Abstract

Background: Acute respiratory infections (ARI) are trie most frequent cause of medical consultation in primary care, emergency room, as well as, for pediatric hospitalization. Objective: To characterize trie morbidity by ARI until trie third month of life and to evalúate its risk factors. Methods: Cohort study in full-term newborns (n = 316) admitted with their mothers at trie Maternity of trie Hospital Clinico Regional of Valdivia. During 3 months of follow-up, medical consultations by ARI were identified, and overall and specific incidence for ARI was estimated. Maternal, neonatal, socioeconomic and environmental factors were evaluated as associated factors with lower respiratory tract infections (LRTI), using stepwise logistic regression. Results: The overall incidence rate of ARI was 20.4 episodes per 100 child-months, while LRTI reached 6.2 episodes per 100 child-months. Incidence rate of common cold, wheezing bronchitis and pneumonia was 11.6, 4.4 and 0.85 per 100 child-months, respectively. Risk factors for LRTI were: unmarried single mother [OR=2.6; Cl95% 1.22-5.60], indoor tobáceo smoke [OR=2.9; CI95o/o 1.34-6.33], use of wood as exclusive fuel [OR=4.0; CI95% 1.66-9.79] and season (March-July) [OR=7.6; CI95%3.25-18.0]. Conclusions: ARI persists as main cause of ambulatory medical consultation in smaller babies, and environmental factors acquire fundamental importance for prevention in its oceurrence.