Aims Following recommendation by the National Institute for Health and Care Excellence early oseltamivir use is recommended for children at risk because of co–morbidities as there is evidence for reduction of duration of illness. We investigated factors associated with the use of oseltamivir and subsequent respiratory outcome in children with influenza virus infection.

Methods Retrospective study of children attending a District General Hospital with influenza virus infection over a five year period with comparison of groups with and without early application of oseltamivir (within 24 h of arrival to hospital) regarding age, gender, co–morbidities, type of virus, respiratory support required and duration of stay.

Results We included a total of 70 children, 39 received oseltamivir. Patients receiving oseltamivir had a median age of 35 months (range 7 to 180), patients without oseltamivir treatment had a median age of 16 months (range 7 to 138) (p = 0.004). There was no significant difference in gender, comorbidities (20/39 in patients treated with oseltamivir and 11/31 in patients not treated with oseltamivir), requirement for respiratory support (13/39 in patients with and 6/31 in patients not receiving oseltamivir) or duration of stay in hospital between groups. Two patients receiving oseltamivir but none in the group without oseltamivir treatment required mechanical ventilation. Patients without oseltamivir treatment were significantly more likely to be infected with influenza B virus.

Conclusions Patients treated with oseltamivir were significantly older and less likely to have influenza B virus infection in our study population.