Once addicted to crack cocaine, Sabrina Heard now works with Women's Collective, a D.C.-based organization that seeks to meet the health needs of low-income women, girls and those living with HIV/AIDS by reducing the barriers to care and strengthening networks of support.

Researchers enlisted local pharmacies in the Bronx and Manhattan to offer free rapid HIV testing to any interested passerby. The disease thrives in some of the most impoverished parts of major cities in the United States with many people not even knowing they are infected.