Prevalence of asthma symptoms in Latin America: The International Study ofAsthma and Allergies in Childhood (ISAAC)

The prevalence of respiratory symptoms indicative of asthma in children fro m Latin America has been largely ignored. As part of the International Stud y of Asthma and Allergies in Childhood (ISAAC), 17 centers in 9 different L atin American countries participated in the study, and data from 52,549 wri tten questionnaires (WQ) in children aged 13-14 years and from 36,264 WQ in 6-7 year olds are described here. In children aged 13-14 years, the prevalence of asthma ever ranged from 5.5 -28%, and the prevalence of wheezing in the last 12 months from 6.6-27%. In children aged 6-7 years, the prevalence of asthma ever ranged from 4.1-26. 9%, and the prevalence of wheezing in the last 12 months ranged from 8.6-32 .1%. The lower prevalence in centers with higher levels of atmospheric poll ution suggests that chronic inhalation of polluted air in children does not contribute to asthma. Furthermore, the high figures for asthma in a region with a high level of gastrointestinal parasite infestation, and a high bur den of acute respiratory infections occurring early in life, suggest that t hese factors, considered as protective in other regions, do not have the sa me effect in this region. The present study indicates that the prevalence of asthma and related sympt oms in Latin America is as high and variable as described in industrialized or developed regions of the world. Pediatr Pulmonol. 2000; 30:439-444. (C) 2000 Wiley-Liss. Inc.