Abstract
Background: Previous studies have reported contradictory evidence on the role of early childhood infections in the development of asthma and other allergic diseases in childhood, some suggesting protective effect mainly based on indirect evidence, while others have reported increased risk of asthma.
Aims and Objectives: To investigate early-life infections as determinants of the development of asthma in a 20-year prospective cohort study.
Methods: Information on upper (URTIs) and lower respiratory tract infections (LRTIs) was collected by a parent-administered baseline questionnaire from the preceding 12 months when the children were one to seven years old (Part 1, n=2228) and on LRTIs leading to hospitalization during the first six years of life from hospital discharge registry (Part 2, n=2568). The incidence of asthma was assessed by 6-year and 20-year follow-up questionnaires. Adjusted hazard ratios (HR) were estimated by Cox proportional hazard models.
Results: Both URTIs (adjusted HR = 1.64; 95% CI: 1.22-2.19) and LRTIs (adjusted HR = 2.11; 95% CI: 1.48-3.00) in early childhood were strong determinants of development of asthma up to young adulthood. A declining age trend was present for both URTIs (P for trend < 0.01) and LRTIs (P for trend < 0.001). In Part 2 a significant risk of asthma was found in relation to LRTIs leading to hospitalization (adjusted HR = 1.93; 95% CI: 1.10-3.38).
Conclusions: The results provide new evidence that experience of respiratory infections in early life predict development of asthma through childhood to young adulthood. Respiratory infections in childhood seem to be harmful in relation to asthma.
- Copyright ©ERS 2015
