Faculty Bibliography

Hepatitis C virus (HCV) vaccine development remains at an early stage. We explored the economic and health consequences of potential HCV vaccines by comparing universal vaccination with a hepatitis C vaccine to no vaccination in two groups: (1) injecting drug users (IDU); (2) all 12 year olds, using a Markov cohort simulation. Among IDUs, vaccination would avert 248 cases of HCV infection and 89 HCV-related deaths per 1000 individuals, and reduce costs. In average risk cohorts, vaccination did not reduce costs but was reasonably cost effective. These results provide encouragement to vaccine developers that a vaccine that is moderately effective and reasonably priced should not face economic barriers to implementation and will be attractive to third party payers.

Sexual relations between drug injectors (IDUs) and crack smokers (CS), and non-drug users are a major means of HIV spread to the broader population. However there is little literature describing community processes that regulate sexual and social partnerships among these groups. We describe these relationships in Bushwick, a low-income, mainly Latino neighbourhood in Brooklyn, NY. In this community, IDU and CS are heavily stigmatized, both by non-users and by some users. Known IDU/CS may find it harder to start and maintain social and sexual relationships, and to get jobs or support. Partially as a result of this stigma, IDU/CS attempt to 'keep it together' and hide either their drug use or its extent from other residents. Nevertheless, other residents believe, sometimes falsely, that they can distinguish users from nonusers. We describe some potential negative consequences of these beliefs and interactions, including their effects on risk for HIV and other sexually transmitted diseases.

There is increasing appreciation of the need to understand how social and structural factors shape HIV risk. Drawing on a review of recently published literature, we seek to describe the social structural production of HIV risk associated with injecting drug use. We adopt an inclusive definition of the HIV 'risk environment' as the space, whether social or physical, in which a variety of factors exogenous to the individual interact to increase vulnerability to HIV. We identify the following factors as critical in the social structural production of HIV risk associated with drug injecting: cross-border trade and transport links; population movement and mixing; urban or neighbourhood deprivation and disadvantage; specific injecting environments (including shooting galleries and prisons); the role of peer groups and social networks; the relevance of 'social capital' at the level of networks, communities and neighbourhoods; the role of macro-social change and political or economic transition; political, social and economic inequities in relation to ethnicity, gender and sexuality; the role of social stigma and discrimination in reproducing inequity and vulnerability; the role of policies, laws and policing; and the role of complex emergencies such as armed conflict and natural disasters. We argue that the HIV risk environment is a product of interplay in which social and structural factors intermingle but where political-economic factors may play a predominant role. We therefore emphasise that much of the most needed 'structural HIV prevention' is unavoidably political in that it calls for community actions and structural changes within a broad framework concerned to alleviate inequity in health, welfare and human rights.

HIV risk and infection are markedly increased among sexual minority women injectors compared to other injecting drug users. Our ethnographic exploration of this well-documented but poorly understood phenomenon included 270 interviews and over 350 field observations with 65 sexual minority women injectors in New York City and Boston. We discuss findings in relation to four preliminary hypotheses. Neither the presence of gay or bisexual men in risk networks, nor a sense of invulnerability due to lesbian (or other sexual minority) identity seem to be plausible explanations of increased HIV among sexual minority women injectors. However, multiple marginalization was found to be pervasive and to have severe consequences that can be traced to increased HIV risk for many women in the study.

BACKGROUND:A substantial decline of HIV prevalence has been observed in injection drug users (IDUs) from Rio de Janeiro, in recent years. Differential characteristics and behaviors of new (injecting for <6 years) and long-term (>=6y) injectors may help to understand recent changes and to implement appropriate prevention strategies. METHODS:Between October 1999 and December 2001, 609 active/ex-IDUs were recruited from different communities, interviewed, and tested for HIV. Contingency table analysis and t-tests were used to assess differences between new and long-term injectors. Multiple logistic regression was used to identify independent predictors of HIV serostatus for long-term and new injectors. RESULTS:HIV prevalence was 11.7% for 309 long-term injectors (95% CI 8.1-15.3) and 4.3% for 300 new injectors (95% CI 2.0-6.6). New injectors reported having engaged in treatment and having received syringes from needle exchange programs (NEPs) more frequently than long-term injectors in the last 6 months, but sharing behaviors remained frequent and even increased vis-à-vis long-term injectors. For male new injectors, "sexual intercourse with another man" was found to be the sole significant risk factor for HIV infection (Adj OR = 8.03; 95% CI 1.52-42.48). Among male long-term injectors, "to have ever injected with anyone infected with HIV" (Adj OR = 3.91; 95% CI 1.09-14.06) and to have "ever been in prison" (Adj OR = 2.56; 95% CI 1.05-6.24) were found to be significantly associated with HIV infection. DISCUSSION/CONCLUSIONS:New injectors are seeking help in drug treatment centers or needle exchange programs. They differ from long-term injectors in terms of their risk factors for HIV infection and have lower prevalence levels for HIV. Such differences may help to understand the recent dynamics of HIV/AIDS in this population and highlight the need to reinforce new injectors' help-seeking behavior and to reduce current unacceptably high levels of unprotected sex and syringe sharing in new injectors despite attendance of prevention/treatment programs.