Viral Respiratory Tract Infections

The goal of this clinical trial is to understand the impact of respiratory microbiome maturation in respiratory health of preterm infants under 32 gestational weeks. The main questions it aims to answer are: * What is the role of microbiome maturation in respiratory health (development of bronchopulmonary dysplasia, childhood asthma and viral respiratory infections) of preterm infants ? * Which environmental or health factors are involved in the maturation of the respiratory microbiome ? Participants will undergo follow-up from birth until 3 years of corrected age including nasal swabs, stool samples, and for some of them blood and milk sample.

This prospective cohort study aims to characterize the natural progression and outcomes of acute respiratory infections among patients presenting to fever clinics. At enrollment, patients' clinical symptoms, laboratory findings, and chest imaging data will be collected. Longitudinal follow-up will be conducted to evaluate disease progression, complications, and long-term outcomes. As an observational study, no interventions are involved; all patients receive routine clinical management as directed by their attending physicians. This real-world study design enables the assessment of the natural course of acute respiratory infections and the identification of factors associated with clinical outcomes.