[Prevalence of asthma and asthma symptoms among 13 and 14-year-old schoolchildren, Brazil].

Objective: Before the use of the ISAAC (International Study of Asthma and Allergies in Childhood) questionnaire in epidemiologic surveys, little could be told about the comparative occurrence of asthma in the world due to differences in employed methods. In Brazil, the ISAAC questionnaire has been used in some urban regions. In this study it was applied in both, urban and rural areas, in order to estimate the prevalence of asthma among schoolchildren living in Montes Claros, Brazil.