ATLANTA - The number of Americans infected by the AIDS virus each year is much higher than the government has been estimating, U.S. health officials reported Sunday, acknowledging that their numbers have understated the level of the epidemic.

The country had roughly 56,300 new HIV infections in 2006 — a dramatic increase from the 40,000 annual estimate used for the last dozen years. The new figure is due to a better blood test and new statistical methods, and not a worsening of the epidemic, officials said.

When I tell someone I have lupus, a puzzled look comes across her face. People have heard about it, but don't really know what it is. Sometimes, someone will ask, "it's an autoimmune disease, isn't it?" Or, "is it a blood disorder?"