Risk factors and prevalence of toxocariasis in pregnant women and diabetic patients compared to healthy adults in Ilam province, western Iran

Serological diagnosis of Toxocara canis in mothers and their neonate referred to selected teaching hospitals, Tehran, Iran, 2020

Toxocariasis is a common zoonotic parasitic disease, primarily caused by the larvae of Toxocara canis or T. cati. Humans become infected through accidental ingestion of infective eggs in soil contaminated with feces of infected animals, or by consuming undercooked meat from paratenic hosts harboring Toxocara larvae. This cross-sectional study aimed to evaluate the seroprevalence of Toxocara spp. in 250 mothers and their 250 neonates referred to selected teaching hospitals affiliated with Shahid Beheshti University of Medical Sciences, Tehran, Iran in 2020. Data were recorded using a specialized questionnaire, and serum and peripheral blood smears (for eosinophil count) were collected. Serum samples were tested using the ELISA serological test for IgG antibodies against Toxocara spp. The collected data were analyzed using IBM SPSS Statistics software version 21.0. A chi-square test was performed, and a P value less than 0.05 was considered statistically significant. Among the 500 participants, 24 cases (4.8%) tested positive for anti-Toxocara canis IgG antibodies. Seropositive cases included 6 mothers only (25%), 6 neonates only (25%), and 12 cases both mother and their neonate (50%). Statistical analysis showed a significant relationship between the presence of anti-Toxocara antibodies and hospital type and nationality (P value < 0.05). However, no significant relationship was found between the presence of antibodies and other demographic variables such as age, sex, eosinophilia, and history of contact with animals in mothers and their neonates (P value > 0.05). This study indicates a substantial rate Toxocara infection in mothers and neonates, necessitating appropriate preventive measures by the relevant authorities.

Seroprevalence of Toxocara spp. in Pregnant Women: A Systematic Review and Meta-Analysis

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.

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

Introduction

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

Materials and Methods

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

Results

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

Conclusion

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

Changes in the expression of miR-103a and miR-21: a functional diagnosis of toxocariasis in rats

Introduction. Toxocariasis is a zoonotic parasitic disease caused by migrating nematode worms, Toxocara species larvae, within tissues. MicroRNAs (miRNAs) are small RNA molecules that regulate gene expression at a post-transcriptional level.Hypothesis/Gap Statement. miRNA-based diagnostic biomarkers for toxocariasis are emerging, but there is limited information about the role of many miRNAs and a more detailed diagnostic evaluation of miRNA expression patterns is needed to understand their immunobiological function.Aim. We investigated the expression levels of circulating miRNA 21 and miRNA 103a as potential biomarkers for the prediction and diagnosis of toxocariasis in Wistar rats infected with Toxocara canis.Methodology. Thirty Wistar rats were inoculated orally with 2500 T. canis embryonated eggs via gavage. Serum samples were collected from infected animals and were tested against T. canis antigens for 60 days post-infection. The plasma samples were isolated for quantitative real-time PCR (qPCR) assays and qPCR was used to assess transcription levels of miRNA 21 and miRNA 103a.Results. The prevalence of anti-Toxocara IgG was detected in 7/30 (23.3 %) infected rats. Molecular analysis of miRNAs 21 and 103a showed that expression levels of miRNAs in both groups of Toxocara-positive and negative samples were the same without significant association. The ratio of housekeeping gene expression (U6) to gene expression of miRNAs 21 and 103a indicated the rate of change (1/1.38 ≈ 0.75 and 1/0.751 ≈ 1.3, respectively).Conclusion. Our study revealed that miRNAs 21 and 103a might play fundamental roles as biomarkers and diagnostic tools for toxocariasis. However, the changes in expression of these miRNAs were not adequate to be used as biomarkers in diagnosis.

Human Toxocariasis in individuals with blood disorders and cancer patients: the first seroepidemiological study in Iran

Toxocara is one of the most prevalent nematodes in Iran, which infect humans as an intermediate host. Infection complications result from the larva migration. Human toxocariasis prevalence was various in Iran according to the area of study and population. This study was designed to evaluate the seropositivity of Toxocara IgG in patients with blood disorders and cancer patients in southwest Iran. Moreover, the study of the associated risk factors for this infection. A total of 1122 serum samples, from February 8, 2019 to August 21, 2019, including 600 healthy individuals and 522 individuals with cancer and blood disorders patients were collected. Serum samples were collected for detection of Toxocara IgG by using ELISA (Enzyme-Linked Immunosorbent Assay) kit. Sociodemographic data of all participants were collected and examined to determine their association with the infection. Out of 101 individuals with white blood cell disorders (5.94%), red blood cell disorders (7.48%) and cancer patients (11.06%) were seropositive for Toxocara IgG antibodies. The infection rate among all study population revealed that (10.76%) were positive for Toxocara IgG. This study showed the fundamental role of contact with pets and infection in groups with blood cell disorders (P-value ≤ 0.05%); while in cancer patients the association wasn't significant. Other factors such as age, location of residence, and sex showed that the association with this infection wasn't significant.

Serosurvey of anti-Toxocara antibodies and risk factors in adolescent and adult pregnant women of southeastern Brazil

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.

Human Toxocariasis: 2010 to 2020 Contributions from Brazilian Researchers

This is a review of the published contributions made by Brazilian researchers between 2010 and 2020 on the natural history of human toxocariasis and the effects of human toxocariasis on nonhuman paratenic hosts.

Expression of Mir-21 and Mir-103a in Toxocara canis: Potential for Diagnosis of Human Toxocariasis

Background:

Toxocariasis is one of the most neglected zoonotic diseases, predominantly caused by Toxocara canis. We aimed to evaluate the expression of microRNAs 21 and 103a in seropositive individuals for human toxocariasis as diagnostic biomarkers.

Methods:

This study was conducted on 324 individuals for ELISA test on toxocariasis in Tehran and Karaj, Iran 2019. Then positive samples for anti-Toxocara IgG were obtained to quantitative Real-time PCR (qRT-PCR) assays to investigate the transcriptional profiles of miRNAs predicted to be involved in developmental and reproductive processes. qPCR was employed to assess levels of transcription for miRNAs of 103a and 21 in plasma samples.

Results:

After the experiments, the results were evaluated by REST software, Livak formula and quantitative t-test. The analyzes performed on human samples showed that in the case group compared to the control group, only in Tc-miR-21 gene, a 0.3-fold increase in expression was obtained with REST software (Fold change ≤ 1.5, P>0.05), which was statistically significant by t-test (P<0.05).

Conclusion:

To our knowledge, this is the first study to evaluate miR-21 and miR-103a in toxocariasis, which shed light on the fundamental role of it as a biomarker and diagnostic tool. However, due to the changes in expression of these miRNAs were not vast to be used as biomarkers in diagnosis. Despite of that the changes in the expression of these miRNAs were not vast but they could serve as novel promising biomarkers for diagnosis of toxocariasis.

The Relation between Toxocariasis and Toxoplasmosis co-infection and the presence of Rheumatoid Factor (RF) in people with hydatidosis in Southwestern Iran, from 2013 to 2018

Toxoplasmosis, toxocariasis, and hydatidosis are parasite diseases with a very human-like pathway of infection. worldwide including Iran, there are infected people with these infections. Between 2013 and 2018, serum samples were collected from 124 patients with hydatidosis and 124 serums from hydatidiosis free. Samples were examined for the presence of toxocariasis by detecting IgG antibodies, using the ELISA (Enzyme-Linked Immunosorbent Assay) IBL kit and for the presence of IgG antibodies for toxoplasmosis, using the ELISA test. Risk factors such as contact with animal pets; cats and dogs, rural or urban living, age, sex, and Presence of rheumatoid factor (RF) in serum were investigated during the study. The presence of RF was examined using an agglutination test in all confirmed cases of hydatidosis, toxocariasis, and toxoplasmosis. Of the 124 positive cases of hydatidosis, 30 (24.2%), 51 (41.1%) and 15 (12.09%) had toxoplasmosis, toxocariasis and simultaneous infection (toxoplasmosis and toxocariasis), respectively. In people with toxocariasis, rheumatoid factor was reported more frequently than in other cases. The relationship between the prevalence of rheumatoid factor in serum in people with toxocariasis was significant (41.18%). Interaction with dogs and cats and area of residence were identified as risk factors for toxocariasis (P value > 0.005). Although hydatidosis and toxocariasis are Less common infections compare with toxoplasmosis, they are considered a threat to public health in some parts of the world, including Iran. Some factors, such as habitat and interaction with animal pets (dogs and cats), play a more significant role in toxocariasis compared to toxoplasmosis in people with hydatidosis.