Battling a Black Epidemic; At home: AIDS now threatens tens of thousands of African-Americans, many of them women, in big cities and small towns alike. A community in peril tries to save itself.(Cover story)

Byline: Claudia Kalb and Andrew Murr (With Sarah Childress, Mary Carmichael and Catharine Skipp)

It's a warm spring morning, and two dozen African-American women are gathered around a conference table at the Women's Collective in Washington, D.C. Easter is just a few days away, but nobody is thinking about painted eggs and bunny rabbits. The collective, less than two miles north of the White House, is a haven for HIV-positive women, and on this day the focus is on sex, condoms and prevention. "Our responsibility," says one woman in a rousing voice, "is to tell the truth!" Together, the women are on a mission to educate, empower themselves and stop the spread of the virus. Patricia Nalls, the collective's founder and executive director, asks the group to read a fact sheet about HIV and AIDS, a staggering array of statistics documenting the impact of the disease in the United States. "So now we know what's happening to us," says Nalls.

What's happening is an epidemic among black women, their husbands, boyfriends, brothers, sisters, sons and daughters. Twenty-five years after the virus was first documented in gay white men, HIV has increasingly become a disease of color, with blacks bearing the heaviest burden by far. African-Americans make up just 13 percent of the U.S. population but account for an astounding 51 percent of new HIV diagnoses. Black men are diagnosed at more than seven times the rate of white men, black females at 20 times the rate of white women.

Decades into the epidemic, scientists have made enormous strides in unlocking the disease at the molecular level. Understanding why HIV has taken hold of black America and how to prevent its spread has proved to be no less daunting a challenge. The root of the problem is poverty and the neglect that comes with it--inadequate health care and a dearth of information about safe sex. IV drug use, sexually transmitted diseases and high-risk sex (marked by multiple partners and no protection) have fueled transmission;…