On March 12, 2010 the CDC posted an updated estimate of the number of deaths due to H1N1 since the start of the Pandemic in April of 2009. These revised estimates include approximately 59 million infected; 265,000 hospitalized;  and 12,000 deaths. These are estimates, not raw numbers, and are based on the assumption that most people with H1N1 are never tested, including many who have died.  Click here to read the full report and for an explanation of the methodology.

These estimates include a mortality rate of 65 per million infected children, 272 per million infected adults under age 65, and 296 per million infected adults over age 65. These numbers are markedly different from those expected from seasonal flu, which infects 5-15% of the population each year and kills about 36,000. Over 90% of the deaths due to seasonal flu each year are in the population over age 65, whereas only about 10% of the deaths due to pandemic H1N1 have been in the elderly. Mortality due to H1N1 in children and young adults has been substantailly higher than for seasonal flu, whereas mortality in the elderly has been substantially lower.