Eighty-one percent of U.S. hepatitis C cases are among baby boomers, according to new prevalence estimates from the Centers for Disease Control and Prevention. CDC researchers examined data on 30,000 people who participated in a national health survey between 2003 and 2010. With 273 of the participants testing hep C positive, the investigators calculated that this equated to a U.S. prevalence rate of 1 percent overall. While the official CDC estimate may have dropped from 3.2 million to 2.7 million people as a result, the new estimate range is actually 2.2 million to 3.2 million people, which overlaps with the old one. The estimated 2.6 percent prevalence rate among baby boomers—those born between 1945 and 1965—is six times that of other adults.