Current Injectors Research Articles

Heroin Sniffing as Self-Regulation among Injecting and Non-Injecting Heroin Users

This paper examines sniffing as a mode of administration among three subgroups who sniff heroin: those who had never injected, those who were also injecting, and those who had ceased injection. Modified life-history interviews were conducted in 1994 with 26 people currently sniffing but not Injecting, recruited in street-based settings in conjunction with an ongoing study of risk behavior and seroprevalence among drug injectors. These were supplemented by survey interviews and brief open-ended interviews with 23 people who combined heroin injecting with heroin sniffing, recruited from a parallel component of the ongoing study, based at a hospital detoxification ward. Not merely a brief precursor to heroin injecting, heroin sniffing can continue for long periods, and persist during and after periods of injection. Each subgroup uses heroin sniffing to regulate different perceived risks: heroin tolerance and financial expenditure (among those who have never injected), situational risks (among current injectors), and personal crises (among former injectors). These findings suggest the importance of personal factors over syringe availability or fear of HIV in use of modes of heroin administration.

Estimation of injecting drug users in the City of Edinburgh, Scotland, and number infected with human immunodeficiency virus.

To estimate (1) the number of current and former injecting drug users (IDU) infected with human immunodeficiency virus (HIV) alive in Edinburgh, and (2) the total number of current injectors in the city. The number of infected IDU was estimated using a local register of HIV infections with correction for incompleteness of the register. The number of injectors was estimated by two independent methods, one based on the HIV register, the other by log-linear modelling of four lists of IDU interviewed in a city-wide survey, and/or attending drug treatment agencies and family doctors because of drug use. Estimates for the period 1992-1994 of number of IDU infected with HIV, total number of IDU, and prevalence of injecting. The HIV register indicated that 371 infected drug users who had ever injected were alive and resident in Edinburgh. In all, 95% of infected survey respondents appeared in the register, leading to a corrected estimate of 472 infected ever injectors. From this the number of IDU currently injecting (i.e. in the previous 6 months) was estimated to be 1770 (95% CI: 1340-2240), and the prevalence of injecting as 8.0 (95% CI: 4.8-10.8) per 1000 Edinburgh residents aged 15-59 years. Log-linear modelling gave an estimate of 2070 (95% CI: 1360-2800) current injectors. The number of HIV-infected IDU in Edinburgh was estimated to be twice that in the larger nearby city of Glasgow, where a higher proportion of young adults currently injected drugs. Knowledge of the high prevalence of HIV in Edinburgh IDU (19.3%), the prescribing of oral substitutes, and counselling by doctors and drug workers are perceived reasons for the reduction in the prevalence of injecting which has occurred in Edinburgh in recent years. Such measures need to be continued to encourage further reduction of injecting.

High rates of drug use, but low rates of HIV risk behaviours among injecting drug users during incarceration in Dutch prisons.

To determine levels of injecting drug use and sexual risk behaviours in injecting drug users during and immediately following imprisonment in The Netherlands. Cross-sectional survey of drug injectors attending methadone clinics, a sexually transmitted disease clinic and a central research site in Amsterdam. The mean age of the 188 participants was 35 years, 78% were male and 34% had HIV antibodies. Self-reported drug use and sexual behaviours during the last period of imprisonment in Dutch prisons within the previous 3 years and injecting drug use in the week following release from prison. A period of imprisonment in the preceding 3 years was reported by 188 (41%) of 463 interviewed drug injectors. The mean duration of last imprisonment was 3.6 months. Any use of cannabis, heroin or cocaine during imprisonment was reported by 55%, 37% and 20%, respectively. Five injectors (3%) admitted to having injected in prison, but no sharing of needles and syringes was reported. Vaginal or anal sex was reported by two (1%) of the men and none of the women. Relapse to drug injecting during the week following release from prison was reported by 78/186 (42%) participants, in most cases (34%) at the very first day of release. Drug use behaviours during imprisonment were similar for those who were designated current injectors at the time of imprisonment and those who were not, but injecting in the first week following release from prison was far higher among 'current' injectors (63%) than among those who were not (11%). Contrary to findings from other countries, low levels of HIV risk behaviours occur among imprisoned drug injectors in The Netherlands. Intra-prison HIV preventive measures should be considered taking into account the nationally, regionally or locally varying conditions within the existing prisons.

Self-reported antiretroviral therapy in injection drug users.

The US Public Health Service and the International AIDS Society-USA recently published recommendations for antiretroviral therapy (ART) for persons infected with human immunodeficiency virus (HIV); however, anecdotal evidence suggests that HIV-infected injection drug users (IDUs) may not be receiving optimal care as defined by the recommendations. To assess ART use in HIV-infected IDUs. A cross-sectional survey of self-reported ART use between July 1996 and June 1997 in IDUs. A community-based clinic affiliated with Johns Hopkins University, Baltimore, Md. A total of 404 HIV-infected IDUs with CD4+ cell counts less than 0.50 x 10(9)/L recruited into a longitudinal study in 1988 and 1989. Self-reported ART use was assessed: no current therapy, monotherapy, or combination therapy with or without a protease inhibitor. One half (199/404 [49%]) of patients reported no recent ART. A total of 14% (58/404) had monotherapy, 23% (90/404) were receiving combination therapy without a protease inhibitor, and 14% (57/404) had triple-combination therapy with a protease inhibitor. A multivariate analysis of factors associated with ART showed that care continuity and recent HIV-related outpatient visit (odds ratio [OR], 4.30; 95% confidence interval [CI], 2.36-7.81 and OR, 2.84; 95% CI, 1.66-4.88, respectively), CD4+ cell count of less than 0.20 x 10(9) (OR, 2.41; 95% CI, 1.51-3.84), no current drug use and being in drug treatment (OR, 2.16; 95% CI, 1.34-3.47; OR, 2.12; 95% CI, 1.23-3.66, respectively), and unemployment (OR, 2.31; 95% CI, 1.21-4.40) were associated with reporting ART use. In other analysis, less likely to receive protease inhibitors were current drug injectors (OR, 0.5; 95% CI, 0.3-1.0) and those recently incarcerated (OR, 0.2; 95% CI, 0.03-0.9), but patients with acquired immunodeficiency syndrome were more likely to receive protease inhibitors (OR, 2.0; 95% CI, 0.9-4.6). Protease inhibitor use doubled (P<.01) from July and December 1996 to January and June 1997 (7.7% and 14.8%, respectively). Those IDUs infected with HIV who were not receiving ART tended to be active drug users without clinical disease who have less contact with health care providers. Although we do not have information on clinical judgment regarding treatment decisions or whether persons were prescribed therapy not taken, the proportion of subjects reporting receiving ART suggests that strategies for improving treatment in this population are indicated. Expanding simultaneous treatment services for HIV infection and substance abuse would enhance the response to these related epidemics.

HIV infection among family planning clinic attenders in Glasgow: why prevalence has remained low in this general population group.

OBJECTIVE: During 1991-2, unlinked anonymous testing of dried blood spots from neonatal metabolic screening cards showed the prevalence of HIV among childbearing women from Glasgow to be extremely low at...

Differentiation in the Amsterdam methadone dispensing circuit: determinants of methadone dosage and site of methadone prescription.

To evaluate the Methadone Dispensing Circuit in Amsterdam by identifying determinants of methadone dosage and client characteristics in the different types of methadone programmes. Four hundred and forty-four participants of a cohort study of drug users in Amsterdam who had consented to link data of the Central Methadone Register to the cohort data. From 1985 to 1994, methadone dosage increased from 41 to 59 mg/day. The mean methadone dosage was higher for ethnic West Europeans, Germans, older drug users, HIV-positive drug users, those with a longer duration of prostitution, current injectors, those with a longer duration of injecting, longer duration of methadone use, higher frequency of being dispensed methadone and clients of the prostitutes' and foreigners' outpatient clinic. For clients of the general practitioner, at the police station and in prison the methadone dosage was lower. We found different sets of client characteristics in those receiving methadone at the methadone outpost, the methadone bus, the prostitutes' and foreigners' outpatient clinic, the general practitioner and the outdoor addiction clinic. These results indicate that the Amsterdam system is highly differentiated in a way that is largely concordant with the intended general policy on methadone treatment.

Transitions between routes of benzodiazepine administration among heroin users in Sydney

A sample of 312 heroin users were interviewed regarding their benzodiazepine use. The majority (94%) had used benzodiazepines, 72% in the 6 months prior to interview. Benzodiazepine injecting was common, with 28% of the sample having injected these drugs, 13% in the 6 months preceding interview. Current benzodiazepine injectors showed greater polydrug use, injection-related HIV risk-taking behaviour, criminal involvement, psychological distress and injection-related health problems, as well as poorer general health, and an increased risk of having overdosed, than other users of benzodiazepines. Of those subjects who had injected benzodiazepines, 55% were no longer current benzodiazepine injectors. Concern for general health emerged as the most common reason for having made a transition away from injecting, and for being likely to make such a transition.

Estimating the Incidence and Prevalence of Injecting Drug use in Glasgow

Previous research indicates that wide scale heroin injecting began in Glasgow in the early 1980s and that by 1990 there were about 8,500 (mainly poly-drug) injectors. Data on year of, and age at, first injection, obtained from 1,425 current injectors in non-treatment settings between 1990 and 1994 are used to address three issues: 1) what was the incidence of drug injecting from, the first reported year of injection, 1967 to 1994, 2) is it possible to predict 1994 period prevalence and 3) how do changes in age at first injection, duration of injecting and age at interview relate to incidence and outcidence rates? Between 1990 and 1994, the mean number of years injected (6.9 to 8.8 years) and age at first injection (17.4 to 18.9 years) increased significantly. The average age of new injectors increased from an average of 17.7 years during 1967-1989 to 21.5 years during 1990-94. These findings could be explained by outcidence outstripping incidence, resulting in decreasing prevalence. Although further work ...

Prevalence and correlates of the injection of methadone syrup in Sydney, Australia

A sample of 312 heroin users was interviewed on their injection of methadone syrup. Methadone injecting was widespread, with 52% of subjects having injected methadone syrup, 29% in the preceding six months. Males and females were equally likely to report methadone injecting. Forty per cent of current methadone injectors reported weekly or more frequent methadone injecting over the preceding six months. A history of methadone injecting was associated with abscesses and infections in injection sites, having been diagnosed with a venous thrombosis and a history of heroin overdose. Current methadone injectors were in poorer general health, had more injection-related symptoms, higher levels of psychological distress, were more likely to have recently passed on used injecting equipment and to have recently committed criminal acts. Implications for the reduction in the prevalence of methadone injecting and associated harm are discussed.

Human immunodeficiency virus infection and infective endocarditis among injecting drug users.

Human immunodeficiency virus (HIV) infection and infective endocarditis are serious complications of injection drug use. To determine whether HIV infection may increase the risk of endocarditis beyond that associated with drug injection, we performed a nested case-control study among injecting drug users taking part in an ongoing cohort. We identified 26 participants with infective endocarditis between cohort enrollment (in 1988-1989) and June 1992, through reviews of medical records and death certificates. We matched each endocarditis case with up to five controls (N = 120) on enrollment date, race/ethnicity, and follow-up time. Data were taken from baseline and from the one follow-up visit: the last visit before the endocarditis occurred for cases and the closest visit (+/- 3 months) for controls. We used conditional logistic regression to quantify the association between HIV serostatus at follow-up and subsequent endocarditis, after adjusting for a history of endocarditis or sepsis before enrollment, injection duration, current injection frequency, and a recent history of abscess at injection sites. Among current injectors at follow-up, the adjusted odds ratio (OR) of developing endocarditis for HIV-seropositive subjects with > or = 350 CD4 cells per microliter, compared with HIV-seronegative subjects, was 2.31 [95% confidence interval (CI) = 0.61-8.78]; the corresponding OR for HIV-seropositive subjects with < 350 CD4 cells per microliter was 8.31 (95% CI = 1.23-56.37). These data indicate that HIV-related immunodeficiency may independently increase the risk of infective endocarditis among injecting drug users.

Synchronic modal equivalencing (SME) for structure-preserving dynamic equivalents

A novel framework for dynamic equivalencing of interconnected power systems that the authors recently introduced in the context of classical swing-equation models is extended in this paper to detailed models in structure-preserving, differential/algebraic-equation form. The system is partitioned into a study area and one or more external areas on the basis of synchrony, a generalization of slow-coherency that forms one leg of their framework. Retaining a detailed model for a single reference generator from each external area, the dynamics of the remaining external generators are then modally equivalenced in the style of selective modal analysis; this modal equivalencing is the other leg of their framework. The equivalenced external generators are thereby collectively replaced by a linear multi-port "admittance", which is easily represented using controlled current injectors at the buses of the replaced generators. The rest of the system model can be retained in its original nonlinear dynamic form. The approach is tested-with encouraging results-on the familiar third-order, 10-machine, 39-bus New England model, using an implementation in the EUROSTAG simulation package.

The cognitive structure underlying heroin-injecting behaviour.

An important objective in the field of drug education is the development of successful intervention programs to deter or reduce use. A vital step in this procedure is the identification of the critical elements that will induce and maintain behavior change. The purpose of this article is to demonstrate how the Theory of Reasoned Action can be used to identify these factors. Data were gathered from a sample of current heroin injectors and the cognitive structure underlying drug use investigated. The findings are discussed with regard to intervention programs aimed at modifying or reducing drug injecting behavior.

Friends and lovers: needle sharing in young people in Western Australia.

The Youth AIDS and Drugs (YAD) Study is a study of young people who inject drugs, and their risk of the transmission of HIV through needle sharing and/or unsafe sex. One hundred and five people, aged less than 21, 75% of whom were current or recent injectors, undertook in-depth interviews which were tape recorded, transcribed and analysed qualitatively. This paper focuses on the ways in which the young people in the group attempted to manage the risk of needle sharing. Needle sharing in the study group was not common behaviour. Almost all injectors employed one of four major Risk Management Strategies some of which included the possibility of sharing unbleached needles with a friend or a lover. These strategies were strongly related to beliefs that such friends and lovers were well enough known by the individual for there to be very little risk. The implications of these findings for health promotion with young people who inject drugs in Perth, a city of low IDU seroprevalence, are outlined.

Evaluation of an AIDS education model for women drug users in jail.

This paper reports outcome evaluation results of an AIDS education program for drug-using women in jail, of whom the majority were current drug injectors, had high-risk sexual partners, and never used condoms for insertive sex. The women participated in four small-group health/HIV education sessions. Education participants and controls were followed-up 7 months after their release from jail; the two groups did not differ significantly on drug- or sex-related HIV risk behaviors at follow-up. However, being in drug dependency treatment (primarily methadone maintenance) at follow-up was associated with reduced heroin use, crack use, drug dealing, and criminal activity. Although improved HIV education in jail is important, better networks of community resources, including more accessible community drug dependency treatment, also must be developed to support drug-dependent women after their release from jail.

Blood-borne virus infections among Australian injecting drug users: Implications for spread of HIV

To describe the epidemiology of infection with hepatitis C virus (HCV), hepatitis B virus (HBV) and human immunodeficiency virus (HIV) among injecting drug users (IDUs) in Australia, in relation to the potential for further spread of HIV in IDUs, a cross-sectional analysis was performed on data from a sample of injecting drug users, correlating markers of exposure to blood-borne viruses with sex, age, sexual orientation, primary current drug injected and duration of injecting in rural and metropolitan Victoria, Australia. The subjects were currently active IDUs from a wide spectrum of age, sex, sexual orientation, geographical location and social background, contacted and recruited through their social networks and from community agencies and prisons by trained peer workers who interviewed and collected blood from them in the field. Sera were tested for antibody to HIV, HCV and hepatitis B core antigen (HBcAg), for hepatitis B surface antigen (HBsAg), and for HCV RNA using reverse transcription and polymerase chain reaction (RT-PCR). At entry to the study, 4.5% (14/311) had antibody to HIV, 47% (146/308) to HBcAg and 68% (206/303) to HCV. Prevalence of HBsAg was 1.8% overall (5/282), and 50% (84/168) were positive for HCV RNA. By multivariate analysis, HIV seropositivity was strongly associated with a history of homosexual contact in males and with exposure to HBV but not to HCV. Those who reported their current primary injected drug to be amphetamines were at greater and continuing risk of HIV infection than were current heroin injectors, while the reverse applied for HCV.(ABSTRACT TRUNCATED AT 250 WORDS)

Estimating the Population Prevalence of Injection Drug Use and Infection with Human Immunodeficiency Virus among Injection Drug Users in Glasgow, Scotland

Although data on the prevalence of injection drug use are an essential prerequisite for estimating the number of individuals infected with the human immunodeficiency virus (HIV), there have been few attempts to utilize statistical methods of population estimation based on multiple data sources. Data on 3,670 cases (2,866 individuals) were obtained from the HIV test register, drug treatment agencies, police records, and needle and syringe exchanges in Glasgow, Scotland, in 1990. Log-linear analysis was used to model the number of individuals in each of the sources. The model incorporating dependency among the three health care agencies (HIV test, drug treatment, and needle exchange) and independence of the police sample fitted the data well, with a residual chi 2 value of 2.9 (6 df). The expected value of the missing cell corresponding to absence from all four samples was 5,628, yielding an overall estimate of 8,494 injectors (95% confidence interval (CI) 7,491-9,721), for a prevalence rate of 1.35% for people aged 15-55 years in Glasgow during 1990. The high ratio of known to unknown injectors (1:2) resulted from the extensive coverage of known injectors and the relatively high level of overlap between the combined health care agency sample and the police sample. While further analysis demonstrated that the probability of appearing in the four samples varied by age and sex, heterogeneity in the population did not affect the choice of model or substantially alter the estimates for the total number of unknown injectors. A concurrent study of a community-wide sample of 503 injectors resulted in an HIV prevalence rate of 1.1% (95% CI 0.4-2.5%). The results of these studies were combined to produce a further estimate of 93 HIV-infected current injectors in Glasgow (95% CI 33-214).

Future time perspective in current and previous injecting drug users

Future time perspective (FTP) is a measure of an individual's ability to conceptualise the future which has been shown to be foreshortened in drug addicts. We studied 100 opiate injecting drug users (IDUs) in New South Wales, Australia, of which half were currently injecting and half were not. There was a significant difference between the two groups on FTP, with those currently injecting having a truncated FTP extension. Factor analysis of the FTP scale suggested that the dimensions of future time may differ between groups, with current injectors having a perspective of loss and isolation compared to the dimension of self-evaluation and self-acceptance in those not currently injecting. These data support previous studies which demonstrated truncated FTP, also demonstrating a difference in currently (as opposed to previously) IDUs and suggest that both extension of FTP and an alteration of the dimensions of FTP are associated with cessation of injecting and entry into treatment.

Estimates of HIV infection among injecting drug users in Glasgow, 1985-1990.

To use research and surveillance studies in Glasgow (Scotland, UK) to estimate the number of current injectors infected with HIV, the total number of injectors infected up to the end of 1990 and the recent incidence of infection. (A) Prevalence of injecting drug use was estimated using log-linear modelling. (B) Prevalence of HIV infection was determined from voluntary testing of a community-wide sample of injectors. (C) The number of infected current injectors was predicted by combining the distributions generated by (A) and (B). (D) Data on known HIV-positive injectors were used in conjunction with (C) to forecast the cumulative number of infected injectors. The number of current injectors was estimated to be 9400; the prevalence of HIV infection among 447 injectors recruited to the HIV prevalence study during 1990 was 1.1%. From these data, the number of HIV-positive current injectors in 1990 was estimated to be between 52 and 138. Between 1985 and 1990, 110 known HIV-positive injectors were registered or received treatment in Glasgow for HIV-related diseases; the total number of cases estimated to have occurred during this period was between 110 and 300. The incidence of infection in Glasgow during 1990 was likely to have been low in light of the finding that only one case in the prevalence study had not previously been diagnosed HIV-positive. Linkage of datasets from a variety of sources and studies has enabled the substantial refinement of estimates of the number of injectors and the proportion infected with HIV in Glasgow up to 1990.

HIV Risk Behavior and Beliefs of HIV-Seropositive Drug Users

To assess HIV risk behavior, beliefs, attitudes and intentions among HIV-seropositive drug users (DUs), we studied 122 HIV-positive DUs (including ninety-five current injectors) participating in a longitudinal HIV-study among DUs in Amsterdam. All were familiar with their serostatus. Over a period of four months, 20% of the sample put others at risk of HIV infection, mainly through unsafe sex. Forty-nine percent think they might infect someone with HIV in the future, again mainly through unsafe sex. Although the majority intends to use condoms, self-efficacy and response efficacy is low; that is, many do not think they are able to use condoms when necessary and many have limited confidence in the efficacy of condoms in preventing HIV transmission. Correlates of HIV risk behavior were non-Dutch nationality and being a female prostitute. The results suggest that, next to efforts which aim to prevent new infections among HIV-negative injectors or sexual partners of injectors, prevention efforts should focus on HIV-seropositive DUs or former DUs.

Interior contacts for probing the equilibrium between magnetic edge channels in the quantum Hall effect.

We demonstrate that interior voltage probes may be used as a class of partially coupled contacts, able to feed or preferentially detect the innermost edge channel, as opposed to quantum point contacts or gated structures, which are simultaneously coupled to the N outermost edge channels. This unique feature of interior contacts has allowed us to measure the potential of the innermost edge channel directly. We find that a significant potential drop occurs between Hall plateaus due to the backscattering in the bulk of the sample, as predicted in a previous report. The temperature dependence of this effect is discussed. The data confirm the low interchannel scattering rate between the innermost and the N-1 other spin-degenerate edge channels. Finally, it is found that interior contacts used as current injectors preferentially populate the innermost channel, thus enhancing the Shubnikov--de Haas oscillations.