Keywords: CDC MMWR m8d0428a2f.png H1N1 illness onset dates - United States svg en Graph showing confirmed human cases of swine-origin influenza A H1N1 infection with known dates of illness onset --- United States April 27 2009 Onset dates were available for 25 of the 64 confirmed cases http //www cdc gov/mmwr/preview/mmwrhtml/mm58d0428a2 htm Morbidity and Mortality Weekly Report Centers for Disease Control and Prevention 2009-04-28 PD-USGov Charts in English Timelines Epidemiology 2009 swine flu outbreak in the United States Medical bar charts Original upload log wikitable - - 2009-04-29 02 09 56 520 × 312 9485 bytes Zigger <nowiki> en Graph showing confirmed human cases of swine-origin influenza A H1N1 infection with known dates of illness onset --- United States April 27 2009 http //www cdc gov/mmwr/preview/mmwrhtml/mm58d0428a2 htm Mo</nowiki> |