Asthma and toxocariasis

Asthma is the most common chronic disease in children and a major public health problem in adults. A relation between asthma and toxocariasis has been hypothesized.To evaluate the strength of association between asthma and Toxocara species seropositivity by conducting a systematic review and a meta-analysis of available data.PubMed, EMBASE, Web of Science, and the reference lists of all relevant articles and books were screened until October 2013. Two authors independently assessed eligibility and study quality and extracted data. A common odds ratio was estimated using a random-effects meta-analysis model of aggregated published data.Ten studies met the inclusion criteria, for a total of 1,530 participants (723 cases and 807 controls). This meta-analysis found a significantly higher prevalence of Toxocara canis infection in patients with asthma than in controls (odds ratio 3.36, 95% confidence interval 1.76-6.42, P.001). Similar results were found when meta-analysis was restricted to the studies considering only children or adults.The results support the existence of a positive association between asthma and Toxocara species seropositivity.