CDC Revises Flu Death Estimate

The number of annual flu deaths, consistently reported to be 36,000 by the U.S. Centers for Disease Control and Prevention (CDC), has been revised. The CDC says that during the past 30 years, the number of annual flu-related deaths in the U.S. has ranged from a low of about 3,300 to a high of about 49,000. The new range of numbers takes into account deaths from the 1976-77 flu season through the 2006-07 season, while the old number looked only at the 1990s, when the influenza A (H3N2) was a dominant strain. In the 31 seasons reflected in the new numbers, about 90 percent of deaths occurred in adults 65 and older.

The update underscores the movingtarget nature of influenza, and that there is no average flu season. “We want to point out the incredible variability of influenza seasons,” says Dr. David Shay, lead author of a report appearing in the Aug. 27, 2010, issue of the Morbidity and Mortality Report. “There are at least four factors that affect mortality in any given year: the specific influenza strain, the length of the season, how many people get sick and who gets sick — whether it’s hitting younger or older people differentially.”