The United Kingdom 2009 Swine Flu Outbreak As Recorded in Real Time by General Practitioners

Background. Initially the course of the 2009 swine flu pandemic was uncertain and impossible to predict with any confidence. An effective prospective data resource exists in the United Kingdom (UK) that could have been utilized to describe the scope and extent of the swine flu outbreak as it unfolded. We describe the 2009 swine flu outbreak in the UK as recorded daily by general practitioners and the potential use of this database for real-time tracking of flu outbreaks. Methods. Using the General Practice Research Database, a real-time general practice, electronic database, we estimated influenza incidence from July 1998 to September 2009 according to age, region, and calendar time. Results. From 1998 to2008, influenza outbreaks regularly occurred yearly from October to March, but did not typically occur from April to September until the swine flu outbreak began in April 2009. The weekly incidence rose gradually, peaking at the end of July, and the outbreak had largely dissipated by early September. Conclusions. The UK swine flu outbreak, recorded in real time by a large group of general practitioners, was mild and limited in time. Simultaneous online access seemed feasible and could have provided additional clinical-based evidence at an early planning stage of the outbreak.