Objective: To analyze the climatic seasonality of primary care visits for respiratory disease (RD) in children less than 15 years old.
Methods: This was a descriptive, epidemiological study based on data from the municipal records of primary care events from basic healthcare centers for the period 2004-2005, for the municipality of Tangará da Serra (MT), Brazil. Population estimates were obtained from the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística, IGBE), and data on temperature and relative humidity of the air, from the National Meteorology Institute (Instituto Nacional de Meteorologia, INMET). Mean rates of primary care visits for RD were calculated according to sex, age group and anatomic location of complaint. The ratio of dry season to rainy season visits was calculated according to anatomic location of the RD. Data were analyzed using Epi-Info 3.2, testing differences between proportions using the chi-square test to a significance level of 5%.
Results: Male children had an almost 50% greater (37.3/25.0) rate of primary care visits for diseases of the lower respiratory tract than did females. The rates of primary care visits due to RD in children under 15 years of age varied as age increased, varying from 457.7 per thousand of children less than 1 year of age to 133.5 per thousand in the 10 to 14 years-of-age group. During the dry season there were an average of 21% (4,148/5,231) fewer visits for RD (p = 0.000). Peaks in numbers of visits were observed during the months of March and August, being more accentuated in March, which is the wet season in the region.
Conclusion: Primary care visits for RD, especially those due to upper airway diseases, are related to the rainy season in this municipality.