Toxocariasis: a silent threat with a progressive public health impact

Developing a serological test for the diagnosis of toxocarasis using a novel recombinant multi-epitope

Human toxocariasis, a zoonotic infection caused by the ingestion of embryonated eggs of Toxocara canis (T. canis) or Toxocara cati (T. cati), or by consuming paratenic hosts, is characterized by diverse clinical manifestations. Diagnosis of this disease predominantly relies on serological testing, for which the selection of appropriate antigens is crucial to ensure accurate detection. Prior research has highlighted the potential of multi-epitope antigens to improve diagnostic precision. This study focused on evaluating the immunogenicity of synthetic proteins containing multiple immunodominant epitopes derived from T. canis antigens, specifically Toxocara excretory-secretory (TES) proteins TES-120, TES-30, and TES-26. A multi-epitope structure was designed, synthesized, and cloned into the pET28-b expression plasmid. The plasmid was then introduced into Escherichia coli (E. coli) BL21 competent cells, and the recombinant protein was expressed and purified after 16 h of bacterial cultivation. The diagnostic utility of the recombinant antigen for detecting anti-toxocariasis IgG antibodies was evaluated using an indirect Enzyme-Linked Immunosorbent Assay (ELISA). The results showed a sensitivity of 94.2 % and a specificity of 100 %, indicating high diagnostic accuracy. These findings underscore the potential of the synthetic multi-epitope recombinant antigen as a valuable diagnostic tool for improving the accuracy of human toxocariasis diagnostic kits. The designed multi-epitope proteins exhibit strong potential as diagnostic markers, offering high sensitivity and specificity for the development of indirect ELISA-based diagnostic assays. This study contributes to the development of more reliable and precise diagnostic tools for toxocariasis.

Toxocara canis: larvicidal activity and bioavailability analysis of 2-pyrimidinyl-hydrazone derivatives

The treatment of human toxocariasis, a parasitic zoonosis with global distribution, is based on the use of benzimidazole anthelmintic, which have limited efficacy against Toxocara spp. larvae at the tissue level. Therefore, innovation and research into candidates for the development of new drugs for toxocariasis are essential. This study aimed to assess the efficacy of pyrimidine compounds against Toxocara canis larvae, as well as their cytotoxicity and bioavailability. The screening test was performed at 1 mg/mL, in duplicate, in a microplate containing 100 T. canis larvae in RPMI-1640 medium, and the active compound was then tested at 0.5 to 0.05 mg/mL to determine the minimum larvicidal concentration. The compound (E)-2-(2-((5-nitrofuran-2-yl)methylene)hydrazinyl)pyrimidine (PNAH 8) showed 100% larvicidal activity at 1 and 0.5 mg/mL and was not cytotoxic at any concentration tested. In silico analysis showed that the compound adhered to Lipinski's "rule of five" with an excellent miLogP value of 0.6, indicating the compound's high water solubility. And the larvicidal activity of the compound was confirmed by inoculating the contents of the microplates tested on Swiss mice, which showed no migration of larvae in the tissues. The absence of cytotoxicity and adequate bioavailability in silico, comparable to albendazole, the anthelmintic of first choice for the treatment of human toxocariasis, along with the other results, suggest the potential of this compound for future investigations in preclinical tests.

The Nematocidal Effect of Leiurus quinquestratus Scorpion Venom on Toxocara canis in Mice Model

One neglected zoonotic illness is toxocariasis. There are not enough anthelmintic drugs in the market to treat low-effectiveness toxocariasis against migrating larvae. Therefore, it is critical to find new, safe alternatives to toxocariasis treatment today. The venom of the Leiurus quinquestratus scorpion (LQV) has numerous medicinal uses. The purpose of this study was to conduct that LQV had an effect on T. canis larvae in the model of mice. Fifty male mice were divided into five groups (n = 10). Group 1 (Gp1) was the negative group, and from Gp2-Gp5 had been infected with 800-1000 T. canis embryonated eggs. Gp2 was left as positive control, Gp3 was orally administrated with albendazole (Alb) (100 mg/kg/b.wt) for 7 consecutive days at first day post infection (pi), Gp4 was injected intra-peritoneal (i.p) with LQV (0.03 mg/kg/b.wt) for 15 consecutive days at the first day pi, and Gp5 was given Alb/LQV in the same way and doses as Gp3 and Gp4. At the end of the experiment, at 30th pi, the blood samples were collected for evaluating the biochemical and hematological parameters. The larval count reduction in brain were evaluated, and the histopathological changes in brain and liver were detected. The results showed that, treatment with LQV or Alb/LQV combinations significantly reduced the larval burden in the brain of the infected mice with reduction percentage reached to 70, and 72%, respectively. Interestingly, LQV and Alb/LQV significantly reduced IL-4, IL-10, and TNF -α levels and increased IFN-γ levels. Also, improved the liver transaminases activity, and ameliorated liver and brain architecture. Collectively, LQV may be a promising treatment for T. canis infection and albendazole alternative.

Coexistent Ankylosing Spondylitis and Ocular Toxocariasis in a Pediatric Patient Manifesting As Bilateral Panuveitis

The coexistence of ankylosing spondylitis and ocular toxocariasis in the literature is rare and limited to a few case reports. Typically, such cases present as acute nongranulomatous anterior uveitis with Toxocara IgG seropositivity. A patient manifesting with findings of both ankylosing spondylitis and toxocariasis bilaterally has not been reported previously in the literature. We present a case of coexistent juvenile spondyloarthritis and ocular toxocariasis in a 16-year-old male presenting with generalized pustules, back pain, peripheral polyarthritis, and bilateral panuveitis. Both eyes displayed abnormalities in the anterior segments, including corectopia, seclusio pupillae, and occlusio pupillae. Posterior segment examination of the right eye showed vitritis, disc edema, and a retinochoroidal granuloma surrounded by infiltrates and perivascular sheathing. A B-scan of the left eye revealed vitritis and the presence of a hyperechoic band from the disc to the retinal periphery. Toxocara IgG and HLA-B27 were positive, and lumbosacral magnetic resonance imaging confirmed sacroiliitis. Treatment involved subtenon injections of triamcinolone and subcutaneous Etanercept injections, resulting in stabilization of visual acuity. This case highlights the rare co-occurrence of two diseases with overlapping symptoms and uncertain pathogenetic contributions from each to cause the observed manifestations. It supports studies proposing a connection between rheumatic disease and parasitosis.

The association between Parkinson disease and Toxocara infection/exposure: A case-control study

Parkinson's disease (PD) is a prevalent neurological disorder and the second most common neurodegenerative disease. Research has explored the impact of infectious agents, such as the parasites, on neurological conditions, including PD. Given the limited studies worldwide and in Iran, this study aims to investigate the relationship between Toxocara infection and PD. This case-control study involved 91 PD patients and 90 healthy controls. After obtaining consent, serum samples and questionnaires were collected. All sera were examined using an ELISA test for IgG antibodies against Toxocara canis. Results were analyzed with SPSS, using chi-square tests, and odds ratios (OR), and confidence intervals (CI) were calculated via univariate and multivariate analyses. The prevalence of anti-Toxocara IgG was 33% (30/91) in PD patients and 33.3% (30/90) in the control group. Both univariate analysis (OR: 0.98; 95% CI: 0.52-1.82) and multivariate analysis (OR: 0.95; 95% CI: 0.49-1.83) indicated no statistically significant association. Additionally, univariate analysis (OR: 0.49; 95% CI: 0.16-1.5) and multivariate analysis (OR: 0.37; 95% CI: 0.09-1.43) suggested non-significant association between Toxocara infection and the severity of PD. Our findings do not support a statistically significant association between Toxocara infection and the PD. While the analysis suggested that Toxocara infection might reduce the severity of PD, these results were also not statistically significant. Further research with larger sample sizes and diverse populations is needed to fully understand the potential relationship between Toxocara infection and PD.

Synthetic camphor derivative (E)-2-((1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)amino)phenol: A novel anthelmintic drug candidate for visceral toxocariasis

Human toxocariasis is a neglected parasitic disease with a global distribution, treated with current anthelmintics that have low to moderate efficacy, and requires the discovery of novel drugs. Camphor derivatives have antimicrobial properties against various pathogens such as fungi and bacteria. This study aimed to identify a camphor derivative with activity against Toxocara canis larvae and evaluate its cytotoxicity, in silico bioavailability, and in vivo activity in Swiss mice infected with this parasite. Three compounds were tested in vitro in duplicate at a concentration of 1.0 to 0.05 mg/mL in a microplate containing 100 T. canis larvae in RPMI-1640 medium incubated for 48 h at 37°C and 5% CO2. The compound (E)-2-((1,7,7-trimethylbicyclo [2.2.1] heptan-2-ylidene)amino)phenol (C2) presented a minimum larvicidal concentration (MLC) of 0.25 mg/mL and was selected for the subsequent steps. This compound showed 100% cell viability in MLC and adequate bioavailability in computational models. Two subsequent in vivo tests were performed on Swiss mice inoculated with 500 T. canis infective eggs through intragastric (IG) intubation, one at 10 days post-inoculation (n=5) and the other at 30 days post-inoculation (n=10). The selected compound (10 mg/kg, via IG) and two controls (albendazole, 40 mg/kg, IG and phosphate buffered saline 0,15M, pH 7,2, via IG) were used for this evaluation. The compound reduced the intensity of infection by 75.7% and 54.8% at 10 and 30 days post inoculation, respectively (p<0.05). The results of this study demonstrate that this compound has potential as an anthelmintic candidate for visceral toxocariasis treatment.

Role of sex hormones in the reactivation of Toxocara canis larvae in pregnant bitches

Based on an exhaustive review, a theory was proposed with an immunoendocrine perspective on the reactivation of dormant Toxocara canis larvae in pregnant bitches and their transmission to fetuses through the placenta, or milk and colostrum to puppies. A historical review was carried out on the reactivation of dormant larvae of T. canis in pregnant bitches which suggested that larval reactivation of T. canis is not solely the effect of a single hormone (prolactin) but is the result of a series of events triggered by progesterone, prolactin, and estrogens. In the first third of gestation, progesterone is capable of directly stimulating the reactivation of larvae through hormonal receptors, indirectly downregulating the granulomatous proinflammatory response around dormant T. canis larvae, and directing the response to a Th2 profile with increased levels of antibodies and blood eosinophils. After a time, when progesterone levels decrease, prolactin and estrogen maintain larval stimulation through hormonal receptors and downregulation of Th1 and the granulomatous proinflammatory response. Collectively, these hormones play major roles in the reactivation of T. canis larvae in pregnant bitches. The series of complex events that occur during larval reactivation is a clear example of transregulation, in which host hormones regulate the vital functions of the parasite to positively influence its establishment and/or proliferation. Understanding larval reactivation from an immunoendocrine perspective helps us to comprehensively understand the complex parasite-host relationship of T. canis.

Coinfection of Ocular Toxoplasmosis and Ocular Toxocariasis in the Same Patient

PURPOSE

To report a rare case of a toxoplasma chorioretinitis in one eye and peripheral ocular toxocariasis granuloma in the fellow eye of the same patient.

MATERIALS AND METHODS

Retrospective case report.

RESULTS

A 44-year-old male presented with gradual loss of vision over the past weeks. The patient was diagnosed with ocular toxoplasma chorioretinitis recurrence in his right eye and an inactive peripheral granuloma of ocular toxocariasis was found in the left eye. The patient was a farmer who had been involved in animal husbandry throughout his life. The patient was treated with antibiotics for toxoplasma chorioretinitis and kept under follow-up for ocular toxocariasis.

CONCLUSION

Coinfections of zoonoses are related to socioeconomic environment and individual characteristics of the host. Ocular toxoplasmosis and ocular toxocariasis may present with different scenarios. To our knowledge, this is the first case of a coinfection of ocular toxoplasmosis and ocular toxocariasis in the same patient. A thorough ophthalmological examination and detailed anamnesis are important for diagnosis.

Schistosome infections and other gastrointestinal parasites in cattle of the Magba sub-division in the West region of Cameroon

Although gastrointestinal parasites affect livestock production and economic development, investigations targeting these infectious diseases have been overlooked in most African countries. This study was designed to determine and map schistosomes and other gastrointestinal parasites in cattle of Magba Sub-division in the West region of Cameroon and to comparatively assess the kato-katz and sedimentation technique for diagnosing livestock schistosomiasis. During a cross-sectional study, fecal material was collected in apparently 264 healthy cattle of one to above 9 years from 4 sub-districts of the Magba sub-division. Kato-katz was used to search schistosomes and other gastrointestinal eggs while the sedimentation technique was only used to search schistosome eggs. Eight gastrointestinal parasites including schistosomes (79.9 %), Eimeria spp. (16.7 %), Fasciola spp. (12.5 %), Dicrocoelium spp. (9.1 %), Strongyloides spp. (7.2 %), Toxocara spp. (2.7 %), Trichuris spp. (2.3 %) and Monieza spp. (1.1 %) were detected in cattle fecal material. The overall prevalence of schistosome infections was 43.9 % with the Kato-katz and 79.9 % with the sedimentation technique. The Kappa coefficient index between the two techniques for detecting schistosome eggs was 0.32 (95 % CI: 0.24-0.40). Among the infected animals, 53.7 % had one gastrointestinal parasite while 21.0 %, 9.1 % and 1.9 % had respectively 2, 3 and 4 different gastrointestinal parasites. The prevalence of schistosomes and that of Fasciola spp. and Eimeria spp. vary significantly between sub-districts. This study revealed a high prevalence of schistosomes and several other gastrointestinal parasites in cattle. It showed a wide distribution of these parasitic infections in all sub-districts; indicating the need to control these infections for improving cattle health and breeders' economy.

Effect of Arum rupicola Boiss rupicola Extracts on Visceral Larva Migrans in Mice

PURPOSE

In the present study, the effects of leaf and rhizome extracts of Arum rupicola Boiss rupicola were searched on the infective stage Toxocara canis larvae (L3) in the experimentally infected mice.

METHODS

Four-six week-old male BALB/c mice were divided into eight groups (G1-8, each group consisted of 7 mice), and they were infected orally with 500 T. canis eggs with L3. After 24 h, the following treatment protocol was applied to the groups for five days: G-1: Albendazole (ABZ) (100 mg/kg), G-2: Leaf Extract (10 mg/mL) + ABZ (100 mg/kg), G-3: Leaf Extract (40 mg/mL) + ABZ (100 mg/kg), G-4: Rhizome Extract + ABZ (100 mg/kg), G-5: Leaf Extract (10 mg/mL), G-6: Leaf Extract (40 mg/mL), G-7: Rhizome extract, G-8: Negative control. The necropsy was performed on the 45th day of experimental infection.

RESULTS

The rhizome extract significantly reduced the effectiveness of ABZ compared to leaf extracts. The number of larvae in rhizome extract-treated mice (G7) was similar to ABZ-treated mice (G1) (P < 0.05). The larval number in mice administered leaf extract (10 mg/mL and 40 mg/mL) was slightly decreased. But no significant difference was detected in the larval number depending on the dose of leaf extracts (P > 0.05).

CONCLUSION

The administration of the leaf and rhizome extracts did not contribute to the effectiveness of ABZ. Also the effect of ABZ on the larvae number obtained from the tissues was reduced by the rhizome extract. The larvae number in the group in which rhizome extract was given alone was almost close to the group in which ABZ was administered. The results provide insight for further research on the antiparasitic properties of A. rupicola Boiss rupicola rhizome extract.

Discovery of Novel Thiazolohydrazone Derivatives as an Alternative Option in the Treatment of Zoonotic Toxocara canis: In Vitro and In Silico Evaluation

Thiazoles serve as pharmacophores in many molecules that exhibit significant biological activity. This study used in vitro assays and in silico methodologies to identify novel medication candidates for preclinical evaluation of visceral toxocariasis treatment. The objective was to assess the impact of 11 thiazolohydrazone derivative compounds on the larval eggs of Toxocara canis. In addition, the inhibitory effects of these compounds on IL-6 levels in THP-1 cells stimulated with larval eggs have been examined. Compounds indicating the most significant inhibitory effect on IL-6 and a suppressive effect on larval eggs have been included in molecular dynamics studies. The study revealed that, when evaluating all thiazolohydrazone derivatives together, Compounds 3g and 3h possessed the highest antiparasitic efficiency, encouraging further molecular dynamics investigations on these compounds. Consequently, it can be theorised that if the results from this study are corroborated by in vivo studies, new anti-nematodal medication candidates may be identified.

Transcriptional responses to in vitro macrocyclic lactone exposure in Toxocara canis larvae using RNA-seq

Toxocara canis, the causative agent of zoonotic toxocariasis in humans, is a parasitic roundworm of canids with a complex lifecycle. While macrocyclic lactones (MLs) are successful at treating adult T. canis infections when used at FDA-approved doses in dogs, they fail to kill somatic third-stage larvae. In this study, we profiled the transcriptome of third-stage larvae derived from larvated eggs and treated in vitro with 10 μM of the MLs - ivermectin and moxidectin with Illumina sequencing. We analyzed transcriptional changes in comparison with untreated control larvae. In ivermectin-treated larvae, we identified 608 differentially expressed genes (DEGs), of which 453 were upregulated and 155 were downregulated. In moxidectin-treated larvae, we identified 1,413 DEGs, of which 902 were upregulated and 511 were downregulated. Notably, many DEGs were involved in critical biological processes and pathways including transcriptional regulation, energy metabolism, neuronal structure and function, physiological processes such as reproduction, excretory/secretory molecule production, host-parasite response mechanisms, and parasite elimination. We also assessed the expression of known ML targets and transporters, including glutamate-gated chloride channels (GluCls), and ATP-binding cassette (ABC) transporters, subfamily B, with a particular focus on P-glycoproteins (P-gps). We present gene names for previously uncharacterized T. canis GluCl genes using phylogenetic analysis of nematode orthologs to provide uniform gene nomenclature. Our study revealed that the expression of Tca-glc-3 and six ABCB genes, particularly four P-gps, were significantly altered in response to ML treatment. Compared to controls, Tca-glc-3, Tca-Pgp-11.2, and Tca-Pgp-13.2 were downregulated in ivermectin-treated larvae, while Tca-abcb1, Tca-abcb7, Tca-Pgp-11.2, and Tca-Pgp-13.2 were downregulated in moxidectin-treated larvae. Conversely, Tca-abcb9.1 and Tca-Pgp-11.3 were upregulated in moxidectin-treated larvae. These findings suggest that MLs broadly impact transcriptional regulation in T. canis larvae.

Silver Nanoparticles from Duddingtonia flagrans: Evaluation of Potential Ovicidal Activity on Toxocara canis Eggs

The filtrate of the nematophagous fungus Duddingtonia flagrans produces silver nanoparticles (AgNPs) with nematicidal potential. However, there are currently no reports of its activity against Toxocara canis eggs. The aim of this study was to investigate the potential ovicidal activity of AgNPs-D. flagrans on T. canis eggs. T. canis eggs were obtained from the dissection of the uterus of adult female nematodes. After the biosynthesis of AgNPs, two experimental assays (A and B) were performed. In assay A, the ovicidal activity of AgNPs on eggs was evaluated after 15 and 30 days of interaction. In assay B, the inhibition (development) of the eggs was measured after 30 days of interaction. The results of assay A showed that the AgNPs destroyed an average of 47% of the eggs tested by the end of the experiment, causing significant structural damage. In assay B, an inhibition rate of 88% was observed at the end of 30 days. The results of the ovicidal activity of AgNP-D. flagrans were promising and indicate the potential for future studies on these biomolecules with ovicidal properties.

Zoonoses in dog and cat shelters in North-East Italy: update on emerging, neglected and known zoonotic agents

Introduction

Shelters for stray dogs and cats deserve careful monitoring for zoonotic risk, as they represent a crucial point for prevention and control of infection spread. Data sorting to prioritize zoonotic agents in a geographic area need constant updating, but no regular official programs are ongoing, to allow an efficient risk survey for these animal species. This study aimed to conduct a comprehensive investigation of the prevalence of certain known, potential and emerging zoonoses within the framework of the routine monitoring of dog and cat shelters in North-East Italy.

Methods

A total of 389 cats and 257 dogs housed in public veterinary services shelters and feline colonies were included in the present investigation. The animals originated from the provinces of Padua, Venice, Rovigo, Vicenza, Verona, Trento and Bolzano. Serological, molecular and microbiological diagnostics were implemented to investigate the prevalence of Leptospira sp., Brucella canis, Leishmania infantum, dermatophytes, gastrointestinal parasites, antimicrobial-resistant bacteria, Capnocytophaga sp., Bartonella sp., Norovirus, Rotavirus A, Cowpox virus, Mammalian Orthoreovirus, Hepatitis E virus, SARS-CoV-2 and Influenza A virus.

Results

Data about some known zoonoses (e.g., serological positivity of Leishmania infantum 25% and Leptospira sp. 44.3% in dogs, and Bartonella henselae 70% in cats) resulted aligned with previous research and recent reports, whereas there was a notable occurrence of some potential, emerging and neglected pathogens (e.g., Mammalian Orthoreovirus 0.38% in dogs and 2.83% in cats). For some other agents (e.g., dermatophytes in dogs and in cats) the prevalence resulted lower than expected.

Discussion

The prevention of the zoonotic risk requires a re-examination of the complex interaction between humans, animals, and environment. This is of particular importance in settings like companion animal shelters, which serve as key sites for disease monitoring and zoonotic risk mitigation. The study highlights the need to monitor and prioritize the zoonotic pathogens, to implement and constantly update surveillance and specific training programs for the kennels' operators, and management of epidemiological risks.

New records of endoparasites and ectoparasites in free-living road-killed wild animals in the Pampa biome, Southern Brazil

Wild animals host a wide variety of parasites, and the disorders caused by these parasites are among the most prevalent and significant infectious diseases affecting wildlife. The investigation of parasitic fauna is crucial for the conservation of wild animals, domestic populations, and humans. Therefore, the aim of the study was to survey endo- and ectoparasites in free-living wildlife in southern Brazil. Carcasses of road-killed wildlife were collected from highways in the Pelotas microregion, Rio Grande do Sul. All carcasses were necropsied, and endo- and ectoparasites were collected and identified. A total of 82 animals were examined; 87.80% were infected by helminths, 51.21% infested by ectoparasites, and 48.78% were affected by both types of parasites. This study presents the first records of parasitism by Rhipicephalus microplus in Ozotoceros bezoarticus in southern Brazil, and by Ancylostoma caninum in Leopardus geoffroyi worldwide. The study contributes to the knowledge about the parasitic fauna in wild animals of the Pampa biome. The presence of parasites in these threatened species underscores the need for further research into parasitism, which is crucial for their effective management and conservation.

Eosinophilic Pneumonia Triggered by Toxocara canis in a Patient with Primary Ciliary Dyskinesia: A Clinical Case Report

Primary ciliary dyskinesia (PCD) is a rare genetic disorder that affects the structure and function of cilia, primarily impacting the respiratory system. Kartagener syndrome, a subset of PCD, is characterized by situs inversus, bronchiectasis, and chronic sinusitis. Patients with PCD are prone to recurrent respiratory infections due to impaired ciliary function, which hinders effective mucus clearance and promotes pathogen colonization. This case report describes a 24-year-old woman with congenital Kartagener syndrome who developed eosinophilic pneumonia caused by Toxocara canis, a rare parasitic infection that less commonly affects the lungs. Despite initial treatment for a presumed bacterial infection, the patient's symptoms persisted. Further diagnostics revealed elevated eosinophil counts, total IgE, and the presence of Toxocara canis antibodies. The patient was treated with albendazole, resulting in significant symptom improvement and a reduction in inflammatory markers. This case underscores the diagnostic challenges in treating PCD patients, where atypical infections must be considered, particularly when standard treatments prove ineffective. The complexity of the patient's condition required interdisciplinary management, integrating parasitological, immunological, and respiratory expertise to ensure appropriate treatment. The case highlights the need for further research into the interactions between congenital respiratory disorders such as Kartagener syndrome and parasitic infections. It also emphasizes the importance of a comprehensive diagnostic approach in managing rare genetic diseases complicated by opportunistic infections. Early detection of parasitic infections in PCD patients is crucial to preventing severe complications, and this case reinforces the necessity of considering parasitic causes in atypical pneumonia cases.

Comparison of different diagnostic protocols for the detection of Toxocara spp. in faecal samples of cats and dogs

BACKGROUND

Toxocara canis and Toxocara cati are parasitic nematodes that occur worldwide. As embryonated Toxocara spp. eggs in the environment pose a zoonotic risk, especially for children, optimal diagnostic approaches are necessary for effective disease response and management, including surveillance. However, little is known about the performance of different diagnostic protocols for detecting Toxocara spp. in the faeces of cats and dogs, hampering movement towards an optimal diagnostic process. This study aimed to compare detection methods, including a newly developed sequential sieving protocol (SF-SSV) and a high-throughput multiplex qPCR-based method to facilitate epidemiological studies.

METHODS

Species-specific Toxocara spp. egg suspensions and canine and feline faecal samples from the field were used to estimate analytical and diagnostic sensitivity of the protocols. The performance of two automated DNA extraction protocols using enzymatic and mechanical lysis were compared by multiplex qPCR, targeting both T. canis and T. cati-specific genomic sequences. All samples were examined by microscopy-based techniques, the sedimentation flotation technique (SF) and a newly developed SF-SSV for the detection, enrichment and purification of parasite eggs. The costs and processing times necessary for all protocols were estimated and compared for both single samples and sets of 100 samples.

RESULTS

To detect Toxocara spp. eggs, SF-SSV showed the highest analytical sensitivity and a significantly higher diagnostic sensitivity than the DNA detection methods. Mechanical lysis performed better than enzymatic lysis for automated DNA extraction. In automated DNA extraction, 96-well plates performed better than 24-well plates. DNA detection and microscopy-based parasitological methods showed substantial agreement between the results generated by each method. Microscopy-based techniques required the lowest costs and least hands-on time for a single sample. However, when costs and labour were estimated for a set of 100 samples, the DNA detection protocol using 96-well plates for extraction revealed costs similar to SF-SSV and the fastest processing times.

CONCLUSIONS

SF-SSV was superior in terms of analytical and diagnostic sensitivity for the detection of Toxocara spp. eggs. For larger sets of samples, multiplex qPCR-based DNA detection represents an alternative to microscopy-based methods, based on the possibility of faster sample processing at similar costs to SF-SSV, and the ability to provide species-specific diagnoses.

Proteomics analysis reveals the differential protein expression of female and male adult Toxocara canis using Orbitrap Astral analyzer

BACKGROUND

Toxocara canis, the most prevalent helminth in dogs and other canines, is one of the socioeconomically important zoonotic parasites, particularly affecting pediatric and adolescent populations in impoverished communities. However, limited information is available regarding the proteomes of female and male adult T. canis. To address this knowledge gap, we performed a comprehensive proteomic analysis to identify the proteins with differential abundance (PDAs) and gender-specifically expressed proteins between the two sexes adult T. canis.

METHODS

The comparative proteomic analysis was carried out by the Orbitrap mass spectrometry (MS) with asymmetric track lossless (Astral) analyzer. The difference analysis was conducted using t-test and the proteins verification was achieved through parallel reaction monitoring (PRM). The potential biological functions of identified adult T. canis proteins and PDAs were predicted by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. The domain, transcription factor and subcellular localization of the identified proteins and PDAs were analyzed by InterPro, AnimalTFDB 4.0 and Cell-mPLOC 2.0 databases, respectively.

RESULTS

A total of 8565 somatic proteins of adult T. canis were identified. Compared to male adult, 682 up-regulated PDAs and 844 down-regulated PDAs were identified in female adult with P-values < 0.05 and |log2FC| > 1, including 139 proteins exclusively expressed in female and 272 proteins exclusively expressed in male. The GO annotation analysis using all PDAs revealed that the main biological processes, cellular components and molecular functions corresponded to aminoglycan metabolic process, extracellular region and protein tyrosine phosphatase activity, respectively. The KEGG analysis using all PDAs showed that the pathways were mainly associated with adipocytokine signaling pathway, proximal tubule bicarbonate reclamation and PPAR signaling pathway.

CONCLUSIONS

This study reveals the differential protein expression between female and male adult T. canis, providing valuable resource for developing the novel intervention strategies against T. canis infection in humans and animals, especially from the perspective of sexual development and reproduction.

Ocular Toxocariasis in Adult Caucasian Patients: Clinical Presentations and Treatment Outcomes

PURPOSE

To report the clinical features and treatment outcomes in adult Caucasians with ocular toxocariasis (OT) and investigate their prognosis depending on their serological status.

METHODS

Retrospective observational cohort study (2016-2021) including consecutive adults with uveitis and positive western blot (WB) in the aqueous humor or vitreous. The presence of serum antibodies was not necessary for inclusion, allowing to compare the outcomes depending on the serological status.

RESULTS

Seventeen eyes of 15 patients were included. Mean age at diagnosis was 51.9 years. Vitreous inflammation was the most frequent sign (100%). Vitreoretinal tractions (41.2%) and chorioretinal granulomas (58.8%) were less prevalent. Atypical features were: spontaneous intravitreal hemorrhage (23.5%), exudative retinal detachment (11.8%), isolated macular edema (17.6%), papillitis (29.4%) and vasculitis (47.1%). Twenty percent of patients had a positive serum serology. Baseline clinical features did not differ statistically depending on the serological status; however, the degree of inflammation was numerically higher in patients with negative serology. Overall, macular thickness, anterior and posterior segment inflammation improved significantly after treatment with oral albendazole, systemic ± local corticosteroids. Vitrectomy (47.1%) was performed in case of persistent vitritis (62.5%), retinal detachment (12.5%) and intravitreous hemorrhage (25%).

CONCLUSION

OT has no pathognomonic sign and atypical presentations were not infrequent in this adult Caucasian cohort. Serum antibodies were rarely positive, stressing on the importance of ocular sample analysis, especially in case of atypical features. Serum antibodies may prove useful in forecasting the rapidity of inflammation clearance. Antiparasitic and anti-inflammatory treatment was safe and efficient in most cases.

A comparative field efficacy trial of three treatment programs against endo- and ectoparasites in naturally infected dogs

Introduction

Tropical climates in remote Aboriginal and Torres Strait Islander communities in northern Australia are conducive to the transmission of canine helminths such as hookworms, as well as ectoparasites such as fleas and ticks. In addition to their veterinary importance, these parasites may present a zoonotic risk either directly, or as potential vectors for bacterial pathogens. These factors necessitate efficacious and effective antiparasitic treatment programs for community dogs.

Methods

A cluster-randomised trial was performed on three islands in the Torres Strait to examine the short-term efficacy and medium-term effectiveness of three treatment programs. Treatments administered included oral oxibendazole/praziquantel (Paragard®) and oral afoxolaner (Nexgard®); topical moxidectin/imidacloprid (Advocate®) and imidacloprid/flumethrin collars (Seresto®); and off-label oral ivermectin (Bomectin®). Canine faecal samples were collected and examined for endoparasites by faecal flotation and real-time PCR at baseline, 7-11 days after treatment and 6 months later.

Results

The proportion of dogs positive for Ancylostoma caninum at baseline and negative at day 7-11 was 9% (95% CI 4.4-17.4) for dogs treated with oxibendazole, 56.4% (95% CI 41-70.7) for moxidectin, and 89.7% (95% CI 73.6-96.4) for ivermectin. Faecal flotation results showed a greater than 90% egg reduction in 29.2% (95% CI 19.9-40.5) of dogs treated with oxibendazole, 79.4% (95% CI 63.2-89.7) for moxidectin, and 95% (95% CI 76.4-99.1) for off-label ivermectin. Elimination of ectoparasite infestation was observed at day 7-11 in 69.9% (95% CI 56.7-80.1) of dogs treated with afoxolaner, 80% (95% CI 60.9-91.1) with imidacloprid/flumethrin collars, and 0% (95% CI 0-11.7) for off-label ivermectin. Mixed effects modelling revealed only treatment group to be significantly associated with outcome measures.

Discussion

Based on these study results, the poor efficacy of oxibendazole against A. caninum renders it inept for treatment, while ivermectin and moxidectin were suitable. Ivermectin was unsuitable for ectoparasite treatment due to its poor efficacy, while afoxolaner and imidacloprid/flumethrin collars appear suitable.

The Liver's hidden foe: A case study on Human Fasciolasis

Human fascioliasis, caused by Fasciola hepatica and Fasciolagigantica, is a neglected tropical disease of increasing public health significance. Reported cases are rare, with only one serologically confirmed instance in Ethiopia to date. We present the case of a male patient in his late twenties, without identified risk factors, who presented with bilateral upper quadrant pain persisting for a year and a history of repeated treatment for H. pylori gastritis. Initial ultrasound findings prompted further investigation with abdominal CT, contrast-enhanced MRI, and MRCP, leading to a diagnostic shift confirmed by a positive enzyme-linked assay for Fasciola hepatica. This case highlights the diagnostic challenges and the critical role of radiological imaging-ultrasound, CT, and MRIin identifying key features such as biliary dilation and parenchymal abnormalities, crucial for early detection and effective management of human fascioliasis.

Larvicidal activity of coumarin derivatives on Toxocara canis larvae, cytotoxicity analysis, and in silico bioavailability studies

Human toxocariasis is a neglected anthropozoonosis with global distribution. Treatment is based on the administration of anthelmintics; however, their effectiveness at the tissue level is low to moderate, necessitating the discovery of new drug candidates. Several groups of synthetic compounds, including coumarin derivatives, have demonstrated bioactivity against fungi, bacteria, and even parasites, such as Dactylogyrus intermedius, Leishmania major, and Plasmodium falciparum. The aim of this study was to evaluate the effect of ten coumarin-derived compounds against Toxocara canis larvae using in vitro, cytotoxicity, and in silico tests for selecting new drug candidates for preclinical tests aimed at evaluating the treatment of visceral toxocariasis. The compounds were tested in vitro in duplicate at a concentration of 1 mg/mL, and compounds with larvicidal activity were serially diluted to obtain concentrations of 0.5 mg/mL; 0.25 mg/mL; 0.125 mg/mL; and 0.05 mg/mL. The tests were performed in a microculture plate containing 100 T. canis larvae in RPMI-1640 medium. One compound (COU 9) was selected for cytotoxicity analysis using J774.A1 murine macrophages and it was found to be non-cytotoxic at any concentration tested. The in silico analysis was performed using computational models; the compound presented adequate results of oral bioavailability. To confirm the non-viability of the larvae, the contents of the microplate wells of COU 9 were inoculated intraperitoneally (IP) into female Swiss mice at 7-8 weeks of age. This confirmed the larvicidal activity of this compound. These results show that COU 9 exhibited larvicidal activity against T. canis larvae, which, after exposure to the compound, were non-viable, and that COU 9 inhibited infection in a murine model. In addition, COU 9 did not exhibit cytotoxicity and presented adequate bioavailability in silico, similar to albendazole, an anthelmintic, which is the first choice for treatment of human toxocariasis, supporting the potential for future investigations and preclinical tests on COU 9.

Ocular Brugia pahangi Filariasis Complicated by Severe Macular Damage in Thailand: Case Report and Literature Review

Extralymphatic filariasis caused by filaria of zoonotic origins has been frequently reported in Thailand over recent years. Here, we report the first case of ocular filariasis in a 7.5-year-old Thai boy who initially presented with progressive conjunctival redness and blurred vision in his right eye. A small, slender, coiled worm was found and surgically removed from the right anterior chamber. Histopathological examination illustrated predominant eosinophilic inflammation surrounding the parasite, which showed smooth and thin cuticle, prominent lateral chords, flat and broad muscle cells, one intestine, and two reproductive tubes with unsegmented ova, typically characteristic of a female adult Brugia filarial nematode. The parasite was also molecularly identified as B. pahangi, based on mitochondrial cytochrome c oxidase subunit I sequence analysis. The patient was then empirically prescribed albendazole, systemic prednisolone, and topical methylprednisolone. Unfortunately, his vision did not recover after 2 months due to severe maculopathy, most likely resulting from parasitic infestation and subsequent vitreous inflammation. To the best of our knowledge, this is the first case of ocular infestation by B. pahangi with visual complications that occurred outside a filariasis-endemic area of Thailand. Furthermore, this report provides clinical data on preceding cases of B. pahangi filariasis formally reported in southeast Asian countries, including Thailand and Malaysia, which facilitate a better understanding of the epidemiology of this sporadic zoonotic infection for effective disease elimination.

Synergistic effects of using sodium hypochlorite (bleach) and desiccation in surface inactivation for Toxocara spp

Toxocara cati and T. canis are parasitic nematodes found in the intestines of cats and dogs respectively, with a cosmopolitan distribution, and the potential for anthropozoonotic transmission, resulting in human toxocariasis. Spread of Toxocara spp. is primarily through the ingestion of embryonated eggs contaminating surfaces or uncooked food, or through the ingestion of a paratenic host containing a third-stage larva. The Toxocara spp. eggshell is composed of a lipid layer providing a permeability barrier, a chitinous layer providing structural strength, and thin vitelline and uterine layers, which combined create a biologically resistant structure, making the Toxocara spp. egg very hardy, and capable of surviving for years in the natural environment. The use of sodium hypochlorite, household bleach, as a disinfectant for Toxocara spp. eggs has been reported, with results varying from ineffective to limited effectiveness depending on parameters including contact time, concentration, and temperature. Desiccation or humidity levels have also been reported to have an impact on larval development and/or survival of Toxocara spp. eggs. However, to date, after a thorough search of the literature, no relevant publications have been found that evaluated the use of sodium hypochlorite and desiccation in combination. These experiments aim to assess the effects of using a combination of desiccation and 10% bleach solution (0.6% sodium hypochlorite) on fertilized or embryonated eggs of T. cati, T. canis, and T. vitulorum. Results of these experiments highlight the synergistic effects of desiccation and bleach, and demonstrate a relatively simple method for surface inactivation, resulting in a decrease in viability or destruction of T. cati, T. canis and T. vitulorum eggs. Implications for these findings may apply to larger scale elimination of ascarid eggs from both research, veterinary, and farming facilities to mitigate transmission.

The impact of Toxocara-seropositivity on attention and motor skills in children with attention-deficit hyperactivity disorder

BACKGROUND

The study aims to compare neurological soft signs and executive functions between Toxocara-seropositive and seronegative groups in children with attention-deficit/hyperactivity disorder.

METHODS

The study included 60 boys with ADHD, aged 7-12. After blood samples were taken, the Stroop Color Word Test and Judgment of Line Orientation test (JLOT) were implemented to measure executive functions. Neurological soft signs were evaluated with Physical and Neurological Examination for Subtle Signs (PANESS).

RESULTS

Serological tests were positive for Toxocara antibodies in 20 cases. There was no significant difference between Toxocara seropositive and seronegative regarding age, socioeconomic status, developmental stages, and ADHD severity. However, Toxocara-seropositive children had higher Stroop time and Stroop interference scores and lower JLOT scores than Toxocara-seronegative children. Furthermore, Toxocara-seropositive children exhibited more neurological soft signs, such as gait and station abnormalities, dysrhythmia, and a longer total time in timed movements compared to Toxocara-seronegative children.

CONCLUSION

Our study indicates a link between Toxocara-seropositivity and impaired neurological soft signs and executive functions in ADHD. Further research is needed to understand ADHD mechanisms, develop practical treatments considering immunological factors, and thoroughly evaluate how Toxocara seropositivity affects executive functions and motor skills in children with ADHD.

Quantifying the neglected: Initial estimation of the global burden and economic impact of human toxocariasis

Toxocariasis is a parasitic zoonotic infection caused by Toxocara spp., ascarid nematodes of companion animals (dogs and cats) affecting people in both high-income and low/middle-income countries. Toxocariasis can manifest as several distinct syndromes. The most frequent, often termed common toxocariasis, is a self-limiting and mild febrile illness. Ocular and visceral larva migrans are severe disease manifestations affecting the eye and other internal organs, respectively, but their reported occurrence is rare. The vast majority of symptomatic cases are thought due to common toxocariasis, which has also been associated with cognitive impairment in children. Few studies to date have sought to quantity the health burden of toxocariasis in humans. In this study we provide a preliminary estimation using the Disability-Adjusted Life Year (DALY) approach. We estimate a total of 23,084 DALYs are lost annually in 28 selected countries due to common toxocariasis. Extrapolating based on a global average seroprevalence rate of 19%, we estimate 91,714 DALYs per year are lost across all countries due to toxocariasis, of which 40,912 are attributable to less severe forms, i.e. common toxocariasis, and 50,731 to cognitive impairment in children. Clinically diagnosed and reported ocular and visceral larva migrans represent a small proportion of estimated total health burden. We also found a positive correlation at national level between prevalence in cats or dogs and seroprevalence in humans, but no correlation between estimated soil contamination and seroprevalence in humans. Finally, we estimate the potential economic impact of toxocariasis in selected countries at 2.5 billion USD per annum, from costs of medical treatment and lost income. These preliminary estimates should serve as a call to action for further research and evidence-based measures to tackle toxocariasis.

Proteomic change in the upper lobe of the left lung of Beagle dogs at the lung migration stage of Toxocara canis infection

BACKGROUND

Toxocara canis is considered one of the most neglected parasitic zoonoses and threatens the health of millions of people worldwide with a predilection for pediatric and adolescent populations in impoverished communities. Exploring the invasion and developmental mechanisms associated with T. canis infection in its definitive canine hosts will help to better control zoonotic toxocariasis.

METHODS

Proteomic changes in samples from the upper lobe of the left lung of Beagle puppies were systematically analyzed by quantitative proteomic technology of data-independent acquisition (DIA) at 96 h post-infection (hpi) with T. canis. Proteins with P-values < 0.05 and fold change > 1.5 or < 0.67 were considered proteins with differential abundance (PDAs).

RESULTS

A total of 28 downregulated PDAs and 407 upregulated PDAs were identified at 96 hpi, including RhoC, TM4SFs and LPCAT1, which could be associated with the maintenance and repair of lung homeostasis. GO annotation and KEGG pathway enrichment analyses of all identified proteins and PDAs revealed that many lung proteins have correlation to signal transduction, lipid metabolism and immune system.

CONCLUSIONS

The present study revealed lung proteomic alterations in Beagle dogs at the lung migration stage of T. canis infection and identified many PDAs of Beagle dog lung, which may play important roles in the pathogenesis of toxocariasis, warranting further experimental validation.

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.

Causes of infectious pediatric uveitis: A review

Infectious pediatric uveitis is a rare disease that can cause severe ocular damage if not detected rapidly and treated properly. Additionally, early identification of an infection can protect the child from life-threatening systemic infection. Infectious uveitis can be congenital or acquired and may manifest as a primary ocular infection or as a reactivation. Nevertheless, publications on infectious paediatric uveitis are usually limited to a small number of patients or a case report. So far, most studies on uveitis in children have focused primarily on noninfectious uveitis, and a systematic study on infectious uveitis is lacking. In this review, we summarize the literature on infectious uveitis in pediatric populations and report on the epidemiology, pathophysiology, clinical signs, diagnostic tests, and treatment. We will describe the different possible pathogens causing uveitis in childhood by microbiological group (i.e. parasites, viruses, bacteria, and fungi). We aim to contribute to early diagnosis and management of infectious pediatric uveitis, which in turn might improve not only visual outcome, but also the general health outcome.

C-type lectin 4 of Toxocara canis activates NF-ĸB and MAPK pathways by modulating NOD1/2 and RIP2 in murine macrophages in vitro

Toxocara canis is a parasitic zoonose that is distributed worldwide and is one of the two pathogens causing toxocariasis. After infection, it causes serious public health and safety problems, which pose significant veterinary and medical challenges. To better understand the regulatory effects of T. canis infection on the host immune cells, murine macrophages (RAW264.7) were incubated with recombinant T. canis C-type lectin 4 (rTc-CTL-4) protein in vitro. The quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to analyze the nucleotide-binding oligomerization domain-containing protein 1/2 (NOD1/2), receptor-interacting protein 2 (RIP2), nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB), and mitogen-activated protein kinase (MAPK) on mRNA level and protein expression level in macrophages. Our results indicated that 10 μg/mL rTc-CTL-4 protein could modulate the expression of NOD1, NOD2, and RIP2 at both the transcriptional and translational levels. The protein translation levels of NF-κB, P-p65, p38, and P-p38 in macrophages were also modulated by rTc-CTL-4 protein. Macrophages were co-incubated with rTc-CTL-4 protein after siRNA silencing of NOD1, NOD2, and RIP2. The expression levels of NF-κB, P-p65, p38, and P-p38 were significantly changed compared with the negative control groups (Neg. Ctrl.). Taken together, rTc-CTL-4 protein seemed to act on NOD1/2-RIP2-NF-κB and MAPK signaling pathways in macrophages and might activate MAPK and NF-κB signaling pathways by regulating NOD1, NOD2, and RIP2. The insights from the above studies could contribute to our understanding of immune recognition and regulatory mechanisms of T. canis infection in the host animals.

Anthelmintic efficacy of nitazoxanide in dogs naturally infected with Toxocara canis

Toxocara canis (T. canis) is a gastrointestinal nematode in dogs, and its larvae also infect humans, causing severe larval migratory disease. Anthelmintic drugs have become the primary means to combat T. canis. In this study, the efficacy of nitazoxanide (NTZ) was tested against all the internal stages of T. canis, including L3 larval stage in vitro experiments and gastrointestinal worm in vivo experiments. In the in vitro experiment, after treatment with NTZ at 7.81 and 62.5 μg/mL for 12 h, the larval mortality efficacy reached 90.0 and 100.0%, respectively. In the in vivo experiments, 100 mg/kg NTZ possessed good anthelmintic efficacy against T. canis, with an egg per gram (EPG) reduction of 99.19%, and 90.00% of dogs cleared with residual worms. These results were comparable to those of the positive control drug. The highest anthelmintic efficacy was observed in the group treated with 150 mg/kg NTZ. Based on faecal egg counts, the number of T. canis eggs decreased by 100.00%, and the percentage of dogs cleared with residual worms achieved 90.00% after 7 days of treatment in the 150-mg/kg NTZ treatment group. In general, NTZ showed great potential to be applied as an anthelmintic against T. canis.

Presumptive pulmonary toxocariasis in a patient affected by acute myeloid leukemia and Hodgkin lymphoma: case report and review of the literature in immunocompromised hosts

Toxocariasis is a zoonosis transmitted by the nematode Toxocara spp. Immunocompromised hosts are more susceptible than general population to bacterial, viral, fungal and parasitic infections. In this population toxocariasis may present as exacerbation or reactivation and could have severe or atypical manifestations being a diagnostic challenge for healthcare providers. We report a case of a presumptive pulmonary toxocariasis during chemotherapy in a patient affected by acute myeloid leukaemia (AML) and Hodgkin lymphoma and we summarize current evidence of pulmonary involvement in immunocompromised population with Toxocara spp infection in a narrative review. The aim of this work is also to revise the current literature on pulmonary involvement during Toxocara spp infection in immunocompromised hosts to improve knowledge on clinical presentation, treatment and outcome. A 66 years old man who had undergone to a cytarabine and idarubicin chemotherapy induction scheme for AML, complained of febrile neutropenia and dry cought. At the chest computed tomography (CT) there were multiple nodular pulmonary lesions with subpleural consolidations. The lung biopsy revealed inflammatory infiltration with diffuse small granulomas with minor eosinophil component. The laboratory analysis showed high immunoglobulin E (IgE) count with normal peripherical eosinophils, among the extended parasitological analysis, Toxocara immunoblot assay resulted positive. In the most accepted hypothesis of a polmunary toxocariasis infection, the patient was treated with a combination of albendazole plus corticosteroids for four weeks, with a positive outcome. Infection complications during chemotherapy are not uncommon, however, this is the first reported case of pulmonary toxocariasis during cytarabine and idarubicin treatment in AML. The revised literature shows male gender and younger age as possible risk factors, nevertheless the majority of cases of seropositivity for Toxocara was reported in solid organ malignancies. In this case, the suspect was mainly based on laboratory total elevated IgE, confirmed by serological, anatomo-pathological and radiological findings. Hypereosinophilia is often not present in chronic infection. In conclusion, pulmonary toxocariasis should be ruled out in patients with pulmonary involvement and high IgE titre, with or without peripheral eosinophilia, especially in those with known immunocompromised status.

Serosurvey of Toxoplasma gondii and Toxocara spp. co-infection in pregnant women in low-income areas of Brazil

Introduction

Despite human toxoplasmosis and toxocariasis having been listed among the top six most neglected parasitic zoonoses worldwide, presenting similar associated risk factors and transmission routes, few studies have been conducted in pregnant women and the consequences of concurrent infection remain to be fully established. Accordingly, the present study has serologically assessed the co-infection and associated risk factors for Toxoplasma gondii and Toxocara spp. in pregnant women, assisted by the public Unified National Health System (SUS) in southeastern Brazil.

Materials and Methods

Blood samples were collected and tested for IgG antibodies against Toxoplasma gondii by chemiluminescence immunoassay and against Toxocara spp. by enzyme-linked immunosorbent assay (ELISA). An epidemiological questionnaire was applied to gather socioeconomic information to assess the risk factors associated with seropositivity to toxocariasis/toxoplasmosis by univariate analysis followed by logistic regression.

Results

Overall, seropositivity was 69/280 (24.6, 95% CI: 19.96-30.01) for T. gondii and 56/280 (20.0, 95% CI: 15.73-25.08) for Toxocara spp. Co-infection was observed in 25/280 (8.9, 95% CI: 6.12-12.85) pregnant women, with increased odds (OR: 3.3, CI 95%: 1.77-6.14, p = 0.0002). Logistic regression revealed that a higher educational level (high school or college) significantly reduced the likelihood of co-infection seropositivity, owning cats increased the odds of toxocariasis, and older pregnant women presented significantly higher T. gondii seropositivity.

Conclusion

Co-infection herein highlights the importance of educational programs in the prevention of toxocariasis and toxoplasmosis in pregnant women and other high-risk populations.

Infectious leukoencephalopathies

Leukoencephalopathy from infectious agents may have a rapid course, such as human simplex virus encephalitis; however, in many diseases, it may take months or years before diagnosis, such as in subacute sclerosing panencephalitis or Whipple disease. There are wide geographic distributions and susceptible populations, including both immunocompetent and immunodeficient patients. Many infections have high mortality rates, such as John Cunningham virus and subacute sclerosing panencephalitis, although others have effective treatments if suspected and treated early, such as herpes simplex encephalitis. This chapter will describe viral, bacterial, and protozoal infections, which predominantly cause leukoencephalopathy. We focus on the clinical presentation of these infectious agents briefly covering epidemiology and subtypes of infections. Next, we detail current pathophysiologic mechanisms causing white matter injury. Diagnostic and confirmatory tests are discussed. We cover predominantly MRI imaging features of leukoencephalopathies, and in addition, summarize the common imaging features. Additionally, we detail how imaging features may be used to narrow the differential of a leukoencephalopathy clinical presentation. Lastly, we present an outline of common treatment approaches where available.

The immunomodulatory effects of the C-type lectin protein of Toxocara canis on experimental autoimmune encephalomyelitis

Toxocara canis is a global zoonosis infection that can cause chronic and long-term toxocariasis in their paratenic host. The excretory-secretory (ES) products of T. canis larvae are considered to be responsible for the Th2 polarization and regulatory immune responses in toxocariasis. The C-type lectin family is one of the most prominent components of ES products of T. canis infective larvae. This study aimed to investigate the ameliorative effect of a T. canis C-type lectin recombinant protein (rCTL), on experimental autoimmune encephalomyelitis (EAE) which is a T-cell-mediated autoimmune disease of the central nervous system. C57BL/6 mice were subcutaneously treated with 30 μg rCTL, three times at an interval of 1 week. EAE was induced by myelin oligodendrocyte glycoprotein 35-55 peptide (MOG35-55 peptide) immunization, and weight and clinical scores were evaluated. Real time polymerase chain reaction was performed to evaluate the expression levels of T-bet, Gata3, and Foxp3 in splenocytes. In addition, the levels of interleukin 4, interferon gamma, and tumour growth factor-β (TGF-β) were quantified by enzyme-linked immunosorbent assay in splenocyte culture supernatants. The results indicated that the rCTL decreased clinical disability scores and delayed the onset of EAE. Furthermore, the data showed that rCTL treatment modulated the immune response, which was associated with upregulation of the mRNA expression of the Foxp3 gene and higher production of TGF-β in rCTL-treated mice. This study demonstrated that rCTL might be a potential agent to ameliorate EAE symptoms by stimulating anti-inflammatory responses.

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.

A Study on the Monitoring of Toxocara spp. in Various Children's Play Facilities in the Republic of Korea (2016-2021)

Toxocara spp. is a zoonotic soil-transmitted parasite that infects canids and felids, which causes toxocariasis in humans, migrating to organ systems, including the lungs, the ocular system, and the central nervous system. Since Toxocara spp. is usually transmitted through soil, children tend to be more susceptible to infection. In order to monitor contamination with Toxocara spp. in children's play facilities in the Republic of Korea, we investigated 11,429 samples of soil from daycare centers, kindergartens, elementary schools, and parks across the country from January 2016 to December 2021. Since the Environmental Health Act in the Republic of Korea was enacted in March 2008, there have been sporadic reports of contamination by Toxocara spp. in children's activity zones. In this study, soil from children's play facilities in regions across the Republic of Korea was monitored according to the Korean standardized procedure to use it as basic data for preventive management and public health promotion. The national average positive rate was 0.16% (18/11,429), and Seoul showed a higher rate of 0.63% (2/318) than any other regions while Incheon, Daegu, Ulsan, Kangwon-do, Jeollabuk-do, and Jeollanam-do were negative (p < 0.05). The positive rates were as follows: 0.37% (4/1089) in daycare centers, 0.13% (3/2365) in kindergartens, 0.2% (7/4193) in elementary schools, 0.09% (1/1143) in apartments, and 0.14% (3/2198) in parks. In addition, it was confirmed that 0.2% (1/498) of elementary schools and 1.17% (2/171) of parks were re-contaminated among play facilities managed with the establishment of a regular inspection cycle. Consequently, there is an essential need for continuous monitoring of Toxocara spp. contamination and regular education for preschool and school children in order to prevent soil-borne parasite infections.

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.

Case report: Probable toxocariasis in a Swiss adult patient with hypereosinophilic syndrome and multiorgan involvement

Hypereosinophilic syndromes are a heterogeneous group of rare diseases characterized by eosinophil-related organ damage and peripheral blood hypereosinophilia. Hypereosinophilic syndromes may occur secondary to a variety of clinical entities, for example, drug hypersensitivity reactions, parasitic infections, autoimmune disorders, and malignancies. Toxocariasis is a parasitic infection caused by the larval stage of the Toxocara species. It is usually a childhood disease and invades organs such as the liver but can affect any organ. Hypereosinophilic syndrome and multiorgan involvement are very rare manifestations of Toxocara infection, especially in adults. However, the disease may be underdiagnosed because of different factors, including a lack of laboratory infrastructure in some countries, a lack of uniform case definitions, and limited surveillance infrastructure, with its estimation constituting a challenge. We, therefore, present a probable case of hypereosinophilic syndrome with multiorgan involvement secondary to infection with Toxocara canis in a 79-year-old Swiss female patient with a medical history of ischemic cerebrovascular insult and a curatively resected non-small-cell bronchial carcinoma, successfully treated with albendazole and steroids.

Helminths in Invasive Raccoons (Procyon lotor) from Southwest Germany

As hosts of numerous zoonotic pathogens, the role of raccoons needs to be considered in the One Health context. Raccoons progressively expand their range as invasive alien species in Europe. This study aimed to investigate the intestinal helminth fauna of raccoons in Baden-Wuerttemberg, Germany, as no such screening had ever been conducted there. In total, we obtained 102 animals from hunters in 2019 and 2020. Intestinal helminths were retrieved using the SSCT (segmented sedimentation and counting technique) and identified morphologically and by PCR-based Sanger sequencing. Fecal samples were assessed using the ELISA PetChek^TM IP assay (IDEXX, Germany) and flotation technique. The artificial digestion method was employed for analyzing muscle tissue. We detected species of four nematode genera (Baylisascaris procyonis, Toxocara canis, Capillaria spp., and Trichuris spp.), three cestode genera (Atriotaenia cf. incisa/procyonis, Taenia martis, and Mesocestoides spp.), and three trematode genera (Isthmiophora hortensis/melis, Plagiorchis muris, and Brachylaima spp.). Echinococcus spp. and Trichinella spp. were not found. The invasive behavior and synanthropic habits of raccoons may increase the infection risk with these helminths in wildlife, domestic and zoo animals, and humans by serving as a connecting link. Therefore, it is crucial to initiate additional studies assessing these risks.

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.

Dogs as a source for the spreading of enteric parasites including zoonotic ones in Giza Province, Egypt

To investigate the impact of domestic and stray dogs on the transmission of zoonotic and other parasites to humans in contact with them, fecal samples were collected from 80 domestic dogs that presented at a clinic with health disturbances and 220 randomly selected stray dogs housed in shelters. The parasitological examination of these samples revealed infection by six zoonotic and four non-zoonotic parasites in varying percentages. The zoonotic parasites included Ancylostoma caninum, Toxocara canis, Dipylidium caninum, Echinococcus granulosus, Cryptosporidium species, and Giardia cysts and trophozoites. The other parasites included Toxascaris leonina, Trichuris vulpis, Taenia species eggs, and Isospora canis oocysts. The infection rate was higher in stray dogs (60%) than in domestic dogs (40%). Infected dogs in both groups were generally unhealthy, with poor body condition recorded in 13.8% of domestic dogs and 63.6% of stray dogs. The infection rate was higher (92%) among shelter workers than among domestic dog owners (66.7%). Giardia assemblages A and D from dogs and assemblage A from humans, as well as two isolates of Cryptosporidium canis (C. canis), one from dogs and the other from humans, were submitted in the GenBank with the accession numbers OQ870443, OQ870444, and OQ919265 for Giardia and OQ917532 & OQ915519 for C. canis of dogs & human, respectively. In conclusion, domestic and stray dogs play an essential role in transmitting zoonotic parasites to humans in contact with them, and regular deworming and strict hygienic measures are recommended to minimize their impact on human health.

Application of Silver Nanoparticles in Parasite Treatment

Silver nanoparticles (AgNPs) are ultra-small silver particles with a size from 1 to 100 nanometers. Unlike bulk silver, they have unique physical and chemical properties. Numerous studies have shown that AgNPs have beneficial biological effects on various diseases, including antibacterial, anti-inflammatory, antioxidant, antiparasitic, and antiviruses. One of the most well-known applications is in the field of antibacterial applications, where AgNPs have strong abilities to kill multi-drug resistant bacteria, making them a potential candidate as an antibacterial drug. Recently, AgNPs synthesized from plant extracts have exhibited outstanding antiparasitic effects, with a shorter duration of use and enhanced ability to inhibit parasite multiplication compared to traditional antiparasitic drugs. This review summarizes the types, characteristics, and the mechanism of action of AgNPs in anti-parasitism, mainly focusing on their effects in leishmaniasis, flukes, cryptosporidiosis, toxoplasmosis, Haemonchus, Blastocystis hominis, and Strongylides. The aim is to provide a reference for the application of AgNPs in the prevention and control of parasitic diseases.

Toxocariasis in Ghanaian neighbourhoods: a need for action

Background

Animal reservoirs of Toxocara spp., a neglected parasitic infection, are frequently found in many Ghanaian neighbourhoods. Despite various interactions occurring between these animals and humans which sustain zoonosis, not much focus has been directed at disease surveillance in Ghana, necessitating this study.

Methods

The study was cross-sectional. It combined the collection of biological samples with the survey approach. The study used purposive and convenience sampling techniques to collect data from eligible participants in the Greater Accra region of Ghana. Besides the collection of biological samples from animals which were processed using molecular techniques, semi-structured questionnaires were administered to the pet owners.

Results

In sum, 32.2% (95% CI, 27.6%-37.0%) of the targeted animals were positive for Toxocara canis, with most of the cases being found in dogs and rodents. Among the 204 rodents, more Praomys tulbergi were positive for this parasite compared to the others. From the survey, some risk factors culminating in high disease exposure were identified: more than one-third of pet owners did not deworm their pets although about a fourth shared bed with them. In addition, many respondents' kids played with these pets but not all supervised them to practice hand hygiene. Also, a good number of pet owners confirmed the frequent exposure of their pets to rodents.

Conclusions

The relatively high prevalence of T. canis recorded in animals and the increasing exposure of humans to this parasite point to a higher risk for human toxocariasis. Furthermore, T. canis found in cats cannot be ignored and merits further investigations. For Ghana to achieve SDG 3 by 2030, priority must also be placed on neglected diseases which calls for an integrated approach to disease surveillance and a redirection of research focus using the one health concept.

Case report: Ultrasound biomicroscopy as a guide for the selection of injection sites for dexamethasone intravitreal implant (Ozurdex) for peripheral granulomatous ocular toxocariasis in children

Purpose

This article aims to report a case of successful treatment of peripheral granulomatous ocular toxocariasis (OT) in an 8-year-old patient using intravitreal injection of dexamethasone (DEX) implant (Ozurdex) under ultrasound biomicroscopy (UBM) guidance.

Case presentation

A previously healthy 8-year-old boy with a history of long-term close contact with dogs complained of blurring of vision in the right eye for a year. Ophthalmic examination of his right eye showed chronic uveitis. Notably, UBM examination identified granulomas and peripheral vitreous strand in the ciliary body from 3 to 8 o'clock positions. Enzyme-linked immunosorbent assay (ELISA) results of the intraocular fluid (IF) and serum showed increased anti-Toxocara immunoglobulin G (IgG) levels, leading to a diagnosis of peripheral granulomatous OT in the right eye. Intraocular surgery was not indicated in this case. The treatment goal was to alleviate uveitis, improve visual acuity, and prevent complications. He was treated with an intravitreal injection of DEX implant, administered as a single dose every three months, total two doses, combined with albendazole, an oral anthelmintic. Under preoperative UBM guidance, two injections were performed at the 12 and 10 o'clock positions in the pars plana where there were no granulomas and peripheral vitreous strand, successfully preventing complications associated with intravitreal injection. After two injections, the patient's right eye vision improved significantly, with the best-corrected visual acuity (BCVA) increasing from 20/400 to 20/50. Vitreous opacity and retinal edema were reduced, preretinal proliferative membrane was stabilized, and no adverse events occurred.

Conclusion

UBM can accurately determine the location and extent of peripheral granulomas in OT patients, facilitating the avoidance of granulomas during intravitreal injection and preventing complications associated with intravitreal injection. Under the close follow-up and strict adherence to indications, preoperative UBM-guided intravitreal injections of DEX implant treatment for pediatric peripheral granulomatous OT are safe and effective, providing a new therapeutic option for pediatric peripheral granulomatous OT.

Zoonotic Parasites in Playgrounds in Southern Spain: A One Health Approach

Zoonotic parasitic diseases are considered a global threat to public health. In this sense, canines and felines may be infected by different cosmopolitan parasites, with playgrounds serving as an important focus of infection for humans, as well as domestic or wild animals. Knowledge of the epidemiological situation of parasites in animal reservoirs integrated into the environment, identifying the spread pathways, is a key element for an effective response to this threat. Thus, the aim of this study was to assess the frequency of intestinal parasites with zoonotic potential in 120 playgrounds in the Malaga province (Spain). Samples were processed and analysed following standard parasitological procedures. Some 36.7% of playgrounds were parasite-positive with one or more zoonotic parasites. The most common parasites recovered were nematodes (60.0%), followed by protozoan species (33.3%) and cestodes (6.7%). In the parasite-positive playgrounds, Toxocara spp. (17.0 ± 3.5%) and Giardia duodenalis (17.0 ± 3.4%) were the most predominant parasites. In addition, 34.1% of playgrounds were infected with multiple parasites. Our results show a high presence of parasitic forms with zoonotic potential in playgrounds in Malaga, Spain. Due to the close contact between pets and humans in playgrounds, the potential zoonotic risk may increase if prevention and control measures are not designed.

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.

Gray Wolf (Canis lupus italicus) and Red Fox (Vulpes vulpes) Parasite Survey in Anthropized and Natural Areas of Central Italy

Gastrointestinal nematodes and protozoa and other parasite occurrences were evaluated in free-ranging wolf (Canis lupus italicus) and red fox (Vulpes vulpes) populations from natural and anthropized areas of Central Italy. Analyzed fecal samples were collected from 60 foxes and 40 wolves in the anthropized areas, and 41 foxes and 39 wolves in the natural areas. In foxes, hookworm infections (p < 0.0001) were more frequently recorded in the anthropized environment, while coccidia (p < 0.05) and Cryptosporidium spp. (p < 0.0001) were more frequent in the natural area. In wolves, a higher frequency of hookworms (p < 0.0001) was observed in natural areas, while coccidia were more common in the anthropized area (p < 0.05). Moreover, in the natural environment, trichuroid nematodes (p < 0.0001) were significantly more frequent in wolves than in foxes, while Cryptosporidium (p < 0.001) and Giardia duodenalis (p < 0.001) were more common in foxes. In the anthropic area, the occurrence of hookworms was found to be significantly higher in foxes (p < 0.0001), while trichuroid nematodes were more common in wolves (p < 0.0001). The obtained data are indicative of a different diffusion of specific parasite taxa in wolves and foxes living in the natural and/or anthropized environments examined herein.

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.

Potential roles of Toxocara canis larval excretory secretory molecules in immunomodulation and immune evasion

Toxocara canis larvae invade various tissues of different vertebrate species without developing into adults in paratenic host. The long-term survival of the larvae despite exposure to the well-armed immune response is a notable achievement. The larvae modulate the immune response to help the survival of both the host and the larvae. They skew the immune response to type 2/regulatory phenotype. The outstanding ability of the larvae to modulate the host immune response and to evade the immune arms is attributed to the secretion of Toxocara excretory-secretory products (TESPs). TESPs are complex mixture of differing molecules. The present review deals with the molecular composition of the TESPs, their interaction with the host molecules, their effect on the innate immune response, the receptor recognition, the downstream signals the adaptive immunity and the repair of tissues. This review also addresses the role of TESPs molecules in the immune evasion strategy and the potential effect of the induced immunomodulation in some diseases. Identification of parasite components that influence the nematode-host interactions could enhance understanding the molecular basis of nematode pathogenicity. Furthermore, the identification of helminths molecules with immunomodulatory potential could be used in immunotherapies for some diseases.