HIV rates remained steady from 2006 to 2009, but have increased among young black gay and bisexual men, according to a report released Wednesday by the Centers for Disease Control and Prevention.

The results were published in the online scientific journal PLoS ONE.

During the four-year period, the lowest number of new infections was in 2008, with 47,800 new HIV infections. The highest number was in 2007, with 56,000 new HIV infections.

The report shows that in 2009, the highest number of new infections occurred among African American men. They were followed by Latino/Hispanic men and African American women.

There was a 21 percent increase in the 13 to 29-year old age group over the four-year period. This was due in part to a 34 percent increase in infection in young gay and bisexual men.

The CDC estimates that there are one million people in the United States living with HIV and that one in five people are unaware of infection. According to the CDC, more than 18,000 people with AIDS in the U.S. die each year.