The Centers for Disease Control and Prevention (CDC) has released updated estimates of annual HIV infections in the US. The report, published in the online journal PLoS ONE, found that the rate of new HIV infections remained steady at roughly 50,000 cases per year between 2006 and 2009.

Most HIV infections each year were among white and black gay and bisexual men, though Hispanic men who have sex with men and black heterosexual women were also heavily affected. The only subgroup whose HIV rates increased considerably over the four years was young black men who have sex with men. Studies suggest that factors like unawareness of HIV status, stigma of HIV and homosexuality, limited access to healthcare, and higher STD rates may be driving the increase in HIV rates among young black men who have sex with men.

Communities of color have been disproportionately affected by HIV/AIDS. While blacks represent roughly 14% of the total U.S. population, they made up 44% of new HIV infections in 2009. The HIV infection rate among Hispanics was nearly three times as high as that of whites. “HIV remains one of the most glaring health disparities in this country,” said Kevin Fenton, M.D., director of the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention in a CDC press release. “It is essential to understand the underlying factors that contribute to these disparities, such as poverty, discrimination and lack of access to health care.”

The CDC notes that prevention efforts over the past few years have managed to curb major increases in HIV infections, though the current rates suggest that more emphasis should be placed on prevention, especially within high-risk populations. “HIV infections can be prevented.  By getting tested, reducing risky behaviors, and getting treatment, people can protect themselves and their loved ones,” said CDC Director Thomas Frieden, M.D. in a CDC press release.

Read the full report from the CDC.