[Respiratory diseases in infants hospitalized during the 1st 2 years of life for viral lower respiratory tract infections: a one-year follow-up]

Background. Epidemiologic data suggest strong links between hospitalisation with bronchiolitis in infancy and subsequent higher risk of developing lower respiratory tract infections (LRTI) and/or hyperreactive airway diseases. The aim of this study was to evaluate in an Italian population the natural history of respiratory diseases in children hospitalised for LRTI when they were <2 years. Methods. An observational, perspective, longitudinal study was performed through telephone interviews. Nine pediatric tertiary care centres participated to the study evaluating a population of 187 children, hospitalised in the previous year (November 1999-April 2000) for bronchiolitis or pneumonia when they were <2 years of age and participated to a previous study on the prevalence of infant LRTI in Italy (RADAR). Results. Twenty-three (12.30%) children had a gestational age <36 weeks. In the 12 months following the first hospitalisation, an elevated frequency of respiratory symptoms was found. Indeed, 152 (81.3%) children suffered from not-requiring-hospital-admission respiratory infections and 21 (11.2%) were hospitalized again for LRTI: 11.6% had bronchiolitis, 23.5% bronchitis and 35.2% pneumonia. In addition, 1.2% had ≥3 infectious episodes and 21.4% ≥6: 68 (36.4%) showed wheezy bronchitis and 17 (9.1%) were reported to have asthma; 132 children (71%) took antibiotics during the last year, 19.4% <3 times; 111 (59.4%) bronchodilators and 49 (26.20%) oral corticosteroids. One year after the first hospitalisation, 19 subjects (10.2%) were found to be positive to at least one class of allergens by prick test or RAST. Conclusions. Thus, the demonstration of a high morbidity rate for LRTI, wheezing and asthma in this study group during the first year follow-up after hospital admission further support the need for prophylactic interventions to reduce the morbidity and severity of sequelae of LRTI, in particularly in premature children and/or with additional risk factors.