 Influenza surveillance information on the 2009 H1N1 flu pandemic is available , but almost no studies attempted to estimate the total number of deaths attributable to H1N1 flu . Two studies were carried out by the CDC ; the later of them estimated that between 7 @,@ 070 and 13 @,@ 930 deaths were attributable to H1N1 flu from April to 14 November 2009 . During the same period , 1642 deaths were officially confirmed as caused by H1N1 flu . The WHO state that total mortality ( including deaths unconfirmed or unreported ) from H1N1 flu is " unquestionably higher " than their own confirmed death statistics . 
