At the end of 2003,an estimated 1,039,000 to 1,185,000 persons in the United States were living with HIV/AIDS. In 2006, 35,314 new cases of HIV/AIDS in adults, adolescents, and children were diagnosed in the 33 states with long-term, confidential name-based HIV reporting. CDC has developed a new and innovative system designed to estimate the number of new HIV infections (or incidence) for the United States in a given year. Using this new technology, CDC estimates that 56,300 new HIV infections occurred in the United States in 2006.

The Centers for Disease Control and Prevention (CDC) estimates that approximately 1.1 million persons are living with HIV in the United States. This number is expected to continue to increase over time, as antiretroviral treatments prolong the lives of those who are infected and more people become infected with HIV than die from the disease each year. As the number of people living with HIV—or HIV prevalence—grows, so does the opportunity for HIV transmission to others. Therefore, it is critical to have not only a clear understanding of the number of new infections that occur annually—or HIV incidence—it is also important to know the rate of HIV transmission in order to accurately gauge the impact of HIV prevention efforts on the US epidemic.