Centers for Disease Control and Prevention www.cdc.gov/mmwr

observed each year on September 27 to focus on the disproportionate effects of the human immunodeficiency virus (HIV) epidemic on gay, bisexual, and other men who have sex with men (MSM). In 2007, the estimated HIV diagnosis rate among MSM was 692 per 100,000, which was 44 to 86 times the rate for other men and 40 to 77 times the rate for women (1). Although MSM represent approximately 2 % of the U.S. population (1), in 2006 they accounted for 57 % of all new HIV infections (2). From 2005 to 2008, estimated diagnoses of HIV infection increased approximately 17% among MSM in 37 states (3). In 2008, black MSM had the highest estimated number of diagnoses of HIV infection, followed by white and Hispanic MSM (3). In recent years, new HIV diagnoses have increased significantly among young black MSM (4). CDC supports a range of efforts to reduce HIV infec-tion among MSM. These include HIV prevention services that aim to reduce the risk for acquiring and transmitting HIV and to increase the linkage of infected MSM to treatment. Additional information about these efforts and National Gay Men’s HIV/AIDS Awareness Day activitie