HIV/AIDS and injection drug use in the neighborhoods of Dar es Salaam, Tanzania.

This study examines the intersection between needle-sharing practices and HIV recovered from used syringes collected from 73 heroin injection drug users (IDUs) in Dar es Salaam, Tanzania, between October 2003 and January 2004. To extract blood residue, syringes were flushed and 10 microliters of solution mixed with 120 microliters of a latex solution was placed on a Capillus HIV-1/2 slide. Thirty-five (57%) of the useable syringes tested positive for HIV antibodies. Results varied significantly: 90% of syringes tested HIV positive in a mixed-income neighborhood 2 kilometers from the city center: 0% of syringes tested HIV positive in the outlying areas. In addition, semistructured interviews were conducted with 51 IDUs. The interviews were content coded, and codes were collapsed into emergent themes regarding syringe-use practices. Injecting is a recent practice, particularly among heroin users in neighborhoods far from the city center. Sharing syringes has resulted in a high proportion of used syringes containing HIV-positive blood residue. Geographic distance is an indicator of recent adoption of IDU in neighborhoods and correlates strongly with the distribution of syringes containing HIV-positive blood residue.