Surveillance reports revealed that the highest number of 2009 H1N1 influenza confirmed and probable cases which is around 57% were occurring among people between 5 and 24 years old and that makes 41% hospitalizations of older children and young adults. Based on previous records of influenza outbreaks and seasonal flu, pregnant women had been identified as a high-risk group early in the outbreak, on May 12, 2009. Based on all the reported deaths, it most often occurred in people from 22 months old to 57 years old. Yet the puzzling fact is that there are only 13% hospitalizations of people at 50 years of age and older, not to mention there were fewer cases and almost no deaths occurring in people older than 65 years unlike the seasonal flu, which was unusual.
The following are the statistical reports of 2009 H1N1 cases in the most affected countries, the partially affected ones and lastly the least affected.
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