Maintaining low HIV seroprevalence in populations of injecting drug users

HIV/AIDS epidemics in Vietnam: evolution and responses

The goal of this study was to describe the evolution of the HIV epidemic in Vietnam and its responses. Surveillance was conducted in 8 provinces in 1994, expanded to 12 in 1995, 20 in 1996, and 30 in 2001. Sentinel populations were sexually transmitted disease (STD) patients, female sex workers (FSWs), injection drug users (IDUs), tuberculosis (TB) patients, antenatal women, and military conscripts. Vietnam is in the concentrated epidemic stage. HIV prevalence had increased significantly in all surveillance population groups in the 1990s. HIV prevalence in the south is higher than in other regions of the country. The national HIV prevalence increased from 10.1% in 1996 to 32% in 2002 among IDUs, from 0.6% in 1994 to 6.6% in 2002 among FSWs, from 0.4% in 1994 to 2.4% in 2002 among STD patients, from 0.03% in 1994 to 0.34% in 2002 among pregnant women, from 0% in 1994 to 0.7% in 2002 among army military recruits, and from 0.5% in 1994 to 3.6% in 2002 among TB patients. The government has a strong commitment to control the epidemic and has implemented many activities for HIV prevention and control. Vietnam's HIV epidemic is predominantly among IDUs. Current intervention activities have not been sufficient to reduce HIV transmission. Vietnam needs to strengthen responses by scaling up the best practices in the most affected population groups by implementing internationally recognised effective interventions appropriately.

Long-term effects of syringe exchange on risk behavior and HIV prevention

The purpose of this study was to assess stability of population-level injection risk behavior over time among participants in a syringe exchange program and compare factors affecting syringe sharing at two points in time. Participants of the Tacoma Syringe Exchange Program were interviewed in 1997 and 2001 using audio computer assisted self-interviewing technology. In each wave of data collection, a random cross section of participants was recruited and interviewed, with no attempt made to follow respondents over time. Rates of injection risk behavior remained stable across the 4-year period, despite increases in factors associated with syringe sharing. Homelessness, rates of depression symptoms, and injection of amphetamines all increased from 1997 to 2001. The central factors associated with syringe sharing in both 1997 and 2001 were depression symptoms and the interaction of younger age with amphetamine injection. The data indicate that the exchange has been able to stabilize risk among a high-risk population for a substantial period of time. This study confirms previous findings that SEPs can play a significant role in the prevention of HIV in marginal and impoverished communities in the United States.

Public funding of US syringe exchange programs

Although there has been no federal government funding of syringe exchange, there is substantial state and local government funding. We report here on program characteristics associated with receiving state and local government funding. Annual telephone surveys were made of program directors of syringe exchange programs known to the North American Syringe Exchange Network. The number of syringe exchange programs known to this network has increased from 63 in 1994-1995 to 127 in 2000. Approximately 80% of programs participated in each of the surveys. Approximately 50% of programs receive state and local government funding, and this has remained constant from 1994 to 2000. Receiving state and local government funding was associated with larger numbers of syringes exchanged per year and providing more on-site services. Among programs that received state or local government funding, this funding accounted for a mean of 87% of the budget for syringe exchange services. In the absence of federal funding, state and local government support is associated with better syringe exchange performance.

Lessons from the History of the Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome Epidemic among Spanish Drug Injectors

In Spain, approximately 10 years passed between the time when human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) harm-reduction programs should have been developed with sufficient coverage to have an optimum impact on public health (before the HIV/AIDS epidemic's explosion in 1984) and the date of their actual implementation. This delay yielded an enormous cost for the country. The introduction of the virus in drug injector networks during a period of widespread diffusion of heroin injection and the lack of political awareness of the growing problem were 2 important factors that contributed to the important diffusion of the HIV infection among Spanish injection drug users. Lessons can be learned that may be of great interest in countries or territories facing similar challenges now and in the future.

Explaining the geographical variation of HIV among injection drug users in the United States

Distinct physical and chemical types of street heroin exist worldwide, but their impact on behavior and disease acquisition is not well understood or documented. This article presents a hypothesis to explain the unequal diffusion of HIV among injection drug users in the United States by examining the distribution and use of one type of heroin--"Mexican black tar." Drawing on ethnographic, clinical, epidemiological, and laboratory data, we suggest that the chemical properties of black tar heroin promote the following safer injection practices: (1) the rinsing of syringes with water to prevent clogging; (2) the heating of cookers to promote dissolution; and (3) a rapid transition from venous injection to subcutaneous or intramuscular injections.

HIV prevention among drug users: outcome of a network-oriented peer outreach intervention

A network-oriented HIV prevention intervention based on social identity theory and peer outreach was implemented for HIV positive and negative drug users. A community sample of 250 were randomly assigned to an equal-attention control condition or a multisession, small-group experimental condition, which encouraged peer outreach; 94% of participants were African American, and 66% used cocaine or opiates. At follow-up, 92% of participants returned, and experimental compared with control group participants were 3 times more likely to report reduction of injection risk behaviors and 4 times more likely to report increased condom use with casual sex partners. Results suggest that psychosocial intervention emphasizing prosocial roles and social identity, and incorporating peer outreach strategies, can reduce HIV risk in low-income, drug-using communities.

Public health interventionists, penny capitalists, or sources of risk?: assessing street syringe sellers in Hartford, Connecticut

Improved access to sterile syringes decreases risks related to blood-borne transmission of HIV and hepatitis among injection drug users (IDUs). While syringe exchange programs and pharmacy sales of over-the-counter syringes have received considerable attention from researchers and interventionists during the past decade, little is known about informal economy street syringe sellers. In Hartford, CT. as well as other regions throughout the United States a large percentage of IDUs utilize street sellers to facilitate their injection activities. A qualitative and ethnographic study was conducted in Hartford between 1999 and 2001 to help elucidate the public health risks and benefits of street syringe sellers.

Readiness for cessation of drug use among recent attenders and nonattenders of a needle exchange program

Needle exchange programs (NEPs) represent a bridge to drug abuse treatment. NEP attenders tend to have more severe drug problems, however, and may be less ready to reduce their drug use than other drug users. This study investigated the relationship between NEP attendance and readiness for cessation of drug use. Since the period from 1988 through 1989, a community-based sample of injection drug users (IDUs) in Baltimore has undergone semiannual interview-administered questionnaires and HIV testing. A total of 288 IDUs completed a questionnaire on readiness for cessation of drug use. Readiness for drug use cessation was assessed from a 28-item validated scale of problem drug use and intention to quit, based on the "stages of change" model. Logistic regression was used to determine factors associated with readiness for cessation of drug use, including sociodemographics, drug use behaviors, and NEP attendance. Thirty percent of respondents attended the NEP in the past month. Stage of change in readiness for cessation of drug use did not differ between NEP attenders and nonattenders (OR = 0.9; 95% CI: 0.5-1.6). Similar proportions of persons recently attending and not attending the NEP were classified as ready to stop drug use (about 30%). In multivariate analysis, readiness for cessation of drug use was associated with speedball injection and previous enrollment in drug treatment but not with NEP attendance. NEP attenders, although exhibiting characteristics consistent with more severe drug dependence, were as motivated for cessation of drug use as were nonattenders. These findings suggest that formal collaboration between NEPs and drug treatment programs could increase the proportion of IDUs in treatment.

Ignoring 'downstream infection' in the evaluation of harm reduction interventions for injection drug users

Harm reduction interventions to reduce blood-borne disease incidence among injection drug users (IDUs). A common strategy to estimate the long-term impact of such interventions is to examine short-term incidence changes within a specific group of individuals exposed to the intervention. Such evaluations may overstate or understate long-term program effectiveness, depending upon the relationship between short-term and long-term incidence and prevalence. This short paper uses steady-state comparisons and a standard random-mixing model to scrutinize this evaluation approach. It shows that evaluations based upon short-term incidence changes can be significantly biased. The size and direction of the resulting bias depends upon a simple rule. For modest interventions, such analyses yield over-optimistic estimates of program effectiveness when steady-state disease prevalence exceeds 50% absent intervention. When steady-state prevalence is below 50%, such analyses display the opposite bias.

HIV infection in young men in northern Thailand, 1991-1998: increasing role of injection drug use

Epidemic HIV-1 infections were first recognized in Thailand in 1988 but increased dramatically in the 1990s primarily as a result of sexual transmission. The Ministry of Public Health instituted programs, including condom promotion during commercial sex, and health education to prevent HIV transmission. We assessed the HIV infection prevalence and risk behaviors among eight cohorts of 21-year-old randomly selected male military conscripts in northern Thailand between 1991 and 1998 to evaluate temporal trends in HIV infection and risk behavior. The prevalence of HIV was 11.4% to 11.9% in 1991 through 1993 and progressively fell to 2.4% in 1998. The men reported progressive decreases in commercial sex from 80% in 1991 to 38% in 1998, increases in condom use for commercial sex to greater than 95% in 1998, and decreases in lifetime history of a sexually transmitted infection from 42% in 1991 to 4.4% in 1997. There was an increasing proportion of men who reported a history of injecting illicit drugs, however, which involved 1.0% of the men in 1991 but 4.2% in 1997. The population attributable risk of drug use for HIV infection increased in recent years; the proportion of HIV-positive men with a history of drug use increased from 1.0% in 1991 to 25.8% in 1998. The public health program to prevent the sexual transmission of HIV in Thailand continues to be highly successful. Nevertheless, injection drug use has emerged as an important risk behavior and is maintaining endemic HIV transmission in Thailand.

Assessing the differential impact of an hiv prevention intervention: who's putting the message into practice?

Recent data suggest that educational interventions aimed at reducing HIV risk behaviors have shown some success. Nonetheless, HIV risk behaviors are not always reduced by interventions and probably do not reduce risk behavior randomly. That is, the success of interventions may be related to participant characteristics. Identifying participant characteristics related to both intervention completion and reduction in risk behaviors may be useful for further developing explanatory models of health behavior and for targeting and customizing interventions. In this study differences between participants who completed an AIDS educational intervention (N = 741) and those who did not complete the intervention are first examined (N = 652) and then variables related to reducing drug and sexual risk behaviors among those who completed the intervention and follow-up interviews are examined. Results show that the majority of respondents report decreasing five out of six risk behaviors, with the smallest percentage (48.8%) decreasing rates of unprotected sex and the largest percentage (83.4%) decreasing frequency of drug injection. Different variables were found to be related to changes in the various risk behaviors. However, some relatively consistent results emerge. For all risk variables, the frequency of the specific behavior at baseline predicted the amount of change in that behavior, with those having higher levels of risk behaviors reducing their behavior the most. Positive HIV test results significantly decreased three of the four sexual risk behaviors examined, and living in a very rural area was found to be significantly related to three of the six risk behaviors. However, perceived chance of getting AIDS did not significantly reduce any of the risk behaviors. Gender and education level were also not related to changes in any of the risk behaviors. Implications include the importance of developing approaches to retain higher proportions of younger participants, males and homeless in interventions. It is particularly important to develop specific approaches to retain women in interventions. Because very rural participants were more likely to decrease crack use and alcohol or drug use with sex, rural interventions should target these behaviors at the outset of the intervention.

Investigation of a secondary syringe exchange program for homeless young adult injection drug users in San Francisco, California, U.S.A

This study investigated an HIV prevention program for homeless young adult injection drug users (IDUs) that combined a secondary syringe exchange program (SEP) with community-level activities. Homeless young IDUs were recruited from street-based settings in San Francisco, and a structured questionnaire was administered. The secondary SEP operated in a circumscribed geographic area, and for analytic purposes respondents were assigned to the intervention site group if they primarily spent time in this area (n = 67), or the comparison site group if they primarily spent time elsewhere (n = 55). Almost all (96%) intervention site youth had used the secondary SEP in the past 30 days and were significantly more likely to regularly use SEP. In bivariate analysis, comparison site IDUs were more likely to share syringes, reuse syringes, share the cotton used to filter drugs, and use condoms with casual sex partners only inconsistently. In multivariate analysis, comparison site remained positively associated with sharing syringes (adjusted odds ratio [AOR], 3.748; 95% confidence interval [CI], 1.406-9.988), reusing syringes (AOR, 2.769; 95% CI,1.120-6.847), and inconsistent condom use with casual sex partners (AOR, 4.825; 95% CI, 1.392- 16.721). This suggests that the intervention was effective in delivering SEP services to homeless young adult IDUs, and that IDUs who frequented the intervention site had a lower HIV risk than comparison group IDUs.

Walking the tightrope: balancing health and drug use

This article stems from a study on San Francisco drug users and their health care experiences. Two hundred thirty-eight study participants were administered depth interviews and questionnaires to reveal a variety of health concerns and health behaviors. For these analyses, which focused on health practices and risky behaviors, the sample was divided into two groups: marijuana users, and other drug users (including methamphetamine, cocaine, heroin, and crack). The findings indicate that drug users behave similarly to the general population regarding health practices, such as eating regularly, sleeping regularly, taking vitamins, and exercising. One finding of interest was the high-risk sexual behaviors of the young, educated marijuana users. A majority of participants demonstrated strong concerns for their health and well-being, and further encouragement on this front is advised. Future research and directions for interventions are recommended.

Global impact of human immunodeficiency virus and AIDS

This review provides information on the epidemiology, economic impact, and intervention strategies for the human immunodeficiency virus (HIV)/AIDS pandemic in developing countries. According to the World Health Organization and the Joint United Nations Programme on HIV/AIDS (UNAIDS) at the end of 1999, an estimated 34.3 million people were living with HIV/AIDS. Most of the people living with HIV, 95% of the global total, live in developing countries. Examples of the impact of HIV/AIDS in Africa, Asia, Latin America, the Caribbean, and the Newly Independent States provide insight into the demographics, modes of exposure, treatment and prevention options, and the economic effect of the epidemic on the global community. The epidemic in each region of the world is influenced by the specific risk factors that are associated with the spread of HIV/AIDS and the responses that have evolved to address it. These influences are important in developing HIV/AIDS policies and programs to effectively address the global pandemic.

HIV surveillance among injecting drug users

Injecting drug users (IDUs) should be considered a 'partially hidden population' at high risk for HIV infection. In almost all locations it should be possible to locate and conduct research with IDUs, but it will probably never be possible to enumerate or draw random samples from an IDU population. Surveillance research studies with IDUs should include risk behaviors, as surveillance of HIV infection only will not be sufficiently time sensitive, and be used to develop and refine HIV prevention programming for the population. Contacts with IDUs can be developed at multiple settings, including voluntary treatment programs, law enforcement settings, and through 'street outreach.' Each type of setting has different advantages, disadvantages and ethical concerns. HIV testing as part of surveillance also raises additional important ethical concerns. The primary risk behaviors that should be included in surveillance studies are 'sharing' of drug injection equipment, the potential for rapid partner change among risk partners, and sexual risk behavior. Additional important objectives for surveillance research include: (1) the size of the local IDU population, (2) patterns of drug use, (3) availability injection equipment, (4) participation in prevention activities, and (5) access to and use of anti-retroviral treatments. HIV incidence is an ultimate objective for surveillance research, but there are no currently available cost-efficient methods for studying HIV incidence, so estimation from indirect measurements is usually required.

Prevalence of hepatitis C among injection drug users in England and Wales: is harm reduction working?

OBJECTIVES

This study sought to establish the prevalence of hepatitis C antibodies (anti-HCV) and hepatitis B antibodies (anti-HBc) among injection drug users in England and Wales.

METHODS

A voluntary cross-sectional survey collected oral fluid samples and behavioral information; 2203 injectors were recruited through drug agencies, and 758 were recruited in the community.

RESULTS

Prevalence was 30% for anti-HCV, 21% for anti-HBc, and 0.9% for HIV antibodies. Anti-HCV prevalence rates were significantly greater among those with longer injecting careers, those in older age groups, those residing in London, those recruited in drug agencies, those positive for anti-HBc, and those with a previous voluntary HIV test.

CONCLUSIONS

Anti-HCV prevalence rates among injectors in England and Wales, where comprehensive harm reduction programs exist, are lower than rates in other industrialized countries.

Evaluating effectiveness of syringe exchange programmes: current issues and future prospects

Although a large body of international literature has found syringe exchange programmes (SEPs) to be associated with reduced incidence of blood borne pathogens among injection drug users, recent studies have fuelled controversy surrounding SEP effectiveness. Existing studies are observational in nature and have seldom considered ecologic aspects affecting SEP functioning and evaluation. The authors apply concepts from infectious disease epidemiology to discuss the direct and indirect effects of SEP upon the spread of blood borne pathogens in drug users, their social networks and the broader community. Further, the authors discuss social policies, particularly drug control policies, which have directly and/or indirectly limited SEP functioning at local and national levels. A critical review of the literature suggests that biases common to observational studies can account for higher HIV incidence among SEP attenders relative to non-attenders. Strong selection factors often lead high-risk drug users to be over-represented among SEP attenders. Failure to account for these factors and the indirect effects of SEPs can bias interpretations of programme effectiveness. Future SEP evaluations should consider behavioural data, the local ethnographic context, the prevalence of infectious disease in the groups under study and the structural components of SEP that are most and least effective at reducing incidence of blood borne pathogens. Hierarchical models that take into account the ecological dimensions of SEP are recommended as an approach for future studies. Beyond methodologic concerns, the authors discuss social, legal and programmatic obstacles that must be overcome in order to maximise SEP effectiveness.

Characteristics and utilization patterns of needle-exchange attendees in Chicago: 1994-1998

The objectives of this study were to describe characteristics and utilization patterns of participants attending a needle-exchange program (NEP) in Chicago, Illinois. Since 1994, demographics of NEP attendees and program utilization data were collected systematically at 22 sites operated by the Chicago Recovery Alliance (CRA). Descriptive statistics were used to assess time trends, site variations, and characteristics of attendees in day sites versus evening sites. A total of 11,855 injection drug users (IDUs) visited the NEP at least once from 1994 to 1998. Median age was 41 years, and 74% were male. Overall race distribution was African-American 50%, Caucasian 38%, Puerto Rican 10%, other 2%. Over time, there was a proportional decrease in African-American users (55.4% to 39.9%, P < .001), a significant increase in Puerto Rican users (1.4% to 14.1%, P < .001), and a stable proportion of Caucasian users (42%). Each year, 15-20% of all clients were first-time attenders. Overall, participants attending evening versus day sites were younger (median age 39 years vs. 42 years, P < .001) and more ethnically diverse. Over a 4-year period, this NEP reached a diverse population of IDUs and recruited a stable proportion of first-time users. Compared to daytime NEP venues, evening NEP sites attracted younger clients and those who were more diverse ethnically. To maximize coverage of sterile syringes, NEPs should strive for diversification in terms of hours of operation and location.

Syringe availability as HIV prevention: a review of modalities

This review examines recent research into modalities for improving access to sterile syringes for injection drug users (IDUs) as a means to reduce human immunodeficiency virus (HIV) transmission. English language studies with empirical data were collected through Uncover reports and MedLine searches from 1998 to 2000. Although syringe-exchange programs are the most established and well-evaluated means of improving access to sterile syringes, research on alternative modalities-such as pharmacy sale, injector-specific packs, mass distribution, and vending machines-and on coverage of special populations suggests the need to pursue multiple avenues of increasing syringe availability simultaneously and, in particular, to explore modalities other than syringe-exchange programs when HIV incidence is under control. The impacts on HIV transmission of cocaine injection and sex with IDUs need to be explored further. Finally, any evidence of declining hepatitis C incidence among young IDUs might serve as a surrogate for a sharp drop in injection-related HIV risk behaviors in that population.

Structural interventions to reduce HIV transmission among injecting drug users

OBJECTIVE

To review current knowledge of 'structural' interventions to reduce HIV transmission among injecting drug users. Structural interventions are defined as programs or policies that change the environments in which risk behavior occurs, without attempting to change knowledge, attitudes or social interaction patterns of the persons at risk. Structural interventions may either facilitate enactment of existing motives to avoid HIV transmission or make enacting risk behavior more difficult.

METHODS

Nonquantitative literature review.

RESULTS AND CONCLUSIONS

Preventing HIV infection among injecting drug users must be considered within the context of the continuing global spread of psychoactive drug use, and injecting drug use in particular. Some policies that are designed to reduce drug use may tend to increase HIV transmission among persons who do inject drugs. Evaluation of structural interventions can be difficult, as populations of drug users are usually the relevant unit of analysis. Typically, pre versus post comparisons must be used, hopefully with multiple pre and post data points. Structural interventions are often associated with 'large effects', increasing confidence that the intervention is the cause of the reduction in HIV-risk behavior. Increasing the availability of sterile injection equipment, through pharmacy sales or syringe exchange or both, is the most common and best-studied structural intervention for injecting drug users. The studies to date indicate that this usually, but not always, leads to large reductions in HIV-risk behavior. Involving drug users in the design and implementation of HIV-prevention programs can be considered a 'meta-structural' intervention that should lead to programs with increased effectiveness.

Comparing new participants of a mobile versus a pharmacy-based needle exchange program

OBJECTIVE

To compare characteristics of first-time needle exchange participants who enrolled at a mobile van-based exchange site versus a fixed pharmacy-based exchange site, in an area where both types of needle exchange programs were available.

METHODS

Demographic and drug use data were collected on needle exchange program participants on enrollment. Participants were included if they were first-time participants at the Baltimore needle exchange program between December 1997 and March 1999, and if their first visit was at either one van-based site or at one of two pharmacy-based sites. Descriptive statistics and inferences were based on the type of needle exchange into which participants enrolled.

RESULTS

Among 286 first-time participants, 92% were African American, 28% were women, 11% were currently employed, 55% completed high school, and the median age was 40 years. In multivariate analyses, van-based enrollment was more common among frequent injectors (odds ratio [OR] = 2.0), but less common among African American participants (OR = 0.21).

CONCLUSIONS

Our data suggest that different venues for needle exchange program settings attract different types of drug injecting participants. This suggests that offering different venue types to reach participants with differing drug use patterns will be important to optimize risk reduction strategies.

Viral subtype and heterosexual acquisition of HIV infections diagnosed in Scotland

OBJECTIVE

As at December 1998, 87% of the estimated 33 million people living with HIV throughout the world resided in Africa and South East Asia. In Scotland (and the United Kingdom), a major public health concern has been that non-B subtypes of HIV which predominate in the regions above might enter the country and spread heterosexually among the indigenous population. The authors conducted an investigation to determine if, and to what extent, such transmission had occurred.

METHODS

Stored blood samples from people who were diagnosed as HIV positive in central Scotland during 1995-7 and who were reported to have acquired their infection heterosexually, were identified. Sequence data were sought from each sample and, where obtained, viral subtype was assigned. For each case, viral subtype was linked to corresponding epidemiological details on heterosexual risk.

RESULTS

Viral sequence was obtained from specimens for 53 of 59 cases. For 43 of the 53 cases, information on region of sexual contact was known. All 19 cases who had a sexual risk in Africa or Asia had a non-B subtype (A, C, or E) while 20 of 24 cases who did not report sexual contact in these regions had a B subtype (p < 0.0001). Of the remaining 10 cases, nine had a subtype B and one a subtype C virus.

CONCLUSION

There is no evidence that non-B viral strains from developing countries have yet disseminated appreciably among indigenous heterosexual men and women within Scotland. Continuing to collect both demographic and molecular data from indigenous heterosexuals who are newly diagnosed with HIV would improve the chances of detecting rapidly any appreciable dissemination of non-B subtypes among this population if it were to occur. Such information would be helpful in informing HIV prevention strategies.

Syringe exchange as a social movement: a case study of harm reduction in Oakland, California

The federal ban on funding for syringe exchange programs (SEPs) has greatly hampered attempts to prevent the spread of HIV among injection drug users in the United States. State laws prohibiting the possession and/or distribution of syringes have made SEPs illegal. These factors have lent a unique social movement quality to harm reduction efforts in the United States. Using a social movement perspective, this paper explores dynamics of the implementation and defense of the syringe exchange program in Oakland, California. The advantages and disadvantages of the social movement aspects of harm reduction are discussed.

"Why I am not infected with HIV": implications for long-term HIV risk reduction and HIV vaccine trials

OBJECTIVE

To describe beliefs about remaining HIV-seronegative in injecting drug users in two high-seroprevalence cities, and to consider implications of these beliefs for ongoing risk reduction efforts and for HIV vaccine efficacy trials.

DESIGN

Cross-sectional survey with open- and closed-ended questions.

SUBJECTS

58 HIV-seronegative injecting drug users participating in HIV vaccine preparation cohort studies in New York City, New York, U.S.A., and Bangkok, Thailand.

MAJOR FINDINGS

Large majorities of subjects in Bangkok (90%) and in New York (89%) believed their "own efforts" to practice safer injection methods and safer sex were very important in avoiding HIV infection. More Bangkok subjects (30%) believed that they would "probably" become infected with HIV in the future than New York subjects (4%). Three percent of Bangkok subjects and 70% of New York subjects believed "having an immune system strong enough to avoid becoming infected with HIV despite exposure to the virus" was very important in avoiding HIV infection. This belief in New York subjects was associated with having previously engaged in high-risk behaviors (i.e., sharing injection equipment, unprotected sex, or both) with partners known to be HIV-seropositive.

CONCLUSIONS

Risk reduction programming for high-HIV-seroprevalence populations and within HIV vaccine trials should address not only specific HIV risk behaviors, but also the complex belief systems about avoiding HIV infection that develop within such groups. The person's "own efforts/self-efficacy" appears to be central in the psychology of risk reduction. Members of some high-risk populations may overestimate greatly the frequency of any possible natural immunity to becoming infected with HIV. Prevention programs for these populations will need to address explicitly the probabilistic nature of HIV transmission.

Impact of law enforcement on syringe exchange programs: a look at Oakland and San Francisco

Drug paraphernalia and prescription laws make syringe exchange programs (SEPs) illegal in most states in the U.S. Nonetheless, SEPs have been started in 25 states and the District of Columbia as of September 1995. In some states like California and New Jersey, SEPs have operated despite police arrest of volunteers and clients. We examine the impact of police action and threat on SEPs by comparing an underground syringe exchange site (SES) in West Oakland to a tolerated SES in the Fillmore neighborhood of San Francisco. The following data sources are utilized: demographic and service utilization data from Alameda County Exchange (ACE) in West Oakland and Prevention Point Needle and Syringe Exchange (PPNSE) in the Fillmore, San Francisco; demographic and syringe exchange utilization information collected from street-recruited samples of injection drug users (IDUs) in West Oakland and the Fillmore; and participant observation of SES in these two communities. We found that police action and the threat of police action in West Oakland decreased utilization of SEP by IDUs, limited the number and diversity of volunteers at SES, and inhibited the operation and expansion of SEP.

Changing the environment of AIDS risk: findings on syringe exchange and pharmacy sales of syringes in Hartford, CT

This paper reports findings from a National Institute on Drug Abuse-funded study designed to test the hypothesis that environmental changes, such as the enactment of laws to increase the accessibility of sterile syringes, including syringe exchange and pharmacy sale of syringes without a prescription, will lower the frequency of HIV risk and the prevalence of HIV among street drug users. Project COPE, a study of AIDS risk and risk prevention, collected longitudinal data on drug use, HIV risk, serostatus, and source of syringes in a sample of 710 out-of-treatment injection drug users in Hartford, CT. Findings support the hypothesis and the growing research-based conclusion that syringe exchange is an effective AIDS risk reduction modality.

Strategies for universalistic and targeted HIV prevention

The controversy over "targeted" versus "universalistic" programs for HIV prevention has persisted throughout the history of the HIV/AIDS epidemic in the United States and in some European countries. Building on previous analyses, we outline methods for integrating universalistic and targeted HIV prevention programming. The outline considers possible synergy between targeted and universalistic programs, rather than a forced choice between the two. Components within this framework include a continuum of the intensity of targeted programs, specification of local risk behavior populations, categories of risk behavior, and HIV seroprevalence within local risk-behavior populations. Given the scarce resources currently available, preventing all new HIV infections is not a realistic public health goal, but with better use of current scientific knowledge, it should be possible to greatly reduce the rate of new HIV infections.

Who uses needle exchange? A study of injection drug users in treatment in San Francisco, 1989-1990

We examined use of the San Francisco needle exchange program (NEP) by 1093 injection drug users (IDUs) recruited in methadone maintenance and out-patient detoxification programs in the first 2 years after the opening of the NEP in 1988. Thirty-one percent of IDUs had ever used the NEP. IDUs who were frequent injectors, homeless, and aware of their serostatus were more likely to use the NEP. To assess self-selection of IDUs at risk for seroconversion for using needle exchange, we calculated pre-needle exchange seroconversion rates. Among 385 IDUs seen twice, the HIV seroconversion rate was 0.38% per person year among subjects who never used needle exchange, but it was 9.34% per person year among those who later used needle exchange (p = 0.003). NEP attracted a subset of IDUs at very high risk for HIV infection. Among injectors who were interviewed before and after the opening of the needle exchanges in San Francisco, the number of sharing partners did not change among IDUs who attended or among IDUs who never attended the NEP. The NEP attracted a very-high-risk subgroup of IDUs, as measured by risk behavior and pre-needle exchange HIV-seroconversion rate. NEPs should be considered prime sites for behavior-change interventions.

The cost-effectiveness of HIV prevention targeting: how much more bang for the buck?

BACKGROUND

Although the targeting of human immunodeficiency virus (HIV) prevention to high-risk populations has been widely discussed, its benefits have not been quantified.

METHODS

This analysis of cost-effectiveness combines an HIV epidemic model, target population scenarios, and data on the cost and impact of prevention.

RESULTS

The number of HIV infections averted in 5 years with $1 million in annual prevention spending ranges from 164 in high-risk populations to 0.4 in very-low-risk populations. Fortyfold to two-hundredfold differences in prevention costs could equalize HIV infections averted.

CONCLUSIONS

Targeting appears to provide substantial benefit and should be considered in allocation decisions about prevention.