THE INFLUENCE OF SEASONAL AND CLIMATIC CONDITIONS ON THE INCIDENCE OF BRONCHIOLITIS IN CHILDREN IN THE STATE OF TOCANTINS

Abstract

Acute viral bronchiolitis (AVB) is one of the main causes of hospitalization for respiratory diseases in children, especially those under one year of age, and is strongly influenced by seasonal and climatic factors. This study aimed to analyze the epidemiological and seasonal pattern of hospitalizations due to acute viral bronchiolitis in children in the state of Tocantins from 2018 to 2025, as well as to evaluate the association between climatic variables and disease incidence. This is an ecological, retrospective study with a quantitative approach, involving time-series analysis and application of Pearson’s correlation coefficient, based on secondary data obtained from the Unified Health System Hospital Information System (SIH/SUS) and the National Institute of Meteorology (INMET). A total of 2,718 hospitalizations were recorded during the analyzed period, with predominance among children under one year of age (73.7%). A well-defined seasonal pattern was observed, with a progressive increase in cases beginning in March and a peak between May and June. Analysis of climatic variables showed a negative correlation with precipitation (r = -0.37) and relative humidity (r = -0.24), indicating an inverse association between these variables and the number of hospitalizations, while temperature showed a negligible association (r = 0.06). The results indicate that low humidity and reduced precipitation are associated with increased hospitalizations due to acute viral bronchiolitis in the state. It is concluded that climatic factors are associated with the seasonality of the disease, supporting the planning of strategic public health actions, especially in the seasonal management of pediatric respiratory diseases.