Asthma and toxocariasis.

BACKGROUND: 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. OBJECTIVE: To evaluate the strength of association between asthma and Toxocara species seropositivity by conducting a systematic review and a meta-analysis of available data. METHODS: 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. RESULTS: 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. CONCLUSION: The results support the existence of a positive association between asthma and Toxocara species seropositivity.