Burden of respiratory syncytial viral infections on paediatric hospitals: a two-year prospective epidemiological study.

This study was designed to prospectively investigate the hospitalisation patterns for respiratory syncytial virus (RSV) disease in children up to 2 years of age, both healthy full-term children and high-risk children. The aim was to evaluate children hospitalised for a respiratory tract infection in four regions and seven paediatric hospital departments or clinics in Greece and to estimate the burden of RSV disease on paediatric hospital beds, as well as to determine the target high-risk age group over two consecutive respiratory infection seasons. Among a total of 1,710 children, the overall prevalence of RSV disease was 33.1%, but prevalence differed between seasons (27% vs. 37.7%, P<0.01). The peak prevalence of RSV disease occurred in February, with the onset in November and the end in May. The monthly distribution was similar in all regions. RSV positivity was strongly associated with young age (4.7 vs. 6.6 months, P<0.001); classification within a high-risk group (43% vs. 32.6%, P=0.04); lower respiratory tract infection (93.8% vs. 86%, P=0.001), particularly bronchiolitis (80.9% vs. 63.9%, P=0.001); more severe disease (P<0.001); longer stay in hospital (P<0.001); and poorer outcome (P<0.001). RSV infections accounted for 38% of the total hospitalisation days for all respiratory infections, and 77% of the hospitalisation days for RSV infection were for infants less than 6 months of age.