While the number of new HIV infections in the U.S. continues to hold steady at about 50,000 a year, infections rates among gay and bisexual men, especially African American men who have sex with men (MSM), continue to rise sharply, according to a new report from the Centers for Disease Control and Prevention.

The Atlanta-based CDC's HIV Supplemental Surveillance Report released today provides the most up-to-day information on the HIV epidemic. According to the report, in 2010 there were 47,500 new infections in the U.S., which shows the rate of new infections remaining approximately the same as in years past.

But among young gay and bisexual men (ages 13-24),  HIV infections rates continue a startling rise — increasing 22 percent from 2008 to 2010, according to the CDC.

Earlier this month, the CDC released a report specifically about HIV infections rates among people ages 13-24. According to that report, "In 2010, 72 percent of estimated new HIV infections in young people occurred in young men who have sex with men. By race/ethnicity, 57 percent of estimated new infections in this age group were in African-Americans."

From the report:

• Gay and bisexual men of all ages, races and ethnicities, African Americans, and Latinos continue to be most affected by the epidemic.

• Gay and bisexual men represent 2 percent of the U.S. population but a majority (63 percent) of new HIV infections, and the number of new infections in this group increased 12 percent comparing 2008 to 2010.

• New infections among young gay and bisexual men (ages 13-24) continued to rise sharply (by 22 percent comparing 2008 to 2010).

• Young, black gay and bisexual men continue to bear the heaviest burden and now account for more new infections than any other subgroup — a total of 4,800 in 2010

• Overall: Among men who have sex with men (MSM), the estimated number of new HIV infections increased overall and among MSM aged 13–24 years. MSM remain the population most heavily affected by HIV infection.

• Comparing 2008 to 2010, the number of new HIV infections among MSM increased 12 percent from 26,700 in 2008 to 29,800 in 2010, with a 22 percent increase among MSM aged 13–24 years from 7,200 in 2008 to 8,800  in 2010.

• Although MSM represent about 4 percent of the male population in the United States, in 2010 MSM accounted for 78 percent of the new HIV infections among males.

• Race/ethnicity and age group: The estimated number of new HIV infections was greatest among young black/African American MSM in the youngest age group (aged 13–24 years).

• The greatest number of new HIV infections among MSM occurred in young black/African American MSM aged 13–24 years (4,800).

• Young black/African American MSM accounted for 45 percent of new HIV infections among black/African American MSM and 55 percent of new HIV infections among young MSM overall.

Graph: Courtesy the CDC