The reason is simple: without information most of sick persons thought that this flu was a simple flu, and we used to underestimate most of the flues. So, the main difference between this swine flu and traditional one (usually we do not have the extreme flu, that one associated to 1918 epidemia). People that did not go to the hospital for this flu, on time, got a complicated illness, with pneumonia. If you do not attend this flu in less than 48 hours, you may die! Once we know more about this illness, nobody should die due to swine flu.