Today, beyond the range of any previous global epidemic, human immunodeficiency virus (HIV) infection, the cause of acquired immune deficiency syndrome (AIDS), has reached the proportions of a pandemic, having infected millions and promising to infect millions more. In many developing countries the HIV / AIDS epidemic is spreading rapidly. The present book focuses on the association between drug use and HIV infection and addresses the challenges that professionals and policy makers must confront in shaping national and local policies, developing and implementing preventive polices and providing treatment and rehabilitative services. It is also aimed at governmental and nongovernmental organizations and those involved in the planning, coordination and implementation of strategies and programmes for HIV prevention among injecting drug users.