I know there's more than one cause here. This may have nothing to do with sexuality or what not. Perhaps black men and black women are knowingly engaging in risky behaviors. It could be sexual behaviors or it could be drug use.
Oh yeah it should be noted that one can also get HIV/AIDS thru the sharing of infected needles. You might see that in those who uses needles to inject into themselves illegal drugs.
All the same here's a story in the Sun-Times today:
New infection rates among black women are nearly 15 times higher than those for white women, according to the CDC report, which breaks down HIV infection by race, gender and age.Also noted in this article was that 80 of gay and bisexual men in 15 cities weren't reached by HIV efforts within the last year.
Among whites, new infection rates in 2006 were highest for gay and bisexual men in their 30s and 40s. But for black gay and bisexual men, 13- to 29-year-olds were the most at-risk.
The age difference might be the result of young black men not having access to HIV prevention services, not having experienced the AIDS epidemic of the 1980s and partnering with older black men who have HIV, said Dr. Richard Wolitski of the CDC.