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Human toxocariasis is a highly prevalent zoonosis worldwide but is underreported in most countries. This study was conducted to evaluate Toxocara canis seropositivity in different exposure sub-groups located in the Mardan, Swabi, and Nowshera districts of the Khyber Pakhtunkhwa province of Northwest Pakistan. A total of 400 blood samples were collected from males 15 years of age and older with no animals, with livestock, with dogs and/or cats living in the house, and from butchers and veterinarians or para-veterinarians. Serum was tested using a commercial ELISA kit for detection of IgG antibodies against T. canis. Proportion seropositive was presented for each group and differences between groups were evaluated using the chi-square or Fisher's exact test as appropriate. Possible risk factors obtained through administration of a questionnaire were also evaluated for each sub-population. Overall T. canis seroprevalence was 14.2%, with a significant difference found between the seroprevalence of individuals with no animals (5.0%; 5/100), individuals with dogs and/or cats living in the household (8.0%; 8/100), individuals with livestock (18.0%; 18/100), veterinarians or para-veterinarians (24.0%; 12/50), and butchers (28.0%; 14/50) (p < 0.001). Significant differences in seropositivity by income bracket, education level, and working in the fields were found for some sub-groups. Study findings demonstrate that certain sub-populations, in Northwest Pakistan, may be at greater risk of T. canis infection. Development and implementation of targeted preventive strategies may, therefore, be needed., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Probiotics have been shown to reduce the intensity of Toxocara canis infection in mice. However, larval transmission of this nematode also occurs via transplacental and transmammary routes. Thus, the aim of this study was to evaluate the effect of the Saccharomyces boulardii probiotic on the vertical transmission of T. canis in Swiss mice. The mice received 107S. boulardii colony-forming units per gram of food. The supplementation began 15 days before mating and was maintained throughout pregnancy and lactation. The animals were inoculated with 300 T. canis embryonated eggs on the 14th day of pregnancy. The presence of larvae was examined in the organs of the females and their offspring. The examined organs included the following: brain, liver, lungs, heart, kidneys, spleen, eye, skeletal muscle (carcass) and mammary glands of lactating females. There was a 42% (P = 0.041) reduction in the number of larvae transmitted to offspring in the group that received probiotic-supplemented food (GI). Additionally, there was a 50% reduction (P = 0.023) in the number of larvae found in the brains of lactating offspring in the GI group. These results reveal the potential of S. boulardii probiotic use as an auxiliary method of controlling visceral toxocariasis.

The nematode Toxocara canis is of public health importance and is the main causative agent of toxocariasis in humans. This disease is difficult to diagnose due to several factors, including the possibility of cross-reactions with other nematodes in the ELISA. To overcome this problem, molecular tests have been recommended as an alternative to identify the parasite. The quantitative real-time polymerase chain reaction (qPCR) technique was used in this study to identify and quantify the parasite load of T. canis in the mouse brain. To this end, 24 mice were divided into six groups, five of which were challenged with different infective doses of T. canis larvae (L3) (1000, 500, 250, 100 and 50 larvae), while the sixth group, uninfected, acted as negative control. Forty-five days after infection, the animals were euthanized to collect the brain, from which two portions of 20 mg of tissue were taken for DNA extraction, while the rest of the brain tissue was digested to quantify the number of larvae by microscopy. The number of DNA copies was calculated from the standard DNA quantification curve, showing values of E = 93.4%, R2 = 0.9655 and Y = -3.415. A strong positive correlation (R = 0, 81; p < .001) was found between the number of copies and the recovery of larvae from brain. However, the parasite's DNA was also identified even in animals from whose brain no larvae were recovered after tissue digestion. The results of this study therefore confirm that the qPCR technique can be a valuable tool for the detection and quantification of T. canis DNA in murine hosts, even in animals whose with tissues contain very few parasites., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Human toxocariasis is a neglected global parasitic zoonosis. The efficacy of drug treatment for this disease has been hindered by the biological complexity of the main etiological agent, the nematode Toxocara canis. Experimental studies have shown the potential of probiotics to promote a reduction in the parasite load of T. canis larvae. This study aimed to evaluate the effect of probiotic Lactobacillus rhamnosus ATCC 7469 on the parasite load of BALB/c mice with acute toxocariasis and evaluate the direct effect of this probiotic on T. canis larvae in vitro. In vivo administration of probiotics reduced the parasite load of T. canis larvae by 53.3% (p = 0.0018) during the early stage of infection in mice. However, when analyzed in vitro, it was observed that the probiotic did not present a deleterious effect on the larvae, as approximately 90% of these remained viable. These results demonstrate the potential of the probiotic L. rhamnosus in the reduction of T. canis larvae in BALB/c mice and suggest it could be used as an alternative means for the controlling of visceral toxocariasis. However, further studies are required to elucidate the mechanisms of action promoted by this probiotic.

Context: Toxocara canis is a parasite known to cause visceral larva migrans. The infection rarely affects the central nervous system but there have been several reports of myelitis caused by visceral larva migrans due to Toxocara canis. In previous reported cases, the lesions were located in the thoracic or cervical spinal cord. To the best of our knowledge, this is the first report of a lesion involving the lumbosacral region., Findings: A 60-year-old man developed weakness and dysesthesia in the lower limbs. The symptoms resolved spontaneously, but recurred after five months. One month later, the patient developed pollakiuria and constipation. He was a dog owner and frequently ate raw chicken meat and beef liver. Sagittal T2-weighted image (T2WI) showed swelling and hyperintensity in the spinal cord from T10 to the lumbosacral region and focal nodular enhancement on the posterior segment of the lumbar spinal cord. Blood cell counts showed slight eosinophilia and elevated serum immunoglobulin E level. Cerebrospinal fluid examination showed slight pleocytosis with eosinophilia. Enzyme-linked immunosorbent assay showed high levels of anti-Toxocara antibodies in the serum and cerebrospinal fluid. In addition, confirmatory test by Western blot was positive. The patient was initially treated with intravenous methylprednisolone with slight improvement in muscle weakness. Albendazole was added with a second course of intravenous methylprednisolone. The muscle weakness in the lower limbs improved considerably, and swelling and hyperintensity on T2WI almost disappeared., Conclusion: Our results suggest that Toxocara canis myelitis cannot be discounted even if the myelitis involves the lumbosacral region.

Experimental studies and registries of cases of human toxocariasis have shown that the consumption of raw or undercooked offal of the paratenic host of Toxocara canis may pose a risk of infection. Thus, we evaluated the risk of infection due to the consumption of liver of chickens inoculated with different doses of embryonated T. canis eggs. Doses were 5-100 times smaller than the ones previously employed in this type of study. Groups of five chickens were inoculated with 5000 (control), 1000, 500, 300 or 50 eggs of T. canis, and at 72 h post-inoculation, the liver of each bird was consumed by a BALB/c receptor mouse. Forty-eight hours after consumption, we examined the organs and carcasses of the mice for larvae of T. canis. All mice were positive for larvae, except the group that consumed the chicken liver inoculated with 50 eggs. This group contained only one positive mouse, in which the larva was lodged in the brain. In mice that consumed livers of chickens inoculated with ≥300 eggs, larvae concentration was primarily in the liver and lungs, characterizing the initial phase of infection. We conclude that the consumption of raw poultry liver, under the studied conditions, poses a risk of infection even with a low number of infected T. canis eggs., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Recently reports on toxocariasis are increasing by serodiagnosis in Korea. A previously healthy 17-yr-old boy complained of headache, fever, dyspnea, and anorexia. He showed symptoms and signs of eosinophilic meningitis with involvement of the lungs and liver. Specific IgG antibody to Toxocara canis larval antigen was positive in serum and cerebrospinal fluid by ELISA. He took raw ostrich liver with his parents 4 weeks before the symptom onset. His parents were seropositive for T. canis antigen but had no symptoms or signs suggesting toxocariasis. This is the first report of toxocariasis in a family due to ingestion of raw ostrich liver in Korea.

The aim of this study is to ascertain the relationship between ingestion of raw cow liver and Toxocara canis infection. A total of 150 apparently healthy adults were divided into 2 groups; 1 group consisted of 86 adults with positive results of Toxocara ELISA, and the other group of 64 adults with negative results. One researcher collected the history of ingestion of raw cow liver within 1 year and recent history of keeping dogs. Among 86 seropositive adults for T. canis, 68 (79.1%) had a recent history of ingestion of raw cow liver. Multivariate statistical analysis showed that a recent ingestion of raw cow liver and keeping dogs were related to an increased risk of toxocariasis (odds ratios, 4.4 and 3.7; and 95% confidence intervals, 1.9-10.2 and 1.2-11.6, respectively). A recent history of ingestion of raw cow liver and keeping dogs was significantly associated with toxocariasis.

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. [ABSTRACT FROM AUTHOR]

Toxocara canis is an important roundworm of canids and a fearsome animal parasite of humans. Human infections can lead to syndromes called visceral larva migrans (VLM), ocular larva migrans, neurotoxocariasis, and covert toxocariasis. VLM is most commonly diagnosed in children younger than 8 years of age, but adult cases are relatively frequent among those infected by ingesting the raw tissue of paratenic hosts in East Asia. This research reports the case of a 59-year-old man with sigmoid colon cancer, who visited our institution for surgery. An intraperitoneal mass was found on preoperative computed tomography, and it was thought to be a metastatic mass from sigmoid colon cancer. A postoperative histologic examination and serum test showed eosinophilic granuloma due to toxocariasis. Diagnosis of VLM is often difficult and highly suspicious in adults. Researchers suggest, although rarely, that VLM be included in the differential diagnosis as a cause of intraperitoneal tumors.

Toxocariasis in humans is considered a rare disease in Turkey, and the absence of specific symptoms of this disease is probably the main reason for clinicians to underestimate and underdiagnose the disease. Although there are several seroepidemiological studies on visceral larva migrans in the country, a comparison between them is difficult as the serological tests are not standardised. After the introduction of the easily accessible ELISA kit in the market, the number of seroepidemiological studies has increased in which the reported rates ranged between 1% and 56%. Similar to other countries, Toxocara seropositivity in Turkey is more common in men, childhood, in those living in rural area, having a low income level, owning dogs, and biting their nails or practicing geophagia. In addition, toxocariasis is a risk factor for veterinarians, farmers, and pet-shop workers. Toxocara seroprevalence is significantly higher in respiratory, neuropsychiatric, musculoskeletal, skin and abdominal disorders. There are also many studies showing the importance of eosinophilia in toxocariasis. In conclusion, although there are many studies on toxocariasis in Turkey, it is still not well understood to what extent the infection is responsible for a plethora ascribed symptoms. Standardisation of the diagnostic methods and the use of molecular techniques could further throw light in the real epidemiology and the role played by the infection to induce signs and symptoms. [ABSTRACT FROM AUTHOR]

The present study illustrates two cases of Toxocara canis infection: a 77-year-old man presenting with bilateral uveitis, sepsis, and non-convulsive status epilepticus (patient A); and a 63-year-old woman with a history of treated breast cancer, presenting with sight loss and paralysis of the right eye, neurological symptoms, pulmonary embolism, pneumonia, and a post traumatic vertebral fracture (patient B). Both diagnoses were challenging because the acute comorbidities withdrew the attention from the actual cause of the disease, and in one case the steroid treatment possibly affected the laboratory indexes. The lack of response to antibiotics and the involvement of specific organs and districts suggested parasitic infection. Indeed, immunoblot assay revealed the presence of specific T. canis immunoglobulin G antibodies. Both patients improved with albendazole 800 mg/die (400 mg ×2) for 28 days; the neurological state normalized, while sight and eye motility remained impaired. Overall, the findings from these two toxocariasis cases indicate that the occurrence of severe neurological symptoms associated with ocular involvement should generate suspicion of parasitic infection rather than leading to differential diagnosis of common presentations such as bacterial and viral infections or autoimmune diseases.

The present study illustrates two cases of Toxocara canis infection: a 77-year-old man presenting with bilateral uveitis, sepsis, and non-convulsive status epilepticus (patient A); and a 63-year-old woman with a history of treated breast cancer, presenting with sight loss and paralysis of the right eye, neurological symptoms, pulmonary embolism, pneumonia, and a post traumatic vertebral fracture (patient B). Both diagnoses were challenging because the acute comorbidities withdrew the attention from the actual cause of the disease, and in one case the steroid treatment possibly affected the laboratory indexes. The lack of response to antibiotics and the involvement of specific organs and districts suggested parasitic infection. Indeed, immunoblot assay revealed the presence of specific T. canis immunoglobulin G antibodies. Both patients improved with albendazole 800 mg/die (400 mg ×2) for 28 days; the neurological state normalized, while sight and eye motility remained impaired. Overall, the findings from these two toxocariasis cases indicate that the occurrence of severe neurological symptoms associated with ocular involvement should generate suspicion of parasitic infection rather than leading to differential diagnosis of common presentations such as bacterial and viral infections or autoimmune diseases. [ABSTRACT FROM AUTHOR]

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Toxocara canis is a zoonotic parasite with worldwide distribution. ATP-binding cassette (ABC) transporters are integral membrane proteins which involve in a range of biological processes in various organisms. In present study, the full-length coding sequence of abcg-5 gene of T. canis (Tc-abcg-5) was cloned and characterized. A 633 aa polypeptide containing two conserved Walker A and Walker B motifs was predicted from a continuous 1902 nt open reading frame. Quantitative real-time PCR was employed to determine the transcriptional levels of Tc-abcg-5 gene in adult male and female worms, which indicated high mRNA level of Tc-abcg-5 in the reproductive tract of adult female T. canis. Tc-abcg-5 was expressed to produce rabbit polyclonal antiserum against recombinant TcABCG5. Indirect-fluorescence immunohistochemical assays were carried out to detect the tissue distribution of TcABCG5, which showed predominant distribution of TcABCG5 in the uterus (especially in the germ cells) of adult female T. canis. Tissue transcription and expression pattern of Tc-abcg-5 indicated that Tc-abcg-5 might play essential roles in the reproduction of this parasitic nematode. [ABSTRACT FROM AUTHOR]

Toxocariasis is a frequent zoonotic parasitosis in Serbia. The aim of the study was to examine anti-Toxocara IgG antibodies in serum and cerebrospinal fluid (CSF) in patients with suspected visceral larva migrans (VLM) in Belgrade, and to estimate the prevalence of T. canis eggs in dog fecal deposits collected in green public areas. A total of 145 patients were examined by ELISA. In 26.39% (38/144) of serum samples, T. canis IgG were detected, and in 6 CSF samples, 2 were positive for antibodies. Seropositivity was detected in 26.1% (34/130) adults and 33.3% (5/15) children. A total number of 155 fresh dog feces were collected in five public parks in Belgrade where T. canis eggs were identified with a prevalence of 33.55% (52/155). Based on the high prevalence of parasite eggs, we estimated a high risk of human infection by T. canis eggs in public green areas in Belgrade.

Background Toxocariasis is a globally distributed zoonosis. The most important definitive hosts are dogs, whereas humans serve as paratenic hosts. Transmission to humans occurs by accidental ingestion of eggs, e.g. by consumption of contaminated fruits or vegetables. Although exposure to Toxocara is usually considered as relatively benign, it is implicated in a range of neurological, ophthalmologic and other organ-specific conditions, some of them with grave consequences. This review provides an overview on the epidemiology, presentation and risk factors of exposure to Toxocara in Africa. Methods A systematic search was performed for studies published after January 1st, 1990, in English, French, Portuguese, Spanish, Dutch or German. The review was prepared according to PRISMA guidelines. Studies on toxocariasis in human populations and contamination in human environments were included. Results Sixty-five papers were included. Antibodies against Toxocara spp. in humans were found to be very common across Africa. Severe manifestations have been reported mainly from North Africa. Environmental contamination including soil, vegetables and fruits sold on markets was demonstrated in various locations in Africa. Conclusions Exposure to Toxocara is prevalent across the African continent. However, the complication frequency, the impact of the condition on the individual and the public health relevance of this zoonosis, and the economic impact have never been systematically evaluated. [ABSTRACT FROM AUTHOR]

One of the neglected soil and/or food-borne diseases with international public health importance is toxocariasis. Human cases are being increasingly reported from Asian, African, Oceania, European and the American countries. Hence, human toxocariasis (HT) is now considered as a major zoonosis with global and regional importance. In Iran, human and animal toxocariasis is an endemic disease with clinical and epidemiologic health problem aspects. Doubtless, understanding the epidemiology and the trend of this important parasitic disease and its affecting factors will provide the establishment of effective prevention and control programs. To better understand the trend of toxocariasis researches in Iran, this study was performed to analyze different aspects of this zoonotic disease including history, life cycle, species, human animals and environmental studies, diagnostic aspects and treatments to find out the gaps, including different aspects of clinical sings in human patients, new and specific recombinant antigens based on the native antigens, new diagnostic tools, especially rapid diagnostic tests, paratenic hosts status and new treatment procedures which is necessary to be investigated in the future studies on this important zoonotic disease. [ABSTRACT FROM AUTHOR]

Human toxocariasis is caused by the nematode, Toxocara canis and it is a poorly understood phenomenon in Nigeria. Seroepidemiological studies have not been previously carried out among the preschool aged children in Nigeria. A cross-sectional study was conducted in pre-school children in four communities from Osun State, Nigeria between January and July 2016. A total of 308 children Aged 9 months and 5 years were studied comprising 53.2% (164/308) male and 46.8% (144/308) female. Blood samples were collected and screened for the presence of anti- Toxocara IgG antibodies by Western blot analysis based on the excretory-secretory antigens of larva T. canis (TcES), targeting low molecular weight bands of 24 − 35 kDa specific for T. canis . Questionnaires were given to parents/guardians of the studied children to collect information regarding relationship between infection and host factors. The overall seroprevalence of Toxocara infection was 37.3%. The seroprevalence in the studied preschool children ranged from 18.2% in children less than one year old to a max of 57.6% in children aged 3 years and above. The logistic regression analysis of risk factors showed that children’s age (odds ratio (OR) = 6.12, 95% confidence interval (CI) = 1.25–29.90, p = 0.02), contact with dogs (OR = 3.17, 95% CI = 1.40–7.20, p = 0.01) and parent’s religion (OR = 0.54, 95% CI = 0.32–0.91, p = 0.02) were the risk factors associated with Toxocara infection. However, after adjustment by multivariate logistic regression analysis, contact with dogs ( p = 0.02) remained the only statistically significant risk factor. Preschool children were exposed early in life to T. canis infection as 18.18% of children less than one year old were infected. This is the first serological investigation of T. canis infection among preschool children in Nigeria. The results show high levels of exposure to T. canis infection among the studied group and contact with the dog plays the predominant risk factor. It indicates high transmission with the consequent of visceral or ocular larva migrans and neurologic disorder in these children. The results also provide baseline data for effective prevention strategies of toxocariasis in Southwest Nigeria and the study recommends prompt interventional measures, particularly health education on personal hygiene. [ABSTRACT FROM AUTHOR]

This study aimed at constructing a draft genome of the adult female worm Toxocara canis using next-generation sequencing (NGS) and de novo assembly, as well as to find new genes after annotation using functional genomics tools. Using an NGS machine, we produced DNA read data of T. canis. The de novo assembly of the read data was performed using SOAPdenovo. RNA read data were assembled using Trinity. Structural annotation, homology search, functional annotation, classification of protein domains, and KEGG pathway analysis were carried out. Besides them, recently developed tools such as MAKER, PASA, Evidence Modeler, and Blast2GO were used. The scaffold DNA was obtained, the N50 was 108,950 bp, and the overall length was 341,776,187 bp. The N50 of the transcriptome was 940 bp, and its length was 53,046,952 bp. The GC content of the entire genome was 39.3%. The total number of genes was 20,178, and the total number of protein sequences was 22,358. Of the 22,358 protein sequences, 4,992 were newly observed in T. canis. Following proteins previously unknown were found: E3 ubiquitin-protein ligase cbl-b and antigen T-cell receptor, zeta chain for T-cell and B-cell regulation; endoprotease bli-4 for cuticle metabolism; mucin 12Ea and polymorphic mucin variant C6/1/40r2.1 for mucin production; tropomodulin-family protein and ryanodine receptor calcium release channels for muscle movement. We were able to find new hypothetical polypeptides sequences unique to T. canis, and the findings of this study are capable of serving as a basis for extending our biological understanding of T. canis. [ABSTRACT FROM AUTHOR]

Background: Toxocara canis is the causative agent of toxocariasis of humans and other animals. This parasitic nematode (roundworm) has a complex life cycle, in which substantial developmental changes and switches occur. As small non-coding RNAs (sRNAs) are key regulators of gene expression in a wide range of organisms, we explored these RNAs in T. canis to provide a basis for future studies of its developmental biology as well as host interactions and disease at the molecular level. Methods: We conducted high-throughput RNA sequencing and bioinformatic analyses to define sRNAs in individual male and female adults of T. canis. Results: Apart from snRNA and snoRNA, 560 and 619 microRNAs (miRNAs), including 5 and 2 novel miRNAs, were identified in male and female worms, respectively, without piRNAs being detected in either sex. An analysis of transcriptional profiles showed that, of 564 miRNAs predicted as being differentially transcribed between male and female individuals of T. canis, 218 miRNAs were transcribed exclusively in male and 277 in female worms. Functional enrichment analysis predicted that both male and female miRNAs were mainly involved in regulating embryonic morphogenesis, hemidesmosome assembly and genetic information processing. The miRNAs differentially transcribed between the sexes were predicted to be associated with sex determination, embryonic morphogenesis and nematode larval development. The roles of miRNAs were predicted based on gene ontology (GO) and KEGG pathway annotations. The miRNAs Tc-miR-2305 and Tc-miR-6090 are proposed to have roles in reproduction, embryo development and larval development, and Tc-let-7-5p, Tc-miR-34 and Tc-miR-100 appear to be involved in host-parasite interactions. Together with published information from previous studies, some miRNAs (such as Tc-miR-2861, Tc-miR-2881 and Tc-miR-5126) are predicted to represent drug targets and/or associated with drug resistance. Conclusions: This is the first exploration of miRNAs in T. canis, which could provide a basis for fundamental investigations of the developmental biology of the parasite, parasite-host interactions and toxocariasis as well as applied areas, such as the diagnosis of infection/disease, drug target discovery and drug resistance detection. [ABSTRACT FROM AUTHOR]

Serodiagnosis of human toxocariasis is based on the detection of specific IgG antibodies by the enzyme-linked immunosorbent assay ( ELISA) using Toxocara larvae excretory-secretory ( TES) antigens, but its production is a laborious and time-consuming process being also limited by the availability of adult females of T. canis as source for ova to obtain larvae. Chemical synthesis of the di- O-methylated (DiM) glycan structure found in the TES antigens has provided material for studying the antibody reactivity in a range of mammalian hosts, showing reactivity with human IgM and IgG. In this study, we have evaluated the performance of the DiM glycan against a panel of sera including patients with toxocariasis ( n = 60), patients with other helminth infections ( n = 75) and healthy individuals ( n = 94), showing that DiM is able to detect IgG antibodies with a sensitivity and specificity of 91·7% and 94·7%, respectively, with a very good agreement with the TES antigens (kappa = 0·825). However, cross-reactivity was observed in some sera from patients with ascariasis, hymenolepiasis and fascioliasis. These results show that the DiM glycan could be a promising antigenic tool for the serodiagnosis of human toxocariasis. [ABSTRACT FROM AUTHOR]

In a transversal study on a sample of 386 children and adolescents from an outpatient clinic for filariasis in Recife, Northeast Brazil, the frequency of anti-Toxocara antibodies and its relation to age, gender, number of peripheral eosinophils, Wuchereria bancrofti microfilariae and intestinal helminths was determined. The total anti-Toxocara IgG antibody frequency was 39.4%, by ELISA technique. The difference in frequency between males (40.1%) and females (37.6%) was not statistically significant. The 6 to 10-year-old subset presented the highest frequency of anti-Toxocara antibodies (60%), and within this age group there was a statistically significant male bias. There was also a significant association between the number of eosinophils and the presence of anti-Toxocara antibodies. Intestinal parasite frequency was 52.1%, but no association was found between this data and the presence of anti-Toxocara antibodies. In the present sample, 42.2% of the patients were Wuchereria bancrofti carriers, however, again this was not associated with the presence of anti-Toxocara antibodies. In conclusion, anti-Toxocara antibodies were highly prevalent in this sample. The present data show that there is no cross correlation between anti-Toxocara IgG antibody and the presence of intestinal helminths and filariasis.

One of the most common zoonotic helminth infections is caused by species in the genus Toxocara, particularly Toxocara canis and T. cati ( Syn. T. mystax). However, their relative contribution to toxocarosis in humans remains largely unknown because causative larvae are seldom recovered and uncertainties regarding the validity of existing serological assays. In this study, we used sera from a pig model experimentally infected with T. canis and T. cati to evaluate whether a Western blot could discriminate between the two species. No proteins were observed that could be used as a diagnostic tool. In addition, a heterogenic protein pattern between individual hosts was found, which was most pronounced in the T. cati-infected pigs. There is therefore an urgent need to optimize and validate current methods or develop new species-specific serological methods in order to implement appropriate control measures. [ABSTRACT FROM AUTHOR]

Toxocariasis is caused by infection of man by Toxocara canis and Toxocara cati larvae, the common roundworm of dogs and cats. Because larvae are difficult to detect in tissues, diagnosis is mostly based on serology. Non specific reactions are observed mainly due to cross-reactivity with Ascaris sp antigens. This investigation aimed at developing and evaluating an indirect antibody competition ELISA (IACE) employing a specific rabbit IgG anti-Toxocara canis excretory-secretory antigens as the competition antibody, in order to improve indirect ELISA specificity performed for toxocariasis diagnosis. For that, the rabbit IgG was previously absorbed by Ascaris suum adult antigens. Sensitivity and specificity of IACE were first evaluated in 28 serum samples of mice experimentally infected with T. canis embryonated eggs. Adopting cut-off value established in this population before infection, sensitivity and specificity were 100% after 20 days post-inoculation. For human population IACE was evaluated using sera from 440 patients with clinical signs of toxocariasis and the cut-off value was established with 60 serum samples from apparently healthy individuals. Using as reference test the indirect ELISA performed by Adolfo Lutz Institute, sensitivity was 60.2%, specificity was 98% and concordance was 77.3%. Repeatability of IACE was evaluated by the inter-reactions variation coefficient (2.4%).

Background: Visceral larva migrans may present with systemic symptoms such as fever, hepatomegaly, pneumonitis or ocular symptoms. Case characteristics: A 7-year-old girl with fever, pain abdomen and persistent eosinophilia. Imaging and histopathology were suggestive of visceral larva migrans. Message: The diagnosis of visceral larva migrans is often delayed since similar symptoms of fever, hepatomegaly and peripheral eosinophilia occur in more common and identifiable tropical parasitic and non-parasitic diseases. [ABSTRACT FROM AUTHOR]

Toxocariasis is a neglected zoonosis caused by the nematodes Toxocara canis and Toxocara cati . This disease is widespread in many countries, reaching high prevalence independently of the economic conditions. However, the true number of cases of toxocariasis is likely to be underestimated owing to the lack of adequate surveillance programs. Although some diagnostic tests are available, their sensitivity and specificity need to be improved. In addition, treatment options for toxocariasis are limited and are non-specific. Toxocariasis is listed as one of the five most important neglected diseases by the CDC. This review presents recent advances related to the control of toxocariasis, including new immunodiagnostics, therapies, and drug formulations, as well as novel interventions using DNA vaccines, immunomodulators, and probiotics. [ABSTRACT FROM AUTHOR]

The dot-enzyme-linked immunosorbent assay (dot-ELISA) was standardized using somatic (S) and excretory-secretory (ES) antigens of Toxocara-canis for the detection of specific antibodies in 22 serum samples from children aged 1 to 15 years, with clinical signs of toxocariasis. Fourteen serum samples from apparently normal individuals and 28 sera from patients with other pathologies were used as controls. All samples were used before and after absorption with Ascaris suum extract. When the results were evaluated in comparison with ELISA, the two tests were found to have similar sensitivity, but dot-ELISA was found to be more specific in the presence of the two antigens studied. Dot-ELISA proved to be effective for the diagnosis of human toxocariasis, presenting advantages in terms of yield, stability, time and ease of execution and low cost.Padronizou-se o teste imunoenzimático dot-ELISA, empregando-se os antígenos somático (S) e excretor-secretor (ES) de Toxocara canis, para pesquisa de anticorpos específicos em 22 soros de pacientes com idades entre 5 a 15 anos, com dados clínicos de toxocaríase. Como grupo controle, foram estudados 14 soros de indivíduos supostamente normais e 28 soros de pacientes com outras patologias. Todas as amostras em estudo foram empregadas antes e após absorção com extrato de Ascaris suum. Os resultados obtidos foram avaliados comparativamente com o teste ELISA evidenciando, nos dois testes estudados, comportamento semelhante quanto à sensibilidade e maior especificidade para o dot-ELISA, com qualquer dos dois antígenos estudados. O teste dot-ELISA mostrou-se eficiente para o diagnóstico da toxocaríase humana, apresentando vantagens quanto ao rendimento, estabilidade, tempo e facilidade de execução e baixo custo.

Most studies from Argentina have focused on toxocariasis as an environmental problem of big cities, and there are no available data about children infection from small or middle-sized cities. In order to assess the prevalence of anti-Toxocara antibodies in infantile population, 206 children from Resistencia, of both sexes, aged 1-14 years old were studied by Elisa testing with E/S T. canis L2 antigens. Hematological parameters and immunoglobulin levels were determined; five days' stool samples were studied and epidemiological data were obtained by means of a questionnaire to parents. Results showed that 73% of the children had one or more dogs living at home, 57% reported geophagia and 37.9% were positive for Toxocara serology, but there was no significant difference in prevalence neither for boys and girls, nor concerning age. An increased risk of infection was observed in age groups 5-6 and 7-8 for boys, and in age groups 3-4 and 5-6 for girls.

São relatados três casos de crianças com larva migrans visceral confirmados através do teste imunoenzimático ELISA, em Goiânia. Quadro pulmonar com infiltrado intersticial, tosse seca e eosinojilia sangüínea caracterizaram o primeiro caso. No segundo, os sinais clínicos presentes foram quadro respiratório com tosse seca, infiltrado pulmonar, além de eosinojilia sangüínea e hipergamaglobulinemia. Uma eosinofilia persistente, entre 1987-1989, sem qualquer outro sinal aparente, foi o que induziu à suspeita e confirmação, da parasitose no terceiro caso.We report three cases of children with visceral larva migrans confirmed by enzyme-linked immu-nosorbent assay (ELISA), in Goiânia, Pulmonary interstitial infiltrates with dry cough and peripheral eosinophilia characterised the first case. Clinical and laboratorial finding in the second case included dry cougn, pulmonary infiltrates, peripheral eosinophilia and hypergammaglobulinaemia. A persistent eosino-philia, between 1987-1989, without apparent cause led to the confirmation of parasite infection in the third case.

An enzyme-linked immunosorbent assay (ELISA), employing antigens from Toxocara canis larvae and the absortion of suspected sera with Ascaris lumbricoides extracts was used in a seroepidemiological study performed in five municipalities of São Paulo State, Brazil (São Paulo, Campinas, Santos, Marília and Presidente Prudente) in order to determine the frequency of antibodies to Toxocara. In 2,025 blood samples collected, 806 proceeded from male subjects and 1,219 from females; 483 samples were collected from subjects under 15 years of age and the remaining 1,542 from subjects aged 15 years or over. Among the 2,025 sera investigated, 3.60% had antibodies to Toxocara at significant levels. A moderate predominance of infection with Toxocara among male subjects (3.72%) was observed, although the difference was not statistically significant when this rate was compared with that for female (3.28%). Related to age, a higher frequency of positive results was detected among subjects under 15 years (6.41%) against the older group (2.53%). A trend of more elevated rates of infection was observed in municipalities with high demographic densities (São Paulo, Campinas and Santos). Nevertheless, such findings only appeared to be statistically significant in subjects younger than 15 years.Realizou-se inquérito soroepidemiológico, para detecção de anticorpos anti-Toxocara, em 2.025 soros de indivíduos residentes em cinco municípios do Estado de São Paulo (São Paulo, Campinas, Santos, Marília e Presidente Prudente), através de técnica imunoenzimática (ELISA) e emprego de antígenos obtidos a partir de larvas de 2º - 3º estádio de Toxocara canis. Após absorção com extratos de Ascaris lumbricoides, revelou-se a presença de anticorpos anti-Toxocara, em níveis significativos, em 3,60% dos soros examinados, com predominância de indivíduos com idade inferior a 15 anos (6,41%). Observou-se, ainda, tendência a ocorrerem índices mais elevados de infecção por larvas de Toxocara entre indivíduos residentes em municípios com maior densidade demográfica (São Paulo, Campinas e Santos), especialmente no grupo com menos de 15 anos de idade.

Highlights: [•] Comprehensive review of toxocariasis with a focus on Toxocara canis and the syndromes it causes in humans. [•] Review of the challenges of diagnosis of T. canis infection in humans. [•] Review of the epidemiology, public health importance and current treatment options for those infected with T. canis. [•] Scientific challenges which have to be met in order to control toxocariasi. [•] How other dog control programmes, societal changes and climate change are effecting T. canis distribution and importance. [ABSTRACT FROM AUTHOR]

Human toxocariasis has been reported to cause a broad spectrum of neurological syndromes, including encephalitis, meningitis and meningo-radiculitis. Nevertheless, cerebral infection by Toxocara may go undiagnosed due to its rarity, elusive symptoms and lack of availability of appropriate testing. We report the case of a 54-year-old man who presented with abdominal pain and paralytic ileus approximately 3 weeks after having eaten raw snails (a folk remedy for peptic ulcer). Three weeks later, marked eosinophilia ensued, associated with mental clouding, nystagmus, diplopia, peripheral limbs ataxia, urinary retention, slackened deep tendon reflexes, arthralgias and myalgias. Cerebrospinal fluid (CSF) examination demonstrated an eosinophilic meningitis, and Toxocara canis cerebral infection was diagnosed by positive serology and by the detection of T. canis DNA in the CSF. The patient made a full recovery following treatment with albendazole and corticosteroids. Physicians should be aware of this rare presentation of toxocariasis, whose diagnosis is, today, facilitated by molecular biology techniques. A history of ingestion of raw snails may alert the clinician to consider the possibility of such an uncommon condition. [ABSTRACT FROM AUTHOR]

Abstract: The zoonotic roundworms Toxocara canis and T. cati are not only present worldwide in their definitive hosts; they also frequently occur in other animal species, including humans. In those so-called paratenic hosts, the larvae do not develop into the adult stage, but rather migrate throughout the somatic tissue and persist as infectious L3 stage for extensive periods. Those arrested larvae may lead to severe inflammatory reactions and consequently to a wide range of pathological and clinical manifestations. However, the infected paratenic hosts also constitute a potential source of infection for the definitive hosts or humans who may also function as paratenic hosts. In the present review, current knowledge of larval migration in a variety of possible paratenic hosts is summarized including variations of migration routes and susceptibilities. Furthermore, information about the clinical and pathological changes for the presented species and possible consequences of the somatic migration of larvae, i.e. the resulting tissue damage as well as adverse host reactions to arrested larvae are reviewed. There are still many questions unanswered regarding larval behaviour in hosts other than their definitive host. Therefore, it is of great importance to continue further elaboration on the biology of Toxocara spp. to prevent further spreading of larvae in both the paratenic and the definitive host. [Copyright &y& Elsevier]

Toxocariasis is a parasitic infection produced by helminths that cannot reach their adult stage in humans. For their etiological species (Toxocara canis and Toxocara cati), man is a paratenic host. Infection by such helminths can produce a variety of clinical manifestations, such as: visceral larvae migrans syndrome, ocular larvae migrans syndrome and covert toxocariasis. In the visceral larvae migrans syndrome, the organs that are mainly involved include liver, lungs, skin, nervous system, muscles, kidneys and the heart. Regarding the latter, the importance of cardiovascular manifestations in toxocariasis, as well as its clinical relevance, has increasingly begun to be recognized. The current article is based on a systematic information search, focused mainly on the clinical and pathological aspects of cardiovascular manifestations in toxocariasis, including its pathophysiology, laboratory findings, diagnosis and therapeutical options, with the objective of highlighting its importance as a zoonosis and its relevance to the fields of cardiovascular medicine in adults and children. [ABSTRACT FROM AUTHOR]

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Purpose: To assess the association between epilepsy and exposure to the parasites, Toxocara canis and Taenia solium in a slum-community in India. Methods: A door-to-door survey to determine the prevalence of epilepsy was carried out by trained field workers. For every case, one age- and gender-matched control was selected from the same community. Serologic evaluation was carried out to detect antibodies against T. canis and T. solium. Key Findings: The crude prevalence of active epilepsy was 7.2 per 1,000. We enrolled 114 people with active epilepsy and 114 controls. The prevalence of antibodies to T. canis was similar in people with active epilepsy (4.7%; 5 of 106 people) and in controls (5.7%; 6 of 106 people). The prevalence of antibodies to T. solium was 25.5% (27 of 106) in people with active epilepsy, significantly higher than in controls (12.3%; 13 of 106 cases; p = 0.02). Adjusted conditional (fixed-effects) logistic regression estimated an odds ratio of 2.8 (95% confidence interval 1.2-6.8) for detection of T. solium antibodies. Nineteen people with active epilepsy demonstrated evidence of neurocysticercosis (NCC) on magnetic resonance imaging (MRI), including 7 (36.5%) with solitary cysticercus granuloma. Significance: Our findings do not support an association between epilepsy and exposure to T. canis in the community studied. A significant association between T. solium exposure and epilepsy was observed. Of those with active epilepsy and evidence of NCC on MRI, a large proportion demonstrated solitary cysticercus granuloma. [ABSTRACT FROM AUTHOR]

A 41-year-old woman who was diagnosed with myocarditis presented eosinophilia. Since the antibody against Toxocara canis (T. cams) was positive, we diagnosed that she had visceral larva migrans due to T. canis associated with myocarditis. She was treated with oral albendazole and prednisolone for two weeks, eosinophil count and hepatic enzymes were normalized after completion of treatment. This is the first report of myocarditis caused by T. canis infection in Korea. [ABSTRACT FROM AUTHOR]

The aim of this study is to ascertain the relationship between ingestion of raw cow liver and Toxocara canis infection. A total of 150 apparently healthy adults were divided into 2 groups; 1 group consisted of 86 adults with positive results of Toxocara ELISA, and the other group of 64 adults with negative results. One researcher collected the history of ingestion of raw cow liver within 1 year and recent history of keeping dogs. Among 86 seropositive adults for T. canis, 68 (79.1%) had a recent history of ingestion of raw cow liver. Multivariate statistical analysis showed that a recent ingestion of raw cow liver and keeping dogs were related to an increased risk of toxocariasis (odds ratios, 4.4 and 3.7; and 95% confidence intervals, 1.9-10.2 and 1.2-11.6, respectively). A recent history of ingestion of raw cow liver and keeping dogs was significantly associated with toxocariasis. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: The purpose of this study is to investigate the MRI findings of visceral larva migrans (VLS) of Toxocara canis in spinal cord. Materials and methods: We retrospectively reviewed spinal MRI findings in eight patients with serologically proven Toxocara canis between 2005 and 2008. We evaluated the location, length, extent and migration of the lesion, MR signal intensity (SI), enhancement pattern, and swelling of the spinal cord. We evaluated clinical features including presenting symptoms and signs and treatment response. Results: Total 8 patients (M=8; age range 36–79 years) were included. The lesions were located in the cervical or thoracic spinal cord in all patients. All lesions showed high SI and minimal or mild swelling of involved spinal cord on T2WI and focal nodular enhancement on posterior or posterolateral segment of spinal cord. The length of involved lesion was relatively short in most patients. There was a migration of lesion in one patient. In spite of albendazole or steroid treatment, neurological symptoms or signs were not significantly improved in all patients. Conclusion: Although all lesions show non-specific imaging findings like non-tumorous myelopathy mimicking transverse myelitis, single lesion, focal nodular enhancement on posterior or posterolateral segment of spinal cord, relatively short segmental involvement and migration of lesion may be characteristic findings of spinal VLM of Toxocara canis. In addition, the reluctant response to the treatment may be characteristic of spinal VLM of Toxocara canis. [ABSTRACT FROM AUTHOR]