G227 THE CLINICO-EPIDEMIOLOGICAL BURDEN OF INFLUENZA IN INFANTS AND YOUNG CHILDREN IN EAST LONDON, UK

E. K. Ajayi-Obe^{1, 3}, P. G. Coen¹, R. Handa¹, K. Hawrami², S. Mieres¹, C. Aitken², E. D. G. McIntosh^{4, 5}, R. Booy¹.¹Center of Child Health, Queen Mary University of London, Barts and the London NHS Trust, London, UK; ²Department of Virology, Queen Mary University of London, Barts and the London NHS Trust, London, UK; ³Department of Paediatrics, Hammersmith Hospitals NHS Trust, London, UK; ⁴Faculty of Medicine, Imperial College of Science, Medicine and Technology, London, UK; ⁵Wyeth, UK, Huntercombe, UK

Objective: Epidemiological studies done in the US have demonstrated high hospitalisation and outpatient rates attributable to influenza in children between 6 and 23 months, rates being comparable to those seen in children with high risk conditions. Based on these results the Advisory Committee on Immunisation Practices has recommended that this age group be immunised against influenza. There are insufficient data on the overall health and economic impact of influenza in European children due to a paucity of epidemiological studies and consequently vaccination is not yet recommended.

Methods: This is a prospective study that recruited children <6 years in the hospital and GP presenting with acute influenza-like illnesses during two winter seasons, 2002/03 and 2003/04. A questionnaire was administered and nasopharyngeal aspirates were sent for viral immunofluorescence and PCR. Influenza incidence rates were stratified by age, clinical diagnoses, and inpatient outpatient status, and rates were also estimated from a predictive clinical diagnosis model.

Results: During the two seasons 977 children were recruited and the influenza A attack rate was 6%. The average influenza A hospitalisation incidence rate was 2.9/10⁴ person-months (95% CI 2.3 to 3.7) whereas the influenza A accident and emergency (A&E) outpatient rate was 30.0/10⁴ person-months …