Global overview of injecting drug use and HIV infection among injecting drug users

OBJECTIVE: To provide global estimates of the prevalence of injecting drug use (IDU) and HIV prevalence among IDU, in particular to provide estimates for developing and transitional countries. METHODS: Collation and review of existing estimates of IDU prevalence and HIV prevalence from published and unpublished documents for the period 1998-2003. The strength of evidence for the information was assessed based on the source and type of study. RESULTS: Estimates of IDU prevalence were available for 130 countries. The number of IDU worldwide was estimated as approximately 13.2 million. Over ten million (78%) live in developing and transitional countries (Eastern Europe and Central Asia, 3.1 million; South and South-east Asia, 3.3 million; East-Asia and Pacific, 2.3 million). Estimates of HIV prevalence were available for 78 countries. HIV prevalence among IDU of over 20% was reported for at least one site in 25 countries and territories: Belarus, Estonia, Kazakhstan, Russia, Ukraine, Italy, Netherlands, Portugal, Serbia and Montenegro, Spain, Libya, India, Indonesia, Malaysia, Myanmar, Nepal, Thailand, Viet Nam, China, Argentina, Brazil, Uruguay, Puerto Rico, USA and Canada. CONCLUSIONS: These findings update previous assessments of the number of countries with IDU and HIV-infected IDU, and the previous quantitative global estimates of the prevalence of IDU. However, gaps remain in the information and the strength of the evidence often was weak.     

Vaccine immunogenicity in injecting drug users: a systematic review

Injection drug use is a prevalent global phenomenon; one not bound by a country's level of development or geographical location. Injection drug users (IDUs) are at high risk for a variety of parenterally acquired and transmitted infections. Licensed vaccines are available for some of these infectious diseases, such as tetanus, influenza, and hepatitis A and B viruses; however, there have been conflicting reports as to their immunogenicity in IDUs. We summarise the lessons learned from studies evaluating the immunogenicity of vaccination strategies in IDUs. A common theme across these diseases is that although there is a tendency towards decreased antibody responses after immunisation, there is no conclusive evidence linking these observations to a decrease in clinical protection from infection. There is a clear need for definitive studies of vaccination strategies in IDUs; however, a synthesis of the available published evidence suggests that immunisation does result in effective clinical protection from disease in this population. The inclusion of IDUs as a high-risk study population in future trials evaluating HIV and hepatitis C virus vaccines will help to assess the immunogenicity of candidate vaccines against parenteral exposure, and also to evaluate the efficacy of candidates as promising antigens become available.     

Geographical injecting locations among injecting drug users in Sydney, Australia

Aims. To document the geographical injection locations of IDU, and the factors and harms associated with injecting in public places. Design. Cross-sectional survey. Setting. Sydney, Australia. Participants. Two hundred injecting drug users. Findings. Nearly all subjects (96%) had injected in a public place, and 89% had done so in the preceding 6 months. Large proportions had injected in all locations studied, including cars (90%), public toilets (81%), the street (80%) and trains (55%). Injecting in public places also occurred frequently, with 53% of subjects having injected often in at least one public location during the preceding 6 months. Twenty-seven per cent of subjects had injected often in the street over the preceding 6 months, 22% had injected often in cars and 17% had injected often in public toilets. Frequent injectors in public places were more likely to be male, and to have overdosed in the preceding 6 months, injected significantly more drug classes in the preceding 6 months, injected in more bodily injecting sites in the preceding 6 months and had more current injection-related problems than other IDU. Conclusions. Injecting in public places was practised by the overwhelming majority of the sample, and a pattern of increased harm was associated with frequent public injecting. In attempting to quantify the harm associated with injecting, and to reduce such harm, the locations injections take place in are of major importance.     

Bloodborne viral infection in Irish injecting drug users

Aims. In Dublin, harm reduction strategies have greatly expanded since 1990. We sought to determine the prevalence of, and factors associated with, hepatitis C (HCV), hepatitis B (HBV) and HIV infections among injecting drug users (IDUs) against this background. Design. Cross-sectional survey. Setting. Addiction treatment clinic. Participants. Seven hundred and thirty-five IDU tested for antibody to HCV (anti-HCV) between September 1992 and September 1997. Measurements. Socio-demographic and drug use characteristics. Serology tests for anti-HCV, HBV surface antigen (HBsAg) and HIV. Findings. The vast majority (89%) commenced injecting since 1990. Prevalence of anti-HCV was 61.8% (453/733), of HBsAg was 1.0% (7/729) and of HIV was 1.2% (7/600). Logistic regression analyses indicated that longer history of injecting and increased daily drug expenditure were the only independent variables associated with significantly increased risk of HCV. The only characteristic associated with increased prevalence of HBsAg was a history of injecting prior to 1990 (3.8%, 3/80). HIV prevalence was significantly higher when aged over 24 years (3.7%, 6/162), when injecting commenced prior to 1990 (6.3%, 4/64) and when injecting over 5 years (6.5%, 4/62). Conclusions. HIV prevalence has sustained a low level in this population. Interventions which aim to halt transmission of HCV are necessary and will need to target IDU very early in their injecting careers and also those at risk of commencing to inject.     

Cross-national studies of AIDS among injecting drug users

HIV infection among injecting drug users has become a world-wide public health problem. This raises fundamental questions about the modifiability of drug-using behavior and of the influence of different national settings upon the modification of drug use behavior. Data from the World Health Organization Multi-site Study of HIV and Injecting Drug Use and studies of HIV among drug injectors in New York City (the US component of the WHO study) are used to address these questions. There is no clear relationship between HIV seroprevalence and current levels of risk behavior in the WHO cities, and the range in seroprevalence is much greater than the range in current risk behavior. Nonetheless, historical trend data enable us to discern at least two broad patterns in different cities. HIV epidemics appear to have been successfully prevented among IDUs in some cities, in that seroprevalence has remained low and stable over several years. These cities are characterized by community outreach programs and good access to sterile injection equipment. On the other hand, high-servoprevalence epidemics have also occurred in many different cities. Stabilization of seroprevalence has eventually also occurred in these cities, but this still includes moderate rates of new HIV infections. How to reverse high-seroprevalence situations remains one of the more difficult questions in HIV epidemiology. The epidemiology of HIV infection among injecting drug users also needs to include analyses of the impacts of decisions by political and public health leaders. A three-category scheme for classifying political decisions is offered: data-free decisions, data-based decisions, and data-proof decisions.     

Social intervention against AIDS among injecting drug users

Many drug injectors continue to engage in behaviors that lead them to become infected with HIV in spite of a wide variety of public health programs. In addition, many persons have begun to inject drugs in spite of knowing the risks of AIDS. The inadequacy of current efforts to prevent these behaviors suggests that additional forms of intervention should be attempted. We suggest that social interventions be tried to complement current programs (almost all of which have an individual focus). Evidence that social factors such as peer pressure and the social relations of race affect risk behavior is presented. Social interventions that are discussed include organizing drug injectors against AIDS in ways analogous to those in which gays organized against the epidemic, and finding ways to change large-scale social relationships that predispose people to inject drugs.     

Longitudinal sexual behavior changes in injecting drug users.

OBJECTIVE: To determine whether injection drug users (IDU) maintained sexual behavior risk reduction over an 18-month period that had been noted previously over a 4-month period. DESIGN: A repeated measures design was utilized with IDU assessed initially at study enrollment and again 18 months later. METHODS: Sexual behaviors of a group of 220 IDU (148 men and 72 women) were assessed by a structured interview at the start of an AIDS prevention project and again 18 months later. RESULTS: Having multiple sex partners during the 12 months before initial assessment was reported by 42.6% of the men and 35.7% of the women. Significantly fewer had multiple sex partners during the 10 months before follow-up assessment (men, 20.9%; women, 14.3%). Condom use for vaginal intercourse increased from a mean of 11.9% initially to 27.8% at follow-up for men. The increase in condom use was greater for those with multiple sex partners. Women did not report significant increases in condom use. Continued involvement in unsafe sexual behaviors was associated with exchanging sex for money or drugs, using drugs to help meet sexual needs, alcohol use and drug use. CONCLUSIONS: Risk reductions noted previously were maintained over 18 months for the majority of the sample. Drug-use treatment and interventions that closely examine the interplay between drug use and sexuality for individual IDU are recommended as strategies to further reduce the sexual risk of HIV transmission among IDU.