About half of gay and bisexual black men will be diagnosed with the AIDS virus in their lifetime, according to new government estimates

Overall, for the average American, the odds of an HIV infection is 1 in 99 and has been declining. But the risk varies widely for different groups. For example, the projection is 1 in 2 for gay black men but fewer than 1 in 2,500 for heterosexual white men. HIV, or human immunodeficiency virus, is spread mainly through sex and sharing needles for injecting drugs. In the United States, infections have long been most common in men who have sex with men. Gay and bisexual men have the highest risk, but there are racial differences within that group. For gay white men it's about 1 in 11 — a significantly smaller proportion than the estimate for blacks and Hispanics. Among heterosexuals, blacks are far more likely to be infected than other racial groups. For example, 1 in 49 black women compared to 1 in 1,083 white women.