Asthma and Seroconversion from Toxocara spp. Infection: Which Comes First?

The aim of this study was to estimate the incidence of seroconversion of Toxocara spp. infection and related variables. We conducted a cohort study of 77 children aged 2-12 years who had negative serology in a previous cross-sectional study. Univariate and bivariate analyses were performed to describe the cohort, using socioeconomic, behavioral, and health conditions as variables. Logistic regression analysis was performed using seroconversion as the dependent variable, and the remaining variables are treated as independent variables. Asthma was the only independent variable that showed an association with seroconversion, with an odds ratio = 3.57 (1.01-12.6). The incidence of seroconversion from Toxocara spp. infection in the children followed was 10.4 per 100 per year. Previous studies reporting an association of asthma with toxocariasis have only been carried out using cross-sectional studies. Therefore, this study is one of only a few describing the incidence of seroconversion from Toxocara spp. infection, which is relevant for understanding the burden of this parasite.