Serious childhood respiratory infections and asthma in adult life. A population based study

Background: A number of epidemiologic studies have tried to establish whether respiratory tract infections in early childhood cause obstructive pulmonary disease in adult life. Objective: To determine whether reported serious respiratory infection before the age of 5 years (SRI) is a significant risk factor for subsequent development of bronchial asthma and/or bronchial hyperresponsiveness in adults. Methods: We investigated a random population sample of 1,104 subjects (aged 20 to 40 years), participating in the European Respiratory Health Survey in Italy. Bronchial response to methacholine and answers to a standardized questionnaire were analyzed. Results: The prevalence of SRI tie, a positive response to the question "Have you ever had a serious respiratory infection before the age of 5 years?") was significantly higher in the subjects with a positive family history of allergic diseases than in those with a negative one(O.R. 1.89; 95% C.I. 1.24 to 2.87, P <.01). No relationship was found between SRI and current adult asthma; however, asthma in the past was found in 20.5% of the SRI positive subjects and in 9.1% of SRI negative subjects (O.R. 2.47; 95% C.I. 1.47 to 4.15, P <.05). No difference in the response to methacholine and in FEV1, FEV1/FVC values was found between SRI positive and SRI negative subjects. Conclusions: We suggest that a positive family history of atopy is associated with a significantly higher prevalence of SRI. Furthermore our results indicate that exposure to SRI is a risk factor for asthma in the past tie, asthma in childhood and adolescence) but not for adult asthma or for the development of bronchial impairment in adult life.