Income and education — not race — predicts HIV risk among inner-city heterosexuals, according to CDC data out today.

“When you look at the heterosexual epidemic throughout the United States, there hasn’t been an overly large impact,” says Dr. Paul Denning of the CDC’s Division of HIV-AIDS Prevention. “The epidemic is highly focused in certain communities.”

Denning and his team found that low-income heterosexuals in 24 urban cities were up to 20 times more likely to become infected with HIV than the rest of the U.S. population.

Contrary to the racial disparities seen in the overall epidemic, there was no difference in HIV prevalence based on race in this study.

Even when examining other high-risk behaviors like crack cocaine use and exchanging sex for money or drugs, income and education remained the stronger predictors.

“The association that you see between crack use and exchange sex is just a symptom for the socioeconomic status, not a risk factor for HIV infection itself,” says Denning.

The only factor more influential than socioeconomic status was having a previously diagnosed sexually transmitted infection — such as herpes, chlamydia or gonorrhea.

Men who have sex with men and intravenous drug users were excluded.

Preliminary data was presented last year at the XVIII International AIDS Conference in Vienna, Austria. Since then, researchers analyzed additional surveys, and are now confirming last year’s findings.

Experts are not using this data to undermine the effect of race in HIV disparities. Instead, Denning says it will help focus HIV prevention efforts on these vulnerable, low-income communities.