectoparásitos de 13,13 %. Se identificaron pulgas de las especies Ctenocephalides felis y C. canis, en tanto que solo un animal presentó parasitosis por Rhipicephalus sanguineus y otro por Trichodectes canis. La prevalencia de D. caninum en pulgas fue del 9,5 %.

Conclusión.

La prevalencia de endoparásitos fue de 37,2 % y, la de ectoparásitos, de 13,1 %. Por primera vez en México se hizo un análisis de endoparásitos y ectoparásitos en una misma población de perros, así como el diagnóstico molecular de D. caninum.

Toxocariasis-associated urinary system diseases: a systematic review of reported cases

BACKGROUND

Toxocariasis is a neglected tropical disease caused by Toxocara canis and Toxocara cati. Toxocara species can involve many organs, such as the brain, heart and lungs, however, the urinary system involvement of toxocariasis is largely unknown.

METHODS

We performed a systematic review to identify cases infected with urinary tract toxocariasis.

RESULTS

We identified seven cases that were eligible to be reviewed. Among the included citations, four studies reported bladder involvement and three reported kidney involvement. Fever, urinary, and abdominal presentations were amongst the most important clinical symptoms. Eosinophilic cystitis and nephrotic syndrome were the most common diagnoses.. The treatment regimen included a combination of anthelmintic drugs and steroids.

CONCLUSIONS

In cases of urinary tract presentations accompanied by eosinophilia or histopathologic findings suggestive of parasitic infection, toxocariasis should be included in the list of differential diagnoses, especially in endemic areas.

Toxocara DNA amplification in serum and tissue samples in BALB/c mice

Toxocariasis is still a neglected parasitic disease worldwide and much about its biology and diagnosis has yet to be understood. The migration of third stage larvae via bloodstream suggests a potential use of molecular tools in diagnosis as well to deepen the knowledge about its migration behaviors. Conventional PCR was applied in serum and tissue samples from BALB/c mice infected with 5 and 500 embryonated eggs. Blood samples were collected at 15, 30, 60, 90 and 120 days post-infection. Organs were excised at 170 days post infection. There was no DNA amplification in serum samples in any group or day post-infection; contrarily, tissue samples showed DNA amplification. These results also support a continuous larval migration after and/or simultaneously with the neurotropic-myotropic phase. Thus, molecular tools might be useful as a differential diagnosis method, but do not replace immunodiagnostics techniques.

The global prevalence of Toxocara spp. in pediatrics: a systematic review and meta-analysis

BACKGROUND

Toxocariasis is a zoonotic parasitic disease caused by Toxocara canis and Toxocara cati in humans. Various types of T. canis are important.

PURPOSE

The current study aimed to investigate the prevalence of Toxocara spp. in pediatrics in the context of a systematic review and meta-analysis.

METHODS

The MEDLINE (PubMed), Web of Sciences, Embase, Google Scholar, Scopus, and Cumulative Index of Nursing and Allied Health databases were searched to identify peer-reviewed studies published between January 2000 and December 2019 that report the prevalence of Toxocara spp. in pediatrics. The evaluation of articles based on the inclusion and exclusion criteria was performed by 2 researchers individually.

RESULTS

The results of 31 relevant studies indicated that the prevalence of Toxocara spp. was 3%-79% in 10,676 cases. The pooled estimate of global prevalence of Toxocara spp. in pediatrics was 30 (95% confidence interval, 22%-37%; I2=99.11%; P=0.00). The prevalence was higher in Asian populations than in European, American, and African populations.

CONCLUSION

Health policymakers should be more attentive to future research and approaches to Toxocara spp. and other zoonotic diseases to improve culture and identify socioeconomically important factors.