Fig. 2

Monthly nucleic acid positivity rates of influenza A, H5, H7 and H9 subtypes. The blue line represents the nucleic acid positivity rate of influenza A; the red line represents the nucleic acid positivity rate of H5 subtype; the light green line represents the nucleic acid positivity rate of H7 subtype; the purple line represents the nucleic acid positivity rate of H9 subtype