Descriptive epidemiology of school outbreaks of seasonal influenza B during 2012/2013 in the Thames Valley, United Kingdom

Highlights • The extent and characteristics of influenza outbreaks in three primary schools have been described. • Routinely collected absentee data are used as a proxy for influenza activity. • Attack rates in these settings can be high, with the highest incidence in younger pupils. • A premature return to school may result in multiple absences. • Provides valuable baseline information for evaluation of the influenza vaccination programme.