Faculty Bibliography

Focusing on the social environment as well as the individual should both enhance our understanding of HIV transmission and assist in the development of more effective prevention programs. Networks are an important aspect of drug injectors' social environment. We distinguish between (1) risk networks (the people among whom HIV risk behaviors occur) as vectors of disease transmission, and (2) social networks (the people among whom there are social interactions with a mutual orientation to one another) as generators and disseminators of social influence. These concepts are applied to analyses of data from interviews with drug injectors in two studies. In the first study drug injectors' risk networks converge with their social networks: 70% inject or share syringes with a spouse or sex partner, a running partner, or with friends or others whom they know. Qualitative data from interviews with injectors in the second study also show that the social relationships between drug injectors and members of their risk network are often based on long-standing and multiplex relationships, such as those based on kinship, friendship, marital and sexual ties, and economic activity. In the first study the vast majority of injectors, over 90%, have social ties with non-injectors. Injectors with more frequent social contacts with non-injectors engage in lower levels of injecting risk behavior. Risk settings may function as risk networks: injectors in this study who inject at shooting galleries are more likely than those who do not to rent used syringes, borrow used syringes and inject with strangers. Since the adoption of a network approach is relatively new, a number of issues require further attention. These include: how to utilize social networks among drug injectors to reduce risk through peer pressure; how to promote risk reduction by encouraging ties between injectors and non-injectors; and how to integrate biographical and historical change into understanding network processes. Appropriate methodologies to study drug injectors' networks should be developed, including techniques to reach hidden populations, computer software for managing and analyzing network data bases, and statistical methods for drawing inferences from data gathered through dependent sampling designs.

Although European and Australian studies of syringe exchange programs have reported safer injection among participants and no increase in drug use, the generalizability of these findings to the US is uncertain. We report on the operations and potential effectiveness of the longest-operating syringe exchange in the US and compare our results to studies of exchange programs outside the US. The sample of 204 study subjects reported no change in the frequency of injection, from 155 to 152 injections per month, and a decline in the frequency of unsafe injections, from 56 to 30 times per month, while participating in the program. In all studies, participants report reduction in unsafe injections, and no increase in illicit drug use. However, the comparison also suggests that a high proportion of Tacoma exchangers have higher initial rates of drug injection, unsafe injection and homelessness, all of which were associated with unsafe injection while using the exchange. These indicate a need for additional services but that the Tacoma program is no less effective than European and Australian programs.