Comparison of a Rapid Antigen Test with Nucleic Acid Testing during Cocirculation of Pandemic Influenza A/H1N1 2009 and Seasonal Influenza A/H3N2

The rapid diagnosis of influenza is critical in optimizing clinical management. Rapid antigen tests have decreased sensitivity in detecting pandemic influenza A/H1N1 2009 virus compared to seasonal influenza A subtypes (53.4% versus 74.2%, P < 0.001). Nucleic acid tests should be used to detect pandemic influenza virus when rapid antigen tests are negative.