Human Toxocariasis Research Articles

In Silico Discovery of Antigenic-Secreted Proteins to Diagnostic Human Toxocariasis

BackgroundHuman toxocariasis is a helminthic zoonosis caused by infection of Toxocara canis or T. cati. Humans can be infected by through ingestion of embryonated eggs from contaminated water, food or soil. Diagnosis is challenging, immunodiagnosis tests are commonly implemented with major pitfalls in the cross-reactivity with other pathogens, particularly in endemic areas.MethodsWith the aim of identify species-specific genes encoding for highly expressed antigenic proteins, a list of parasites that may infect humans and that might present similar clinical symptoms to T. canis infections was built. Only organisms whose genomes were completely sequenced and the proteome predicted were included. First, orthologous proteins were detected and the subcellular localization of T. canis proteins was predicted. In order to identify differentially expressed genes encoding proteins in larvae L3, pair-wise comparisons among transcriptomes from body parts and genders were performed. Finally, all secreted proteins classified as species-specific of T. canis, whose genes were upregulated in larvae L3 were included in an antigenic prediction.ResultsTwenty-eight parasites were included in the analyses, proteins of T. canis were clustered in 11,399 groups, however, 279 were species-specific groups which represent 816 proteins. Three hundred and twenty-two proteins were predicted to be secreted and upregulated in larvae L3, however, after filtering these proteins by their orthology inference, only three proteins met all the features included in this study (species-specific, upregulated, secreted, and antigenic potential). To conclude, our strategy in the study is a rational approach for discovering antigenic proteins to be used in diagnosis.

IDENTIFICATION OF TOXOCARA SPP. IN STOOL SAMPLES OF ELEMENTARY SCHOOL-AGED CHILDREN IN NIMBOKRANG DISTRICT, JAYAPURA REGENCY, PAPUA

Background: Toxocariasis is a parasitic disease caused by Toxocara spp. Two species of Toxocara are highly significant in the medical field: Toxocara canis, found in dogs, and Toxocara cati, found in cats. The occurrence of toxocariasis in humans is linked to its occurrence in pets. Morphological identification of eggs and larvae through microscopy is the most commonly used method but has limitations in diagnostic accuracy. The polymerase chain reaction (PCR) method is a molecular approach developed for identifying Toxocara spp. This study aimed to identify Toxocara spp. in stool samples from children using the PCR method. Methods: The study was conducted from January to November 2024 in Nimbokrang District, Jayapura Regency, Papua. A total of 327 stool samples from elementary school-aged children were collected and analyzed for Toxocara spp. using multiplex polymerase chain reaction (PCR) with specific primers for Toxocara cati and Toxocara canis. PCR products were analyzed using gel electrophoresis with a 100 bp DNA ladder marker and visualized using a gel documentation system. Results: Identification of Toxocara spp. using multiplex PCR was successfully performed on 327 stool samples from elementary school-aged children. The prevalence of toxocariasis was 14.7% (48/327), with Toxocara canis found in 12.8% (42/327) and Toxocara cati in 1.8% (6/327). Conclusion: Toxocara spp. were successfully identified in stool samples from elementary school-aged children using the PCR method. This method is expected to aid in helminthiasis surveillance efforts within the community.

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.

Prevalence of Toxoplasma Gondii and Toxocara Canis Antibodies among Owners of Dogs and Cats in Ekiti State Nigeria

Zoonoses are still a serious public health concern since the number of homeless animals, particularly dogs and cats, is increasing. As the causative agents of human toxoplasmosis and toxocariasis, respectively, Toxoplasma gondii and Toxocara canis are significant zoonotic agents from an epidemiological perspective. We have ascertained the seroprevalence of T. gondii and T. canis antibodies among dog and cat owners by a cross-sectional study. Between May and July of 2024, serum samples were taken from 185 owners in Ekiti State, Nigeria. Using an enzyme-linked immunosorbent test (ELISA), the pet owners' sera were collected. The seroprevalence of IgM and IgG antibodies for T. gondii was 3.8% and 9.4%, respectively, in dogs, whereas the IgG antibody seroprevalence for T. canis was 7.5%. Additionally, our seroprevalence findings indicate that dog owners may be more susceptible to contracting T. gondii and T. canis infections, especially if they are female owners. Dog owners in Ekiti State, Nigeria, have significant levels of anti-T. gondii and anti-toxocara antibodies, suggesting a possible zoonotic risk. In order to mitigate the risk of T. gondii and T. canis environmental contamination, it is recommended that dogs and cats have appropriate deworming, be leashed, and have their waste cleaned up. These steps should aid in preventing the morbidity that these two different but extremely adaptable parasites produce in humans

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

BackgroundHuman 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.MethodsSmall 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.ResultsThis 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.ConclusionsOur 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.Graphical

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 1mg/mL, and compounds with larvicidal activity were serially diluted to obtain concentrations of 0.5mg/mL; 0.25mg/mL; 0.125mg/mL; and 0.05mg/mL. The tests were performed in a microculture plate containing 100T. 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 7-8weeks 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.

Molecular Determination of Toxocara spp. Eggs Isolated from Public Parks and Playgrounds in Zahedan, Southeast Iran.

Human toxocariasis (HT) is a zoonotic disease with a global expansion. Contaminated soil with Toxocara spp. eggs is the main source of human infection, which may lead to severe complications depending on the organs invaded by migrating larvae. This study is aimed at eliciting the prevalence of Toxocara spp. eggs in public parks in Zahedan, southeast Iran, and providing new insight into the soil contamination rate in this area using microscopic and molecular methods. Based on five municipal districts, 240 soil samples were collected from public parks and playgrounds in Zahedan. The modified Sheather's flotation technique was employed to isolate Toxocara spp. eggs from the soil, followed by microscopic assessment and molecular evaluation of internal transcribed spacer 1 and 2 ribosomal deoxyribonucleic acid (ITS1 and 2 rDNA) using nested polymerase chain reaction (nested PCR) to identify the presence of Toxocara spp. eggs. The Sanger sequence was used to differentiate the Toxocara species. Subsequently, all the sequenced data were blasted and compared with other sequences available in the GenBank. Out of 240 soil samples collected, 7 (2.9%) samples were identified to contain Toxocara spp. eggs using Sheather's flotation and microscopic techniques. Meanwhile, 19 (7.9%) samples were positive using nested PCR. According to the Sanger sequencing analysis findings, all positive samples were contaminated with Toxocara cati. As evidenced by the obtained results, only T. cati species were detected in public parks and playgrounds in Zahedan; therefore, control and prevention programs against this species should be considered in human and animal communities.

Organ-specific Toxocara canis larvae migration and host immune response in experimentally infected mice.

We investigated organ specific Toxocara canis larval migration in mice infected with T. canis larvae. We observed the worm burden and systemic immune responses. Three groups of BALB/c mice (n=5 each) were orally administered 1,000 T. canis 2nd stage larvae to induce larva migrans. Mice were sacrificed at 1, 3, and 5 weeks post-infection. Liver, lung, brain, and eye tissues were collected. Tissue from 2 mice per group was digested for larval count, while the remaining 3 mice underwent histological analysis. Blood hematology and serology were evaluated and compared to that in a control uninfected group (n=5) to assess the immune response. Cytokine levels in bronchoalveolar lavage (BAL) fluid were also analyzed. We found that, 1 week post-infection, the mean parasite load in the liver (72±7.1), brain (31±4.2), lungs (20±5.7), and eyes (2±0) peaked and stayed constant until the 3 weeks. By 5-week post-infection, the worm burden in the liver and lungs significantly decreased to 10±4.2 and 9±5.7, respectively, while they remained relatively stable in the brain and eyes (18±4.2 and 1±0, respectively). Interestingly, ocular larvae resided in all retinal layers, without notable inflammation in outer retina. Mice infected with T. canis exhibited elevated levels of neutrophils, monocytes, eosinophils, and immunoglobulin E. At 5 weeks post-infection, interleukin (IL)-5 and IL-13 levels were elevated in BAL fluid. Whereas IL-4, IL-10, IL-17, and interferon-γ levels in BAL fluid were similar to that in controls. Our findings demonstrate that a small portion of T. canis larvae migrate to the eyes and brain within the first week of infection. Minimal tissue inflammation was observed, probably due to increase of anti-inflammatory cytokines. This study contributes to our understanding of the histological and immunological responses to T. canis infection in mice, which may have implications to further understand human toxocariasis.

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.

Toxocara canis infection in multiple types of animals: ophthalmological and pathological observations.

Human ocular toxocariasis (OT), caused by pet roundworm Toxocara canis (Nematoda Ascaridoidea), is a worldwide ocular parasitic infection that poses a severe threat to eyesight, especially in school-aged children. However, the infection process and pathological mechanism of Toxocara are difficult to study in the human body. This study was designed to explore long-term ocular manifestations in different rodents infected with Toxocara canis, uncovering the specific pathological mechanism and migration pathway of larvae after infection. The three types of experimental animals we selected were C57BL/6 mice, Mongolian gerbils and Brown Norway rats. Mice were randomly divided into five groups and infected orally with 1000, 2000, 4000, 8000 and 10,000 T. canis eggs; gerbils were randomly divided into four groups and infected orally with 1000, 2000, 4000 and 10,000 T. canis eggs; rats were randomly divided into three groups and infected orally with 2000, 6000 and 10,000 T. canis eggs. Their ocular changes were closely observed and recorded for at least 2months. We also enucleated the eyeballs of some animals to perform pathological sectioning and hematoxylin-eosin staining. After 3 dpi (days post-infection), hemorrhagic lesions, mechanical injury of the retina and larval migration could be observed in some infected animals. The ocular infection and mortality rates tended to be stable at 7 dpi. Larval tissue, structure disorder and inflammation could be observed in the pathological sections. In conclusion, the mice infected with 2000T. canis eggs and gerbils infected with 1000, 2000 and 4000T. canis eggs showing obvious ocular lesions and lower mortality rates could provide a basis for long-term observation.

The larvicidal effect of the supernatant of Lactobacillus acidophilus ATCC 4356 on Toxocara canis

Human toxocariasis is a parasitic anthropozoonosis that is difficult to treat and control. A previous study carried out with Lactobacillus acidophilus ATCC 4356 revealed that the cell free supernatant (CFS) of this probiotic killed 100% of Toxocara canis larvae in vitro. The present study aimed to investigate the characteristics of the CFS of L. acidophilus ATCC 4356, which may be involved in its larvicidal effects on T. canis. L. acidophilus ATCC 4356 was cultured, and lactic and acetic acids present in the CFS were quantified by high performance liquid chromatography (HPLC). The levels of pH and H2O2 were also analyzed. To assess the larvicidal effect of the CFS, this was tested pure and diluted (1:2 to 1:128) on T. canis larvae. High concentrations of lactic and acetic acids were detected in the CFS. The acidity of the pure CFS was observed at pH 3.8, remaining acidic at dilutions of 1:2 to 1:16. Regarding the in vitro larvicidal effect, 100% death of T. canis larvae was observed using the pure CFS and 1:2 dilution. Based on these results, it can be inferred that the presence of higher concentrations of organic acids and low pH of the medium contributed to the larvicidal activity of the CFS of L. acidophilus ATCC 4356. In addition, the maintenance of the larvicidal effect, even after dilution, suggests a greater chance of the larvicidal effect of this CFS against T. canis in vivo.

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.

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

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

Epidemiological profile of human toxocariasis in patients examined at Evandro Chagas Institute (IEC/SVSA/MS) between 2014 and 2019

Toxocariasis is caused by nematodes of Toxocara genus, which infest dogs and cats, with humans serving as paratenic hosts. The epidemiological profile of patients examined for toxocariasis between October 2014 and October 2019 at Evandro Chagas Institute (IEC) was outlined. The frequency of anti-T. canis IgG antibodies were evaluated using the Enzyme Linked Immunosorbent Assay (ELISA) method. From a total of 734 samples, 56% were from male (p<0.05). Regarding age, the group with the most solicitations were from ≤11 years old individuals (p<0.05). Pará state had the highest number of exams requested (92%), with the majority from residents of urban areas, accounting for 81.5% of samples (p<0.05). The overall toxocariasis seroprevalence was 41.8%, the male sex being the most frequent with 60.9% (p<0.05). The most affected age group was ≤11 years old, with a total of 67.8% of positive samples (p<0.05). The high rates obtained emphasize the need for complementary studies on toxocariasis in Brazil, especially in Pará state, contributing to epidemiological surveillance actions in the control of this infection. Besides, health campaigns for domestic and stray animals, also can contribute to a more effective surveillance in controlling parasitic infections and encourages the One Health approach.

SEROPREVALENCE OF IgG ANTIBODIES OF HUMAN TOXOCARIASIS AND ASOCIATED RISK FACTORS IN KHANH HOA PROVINCE

Background: Human toxocariasis is a zoonotic parasitic disease caused by Toxocara canis and T. cati roundworm larvae. While many studies have shown that dog and cat owners are at a higher risk of acquiring Toxocara spp. infection, there is no available evidence regarding the seroprevalence of Toxocara spp. infection among dog and cat owners in Khanh Hoa. Therefore, this study aims to investigate the prevalence of anti-IgG of Toxocara spp. infection and associated risk factors for visceral larval migrans among dog owners in three different areas of Khanh Hoa province..Subjects and methods: A descriptive cross-sectional study was conducted from 2022 to 2024 in three localities representing different socio-geographic areas (urban, rural, and mountainous) of Khanh Hoa province. A total of 1502 blood samples were collected from local individuals aged 5 to 75 for this study. Serum anti-T.canis IgG antibodies were detected using a commercial enzyme-linked immunosorbent assay (ELISA) kit: NovaLisaTM, Toxocara canis IgG ELISA. Simultaneously, a survey using structured questionnaire about information on risk factors associated with Toxocariasis was conducted among 720 people (aged 18 and over) from 1,502 individuals whose bloods were taken for testing.Results and conclusions: A total of 1,502 blood samples were examined for the presence of antibodies to dog and cat roundworm larval infection. Results revealed an overall positive rate of 57.66% across the three localities, with variations depending on geography. In Khanh Vinh, a mountainous district, the infection rate was 75.44%, and in its commune Khanh Trung, it was 81.20%. For the two urban wards, the rates were significantly lower (Phuoc Long Ward: 44.40% and Van Thanh Ward: 54.18%). A structured questionnaire was used to investigate risk factors among 720 individuals (aged 18 years old and over) out of the 1,502 individuals whose bloods were tested. Results indicated that 389 of them tested positive for the ELISA test. Infection rates varied among age groups: under 25 years old (6.94%), 25-50 years old (66.78%), and over 50 years old (37.28%). Notably, 49.87% of infected individuals owned dogs or cats, 93.32% regularly consumed raw vegetables, and 25.71% frequently handled dogs or cats. The high infection rate of dog and cat roundworm larvae in Khanh Hoa underscores the presence of several identified high-risk factors.

Seroprevalence of Toxocara at Tra Vinh University Hospital in Vietnam.

The study aims to assess the seroprevalence of Toxocariasis and its associated risk factors among individuals attending the outpatient department at Tra Vinh University Hospital, Vietnam, in 2022. A cross-sectional survey was conducted among outpatients of Tra Vinh University Hospital. Toxocariasis diagnosis was based on the Enzyme-Linked Immunosorbent Assay (ELISA) performed at the hospital's laboratory department. We assessed the seroprevalence of Toxocariasis and evaluated associated risk factors, including demographics and certain behaviors. Of the 249 participants surveyed, 165 tested positive for Toxocariasis, yielding a seroprevalence of 66.3% (95% CI: 60.4-72.1). Multivariate analysis revealed that age groups up to 30 and 30-60 years had higher odds of Toxocariasis infection, with adjusted odds ratios (aOR) of 2.52 (95% CI: 1.04-6.11) and 3.21 (95% CI: 1.44-7.15) respectively. Additionally, individuals residing in rural areas and those in contact with dogs or cats had increased risks, with aORs of 2.21 (95% CI: 1.21-4.01) and 2.04 (95% CI: 1.10-3.79), respectively. Notably, hand washing before eating emerged as a protective factor against Toxocariasis, presenting an aOR of 0.38 (95% CI: 0.19-0.76). Our findings underscore a significant seroprevalence (66.3%) of Toxocara spp. among outpatients at Tra Vinh University Hospital. Proactive measures, including hand hygiene before meals and after pet interactions, are advocated. There is a pronounced need for community-level epidemiological surveillance for human Toxocariasis.

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.

Diagnosis and correction of immunological reactivity disorders in tuberculosis and toxocariasis infection

The article is a systematic review of the literature on toxocariasis and tuberculosis. Human toxocariasis is a neglected tropical disease that has a global distribution and a significant impact on global public health. The infection can lead to a number of serious conditions in humans, including in cases associated with other infections. Invasion with Toxocara canis represents a strong endogenous factor in the formation of the regulatory imbalance of the immune system, which is manifested by the decrease in phagocytosis indices, the increase in the content of circulating immune complexes, and total IgE. The integral evaluation of these indices serves as an important criterion in the diagnosis of toxocariasis and the effectiveness of the applied therapy. Immunosuppression caused by parasites inhibits metabolic processes in the human body, and enzyme activity, making it difficult to absorb antiparasitic, antibacterial, and other chemotherapeutic drugs. Therefore, the treatment of tissue helminthiasis is difficult, because the larvae are in the tissues, while antiparasitic drugs do not have a high absorption capacity. Decreased eosinophils and IL-10 indicate that asymptomatic helminth infection significantly suppresses immunity in tuberculosis patients. The association of pulmonary tuberculosis wit toxocariasis is a combination of two diseases with severe endogenous intoxication, which is insufficiently elucidated.

Deglycosylation of Excretory-Secretory Antigens of the Second-Stage Larvae of Toxocara cati Improves Its Efficacy in the Diagnosis of Human Toxocariasis.

Toxocariasis is an important zoonotic infection, especially in tropical areas. One of the significant challenges in the serodiagnosis of human toxocariasis is the cross-reaction of Toxocara antigens with other parasites due to their relatively similar glycan structures. Removing the glycan structure from Toxocara excretory-secretory (TES) antigens may increase the efficacy of these antigens in the diagnosis of toxocariasis. The current study aimed to assess the efficacy of deglycosylated Toxocara cati excretory-secretory (dTES) antigens for the serodiagnosis of human toxocariasis. Toxocara ES antigens were prepared from T. cati second-stage larvae and deglycosylated using sodium hydroxide (NaOH). The TES antigens, along with the dTES antigens, were used in an ELISA as well as a western blotting system for the detection of anti-Toxocara antibodies. Sera samples collected from 30 confirmed cases of toxocariasis, 30 patients with other diseases, and 30 healthy subjects were evaluated by both systems. The sensitivity of TES and dTES ELISA for the diagnosis of human toxocariasis was 96.67% (95% CI = 82.78-99.92) and 93.33% (95% CI = 77.93-99.18), respectively, while the specificity of dTES (88.33%; 95% CI = 77.43-95.18) increased significantly compared to the TES (80.00%; 95% CI = 67.67-89.22). The sensitivity of both antigens was 100% (95% CI = 88.43-100) by the western blotting system. Moreover, the specificity of TES and dTES antigens was 95% (95% CI = 86.08-98.96) and 98.33% (95% CI = 91.06-99.96), respectively, when using the western blotting system. Results of the current study indicate that the chemical removal of the glycan epitopes of T. cati ES antigens significantly reduces cross-reactivity rates with other parasitic infections. Considering the findings of the present study, the dTES antigens seem to be suitable antigens for the serodiagnosis of human toxocariasis.

Toxocariasis as a cause of multiple pulmonary and liver nodules in an immunocompetent adult

Human toxocariasis is a cosmopolite parasitic infection due to an helminth Toxocara canis (T.canis) and Toxocara catis(T.catis). Visceral larva migrans constitutes a rare and doubtful form. We reported the case of a visceral larva migrans with a concomitant localization in lung and liver.