RESUMEN
We aimed to develop an indirect enzyme-linked immunosorbent assay (ELISA) to evaluate the presence of specific IgG against Toxocara canis and Toxocara cati somatic antigens on the serum of patients with toxocariasis. The sensitivity, specificity, positive and negative predictive values for indirect-ELISA were calculated by receiver operating characteristic curve (ROC) analysis and Youden's J using Likelihood ratio. All statistics were analysed and graphs are plotted using GraphPad Prism version 8.4.3 (Graph Pad Software, La Jolla, CA, USA), with 95% confidence interval (CI). The sensitivity, specificity, positive and negative predictive values for T. canis were 100%, 82%, 79% and 100%, respectively. The mentioned variables for T. cati were 97%, 82%, 78% and 98%, respectively. Five immune reactive bands of 38, 40, 72, 100 and 250 kDa were common in both species. Toxocara crude antigens were highly immunogenic in human sera. Immunoreactive bands against T. canis compared to T. cati somatic antigen were about two times more. Unlike Toxocara excretory-secretory antigen, that was homologue in two species, somatic antigens of T. canis and T. cati showed different immunoreactive bands in our western blot.
Asunto(s)
Anticuerpos Antihelmínticos , Antígenos Helmínticos , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina G , Sensibilidad y Especificidad , Toxocara canis , Toxocara , Toxocariasis , Humanos , Animales , Antígenos Helmínticos/inmunología , Antígenos Helmínticos/sangre , Toxocariasis/inmunología , Toxocariasis/diagnóstico , Toxocariasis/sangre , Toxocara/inmunología , Anticuerpos Antihelmínticos/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina G/sangre , Toxocara canis/inmunología , Adulto , Valor Predictivo de las Pruebas , Curva ROC , Femenino , MasculinoRESUMEN
BACKGROUND: The hygiene hypothesis suggests that early life exposure to helminth infections can reduce hypersensitivity in the immune system. OBJECTIVE: The present study aims to evaluate the effects of Toxocara cati (T. cati) somatic products on allergic airway inflammation. METHODS: Between 2018 and 2020, T. cati adult worms were collected from stray cats in Mashhad, Iran (31 out of 186 cats), and their somatic extract was collected. Thirty BALB/c mice were equally divided into three groups, including the OVA group (sensitized and challenged with ovalbumin), the somatic administered group (received somatic extract along with ovalbumin sensitization), and the PBS group (sensitized and challenged with phosphate buffer saline). Bronchoalveolar lavage (BAL) fluid was collected to assess the number of cells, and lung homogenates were prepared for cytokine analysis. Histopathological analysis of the lungs was performed, and inflammatory cells and mucus were detected. Cytokine levels (IL-4, IL-5, IL-10) were measured using enzyme-linked immunosorbent assay (ELISA), and ovalbumin-specific immunoglobulin E (IgE) levels were determined using a capture ELISA. RESULTS: The somatic group significantly decreased regarding the lung pathological changes, including peribronchiolitis, perivasculitis, and eosinophil influx, compared to the group treated with ovalbumin alone. These changes were accompanied by a decrease in proinflammatory cytokines IL-4 and IL-5 and an increase in the anti-inflammatory cytokine IL-10, indicating a shift toward a more balanced immune response. The number of inflammatory cells in the BAL fluid was also significantly reduced in the somatic group, indicating a decrease in inflammation. CONCLUSION: These preclinical findings suggest that in experimental models, T. cati somatic extract exhibits promising potential as a therapeutic agent for mitigating allergic airway inflammation. Its observed effects on immune response modulation and reduction of inflammatory cell infiltration warrant further investigation in clinical studies to assess its efficacy and safety in human patients.
Asunto(s)
Citocinas , Ratones Endogámicos BALB C , Toxocara , Animales , Ratones , Toxocara/inmunología , Toxocara/efectos de los fármacos , Citocinas/metabolismo , Citocinas/inmunología , Inmunoglobulina E/inmunología , Inmunoglobulina E/sangre , Ovalbúmina/inmunología , Pulmón/inmunología , Pulmón/patología , Pulmón/parasitología , Pulmón/efectos de los fármacos , Líquido del Lavado Bronquioalveolar/inmunología , Asma/inmunología , Asma/tratamiento farmacológico , Modelos Animales de Enfermedad , Gatos , Femenino , Toxocariasis/tratamiento farmacológico , Toxocariasis/inmunología , Toxocariasis/parasitologíaRESUMEN
Background: Toxocariasis is an important health problem caused by the parasitic species Toxocara canis (T. canis) and Toxocara cati (T. cati). Prevalence of toxocariasis in pregnant women as a vulnerable population is doubly important, and the aim of this study is to estimate the overall prevalence of toxocariasis infection in pregnant women according to the available reports. Methods: The present study followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) checklists. A systematic search was carried out in international scientific databases (Google Scholar, Web of Science, ScienceDirect, Scopus, and PubMed) between 1990 and 2023. The overall prevalence of parasitic infection was estimated with a random-effects model. All analyses (overall prevalence, heterogeneity, publication bias, and sensitivity analysis) were performed with comprehensive meta-analysis (V2.2, Bio stat) software. Results: Amid the final eleven included studies, based on the random-effects model, the estimation of the pooled prevalence of Toxocara spp. was 20.8% (95% CI, 9.8-38.7%). The association between the risk factors of toxocariasis and the prevalence of the disease was not statistically significant. Conclusions: In the present study, significant prevalence was reported; however, considering the limited number of studies, it seems that the actual prevalence of the disease is higher. Therefore, it seems necessary to monitor this health problem in pregnant women.
Asunto(s)
Complicaciones Parasitarias del Embarazo , Toxocara , Toxocariasis , Humanos , Femenino , Embarazo , Toxocariasis/epidemiología , Animales , Toxocara/inmunología , Estudios Seroepidemiológicos , Complicaciones Parasitarias del Embarazo/epidemiología , Prevalencia , Toxocara canis/inmunologíaRESUMEN
PURPOSE: Animal hoarding has been associated with unhealthy human, animal and environmental conditions that predispose such individuals to serious life-threatening risks such as arson, malnutrition, cruelty and zoonosis. The study aimed to evaluate the presence of anti-Toxocara spp. antibodies among individuals with animal hoarding disorder in Curitiba, Brazil. METHODS: 65 residences with register of animal hoarder behavior were visited and 11 residences were included in the study, with a total of 19 individuals consenting participation. A short questionnaire was applied to gather information regarding hoarders and their dogs/cats, and serum samples were screened to detect antibodies (IgG) against antigens of Toxocara spp. RESULTS: Overall, 14/19 individuals (73.7%) presented anti-Toxocara spp. antibodies. In 8/11 (72.7%) households at least one person was seropositive. Seropositivity was higher among women (10/13; 76.9%) than men (4/6; 66.7%). A total of 442 dogs (14-30 dogs; average = 23.3 per household) and 31 cats (1-20 cats; average = 4.8 per household) were observed. To the authors' knowledge, this was the first study to survey occurrences of toxocariasis among animal hoarders. The high population densities of dogs observed during visits, in conjunction with absence of veterinary care and unsanitary conditions, may indicate that situations of high levels of animal infection and soil contamination were present. CONCLUSION: In summary, the seroprevalence observed in this study indicated that there was a high risk of Toxocara spp. infection among individuals with animal hoarding disorder. Provision of educational programs to reduce the risk of infection in this population is warranted.
Asunto(s)
Anticuerpos Antihelmínticos , Enfermedades de los Perros , Trastorno de Acumulación , Toxocara , Toxocariasis , Animales , Brasil/epidemiología , Humanos , Perros , Toxocara/inmunología , Gatos , Femenino , Masculino , Toxocariasis/epidemiología , Trastorno de Acumulación/epidemiología , Estudios Seroepidemiológicos , Enfermedades de los Perros/parasitología , Enfermedades de los Perros/epidemiología , Anticuerpos Antihelmínticos/sangre , Adulto , Enfermedades de los Gatos/parasitología , Enfermedades de los Gatos/epidemiología , Salud Pública , Persona de Mediana Edad , Adulto Joven , Encuestas y Cuestionarios , AdolescenteRESUMEN
Toxocara canis and Toxocara cati are globally distributed, zoonotic roundworm parasites. Human infection can have serious clinical consequences including blindness and brain disorders. In addition to ingesting environmental eggs, humans can become infected by eating infective larvae in raw or undercooked meat products. To date, no studies have assessed the prevalence of Toxocara spp. larvae in meat from animals consumed as food in the UK or assessed tissue exudates for the presence of anti-Toxocara antibodies. This study aimed to assess the potential risk to consumers eating meat products from animals infected with Toxocara spp. Tissue samples were obtained from 155 different food producing animals in the south, southwest and east of England, UK. Tissue samples (n = 226), either muscle or liver, were processed by artificial digestion followed by microscopic sediment evaluation for Toxocara spp. larvae, and tissue exudate samples (n = 141) were tested for the presence of anti-Toxocara antibodies using a commercial ELISA kit. A logistic regression model was used to compare anti-Toxocara antibody prevalence by host species, tissue type and source. While no larvae were found by microscopic examination after tissue digestion, the overall prevalence of anti-Toxocara antibodies in tissue exudates was 27.7%. By species, 35.3% of cattle (n = 34), 15.0% of sheep (n = 60), 54.6% of goats (n = 11) and 61.1% of pigs (n = 18) had anti-Toxocara antibodies. Logistic regression analysis found pigs were more likely to be positive for anti-Toxocara antibodies (odds ration (OR) = 2.89, P = 0.0786) compared with the other species sampled but only at a 10% significance level. The high prevalence of anti-Toxocara antibodies in tissue exudates suggests that exposure of food animals to this parasite is common in England. Tissue exudate serology on meat products within the human food chain could be applied in support of food safety and to identify practices that increase risks of foodborne transmission of zoonotic toxocariasis.
Asunto(s)
Anticuerpos Antihelmínticos , Toxocara , Toxocariasis , Animales , Toxocariasis/epidemiología , Toxocariasis/parasitología , Toxocara/inmunología , Toxocara/aislamiento & purificación , Anticuerpos Antihelmínticos/sangre , Anticuerpos Antihelmínticos/análisis , Ovinos , Porcinos , Bovinos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Inglaterra/epidemiología , Carne/parasitología , Hígado/parasitología , Cabras , Exudados y Transudados/parasitología , Enfermedades de los Porcinos/parasitología , Humanos , Músculos/parasitología , Enfermedades de las Ovejas/parasitología , Enfermedades de las Ovejas/epidemiología , Parasitología de AlimentosRESUMEN
BACKGROUND: Children are especially vulnerable to Toxocara infection and its severe complications; however, there have not been any published data on the disease prevalence and treatment effectiveness in the population of Vietnamese children. This study was conducted to determine the prevalence of toxocariasis and explore factors associated with Toxocara infection in children aged 3-15 y in Ho Chi Minh City, Vietnam. METHODS: We conducted a cross-sectional study using a multistage cluster sampling approach in public schools. Blood samples were collected, and toxocariasis cases were confirmed, based on a history of contact with dogs/cats and positive anti-Toxocara antibody detection via ELISA. We calculated the percentage of seropositive children across gender, grade levels, districts and caregiver education. Multiple regression models were employed to identify potential risk factors. RESULTS: Anti-Toxocara antibodies were found in 14.2% of the 986 children studied. Significant variations in seropositivity were observed across grade levels, districts and caregiver education levels. Multivariable analysis identified caregiver education, contact with dogs/cats and improper handling of pet feces as seropositivity risk factors. CONCLUSION: This was the first community-based prevalence study of toxocariasis in a pediatric population in Vietnam. Implementation of preventive measures such as public education, routine fecal examinations and chemotherapeutic treatment of animals is highly recommended.
Asunto(s)
Toxocara , Toxocariasis , Humanos , Vietnam/epidemiología , Niño , Toxocariasis/epidemiología , Estudios Transversales , Masculino , Femenino , Animales , Adolescente , Factores de Riesgo , Preescolar , Perros , Estudios Seroepidemiológicos , Toxocara/inmunología , Gatos , Anticuerpos Antihelmínticos/sangre , Ensayo de Inmunoadsorción Enzimática , Prevalencia , Instituciones AcadémicasRESUMEN
BACKGROUND: In the present study, we performed a systematic review and meta-analysis to assess the global and regional seroprevalence of Toxocara spp. and associated risk factors among children. METHODS: The present systematic review and meta-analysis was followed based on the Preferred Reporting. Items for Systematic Reviews and Meta-analyses (PRISMA) protocol. We searched the online databases (PubMed, Scopus, and Web of Science) and Google Scholar search engine for studies that measured seroprevalence of Toxocara spp. among children, published between 1 January 2000 and 15 January 2022. Accordingly, the pooled seroprevalence and 95% confidence intervals (CI) were estimated using a random-effects meta-analysis model. RESULTS: A total of 65 articles from 22 countries met the inclusion criteria. The global seroprevalence of Toxocara spp. infection among children was estimated as 25% (95% CI 22-29). Meta-regression analysis showed that the type of population studied (p = 0.002) and year of publication (p = 0.044) it may be the source of heterogeneity. The highest and lowest pooled seroprevalence of Toxocara spp. infection were estimated in Thailand and Colombia as 58.2% (95% CI 50.9-65.5) and 7.04% (95% CI 3.05-11.3), respectively. Male gender was associated with a higher risk of Toxocara spp. compared to females, and this association was statistically significant (OR = 1.24; 95% CI 1.09-1.41, p = 0.001). However, residing in rural areas did not show a statistically significant increase in risk compared to living in urban areas (OR = 1.39; 95% CI 0.88-2.21, p = 0.143). CONCLUSION: Toxocariasis is common among children, hence, prevention and control scheme of this helminth in children should be considered by health officials and health policymakers, especially in developing countries, where seroprevalence is highest.
Asunto(s)
Toxocara , Toxocariasis , Animales , Niño , Humanos , Salud Global , Factores de Riesgo , Estudios Seroepidemiológicos , Toxocara/inmunología , Toxocariasis/epidemiologíaRESUMEN
OBJECTIVES: Human toxocariasis is a widespread zoonosis for which a chemotherapy decision and therapy effectiveness are difficult to determine. We aimed to investigate the kinetic profile of clinical and laboratory findings and treatment outcome of patients with toxocariasis in Vietnam. METHODS: The prospective study was conducted between October 2017 and June 2019. The diagnosis of toxocariasis was established based on clinical, laboratory (eosinophilia, raised IgE concentration) and serological (positive Toxocara IgG ELISA) evaluation as well as the exclusion of another helminthic co-infection. The patients were followed up after seven days, then one, three and six months after chemotherapy by thiabendazole. RESULTS: The study involved 80 patients with a mean age of 41.6 ± 15.2 years of whom 58.8% were female. At three and six months after chemotherapy, most patients demonstrated resolution of clinical signs and symptoms, eosinophil count and IgE concentration but not in the proportion of IgG seropositivity. Skin lesions and eosinophilia resolved earlier than the other symptoms (one month after treatment). About four-fifths of the patients were "cured" after three and six months of follow-up; 33.8% showed side effects to thiabendazole therapy but no severe events were reported. The most common adverse reaction was neurologic symptoms followed by gastrointestinal or skin manifestations which lasted as long as 4 days. CONCLUSIONS: In toxocariasis patients, cutaneous manifestations and eosinophilia resolve more rapidly than other clinical and laboratory findings while IgG titre has a very slow kinetic after therapy. Thiabendazole seems to be a potential alternative for the treatment of human toxocariasis.
Asunto(s)
Toxocariasis/diagnóstico , Adolescente , Adulto , Anciano , Animales , Antihelmínticos/administración & dosificación , Antihelmínticos/uso terapéutico , Anticuerpos Antihelmínticos/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Tiabendazol/administración & dosificación , Tiabendazol/uso terapéutico , Toxocara/inmunología , Toxocariasis/sangre , Toxocariasis/tratamiento farmacológico , Toxocariasis/epidemiología , Vietnam/epidemiología , Adulto Joven , Zoonosis/diagnóstico , Zoonosis/tratamiento farmacológicoRESUMEN
Toxocariasis is worldwide endemic parasitic anthropozoonosis with high risk to those in in vulnerable populations and particularly during pregnancy and childhood. Although the prevalence of anti-Toxocara spp. antibodies has been extensively studied, risk factors of pregnant women of different ages remains to be established. This study was designed to i) assess the presence of anti-Toxocara spp. antibodies in pregnant women that presented to the public health system in a city of southeastern Brazil, and ii) determine the risk factors for toxocariasis in adolescent and adult pregnant women. This cross-sectional study included 280 pregnant women (71 aged up to and including 17 years [adolescents] and 209 aged 18 years and older [adults]). Pregnant women voluntarily agreed to complete a socioeconomic questionnaire and provide serum samples. Anti-Toxocara IgG antibodies were screened by Enzyme-Linked Immunosorbent Assay (ELISA). Univariable and multivariable logistic regression models were performed to assess the risks for toxocariasis. Overall, 20.7% of pregnant women were seropositive (33.8% of adolescents and 16.3% of adults). Prevalence in pregnant adolescents was 2.6-fold higher than in adults (Odds ration [OR]: 2.63; 95% CI: 1.42-4.86, p = 0.003). Multivariate analysis revealed that contact with soil (p = 0.01; OR = 4.76) and being in the first trimester of pregnancy (p = 0.03; OR = 0.17) had significantly greater risk of toxocariasis for adolescents, and attainment of elementary through middle school education level (p = 0.05; OR = 8.33) was a risk factor in adult pregnant women. Toxocariasis is likely underreported and neglected in adolescent pregnant women; this age group should always be monitored for toxocariasis and correspondent clinical signs, particularly at late pregnancy.
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Anticuerpos Antihelmínticos/sangre , Toxocara/inmunología , Toxocariasis/epidemiología , Adolescente , Adulto , Animales , Brasil/epidemiología , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Modelos Logísticos , Análisis Multivariante , Embarazo , Complicaciones Infecciosas del Embarazo/sangre , Complicaciones Infecciosas del Embarazo/diagnóstico , Complicaciones Infecciosas del Embarazo/epidemiología , Factores de Riesgo , Toxocariasis/sangre , Toxocariasis/diagnóstico , Adulto JovenRESUMEN
BACKGROUND: Toxocariasis, caused by a nematode species of the genus Toxocara, has been described as one of the most prevalent zoonotic helminthiases worldwide. Human transmission may occur by ingesting Toxocara spp. larvae from raw or undercooked meat or organs; however, no comprehensive serosurvey study has been conducted to date investigating the role of cattle as paratenic hosts. The aim of the study reported here was to assess the prevalence of anti-Toxocara spp. antibodies and associated risk factors in bovines from two slaughterhouses located in Presidente Prudente, southeastern Brazil. METHODS: Blood samples were collected and tested by indirect enzyme-linked immunosorbent assay (ELISA). Cattle farmers voluntarily responded to an epidemiologic questionnaire. RESULTS: Overall, 213 of the 553 (38.5%) bovine samples were assessed as seropositive for anti-Toxocara spp. antibodies by indirect ELISA. Multivariate analysis revealed that the source of beef cattle and the presence of dogs or cats at the farm were associated with seropositivity. The use of feedlot systems was associated with lower likelihood of seropositivity. CONCLUSIONS: These results indicate a high level of anti-Toxocara seropositivity in slaughterhouse cattle, with potentially contaminated meat posing an infection risk to humans. In addition, the presence of dogs and cats where the slaughtered beef cattle were raised was statistically associated with bovine seropositivity, probably due to the overlapping environment at the farm and the lack of pet deworming. The use of feedlot systems was a protective factor likely due to the absence of dog and cat contact, elevated feeding troughs that avoid contact with contaminated soil or grass, and younger age at slaughter of feedlot cattle. In summary, bovines may be used as environmental sentinels of Toxocara spp. contamination, and high seropositivity of slaughterhouse cattle may indicate a potential risk of human toxocariasis through the ingestion of raw or undercooked contaminated meat.
Asunto(s)
Anticuerpos Antihelmínticos/sangre , Enfermedades de los Bovinos/sangre , Toxocariasis/sangre , Mataderos/estadística & datos numéricos , Animales , Brasil/epidemiología , Enfermedades de los Gatos/epidemiología , Enfermedades de los Gatos/parasitología , Gatos , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/parasitología , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/parasitología , Perros , Ensayo de Inmunoadsorción Enzimática , Prevalencia , Estudios Seroepidemiológicos , Toxocara/clasificación , Toxocara/inmunología , Toxocara/aislamiento & purificación , Toxocariasis/epidemiología , Toxocariasis/parasitologíaRESUMEN
PURPOSE: To report a case of strabismus in a five-week-old infant, likely secondary to a rare occurrence of congenitally acquired ocular toxocariasis. METHODS: Retrospective case report. RESULTS: A five-week-old male infant with left exotropia was referred to pediatric ophthalmology and to a vitreoretinal specialist. Fundoscopic examination revealed a granuloma with associated retinal folds and tractional retinal detachment typical for ocular toxocariasis. Serology revealed positivity for Toxocara antibodies, consistent with the clinical diagnosis of ocular toxocariasis. CONCLUSION: Ocular toxocariasis is typically thought to be secondary to acquired Toxocara infection secondary to fecal-oral transmission. In this case of early-onset strabismus secondary to ocular toxocariasis, it is hypothesized that this is a presentation of congenitally acquired toxocariasis.
Asunto(s)
Infecciones Parasitarias del Ojo/congénito , Transmisión Vertical de Enfermedad Infecciosa , Enfermedades de la Retina/congénito , Toxocariasis/congénito , Animales , Anticuerpos Antihelmínticos/sangre , Infecciones Parasitarias del Ojo/diagnóstico , Infecciones Parasitarias del Ojo/transmisión , Humanos , Lactante , Masculino , Enfermedades de la Retina/diagnóstico , Estudios Retrospectivos , Estrabismo/congénito , Estrabismo/diagnóstico , Toxocara/inmunología , Toxocariasis/diagnóstico , Toxocariasis/transmisiónRESUMEN
BACKGROUND: Although Toxocara spp. infection has a worldwide distribution, to our knowledge, no data from birth cohorts have been reported in published studies on the potential for congenital transmission and determinants of infection in early childhood. METHODS: We followed 290 mother-infant pairs from birth to 5 years of age through periodic collection of data and samples at birth, 7 and 13 months and 2, 3 and 5 years of age. Data on potential risk factors and confounders were collected by maternal questionnaire. Blood for plasma was collected from the mother at time of birth and periodically from the child for detection of anti-Toxocara spp. immunoglobulin G (IgG) antibodies using a Toxocara canis larval excretory-secretory antigen-based enzyme-linked immunosorbent assay. Stool samples were collected from the mother around the time of birth and periodically from the child for microscopic detection of soil-transmitted helminths (STH). Associations between potential risk factors and Toxocara spp. seroprevalence and seroconversion were estimated using multivariable logistic regression and generalized estimating equations. RESULTS: Toxocara spp. seroprevalence was 80.7% in mothers and in children was 0%, 9.3%, 48.4%, 64.9%, and 80.9% at 7 months, 13 months, 2, 3 and 5 years, respectively. Risk factors significantly associated with increases in seroprevalence over the first 5 years of life in multivariable analyses were age [Odds ratio (OR) 2.06, 95% confidence interval (CI) 1.39-2.27, P < 0001], male sex (female vs. male: OR 0.66, 95% CI 0.48-0.89, P = 0.006), maternal ethnicity (non-Afro vs. Afro-Ecuadorian: OR 0.65, 95% CI 0.47-0.91, P = 0.011), lower maternal educational and socioeconomic level, and childhood STH (OR 2.29, 95% CI 1.51-3.47, P < 0.001). Seroconversion rates for infection were greatest at 2 years of age (3.8%/month). Factors associated significantly with seroconversion at 2, 3 or 5 years were childhood STH infection, male sex, and more frequent domestic cat exposure. CONCLUSIONS: Our data, from an area of high Toxocara spp. endemicity, indicate no congenital transmission but high rates of seroconversion after 13 months of age reaching maternal levels of seroprevalence by 5 years of age. Factors associated with seroprevalence and seroconversion included STH infections, domestic cats, maternal ethnicity, male sex, STH infections, and markers of greater poverty.
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Anticuerpos Antihelmínticos/sangre , Toxocara/inmunología , Toxocariasis/congénito , Toxocariasis/transmisión , Animales , Preescolar , Ecuador/epidemiología , Heces/parasitología , Femenino , Humanos , Inmunoglobulina G/sangre , Lactante , Recién Nacido , Masculino , Madres , Estudios Prospectivos , Factores de Riesgo , Estudios Seroepidemiológicos , Encuestas y Cuestionarios , Toxocariasis/epidemiología , Toxocariasis/inmunologíaRESUMEN
BACKGROUND: Besides the well-known risk factors, Toxocara infection is thought to play a significant etiological role in the development of childhood asthma. To further explore this association, the prevalence of Toxocara infection in sera of asthmatic children and healthy controls in northern Iran was investigated. METHODS: In this case-control study, cases were 145 physician-confirmed asthmatic children diagnosed according to the Global Initiative for Asthma (GINA) guidelines. Controls were 115 age-sex-residence-matched children who did not have physician-diagnosed asthma. The presence of anti-Toxocara immunoglobulin G (IgG) was tested using enzyme-linked immunosorbent assay. Univariate and multivariate logistic regression methods were used for case-control comparisons. RESULTS: Seropositivity rate was 4.1% (95% CI, 3.4-4.7%) in asthmatic children and 0.86% (95% CI, 0.71-1.0%) in controls, suggesting a strong association (P-value < 0.02). Moreover, Toxocara infection was not significantly more prevalent (P-value = 0.12) in children with moderate sustainable asthma (9.3%, 3/32) than in children with mild sustainable asthma (2.3%, 3/113). Mean total immunoglobulin E (IgE) level was significantly higher in Toxocara-infected children (222.3 ± 367.1) than in non-infected children (143.19 ± 218.05) in the case group (P-value < 0.05). CONCLUSIONS: Our findings indicated that Toxocara infection can play an important role in childhood asthma. Further experimental and epidemiological studies are needed to clarify this hypothesis.
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Asma/epidemiología , Toxocariasis/epidemiología , Adolescente , Animales , Anticuerpos Antihelmínticos/sangre , Asma/sangre , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Humanos , Irán/epidemiología , Masculino , Prevalencia , Factores de Riesgo , Toxocara/inmunología , Toxocariasis/sangreRESUMEN
Although human toxocariasis can lead to serious complications including neurological, ocular and visceral complications, there is a lack of comprehensive epidemiological information about the seroprevalence of Toxocara species in humans. In the present study, we analysed and reviewed the overall seroprevalence of human toxocariasis in Iran. The data collection was systematically undertaken on published articles using the PubMed, Google Scholar, ScienceDirect and Scopus databases. A total of 27 studies from the past two decades reporting seroprevalence of human toxocariasis met our eligibility criteria. The pooled proportion of Toxocara infection was estimated as 6.58% (95% confidence interval = 3.98-9.77). A wide variation between different studies was observed (Q statistic = 799.37, df = 26, P < 0.0001, and I2 = 96.7%). The seroprevalence rate of toxocariasis in the Iranian population is relatively high; contamination of the environment by eggs from the host as well as from household dogs and cats should be blamed.
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Larva Migrans Visceral/epidemiología , Larva Migrans Visceral/transmisión , Zoonosis/epidemiología , Zoonosis/transmisión , Animales , Gatos , Perros , Humanos , Irán/epidemiología , Larva Migrans Visceral/parasitología , Estudios Seroepidemiológicos , Toxocara/inmunología , Toxocara/aislamiento & purificación , Toxocariasis/epidemiología , Toxocariasis/parasitología , Toxocariasis/transmisión , Zoonosis/parasitologíaRESUMEN
Toxocara cati is one of the causative agents of human toxocariasis. Serological methods are used for diagnosis in paratenic hosts like humans but the humoral immune response triggered by this parasite is unknown. We characterized the humoral immune response to T. cati excretory-secretory antigens (TES) in pigs as animal model during the acute and chronic stages of infection. ELISA and Western Blot techniques were used to determine antibody response. Pigs were experimentally inoculated with 100,000 infective Toxocara cati eggs. Blood was collected at 7, 14, 21 and 28 days post-inoculation (d.p.i.) to assess the acute stage of infection and 90, 120 and 180 d. p.i. for chronic stage analysis. ELISA showed values higher than the cut-off of specific IgM and IgG at 7 d. p.i. with significant differences at 0 and 7 d. p.i. for IgM and at 14, 21 and 28 d. p.i. for IgG in the acute stage. Higher and stable levels were detected in the chronic stage. Western Blot showed bands from 102 to 38 kDa detected by specific IgM and IgG. More immunogenic bands were identified by specific IgG. In the chronic stage of infection a band near 31 kDa was the only band detected by IgM until 150 d. p.i. Specific IgG recognized bands between 102 and 31 kDa. This study demonstrates how the humoral immune response evolves in the acute and chronic stages of infection and provides evidence on the role of the pig as a paratenic host of T. cati.
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Anticuerpos Antihelmínticos/biosíntesis , Inmunidad Humoral , Enfermedades de los Porcinos/inmunología , Toxocara/inmunología , Toxocariasis/inmunología , Análisis de Varianza , Animales , Anticuerpos Antihelmínticos/sangre , Área Bajo la Curva , Western Blotting , Gatos , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Heces/parasitología , Inmunoglobulina G/biosíntesis , Inmunoglobulina G/sangre , Inmunoglobulina M/biosíntesis , Inmunoglobulina M/sangre , Masculino , Curva ROC , Sensibilidad y Especificidad , Porcinos , Enfermedades de los Porcinos/parasitología , Toxocariasis/parasitologíaRESUMEN
Toxocariasis is a human infection primarily caused by larvae of Toxocara canis from dogs, and also by T. cati from cats. Children have a more significant risk of acquiring the infection due to their closer contact with pets, and greater chances of ingesting soil. Diagnosis of toxocariasis is based on clinical, epidemiological, and serological data. Indirect IgG ELISA is a widely used serodiagnostic method for toxocariasis, with native T. canis TES most commonly used as the antigen. Western blots, using the same antigen, can be used to confirm positive ELISA findings to reduce false-positive results. Improvements in Toxocara serodiagnosis include the use of recombinant TES antigens, simpler and more rapid assay formats, and IgG4 subclass detection. Also, incorporation of recombinant T. cati TES protein increases the diagnostic sensitivity. Development of antigen detection tests using polyclonal and monoclonal antibodies, nanobodies, or aptamers can complement the antibody detection assays, and enhance the effectiveness of the serodiagnosis.
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Pruebas Serológicas , Toxocariasis/diagnóstico , Animales , Antígenos Helmínticos/inmunología , Western Blotting/métodos , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Pruebas Serológicas/métodos , Toxocara/inmunologíaRESUMEN
BACKGROUND: Human toxocariasis occurs worldwide and is caused by nematodes of the species of the genus Toxocara. Infection occurs by the ingestion of eggs and is usually asymptomatic or oligosymptomatic. However, severe manifestations occur. The burden of disease and its public health impact remain ill-defined. The aim of this review was to summarize all available data on the seroprevalence of toxocariasis on the African continent and factors associated with seropositivity. METHODS: Twenty-seven original papers published between 1991 and 2017 were identified that provided data suitable for this review. Case-control studies were included and the seroprevalence in the (healthy) control group was used as a surrogate parameter. RESULTS: Antibodies against Toxocara spp. were found to be frequent in most populations and regions in Africa with the exception of two publications, one from the Democratic Republic of the Congo and one from Djibouti, where all participants were seronegative. The highest proportion of participants with antibodies was found on the island of La Réunion with 359 out 387 study participants being positive (92.8%). Factors associated with seropositivity were reported across studies, including-among others-older age, contact with soil via geophagia, agricultural activity or playing with soil, contact with animals, especially dogs, and low socio-economic status, defined as absence of water supply or poor housing. Three Egyptian studies found male gender to be associated with toxocariasis, whereas in La Réunion females were at increased risk. CONCLUSIONS: Exposure to toxocariasis seems to be very frequent and common in large parts of the African continent. However, no data are available for most countries. The public health impact of human toxocariasis and the frequency of severe manifestations remain unclear.
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Toxocara , Toxocariasis/epidemiología , África/epidemiología , Animales , Humanos , Factores de Riesgo , Estudios Seroepidemiológicos , Toxocara/inmunología , Toxocariasis/etiologíaRESUMEN
Detection of ascarid excreted or secreted (E/S) molecules is an alternative approach to the identification of infection by egg flotation. E/S molecules serve as direct markers for the ascarid nematode commonly found in cats and dogs (Toxocara spp., Toxascaris leonina and Baylisascaris procyonis). The nematode derived E/S material mixes with the intestinal contents of the host animal and is available for detection as a coproantigen in the host's faeces. Antigen capture immunological techniques allow sensitive coproantigen detection. Different patterns of antigen to egg agreement are demonstrated in an experimental Toxocara canis infection throughout the prepatent, patent, and post-treatment phases. Examination of faecal samples from a large field population of dogs and cats tested for both egg shedding and antigen indicates that more infections were identified by antigen. Host age influences the agreement of antigen and Toxocara egg results. Older dogs and cats were less likely to have a patent infection (egg positive and antigen positive) result pattern. An egg observation in the absence of antigen detection may indicate a spurious egg. The impact of spurious eggs was further examined by comparisons of cohorts of dogs separated by presence or absence of a pseudoparasite observation or by egg semi-quantification bin. Lastly, the antigen to egg agreement was calculated for other ascarid species.
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Antígenos Helmínticos/inmunología , Enfermedades de los Gatos/diagnóstico , Enfermedades de los Perros/diagnóstico , Toxocara/inmunología , Toxocariasis/diagnóstico , Animales , Infecciones por Ascaridida/diagnóstico , Infecciones por Ascaridida/inmunología , Infecciones por Ascaridida/parasitología , Infecciones por Ascaridida/veterinaria , Ascaridoidea/inmunología , Enfermedades de los Gatos/inmunología , Enfermedades de los Gatos/parasitología , Gatos , Enfermedades de los Perros/inmunología , Enfermedades de los Perros/parasitología , Perros , Toxocariasis/inmunología , Toxocariasis/parasitologíaRESUMEN
Purpose: To investigate the outcomes of surgical treatment in patients with ocular toxocariasis and identify prognostic factors.Methods: We retrospectively reviewed the medical records of 56 consecutive patients who underwent vitrectomy.Results: The mean follow-up was 20.7 months. Visual acuity (VA) improved in 70.4% of patients by the final visit, but VA was better than Snellen 20/70 in only 31.5% of patients. Preoperative VA was closely correlated with final VA (P = 0.001). Macular involvement was associated with final VA worse than 20/70 (P = 0.03). The most common postoperative complications were ocular hypertension (19.6%) and retinal detachment (12.5%). Seven patients (12.5%) experienced recurrent inflammation postoperatively, but no preoperative factors were associated with recurrent inflammation.Conclusion: Surgical treatment could rescue visual function in patients with ocular toxocariasis but their prognosis was unfavorable. Preoperative VA was associated with final VA, whereas macular involvement was associated with poor visual outcomes.
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Infecciones Parasitarias del Ojo/cirugía , Toxocariasis/cirugía , Agudeza Visual , Vitrectomía/métodos , Adolescente , Adulto , Animales , Anticuerpos Antihelmínticos/análisis , Niño , Preescolar , Infecciones Parasitarias del Ojo/diagnóstico , Infecciones Parasitarias del Ojo/parasitología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Oftalmoscopía , Periodo Posoperatorio , Pronóstico , Estudios Retrospectivos , Microscopía con Lámpara de Hendidura , Factores de Tiempo , Toxocara/inmunología , Toxocariasis/diagnóstico , Toxocariasis/parasitología , Adulto JovenRESUMEN
BACKGROUND: Human toxocariasis is an important neglected disease. We performed a systematic review and meta-analysis study to estimate the global and regional prevalence of anti-Toxocara serum antibodies (referred to as 'T-seroprevalence') in human populations around the world. METHODS: We searched five international databases (PubMed, EMBASE, Web of Science, SciELO and Scopus) for seroprevalence studies published from 1 January 1980 to 15 March 2019. We used random effect models to calculate the overall T-seroprevalence (with 95% CIs) in all six WHO regions and worldwide. We also conducted subgroup and linear meta-regression analyses to evaluate the impact of socio-demographic, geographical and climatic parameters on seroprevalence. RESULTS: We identified 250 eligible studies (253 datasets) comprising 265,327 participants in 71 countries for inclusion in the present meta-analysis. The estimated global T-seroprevalence rate was 19.0% (95%CI, 16.6-21.4%; 62,927/265,327); seroprevalence was highest in the African region (37.7%; 25.7-50.6%) and lowest in the Eastern Mediterranean region (8.2%; 5.1-12.0%). The pooled seroprevalence for other WHO regions was 34.1% (20.2-49.4%) in the South-East Asia; 24.2% (16.0-33.5%) in the Western Pacific; 22.8% (19.7-26.0%) in the American; and 10.5% (8.5-12.8%) in the European regions. A significantly higher T-seroprevalence was associated with a lower income level; lower human development index (HDI); lower latitude; higher humidity; higher temperature; and higher precipitation (P-value < 0.001). Potential risk factors associated with seropositivity to Toxocara included male gender; living in a rural area; young age; close contact with dogs, cats or soil; consumption of raw meat; and the drinking of untreated water. CONCLUSIONS: The present findings indicate high levels of infection with, or exposure to Toxocara spp. in many countries, which calls for increased attention to human toxocariasis and improved measures to prevent adverse health risks of this disease.