Injecting Drug Users Population Research Articles

The epidemic history of hepatitis C among injecting drug users in Flanders, Belgium

We employed recently developed statistical methods to explore the epidemic behaviour of hepatitis C subtype 1a and subtype 3a among injecting drug users (IDUs) in Flanders, Belgium, using new gene sequence data sampled among two geographically distinct populations of IDUs. First the extent of hepatitis C transmission across regions/countries was studied through calculation of association indices. It was shown that viral exchange had occurred between both populations in Flanders as well as across international borders. Furthermore, evidence was found suggestive of subtypes 1a and 3a predominantly circulating in subpopulations of Flemish IDUs, exhibiting different degrees of travelling/migration behaviour. Secondly, through coalescent-based analysis the viral epidemic history of the hepatitis C subtype 1a and 3a epidemics was inferred. Evidence was found for different dynamic forces driving both epidemics. Moreover, results suggested that the hepatitis C subtype 3a epidemic has reached a steady state, while the hepatitis C 1a epidemic has not, which therefore might become the predominant subtype among IDUs.

HIV transmission in Bangladesh: An analysis of IDU programme coverage

Background Sentinel Surveillance found HIV had increased to 7% among street-based injection drug users (IDUs) in Central Bangladesh in 2006–2007, indicating the urgent need to increase prevention. In 2004, size estimation of groups vulnerable to HIV was done by an expert committee under the National AIDS/STD Programme, making programme coverage estimates possible for the first time. Methods Appropriate multipliers were applied to size information to estimate a total of 20,000–40,000 IDUs throughout the country. Data from 2003 onwards from the major needle-exchange programmes (NEPs) and detoxification services were analysed to estimate programme coverage as the proportion of the total IDU population reached by interventions, and to assess the proportion of safe injections. Results An estimated 31–61% of the upper and lower national size estimates of IDUs, respectively, were in contact with any HIV prevention effort by 2006, with an increasing trend evident over the years. Of these, 24–49% were enrolled at NEPs, and 8–16% had been through detoxification. Although there was a marked improvement over the years, it appears NEPs only provided 160 days of safe injections for every IDU reached in 2006 in the North and Southeast, and 50 days in the South and Southwest, assuming IDU inject twice daily with new needles. If all IDUs reached by programmes in the North and Southeast injected every day, 44% of injections were covered by new needles, and 14% in the South and Southwest. Conclusion Within the context of an HIV epidemic among some IDU, and high levels of needle-sharing and risky sexual behaviour, the implications of the low level of programme coverage are alarming, and it is clear Bangladesh needs to take action to improve it in order to control the spread of HIV.

Seroprevalence of select bloodborne pathogens and associated risk behaviors among injection drug users in the Paso del Norte region of the United States – Mexico border

BackgroundThe region situated where the borders of Mexico, Texas and New Mexico meet is known as 'Paso del Norte'. The Paso del Norte Collaborative was formed to study the seroprevalence of select pathogens and associated risk behaviors among injection drug users (IDUs) in the region.MethodsRespondent-driven sampling (RDS) was used: 459 IDU participants included 204 from Mexico; 155 from Texas; and 100 from New Mexico. Each of the three sites used a standardized questionnaire that was verbally administered and testing was performed for select bloodborne infections.ResultsParticipants were mostly male (87.4%) and Hispanic/Latino (84.7%) whose median age was 38. In Mexico, Texas and New Mexico, respectively: hepatitis B virus (HBV) was seen in 88.3%, 48.6% and 59.6% of participants; hepatitis C virus (HCV) in 98.7%, 76.4% and 80.0%; human immunodeficiency virus (HIV) in 2.1%, 10.0% and 1.0%; and syphilis in 4.0%, 9.9% and 3.0%. Heroin was the drug injected most often. More IDUs in New Mexico were aware of and used needle exchange programs compared with Texas and Mexico.ConclusionThere was mixed success using RDS: it was more successfully applied after establishing good working relationships with IDU populations. Study findings included similarities and distinctions between the three sites that will be used to inform prevention interventions.

Barriers and missed opportunities to HIV testing among injection drug users in two Mexico–US border cities

Despite increasing HIV prevalence in cities along the Mexico--US border, HIV testing among high-risk populations remains low. We sought to identify barriers associated with HIV testing among injection drug users (IDUs) in Tijuana and Ciudad Juarez, the two largest Mexican border cities located across from San Diego, California and El Paso, Texas, respectively. In 2005, 222 IDUs in Tijuana and 205 IDUs in Ciudad Juarez were recruited by respondent-driven sampling and administered a questionnaire to collect socio-demographic, behavioural and HIV testing history data. Blood samples were provided for serological testing of HIV, hepatitis C virus (HCV) and syphilis. Only 38% and 30% of respondents in Tijuana and Ciudad Juarez, respectively, had ever had an HIV test. The factors independently associated with never having been tested for HIV differed between the two sites, except for lack of knowledge on HIV transmission, which was independently associated in both locales. Importantly, 65% of those who had never been tested for HIV in both cities experienced at least one missed opportunity for voluntary testing, including medical visits, drug treatment and spending time in jail. Among this high-risk IDU population we found HIV testing to be low, with voluntary testing in public and private settings utilised inadequately. These findings underscore the need to expand voluntary HIV education and testing and to integrate it into services and locales frequented by IDUs in these Mexico--US border cities.

Limited Uptake of Hepatitis C Treatment Among Injection Drug Users

We characterized hepatitis C virus (HCV) treatment knowledge, experience and barriers in a cohort of community-based injection drug users (IDUs) in Baltimore, MD. In 2005, a questionnaire on HCV treatment knowledge, experience and barriers was administered to HCV-infected IDUs. Self-reported treatment was confirmed from medical records. Of 597 participants, 71% were male, 95% African-American, 31% HIV co-infected and 94% were infected with HCV genotype 1; 70% were aware that treatment was available, but only 22% understood that HCV could be cured. Of 418 who had heard of treatment, 86 (21%) reported an evaluation by a provider that included a discussion of treatment of whom 30 refused treatment, 20 deferred and 36 reported initiating treatment (6% overall). The most common reasons for refusal were related to treatment-related perceptions and a low perceived need of treatment. Compared to those who had discussed treatment with their provider, those who had not were more likely to be injecting drugs, less likely to have health insurance, and less knowledgeable about treatment. Low HCV treatment effectiveness was observed in this IDU population. Comprehensive integrated care strategies that incorporate education, case-management and peer support are needed to improve care and treatment of HCV-infected IDUs.

HIV-1 incidence estimates using IgG-capture BED-enzyme immunoassay from surveillance sites of injection drug users in three cities of China

To detect recent infection in injection drug users (IDU) using the HIV-1 subtypes B, E, and D IgG-capture enzyme immunoassay (BED-CEIA) and estimate HIV-1 incidence in the IDU population in three cities of China. HIV-1-positive samples from IDU surveillance sentinel sites were collected for BED-CEIA, including 215 from city C (2001-2006), 433 from city D (2005), and 912 from city E (2000-2003). All 1560 samples were confirmed HIV positive with Western blot or alternative strategy. HIV-1 incidence was calculated with BED-CEIA statistics software. City C: Annualized HIV-1 incidence among IDU of surveillance sentinel sites was 0.57-0.93% from 2000 to 2001, and approximately 1.0% from 2004 to 2006. City D: In IDU surveillance sentinel sites in 2005, the HIV-1 incidence was estimated to be 9.6%, whereas the incidence in all drug users was 2.1%. City E: IDU sentinel surveillance indicated a slight decrease in HIV-1 incidence from 9.2% in 2000 to 7.9% in 2003. The HIV-1 incidence in IDU in city C was stable and relatively low. In contrast, there is a high HIV-1 incidence among IDU in cities D and E. The adjusted BED-CEIA estimated incidence rates indicate clearly that interventions must be strengthened continuously in IDU, especially in two Chinese cities.

Interaction of Cognitive Performance and Knowing Someone Who Has Died from AIDS on HIV Risk Behaviors

This study examined the association among knowledge of someone who has died from AIDS, cognitive functioning, and performance of protective health behaviors to reduce the risk of contracting HIV. Baseline data were analyzed from a sample of 229 injection drug users (IDUs) of heroin, a subset of the respondents from the Baltimore site of the International Neurobehavioral HIV Study. Multivariate logistic regression equations were fitted to predict risky injection drug use practices and sexual behavior based on cognitive performance scores and knowledge of someone who had died from AIDS. Among IDUs with lower cognitive reserves, knowing someone who had died from AIDS was associated with increased risk. This finding indicates that more intensive efforts may be required to reduce the risky behaviors among those IDUs with lower cognitive scores in higher risk social groups. Among IDUs with greater cognitive reserves, knowing someone who had died from AIDS was associated with decreased risk. This suggests that cognitive performance can provide protection to individuals in riskier social environments. These findings can aid in targeting HIV prevention efforts toward higher risk individuals within the IDU population.

Improving Survival among HIV-Infected Injection Drug Users: How Should We Define Success?

More than a decade after highly active antiretroviral therapy (HAART) became available, extensive literature has documented the dramatic impact of HAART in reducing progression to AIDS and in improving survival among HIV-infected persons. However, a lingering issue regarding the effectiveness of HAART has been whether the survival benefit is fully extended to all risk groups—in particular, to injection drug users (IDUs). In this issue of Clinical Infectious Diseases, Muga et al. [1] provide evidence that the duration of survival among HIV-infected IDUs in Barcelona, Spain, has improved during the HAART era. In fact, among IDUs who were admitted to a drug treatment program since 1997, mortality rates for persons with and persons without HIV infection were roughly equivalent. The study reinforces the fact that HIV treatments are indeed effective among IDUs, and it highlights the discrepant results observed in comparisons of the effectiveness of HAART among IDU and non-IDU populations.

Respondent-driven sampling to assess characteristics and estimate the number of injection drug users in Bangkok, Thailand

Background Since early in Thailand's HIV epidemic, HIV seroprevalence among injection drug users (IDUs) in Bangkok has been around 40%. As Thailand moves to strengthen HIV prevention and care programs for Bangkok IDUs, information on current patterns of drug use and an estimate of the size and composition of the IDU population are essential. Methods We used respondent-driven sampling (RDS) to recruit Bangkok IDUs who reported injecting in the past 6 months. IDUs were interviewed with a standardized questionnaire. Logistic regression was used to compare IDUs currently or previously in treatment with those never treated. RDS software was used to estimate IDU population size based on the proportion in treatment. Results Of 963 IDUs recruited, 828 (86%) were men. One hundred and twelve IDUs (12%) reported never having attended a drug treatment clinic. Young age, unemployment, injection of single drug, and never having been HIV tested were significantly associated with never-in-treatment status. The estimated proportion of IDUs in treatment was 0.55 (95% confidence interval, 0.52–0.60). Dividing the known number of IDUs in treatment (1981 IDUs attending Bangkok drug treatment clinics during October 2003 through March 2004) by this proportion, we estimated the number of IDUs in Bangkok during the period of RDS to be 3595 (95% confidence interval, 3296–3810). Conclusions Data obtained through RDS, although subject to limitations from co-existing government drug control policies and possible under-recruitment of out-of-treatment IDUs, will be useful in informing policy, strengthening prevention approaches, and improving methods to monitor the HIV epidemic among Thai IDUs.

Hospital- Versus Community–Based Syringe Exchange: A Randomized Controlled Trial

This study examined the effect of syringe exchange program setting on the injection practices, health status, and health service utilization patterns of injection drug users (IDUs) recruited from a public urban hospital. One hundred sixty-six participants were randomized to either community- or hospital-based syringe exchange services. Poisson regression models were used to compare service utilization between groups. In both conditions, risky drug use practices decreased, and physical health functioning improved over time. Hospital-based syringe exchange program (SEP) attendees had 83% more inpatient admissions (p < .0001) and 22% more ambulatory care visits (p < .0001) than those assigned to the community-based SEP condition. Syringe exchange services that are integrated into public hospital settings may serve as a valuable strategy to engage hard to reach IDU populations in behavioral interventions designed to reduce HIV risk transmission behaviors and increase access to, or engagement in, the use of secondary and tertiary preventive medical care.

HIV outbreak among injecting drug users in the Helsinki region: social and geographical pockets

Incidence of newly diagnosed HIV infections among injecting drug users (IDUs) in Helsinki rose from 0 per 100,000 inhabitants in 1997 to 2.9 in 1998 and to 11.1 in 1999. Thereafter incidence declined to 2.1 in 2003. Data were collected from interviews with HIV-positive IDUs who attended the University Hospital in Helsinki from 1998 until 2003. We studied the sociodemographic profile and spatial distribution of IDUs who were diagnosed in the beginning of the outbreak and those diagnosed later. The indicator for the spatial differentiation within the metropolitan area is % employed males aged 25-64. The outbreak occurred among a marginalized population of IDUs characterized by a long history of injecting drug use (10.7 years), mean age 32 years, homelessness (66.3%), history of imprisonment (74.7%) and psychiatric hospital care (40.6%). Compared with 98 early cases diagnosed during the first 2 years until 2000, 47 recent cases diagnosed after 2001 were 4 years older, and as marginalized. Except for the city centre, both early and recent cases had been living or using drugs in the same deprived neighbourhoods with the highest unemployment rates. Up to 40% of cases in the two big geographical clusters did not have contact with the city centre, where the needle exchange services were available. The Finnish HIV outbreak is restricted socially to a very marginalized IDU population, and spatially to local pockets of poverty. In low prevalence countries, prevention programs should be targeted early at high-risk areas and populations.

Obstacles in provision of anti-retroviral treatment to drug users in Central and Eastern Europe and Central Asia: A regional overview

Central and Eastern Europe and Central Asia is currently the region with the fastest growing HIV epidemic, mainly among injecting drug users (IDUs). This study explored access to anti-retroviral (ARV) treatment among IDUs and evaluated obstacles to gaining access to treatment. Semi-structured questionnaires were collected from 21 countries from agencies which deliver services to IDUs ( N = 55), including AIDS centres, drug treatment institutions and Non-governmental Organisations. Results showed that there was poor access to ARV treatment for IDUs. The major obstacles reported were: limited range of institutions for the provision of ARVs, lack of treatment due to high cost of ARVs, lack of clear policies and regulations in providing treatment for IDUs, lack of infrastructure and trained staff to provide treatment, and in some countries, absence of mechanisms such as methadone substitution programmes to support IDUs receiving ARV. There is a need for human and capital resources to bring ARV treatment to IDU populations in the region. Regulations and treatment protocols need to be developed to address this particular group of HIV positive clients to insure better adherence and monitoring of clients with HCV co-infection. Integration of provision of ARV treatment with drug treatment and low-threshold services is advised. Substitution therapy should be advocated for in countries where it is not available or where access is limited. Finally, more research needs to be conducted to understand what will work best in each country, region or setting.

HIV incidence estimates are key to understanding the changing HIV epidemic in South Africa.

The study by Rehle et al. in this issue of the SAMJ makes an important contribution to understanding the dynamics of the HIV epidemic in South Africa. While the high prevalence of HIV confirms that HIV continues to be hyper-endemic in South Africa their estimates of HIV incidence highlight the extraordinarily high levels of ongoing HIV transmission in South Africa. A deep concern is the unrelenting epidemic in youth with particularly high incidence rates in young women. In their study Rehle et al. utilise the IgG-Capture BED enzyme immunoassay (BED-CEIA) to detect recent HIV seroconversion for the purpose of calculating HIV incidence rates. This technology has been applied to several cross-sectional surveys to estimate incidence including an injecting drug user population from Bangkok. Since this method is still being validated for different conditions such as viral clade the absolute estimates of incidence should be regarded as tentative but the subgroup comparisons in the study remain highly informative. In order to understand the dynamics of HIV infection and epidemic trends more data are needed on the current burden of disease the rate of new HIV infections and mortality rates. At a time when prevalence trends in pregnant South African women suggest that incident cases of HIV infection are being masked by rising mortality it is of particular importance to monitor changes in the number of new infections in South Africa. (excerpt)

Hepatitis infection rates in addicted migrants

The article examines infection with viral hepatitis A, B, and C and socio-ethnic factors in a population of injection drug users seeking treatment. The study was conducted between 2001 and 2003 in a rural German hospital; selected sociodemographic and drug-related data as well as a serology for hepatitis A, B and C were obtained from 1499 patients. Statistical analyses were performed by univariate analysis of variance and post-hoc Scheffe tests or with the c2-test and Bonferroni-adjustment. Ethnic minority patients manifested a more severe course of addiction and showed a higher frequency of infection with hepatitis A, B, and C. Low-threshold culture sensitive drug user treatment programs should be implemented and evaluated.

Injection Drug Use, Multiple Hepatitis Virus Infections, and Migration: A German Study

This article examines infection with viral hepatitis A, B, and C and socioethnic factors in a population of injection drug users seeking treatment. The study was conducted between 2001 and 2003 in a rural German hospital; selected sociodemographic and drug-related data as well as a serology for hepatitis A, B, and C were obtained from 1499 patients. Statistical analyses were performed by univariate analysis of variance and post hoc Scheffé tests or with the χ2 test and Bonferroni adjustment. Ethnic minority patients manifested a more severe course of addiction and showed a higher frequency of infection with hepatitis A, B, and C. Low-threshold culture-sensitive drug user treatment programs should be implemented and evaluated. The study's limitations are noted.

Developing an HIV behavioral surveillance system for injecting drug users: the National HIV Behavioral Surveillance System.

While disease surveillance for HIV/AIDS is now widely conducted in the United States, effective HIV prevention programs rely primarily on changing behavior; therefore, behavioral data are needed to inform these programs. To achieve the goal of reducing HIV infections in the U.S., the Centers for Disease Control and Prevention, in cooperation with state and local health departments, implemented the National HIV Behavioral Surveillance System (NHBS) for injecting drug users (IDUs) in 25 selected metropolitan statistical areas (MSAs) throughout the United States in 2005. The surveillance system used respondent-driven sampling (RDS), a modified chain-referral method, to recruit IDUs for a survey measuring HIV-associated drug use and sexual risk behavior. RDS can produce population estimates for specific risk behaviors and demographic characteristics. Formative assessment activities-primarily the collection of qualitative data-provided information to better understand the IDU population and implement the surveillance activities in each city. This is the first behavioral surveillance system of its kind in the U.S. that will provide local and national data on risk for HIV and other blood-borne and sexually transmitted infections among IDUs for monitoring changes in the epidemic and prevention programs.

Blood-borne Viruses and Risk Behaviours among Injecting Drug Users Recruited from Needle and Syringe Programs in Victoria's Eastern Metropolitan Region

Little has been reported about the risk behaviour and service accessibility of injecting drug users (IDU) living beyond the inner suburbs of Melbourne. This study describes IDUs in the Department of Human Services' Eastern metropolitan region (EMR), including the prevalence of blood-borne viruses and risk behaviours. Fifty-two IDUs were recruited directly from EMR Needle and Syringe Programs (NSP) and through snowball recruitment. IDUs completed a questionnaire and provided a finger-prick blood specimen that was tested for the presence of HIV and Hepatitis C virus (HCV) antibodies. No participants were HIV antibody positive; 29 (56%) were HCV antibody positive. HCV seropositivity was associated with having a tattoo in univariate analysis. The prevalence of HCV in surveyed EMR IDUs was similar to that of Victorian IDUs surveyed in the National Needle and Syringe Program Survey; however, the EMR sample exhibited significantly greater levels of risk behaviour, including the sharing of needles and other injecting equipment, and unsafe sex. Similarly, EMR IDUs from outer and rural suburbs reported greater levels of risk behaviours and lower levels of HCV infection than those from the inner EMR. This study shows that with high levels of risk behaviour and relatively low access to NSP services, Victoria's EMR IDU population is vulnerable to future blood-borne virus outbreaks.

Effectiveness and cost-effectiveness of strategies to expand antiretroviral therapy in St. Petersburg, Russia

To assess the effectiveness and cost-effectiveness of treating HIV-infected injection drug users (IDUs) and non-IDUs in Russia with highly active antiretroviral therapy HAART. A dynamic HIV epidemic model was developed for a population of IDUs and non-IDUs. The location for the study was St. Petersburg, Russia. The adult population aged 15 to 49 years was subdivided on the basis of injection drug use and HIV status. HIV treatment targeted to IDUs and non-IDUs, and untargeted treatment interventions were considered. Health care costs and quality-adjusted life years (QALYs) experienced in the population were measured, and HIV prevalence, HIV infections averted, and incremental cost-effectiveness ratios of different HAART strategies were calculated. With no incremental HAART programs, HIV prevalence reached 64% among IDUs and 1.7% among non-IDUs after 20 years. If treatment were targeted to IDUs, over 40 000 infections would be prevented (75% among non-IDUs), adding 650 000 QALYs at a cost of USD 1501 per QALY gained. If treatment were targeted to non-IDUs, fewer than 10 000 infections would be prevented, adding 400 000 QALYs at a cost of USD 2572 per QALY gained. Untargeted strategies prevented the most infections, adding 950 000 QALYs at a cost of USD 1827 per QALY gained. Our results were sensitive to HIV transmission parameters. Expanded use of antiretroviral therapy in St. Petersburg, Russia would generate enormous population-wide health benefits and be economically efficient. Exclusively treating non-IDUs provided the least health benefit, and was the least economically efficient. Our findings highlight the urgency of initiating HAART for both IDUs and non-IDUs in Russia.

HIV Epidemiology in the Northwestern Federal District of Russia: Dominance of HIV Type 1 Subtype A

A rapidly advancing epidemic of HIV-1 infection has been documented among injecting drug users (IDUs) in Russia. The Northwestern Federal District was the first of the seven Russian Federal Districts involved in a drug-related HIV epidemic through an outbreak in Kaliningrad in 1996. The Northwestern Federal District has a high HIV prevalence rate having reached 252 per 100,000 by the end of 2003, exceeding the Russian average (180) by 1.4 times. The epidemic peaked in 2001. Since then the annual number of new cases has decreased, probably reflecting saturation among at least some IDU populations. However, at the same time, the heterosexual spread of HIV has become more prominent. To study the genetic epidemiology of HIV-1, samples were collected from 150 individuals covering a wide geographical area and different transmission groups in the Northwestern Federal District. Phylogenetic analysis revealed that an Eastern European subtype A HIV-1 strain similar to those reported earlier among IDUs in other regions of Russia accounted for 80% of HIV-1 infections and was the predominant subtype in six out of seven administrative territories studied both among IDUs and heterosexually infected persons. As an exception to the dominant role of the Eastern European subtype A strain, the CRF03-AB strain was found to be dominant in the city of Cherepovets located in the north central European Russian territory of Vologda Oblast. This is the first report of the CRF03-AB strain causing an outbreak outside the Kaliningrad region.

Methods to Recruit Hard-to-Reach Groups: Comparing Two Chain Referral Sampling Methods of Recruiting Injecting Drug Users Across Nine Studies in Russia and Estonia

Evidence suggests rapid diffusion of injecting drug use and associated outbreaks of HIV among injecting drug users (IDUs) in the Russian Federation and Eastern Europe. There remains a need for research among non-treatment and community-recruited samples of IDUs to better estimate the dynamics of HIV transmission and to improve treatment and health services access. We compare two sampling methodologies “respondent-driven sampling” (RDS) and chain referral sampling using “indigenous field workers” (IFS) to investigate the relative effectiveness of RDS to reach more marginal and hard-to-reach groups and perhaps to include those with the riskiest behaviour around HIV transmission. We evaluate the relative efficiency of RDS to recruit a lower cost sample in comparison to IFS. We also provide a theoretical comparison of the two approaches. We draw upon nine community-recruited surveys of IDUs undertaken in the Russian Federation and Estonia between 2001 and 2005 that used either IFS or RDS. Sampling effects on the demographic composition and injecting risk behaviours of the samples generated are compared using multivariate analysis. Our findings suggest that RDS does not appear to recruit more marginalised sections of the IDU community nor those engaging in riskier injecting behaviours in comparison with IFS. RDS appears to have practical advantages over IFS in the implementation of fieldwork in terms of greater recruitment efficiency and safety of field workers, but at a greater cost. Further research is needed to assess how the practicalities of implementing RDS in the field compromises the requirements mandated by the theoretical guidelines of RDS for adjusting the sample estimates to obtain estimates of the wider IDU population.