Methods: In a prospective observational birth-cohort study Steps to the Healthy Development and Well-being of Children (STEPS), 923 children were followed intensively for respiratory tract infections during the first two years of life. Respiratory symptoms, physician visits with diagnoses, and treatment were documented in a daily symptom diary, and the data on hospitalizations was collected from electronic registries. Nasal swabs were obtained either at home by the parents or at the study clinic at the onset of symptoms and during scheduled visits at the age of 2, 13, and 24 months. Quantitative PCR and antigen tests were used for detection of 10 respiratory viruses.
Results: Data on respiratory infections was available from 867 (94%) children. The mean follow-up time was 1.67 ± 0.49 (SD) years. At the scheduled visits, 28% had respiratory symptoms, and RV was found in 18% of the children (403/2270). In asymptomatic children at 2, 13, and 24 mo of age, RV was detected in 10% (76/754), 9% (38/497) and 10% (36/358), respectively. Nasal swabs were taken during 4726 of the total of 8842 ARI episodes (53%). RVs were detected in 2775 (59%) and other respiratory viruses in 565 (12%) ARI episodes. ARIs caused by RV were associated with less frequent diagnosis of AOM than other ARIs (13% vs. 18%, P<0.001) and with less frequent use of antibiotics (16% vs. 21%, P<0.001). Of the total number, 52% of all AOMs and 51% of antibiotic prescriptions during ARIs were associated with RV infections. RVs were detected in 1.5 ± 1.4 (mean ± SD) ARIs per year in children 0-24 mo of age, and taking into account also ARIs lacking diagnostic samples, they were estimated to cause 2.9 infections per child-year during the first two years of life.
Conclusion: RV infections impose a major burden of acute respiratory disease on infants and young children and contribute substantially to the use of antibiotics.
S. Karppinen, None
T. Teros-Jaakkola, None
M. Rulli, None
J. Mertsola, None
M. Waris, None
V. Peltola, None