Toxoplasma infection and risk of epilepsy: A case-control study of incident patients.

We performed an age matched case-control study of incident epileptic patients to assess the relationship between Toxoplasma gondii seropositivity and epilepsy. Cases were 94 newly diagnosed patients (mean age, 36.7 ± 15.9) with unprovoked convulsive epilepsy of unknown etiology and controls were 88 healthy individuals (mean age, 37.5 ± 17.1) with no history of epilepsy or neurological disorders. Sera of all subjects were examined for anti-Toxoplasma IgG antibodies using commercially enzyme-linked immunoassays. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using univariate analysis and logistic regression, adjusted for potential confounders. The prevalence of anti-Toxoplasma IgG antibodies in epileptic patients (68.1%; 95%CI, 57.6-77.3%) was significantly higher than healthy controls (47.7%; 95%CI, 36.9-58.6%), indicating a significant relationship between Toxoplasma infection seropositivity and epilepsy (adjusted OR, 2.58; 95%CI, 1.16-5.72; P value < 0.05). The univariate analyses showed more than two-fold higher Toxoplasma seropositivity in patients with focal (OR, 2.31; 95%CI, 0.94-5.67) and generalized (OR, 2.35; 95%CI, 1.215-4.57) seizures versus healthy controls. Our findings support hypothesis that Toxoplasma infection/exposure may play an important role in development of epilepsy. Preventive measures to control of Toxoplasma infection especially in north of Iran and early treatment might be effective to reduce the occurrence of epilepsy in this region.

Exposure to Toxocara spp. and Ascaris lumbricoides infections and risk of allergic rhinitis in children.

BACKGROUND: Substantial experimental studies suggest a role for helminthes infections in the pathogenesis of allergies, but epidemiologic data have been inconsistent. Unlike to asthma, the association between helminthes infection and allergic rhinitis (AR) has been poorly studied. Therefore, we sought to evaluate the association between exposure to Ascaris and Toxocara infections and AR. METHODS: We did an age- and gender-matched case-control study of 81 children with physician-confirmed AR and 101 control subjects in a referral hospital for pediatric diseases in northern Iran. Exposure to Ascaris and Toxocara infections was evaluated by anti-A. lumbricoides- and anti-Toxocara- IgG antibodies using a commercial enzyme-linked immunosorbent assay. Associations were determined using multivariate logistic regression. RESULTS: Ascaris seropositivity was higher in children with rhinitis than in controls (12.34 vs. 3.96%). Ascaris seropositivity was positively associated with AR in univariate analysis (OR, 3.42; 95% CI 1.03-11.3; P value = 0.035), but this association was not significant after adjustment for potential confounders (OR, 1.85; 95% CI 0.42-8.18). Also Toxocara seropositivity was higher in children with AR than in healthy subjects (3.7% vs. 0.99), indicating non-significant association with AR in both univariate (OR, 3.84; 95% CI 0.39-37.7) and multivariate analyses (OR, 0.8; 95% CI 0.04-15.44). CONCLUSION: Our results revealed that AR is not associated with seropositivity to Ascaris and Toxocara infections in general; however, a higher seropositivity rate was found for both parasites in children with AR. More studies with longitudinal design and larger sample size are needed to elucidate this association.

An updated meta-analysis of the association between Toxoplasma gondii infection and risk of epilepsy.

Toxoplasma gondii is a neurotropic pathogen with worldwide distribution. To evaluate the association between Toxoplasma infection and the risk of epilepsy by meta-analysis, observational peer-reviewed studies were retrieved from PubMed, Embase, Web of Science, Scopus and Google Scholar (up to 10 October 2018) and by reference review. Pooled risk estimates were calculated using a random effects model. Heterogeneity was assessed using Cochrane's Q-test and I2. In total, 16 eligible studies involving 19 data sets were included for the final analysis. A total 7897 participants (3771 epileptic patients, 4026 healthy controls) were included. The pooled odds ratio (OR) for Toxoplasma infection was increased to 1.72 (95% confidence interval [CI] 1.37 to 2.16) among patients with epilepsy. There was moderate heterogeneity among the studies (χ2=39.8, I2=62.3%, p=0.001). The ORs from subgroup analyses showed that both cryptogenic epilepsy (OR 2.65 [95% CI 1.91 to 3.68]) and active convulsive epilepsy (OR 1.37 [95% CI 1.09 to 1.72]) were significantly associated with Toxoplasma infection. Another subgroup analyses according to age showed a significant positive association in children (OR 1.33), adults (OR 1.57) and in all ages (OR 1.89). Our findings support the association between Toxoplasma infection and epilepsy. More prospective studies with larger sample sizes and more experimental studies are recommended to elucidate a causative relationship.