Last summer, the Centers for Disease Control and Prevention announced that the 2006 HIV prevalence rate in the United States was 40 percent higher than expected: 56,300 estimated new infections each year versus 40,000. More daunting: 45 percent of those cases were among African Americans.

What causes this disproportionately high rate of HIV infection in our community? Several studies show that we have no more and even fewer sexual risk factors than our white counterparts. For example, black women report fewer lifetime sexual partners than white women, yet they are more likely to be diagnosed with a sexually transmitted infection. So the myths of black promiscuity and irresponsibility don’t truly explain the numbers.

And while systematic oppression and social conditions continue to fuel the epidemic, new evidence suggests that good old biology may be in play. Matthew J. Dolan, MD, with the Uniformed Services University in Maryland, found that DARC—a gene that once protected Africans against malaria—might cause people of African descent to be 40 percent more likely to contract HIV than other races. “It has accounted for almost 2.7 million infections in Africa,” Dolan says.

While this discovery is extremely significant, any discussion about a possible genetic predisposition to acquire HIV may create deep distrust in the black community. Historically, scientists have used DNA studies to label groups of people as inferior and to justify abominable acts such as slavery, the Tuskegee experiments (a 40-year study that left 399 black men untreated for syphilis) and forced sterilizations of black women in the ’50 and ’60s. Racial prejudice in the medical field is still real—a 2007 study exposed implicit doctor bias toward African-American patients.

But if we refuse to discuss genetic racial differences, who pays the price? “We all lose out: the patients with the disease, the researchers and the medical workers,” Dolan says. “Practicing good science [will help us] better understand the rich diversity of the human race.” Dolan also hopes that the new genetic findings will help develop an AIDS vaccine and refine existing treatment. Phill Wilson, the founder of The Black AIDS Institute, agrees. “The more we know about how the virus works in different people, the more successful we are going to be in fighting the epidemic.”

The DARC discovery, however, doesn’t eliminate the need to address the social and cultural issues the black community faces that lead to greater risk for HIV. “Although this is an interesting development, this doesn’t change the work that we have to do,” says Helene Gayle, the CEO of Cooperative for Assistance and Relief Everywhere Inc. (CARE). “We know what it takes to reduce people’s chances of contracting the disease, and we need to make sure that we have more resources for education, prevention and treatment.”