Last week, the CDC substantially lowered its often-quoted estimate of how many people die in a typical influenza season from 36,000 to 24,000. Now, that is quite a drop isn’t it?

What led them to this announcement? CDC staff noted that the previous estimate was based on a study of the years 1990 to 1999, during which the H3N2 strain of flu predominated, and H3N2 is far more deadly to the elderly than the other two common seasonal strains, Influenza A H1N1 and the B strains.

The new estimate is based on a reassessment and a broadening of the sample size of years, extending it now from 1976 to 2007. Deaths attributed to flu swung widely, from a low of 3,349 in the winter of 1986-7 to a high of 48,614 in 2003-4.  Neither estimate is affected by the 2009 H1N1 pandemic, which was caused by a new variant of the H1N1 strain. In March, the centers estimated that about 12,000 people died of that strain — far fewer than expected — although 90 percent of them were under 65, while seasonal flu normally kills elderly people.

CDC also had what seems to be an unusual request of the journalist community when they presenting the new numbers. They requested that reporters stop using annual averages like 36,000 or 24,000 and to use more vague estimates like “tens of thousands of people may die.” I guess they don’t like to feel pegged down to a number that then gets quoted over and over again.  However, last year as the pandemic was kicking in and press briefings about the flu were a daily occurrence, top C.D.C. officials repeatedly said that 36,000 people die in a typical flu season.

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5933a1.htm?s_cid=mm5933a1_e%0D%0A