High HIV and hepatitis C prevalence amongst injecting drug users in Mauritius: findings from a population size estimation and respondent driven sampling survey

Background

Mauritius, an Indian Ocean Island nation of approximately 1,000,000 people, has a large number of injecting drug users (IDUs), many of whom are infected with HIV and HCV. Mauritius has been expanding harm reduction and HIV services based in the belief that HIV prevalence amongst IDUs is somewhere between 30 and 60% and the IDU population size is around 20,000. In 2009, the government of Mauritius conducted a survey to estimate the infection prevalence and risk factors and to estimate the population size of IDUs in order to more effectively expand programmes.

Methods

Men and women aged >15 years living in Mauritius and injecting illicit drugs in the past three months were recruited using respondent driven sampling (RDS). Consenting participants were interviewed about HIV-risk behaviours and tested for HIV, syphilis, HCV and HBV. Six multipliers were collected from service data and by the ‘unique identifier’ method in conjunction with the RDS survey. Proportions were calculated using the RDS analysis tool.

Results

511 IDUs enrolled in the survey; 61.2% reported injecting 2-3 times/day and 29.3% reported past month injection with a previously used needle. Amongst the 60% of IDUs who reported having sexual intercourse in the past three months, 39.5% did so with ≥2 partners. Almost all IDUs (98.1%) reported inconsistent condom use in the past 12 months. HIV prevalence was 47.4%, HCV 97.3%, HBV 9.0%, and syphilis 2.7%; 99.7% of those infected with HIV were also infected with HCV. Our population size estimates put the number of IDUs in Mauritius at around 9500, lower than previous estimates.

Conclusions

We observed high rates of HCV and HIV infection amongst IDUs in Mauritius. The scale up of targeted HCV and HIV prevention, care and treatment services for IDUs should be a high priority.     

HIV risk exposure of injecting drug users in Sydney

One thousand two hundred and forty-five Sydney injecting drug users (IDUs) were interviewed by questionnaire in 1989 to determine demographic and behavioural characteristics. One-sixth (16.7%) were considered to be at low risk of HIV from either needle sharing or sexual transmission as they had either never shared injecting equipment, or had not shared for years, or cleaned their injecting equipment effectively on 100% of the occasions when they did share; and were either celibate or monogamous or, if they had multiple partners, had not had unsafe sex in the previous 6 months. Over half (50.7%) had either unsafe injecting or sexual behaviour with the remaining third (32.6%) engaging in both unsafe injecting and sexual practises. Women were more at risk from sharing injection equipment than men but men were more at risk from sexual transmission than women. Increasing age was associated with greater likelihood of safer sex but age had no effect on injecting practises. There was no relationship between unsafe injecting and sexual practises. Amphetamine use was associated with low risk injecting practises while heroin use was associated with low risk sexual transmission. These findings indicate appreciable residual risk behaviour sufficient to allow for at least a slow diffusion of HIV among injecting drug users.     

Risk of Hepatitis C virus re-infection following spontaneous viral clearance in injecting drug users: a systematic review

Background

In order to develop new ways to prevent Hepatitis C virus (HCV) transmission amongst injecting drug users (IDUs), it is necessary to fully understand the dynamics of this disease. We reviewed the evidence on three key areas of HCV transmission in this population: the rate of acute HCV infection amongst IDUs who have spontaneously resolved a previous infection, the rate of chronic HCV infection amongst IDUs who have spontaneously resolved a previous infection, and the ability of IDUs to be re-infected with either the same or a different HCV genotype.

Methods

A literature search of PUBMED (January 1950 to January 2009), EMBASE (January 1980 to January 2009) and PsycINFO (January 1967 to January 2009) for English language, primary research papers was undertaken to identify longitudinal studies examining HCV re-infection following spontaneous viral clearance amongst IDUs.

Results

The systematic review identified three studies that satisfied the inclusion and exclusion criteria. Regarding the risk of acute HCV infection amongst IDUs, the findings from the three studies were conflicting and thus provided no compelling evidence in support of an increased or decreased risk of acute infection amongst IDUs who have spontaneously resolved compared to those previously uninfected. Limited evidence was found from two studies to support a reduced risk of subsequent chronic HCV infection in those who have previously spontaneously resolved an infection. Further, two studies found IDUs who spontaneously resolved an infection can be re-infected (with comparable proportions) with either the same or a different HCV genotype.

Conclusion

The limited, and sometimes contradictory, evidence published in the worldwide literature highlights the need for more longitudinal studies of IDUs to fully understand the dynamics of the disease in this population.     

The prevalence and characteristics of injecting drug users in Australia

The prevalence of injecting drug use has increased significantly in Australia in recent years. Using the nationally representative 1998 National Drug Strategy Household Survey we estimate the size of the lifetime prevalence injecting drug use population at 302710 people, compared to 67474 in 1988. Those who have injected drugs in the previous year are estimated at 108750 people in 1998. Amphetamines have displaced heroin as the most popular drug to inject among the general population. Those who have ever injected are more likely to be male, young, unemployed and to possess fewer educational qualifications. A variety of factors are discussed which may account for increases in injecting drug use. \[McAllister I, Makkai T. The prevalence and characteristics of drug users in Australia. Drug Alcohol Rev 2001;20:29-36]     

Optimal provision of needle and syringe programmes for injecting drug users: A systematic review

The introduction of needle and syringe programmes (NSPs) during the 1980s is credited with averting an HIV epidemic in the United Kingdom and Australia, but hepatitis C (HCV) incidence continues to rise among injecting drug users (IDUs). NSPs incorporating additional harm reduction strategies have been highlighted as an approach that may impact on HCV incidence. This systematic review sought to determine which approaches to the organisation and delivery of NSPs are effective. Fifteen databases were searched for studies published since 1990. Two reviewers screened all titles and abstracts, and data extraction and quality assessment of individual studies were undertaken independently by one reviewer and checked for accuracy by a second. Sixteen studies met the criteria for inclusion. Based on 11 studies there was no evidence of an impact of different NSP settings or syringe dispensation policies on drug injecting behaviours, but mobile van sites and vending machines appeared to attract younger IDUs and IDUs with higher risk profiles. Two studies of interventions aimed at encouraging IDUs to enter drug treatment reported limited effects, but one study found that the combination of methadone treatment and full participation in NSPs was associated with a lower incidence of HIV and HCV. In addition, one study indicated that hospital-based programmes may improve access to health care services among IDUs. Currently, it is difficult to draw conclusions on ‘what works best’ within the range of harm reduction services available to IDUs. Further studies are required which have a stated aim of evaluating how different approaches to the organisation and delivery NSPs impact on effectiveness.     

Do needle syringe programs reduce HIV infection among injecting drug users: a comprehensive review of the international evidence

This first international review of the evidence that needle syringe programs reduce HIV infection among injecting drug users found that conservative interpretation of the published data fulfills six of the nine Bradford Hill criteria (strength of association, replication of findings, temporal sequence, biological plausibility, coherence of evidence, and reasoning by analogy) and all six additional criteria (cost-effectiveness, absence of negative consequences, feasibility of implementation, expansion and coverage, unanticipated benefits, and application to special populations). The Bradford Hill criteria are often used to evaluate public health interventions. The principal finding of this review was that there is compelling evidence of effectiveness, safety, and cost-effectiveness, consistent with seven previous reviews conducted by or on behalf of U.S. government agencies. Authorities in countries affected or threatened by HIV infection among injecting drug users should carefully consider this convincing evidence now available for needle syringe programs with a view to establishing or expanding needle syringe programs to scale.     

Prevalence of HIV, hepatitis B and hepatitis C and associated risk behaviours amongst injecting drug users in three Afghan cities

Background

HIV amongst injecting drug users (IDUs) has been described in Kabul but little data exists for other Afghan cities. We assessed HIV, hepatitis B virus (HBV), and C virus (HCV) prevalence and associated risk behaviours amongst IDUs in Hirat, Jalalabad, and Mazar-i-Sharif, Afghanistan.

Methods

Consented participants reporting injecting drugs within the previous 6 months completed interviewer-administered questionnaires and testing for HIV, hepatitis C antibody (HCV Ab), and hepatitis B surface antigen (HBsAg). Logistic regression was used to determine characteristics associated with each infection.

Results

Of 623 participants, most (98.7%) were male. Prevalence of HIV, HCV, and HBV was 1.8% (95% CI: 0.88-3.2), 36.0% (95% CI: 33-41), and 5.8% (95% CI: 3.9-7.6), respectively. All HIV cases and highest HCV prevalence were detected in Hirat; HBV prevalence was highest in Jalalabad. Amongst male IDUs, 62.9% had been imprisoned, of whom 17.2% (n = 66) injected in prison. High risk behaviours were common; 30.2% reported needle sharing in the last 6 months, 23.1% reported sex with another male, and 50.4% reported paying females for sex. Behaviours varied significantly by site; generally, Hirat participants reported fewer sexual risk behaviours. Sex with other males was negatively associated with both HBV and HCV in multivariate logistic regression analysis; no injecting behaviours were associated with both HBV and HCV.

Conclusions

Whilst HIV prevalence is low, HCV prevalence and high risk behaviours were common in these populations. Regional variations should be considered in programming to prevent transmission of HIV and viral hepatitis amongst IDUs in Afghanistan.     

AIDS and injecting drug use: very risky behaviour in a Perth sample of injecting drug users

This research was carried out in 1990 to examine high-risk injecting and sexual behaviour in a sample of injecting drug users (IDUs) in Perth. The study was a cross-sectional survey with a convenience sample drawn from drug treatment (54%) and non-treatment (46%) populations. In the sample of 150 IDUs, there were 11 very risky drug behaviour (VRDB) and 63 very risky sex behaviour (VRSB) respondents. Four respondents fell into both categories. Independent comparisons were made between each risk group and the rest of the sample. The VRDB respondents were heterosexual men, most of whom were in long-term monogamous relationships, with heavier levels of drug use than the rest of the sample. The VRSB respondents were largely single and mainly heterosexual, with more sexual partners than the rest of the sample. It was concluded that there was little evidence that very risky behaviour was related to a general risk-taking dimension, to inadequate knowledge about AIDS or to a low assessment of personal vulnerability to AIDS. However, situational influences in association with heavy drug use appeared to be a major component of high-risk injecting behaviour, while high-risk sexual behaviour appeared more to be a reflection of community norms about heterosexual sexual behaviour. The study should be replicated with larger samples, particularly as the VRDB group was so small, but if the findings are reproduced in other studies, it suggests that serious attention should be paid to the promotion of safer sex among injecting drug users.     

Effectiveness of community-based outreach in preventing HIV/AIDS among injecting drug users

This paper focuses on the evidence for the effectiveness of community-based outreach intervention as one component of a comprehensive HIV prevention model for preventing HIV infection in injecting drug user (IDU) populations. Three empirical questions guided the review of the evidence. This article includes primarily published literature on community-based outreach derived mostly from developing countries but also unpublished literature. Wherever possible, evidence from multi-country, multi-site studies or meta-analytical studies is included. More than 40 published studies reveal that injecting drug users (IDUs), who are reached by community-based outreach and provided with access to risk reduction services, report reducing HIV risk behaviours. The strength of the evidence was assessed using Hill's criteria, which permit a review of multiple studies with different designs. Using the criteria, it is possible to infer causation about the evidence of effectiveness of the intervention. The evidence for the effectiveness of a community-based outreach strategy is strong. Despite evidence from 20 years of evaluation studies of the effectiveness of community-based outreach, a huge gap exists in most countries between the number of IDUs who want or could benefit from outreach services and the number of IDUs who actually receive them. Findings from evaluation studies on the effectiveness of community-based outreach must be made accessible, disseminated globally and provided to policy- and decision-makers to persuade them to take action and implement scaled-up prevention programmes. This requires ongoing advocacy and constant strengthening of the evidence base. Plans are needed to link evidence-based findings with technical assistance as well as training to enhance the capacity of regions and countries to introduce, scale up and sustain HIV prevention outreach to IDUs as part of a comprehensive HIV prevention strategy.     

Structure and measurement of dimensions of risk for HIV transmission in injecting drug users

Dimensions of HIV infection risks were investigated in 1,245 injecting drug users (IDUs) in Sydney, Australia. Factor analysis of the degree of risk of the 33 items of risk behaviours revealed ten dimensions, which covered the domains of oral sex, withdrawal before ejaculation, protected intercourse, unprotected vaginal intercourse, saliva, blood products, manual sex, needles and syringes, unprotected anal sex, and social transmission. The perceived riskiness of particular activities closely approximated the objectively assessed risk of particular practices. Women assessed the risks of classes of activities (with the exception of oral sex) as being higher than did men. IDUs appear to have readily interpretable and consistent perceptions of HIV transmission risks, and these dimensions have utility for measuring perception and knowledge of HIV transmission risks.     

Towards a public health response for preventing the spread of HIV amongst injecting drug users within Nepal and the development of a treatment,rehabilitation and prevention programme in Pokhara

Within Nepal there remains an urgent need to develop strategies and policies aimed at reducing the spread of HIV infection amongst injecting drug users. Programmes currently operating within the country need to be evaluated and these programmes need to be expanded and strengthened and encouraged to work together in a more cohesive way. A programme for drug users in Pokhara, Nepal which was initiated in 1994 is attempting to provide an integrated and co-ordinated approach, and to give a comprehensive range of services to Nepali people which includes education, prevention, treatment, support, care and rehabilitation in a way which is both culturally appropriate and sensitive to the local scene.     

High dead-space syringes and the risk of HIV and HCV infection among injecting drug users

This study examines the association between using and sharing high dead-space syringes (HDSSs)—which retain over 1000 times more blood after rinsing than low dead-space syringes (LDSSs)—and prevalent HIV and hepatitis C virus (HCV) infections among injecting drug users (IDUs). A sample of 851 out-of-treatment IDUs was recruited in Raleigh–Durham, North Carolina, between 2003 and 2005. Participants were tested for HIV and HCV antibodies. Demographic, drug use, and injection practice data were collected via interviews. Data were analyzed using multiple logistic regression analysis. Participants had a mean age of 40 years and 74% are male, 63% are African American, 29% are non-Hispanic white, and 8% are of other race/ethnicity. Overall, 42% of participants had ever used an HDSS and 12% had shared one. HIV prevalence was 5% among IDUs who had never used an HDSS compared with 16% among IDUs who had shared one. The HIV model used a propensity score approach to adjust for differences between IDUs who had used an HDSS and those who had never used one. The HCV models included all potential confounders as covariates. A history of sharing HDSSs was associated with prevalent HIV (odds ratio = 2.50; 95% confidence interval = 1.01, 6.15). Use and sharing of HDSSs were also associated with increased odds of HCV infection. Prospective studies are needed to determine if sharing HDSSs is associated with increased HIV and HCV incidence among IDUs.