Findings presented at the International AIDS Conference in Mexico City last weekend show that the number of Americans newly infected with HIV each year is higher than previous estimates. These findings, which will be published in the Aug. 6 issues of the Journal of the American Medical Association, indicate that approximately 56,300 new HIV infections occurred in the United States in 2006. This figure is 40% higher than a previous estimate of 40,000.

This study was conducted by the division of HIV/AIDS Prevention at the U.S. Centers for Disease Control and Prevention (CDC) using new technology that can differentiate between recent and older HIV infections. The new estimate doesn't mean that the HIV epidemic is worse than previously thought; the rate of new HIV infections has been stable, but is higher than previously assumed. The new estimate also confirms that the highest-risk populations remain gay and bisexual men, as well as black men and women.

More accurate estimates of new HIV infections will allow scientists to better evaluate strategies for HIV prevention, and hopefully, to develop more effective strategies for educating Americans about HIV risk.