To determine the prevalence of symptoms of asthma, rhinitis, and atopic eczema among schoolchildren aged 6 to 7 years and adolescents aged 13 to 14 years in 20 Brazilian cities by using the standardized ISAAC written questionnaire, and to assess the association of this prevalence with latitude, altitude and average annual temperature of collaborating centers.
MethodsSchoolchildren and adolescents from five Brazilian regions participated in the study, totaling 23,422 ISAAC questionnaires answered by schoolchildren's parents and 58,144 questionnaires answered by adolescents. The values for latitude, altitude and average annual temperature were obtained from the Brazilian Institute of Geography and Statistics.
ResultsThe mean prevalence rates among schoolchildren and adolescents were respectively 24.3 and 19.0% for active asthma; 12.6 and 14.6% for rhinoconjunctivitis; and 8.2 and 5.0% for atopic eczema. A significant negative association was observed between latitude and physician-diagnosed asthma among schoolchildren, severe asthma, physician-diagnosed asthma, eczema and atopic eczema among adolescents. No association with altitude was found.
ConclusionsThe prevalence of asthma, rhinitis and atopic eczema in Brazil varies considerably. Higher prevalence rates, especially of asthma and eczema, were found at centers located closer to the equator.
Determinar a prevalência de sintomas relacionados à asma, rinite e eczema atópico em escolares (EC) entre 6 e 7 anos e adolescentes (AD) entre 13 e 14 anos, residentes em 20 cidades brasileiras, empregando o questionário escrito padronizado do ISAAC, e avaliar a sua associação com a latitude, altitude e temperatura média anual dos centros de residência.
MétodosParticiparam do estudo EC e AD das cinco regiões do Brasil, totalizando 23.422 questionários ISAAC respondidos pelos pais de EC e 58.144 pelos próprios AD. Os índices de latitude, altitude e temperatura média anual foram obtidos do Instituto Brasileiro de Geografia e Estatística.
ResultadosAs prevalências médias para os EC e AD, respectivamente, foram: asma ativa, 24,3 e 19,0%; rinoconjuntivite, 12,6 e 14,6%; e eczema flexural, 8,2 e 5,0%. Associação significante e negativa foi observada entre latitude e prevalência de asma diagnosticada por médico para os EC, asma grave, asma diagnosticada por médico, eczema e eczema flexural para os AD. Não houve associação com a altitude dos centros.
ConclusõesA prevalência de asma, rinite e eczema atópico no Brasil foi variável. Valores mais altos, sobretudo de asma e eczema, foram observados nos centros localizados mais próximos ao Equador.