Understanding the dynamics of sexual transmission of HIV among drug-using populations: an integration of biological, behavioral, and environmental perspectives

In October 2002, the Center on AIDS and Other Medical Consequences of Drug Abuse (CAMCODA) of the National Institute on Drug Abuse (NIDA) sponsored a science meeting, HIV Acquisition and Transmission Among Drug-Using Populations: Future Research Strategies. The meeting, chaired by Dr. David Vlahov, Director of the Center for Urban Epidemiologic Studies at the New York Academy of Medicine, convened experts in HIV/AIDS and drug abuse research to examine the dynamics of HIV disease transmission among drug users and other at-risk populations, and to explore why new infections continue apace despite our best efforts at HIV prevention and control. This special issue of the Journal of Urban Health represents one step in the process of addressing new and emerging research gaps and unanswered questions that challenge our best efforts to prevent the continuing spread of HIV/AIDS. The particular focus of the issue is on identifying and understanding some of the dynamic factors involved in the sexual transmission of HIV among drug-using populations. It is hoped that, as we are challenged by yet another decade of HIV/AIDS, we will develop novel, more effective behavioral and biomedical strategies to reduce and prevent—and possibly even to eliminate—this disease. Since HIV/AIDS was first identified in the early 1980s, knowledge and understanding about the disease have grown exponentially. Today, we know more than we ever imagined possible about the natural history, epidemiology, virology, etiology, pathogenesis, prevention, and treatment of HIV/AIDS. Yet despite these gains, dynamic changes in the epidemic continue as new infections spread among drug users and their sexual partners both in the United States and around the world. In the United States today, the estimated annual rate of 40,000 new HIV infections continues, as it did throughout the 1990s. This persistent rate of new infections reminds us that, while we have made advances in the science of HIV prevention, there is much that we have yet to do to make HIV prevention efforts better, more far-reaching, and sustainable. The HIV/AIDS surveillance data from the US Centers for Disease Control and Prevention 1 reveal that, since the 1980s, there have been notable shifts in the demo