Influenza A and respiratory syncytial virus hospital burden in young children in East London

Epidemiological studies have demonstrated high hospitalization rates attributable to influenza and RSV in children aged <24 months. We prospectively recruited 977 children, aged <6 years, presenting with influenza-like illnesses at a hospital during two winter seasons between 2002 and 2004. Nasopharyngeal aspirates were performed and sent for viral immunofluorescence and PCR. Influenza and respiratory syncytial virus (RSV) rates were stratified by age, in-patient/outpatient status and clinical diagnosis. The influenza A and RSV hospitalization incidence rates were 4 and 11/10 000 person-months respectively, whereas the accident and emergency (A&E) outpatient rates were both 32/10000 person-months in those aged <6 years. The influenza A and RSV hospitalization rates were highest in children aged < 24 months and < 12 months (9.1 and 35.7/10 000 person-months) respectively. Infection rates were particularly high in those aged <6 months for both viruses. The age-specific influenza A and RSV A&E admission rates were highest in those aged >6 months and those aged < 12 months, respectively (43 and 92.5/10 000 person-months, respectively). In conclusion, these high paediatric RSV and influenza incidence rates can be used to inform UK policy on childhood influenza immunization and subsequent RSV immunization in the future.