Frequency, Burden and Pathogens of Acute Respiratory Illness in Very Preterm Infants During Infancy.

AIM: To describe the frequency, burden, and pathogen profile of acute respiratory illnesses (ARIs) in very preterm infants during the first year after neonatal intensive care unit (NICU) discharge. METHODS: Very preterm infants were followed prospectively (August 2015-January 2017) with monthly assessments of symptoms, medication use, and healthcare utilisation. Parent-reported ARIs triggered additional clinical follow-up. Nasal swabs were collected monthly and during ARIs and tested for respiratory pathogens using real-time PCR. RESULTS: Of 125 eligible infants, 99 (79.2%) were enrolled, and 89 completed the 12-month follow-up. All infants experienced at least one ARI during the first year. Male sex was associated with increased risk of wheezy lower respiratory tract illness (LRTI) (RR 1.61), hospitalisation (RR 3.89), and asthma medication use (RR 5.89). NICU discharge during summer was associated with higher ARI rates (RR 1.33) and hospitalisation (RR 2.54). Rhinovirus was most frequently detected (13.5% of monthly swabs; 43.8% of ARI swabs), whereas respiratory syncytial predominated in emergency department presentations and hospital admissions (18.8% and 20.0%, respectively). CONCLUSIONS: Very preterm infants experienced substantial respiratory morbidity during the first year after NICU discharge. These findings highlight the need for improved preventive and post-discharge strategies in this high-risk population.