Fig. 2

Pooled number of positive cases of influenza infection by week. Gray and hashed bars indicate the number of positive cases determined by rapid antigen test (RAT) for influenza A and B infection, respectively. Cases are pooled for each week from 2007 until 2014 using the RAT results from four representative hospitals. Triangles indicate the number of influenza A infections determined by RAT during the pandemic year of 2009 from four representative hospitals (from June 2009 to March 2010)