Toxocara Infection in Asthmatic Children: A Case-Control Study in Karaj District, Iran

Background: It has been proposed that the migration of Toxocara canis larvae through the lungs is a contributing factor in the development of asthma and association of asthma and toxocariasis has been reported. The seroprevalence of toxocariasis varies widely among children living in different countries and even in different regions of a single country. Objectives: The aim of this study is to compare seroprevalence of anti-Toxocara antibodies in asthmatic and healthy children in Karaj, Iran. Methods: A serological study was conducted in children aged 1 to 15 years old for detection of antibodies to Toxocara canis in two groups (92 asthmatic children and 100 non-asthmatic children as control group), using commercial ELISA method for determination of IgG antibodies against Toxocara. Results: Only one patient (1.09%) had positive levels of anti-Toxocara antibodies in the case group, while no one had them in the control group. The results showed that there was no significant correlation between IgG antibodies against Toxocara canis and asthma. More than 90% of children in both case and control groups were residents of urban areas. Conclusions: We did not find any association between Toxocara infection and childhood asthma, suggesting that it may not be a common risk factor for childhood asthma in our urban area.