Ecological models of the determinants of health and the consequent importance of structural interventions have been widely accepted, but using these models in research and practice has been ...challenging. Examining the role of criminal law enforcement in the "risk environment" of injection drug users (IDUs) provides an opportunity to apply structural thinking to the health problems associated with drug use. This article reviews international evidence that laws and law enforcement practices influence IDU risk. It argues that more research is needed at four levels-laws; management of law enforcement agencies; knowledge, attitudes, beliefs, and practices of frontline officers; and attitudes and experiences of IDUs-and that such research can be the basis of interventions within law enforcement to enhance IDU health.
It is important not only to collect epidemiologic data on HIV but to also fully utilize such information to understand the epidemic over time and to help inform and monitor the impact of policies and ...interventions. We describe and apply a novel method to estimate the size and characteristics of HIV-positive populations. The method was applied to data on men who have sex with men living in the UK and to a pseudo dataset to assess performance for different data availability. The individual-based simulation model was calibrated using an approximate Bayesian computation-based approach. In 2013, 48,310 (90% plausibility range: 39,900–45,560) men who have sex with men were estimated to be living with HIV in the UK, of whom 10,400 (6,160–17,350) were undiagnosed. There were an estimated 3,210 (1,730–5,350) infections per year on average between 2010 and 2013. Sixty-two percent of the total HIV-positive population are thought to have viral load <500 copies/ml. In the pseudo-epidemic example, HIV estimates have narrower plausibility ranges and are closer to the true number, the greater the data availability to calibrate the model. We demonstrate that our method can be applied to settings with less data, however plausibility ranges for estimates will be wider to reflect greater uncertainty of the data used to fit the model.
Concerns about the risks of HIV infection among drug injectors have eclipsed concerns about the prevalence and transmission of hepatitis, and in particular hepatitis B virus infection. Findings are ...reported from surveys undertaken with two separate community‐recruited samples of drug injectors in London collected in 1992 (n = 505) and in 1993 (n = 507). Anonymized confirmed testing of saliva snows 51.5% of drug injectors in 1992 and 47.9% in 1993 to be antibody positive to the core antigen of hepatitis B virus (anti‐HBc). Approximately half of the drug injectors confirmed as anti‐HBc positive were unaware that they had been infected with hepatitis, Anti‐HIV‐1 prevalence was considerably lower at 7.0% in 1992 and 6.9% in 1993. Multivariate analyses showed anti‐HBc positivity to be most likely among older injectors with longer injecting careers who had a history of having shared used needles and syringes. HIV‐1 positivity was also associated with a history of having shared injecting equipment as well as with recent sharing (i.e. in the last 6 months). Unlike anti‐HBc positivity, there were no associations between HIV‐1 positivity and age or length of injecting career. Younger injectors with shorter injecting careers were more likely to report recent sharing of used injecting equipment than older injectors with longer injecting careers. We note the potential for continued transmission of HBV and HIV‐1, particularly among younger injectors. We recommend an integrated strategy to maximize the health of drug injectors, of which HIV and HBV prevention is a part. There is a need to widen the availability of HBV vaccinations for HBV negative drug injectors and their sexual partners and for clear guidelines to drug injectors about the relative efficacy of bleach to disinfect injecting equipment of HBV and HIV.
Findings are reported on the risk behaviour of 104 confirmed HIV‐1 antibody positive drug injectors in London. Findings indicate that 41.3% of respondents had never received treatment or help for ...their drug use, and that 52.0% had never received a named test for HIV antibodies. The majority of confirmed HIV positive respondents (70.1%) were unaware of their HIV positive status. Respondents unaware of their HIV positive status were less likely to use condoms with primary sexual partners than respondents aware of their HIV status, and were marginally (though not significantly) more likely to report borrowing and lending used injecting equipment. Overall levels of risk‐taking were similar to those reported in UK studies of injecting drug use as a whole. The paper concludes by emphasising the high potential for HIV transmission among the equipment sharing and sexual partners of HIV positive drug injectors and by stressing the importance of low‐threshold HIV testing, education and treatment interventions in the community. If significant proportions of HIV positive drug injectors remain unaware of their antibody status, and if they also continue to engage in behaviours of risk to others, the spread of HIV among drug injectors and their partners may escape current efforts of prevention and prevalence control.
To provide time-trend estimates of HIV-1 prevalence among injecting drug users (IDU) in London.
HIV-1 prevalence and HIV testing behaviour were measured in four serial point prevalence surveys of IDU ...recruited at multiple sites in community-based non-treatment and drug treatment settings between 1990 and 1993.
Community subjects were recruited through social network sampling by trained indigenous interviewers; treatment subjects were interviewed at agencies. With informed consent, subjects responded to a structured questionnaire covering risk behaviour. Volunteered saliva samples were tested anonymously for anti-HIV-1. Statistical comparisons across years were examined using mixed binomial logistic and log-linear models. Pearson's chi 2 and Fisher's exact tests were also used for some two-group comparisons.
Similar samples were recruited each year. HIV-1 prevalence rate declined from 12.8% in 1990, 9.8% in 1991, 7.0% in 1992, to 6.9% in 1993. The statistical modelling suggested that the overall trend in prevalence rates was one of decelerating decline. There was no difference in prevalence rate by gender and length of injecting. Less than one-half (46%) had received a named HIV test. Over one-half of the HIV-positive IDU were unaware of their status.
The pattern of decline in HIV prevalence rate is attributed to changes in risk behaviour following HIV prevention interventions.
The impact of syringe-exchange schemes on the behaviour of injecting drug users was investigated through self-reported behaviour change. Fifteen syringe-exchange schemes in England and Scotland ...participated in a government-sponsored pilot programme from April 1987. Clients were provided with sterile injecting equipment and condoms, and with knowledge of HIV risks. One hundred and forty-two injecting drug users who first attended between April 1987 and March 1988 participated in a prospective interview-based survey with questions at two points in time. Measurements were self-reported attitudinal, knowledge and behavioural changes relevant to HIV infection and transmission. Many clients maintained or adopted low-risk behaviours: 79% sustained or adopted low or lower levels of syringe sharing. Trends identified include decreases in syringe-sharing, from 34 to 27%; using others' syringes (risk of infection) from 25 to 19%; passing on syringes (risk of transmission) from 30 to 25%. Many clients reported changes in sexual behaviour; those with sexual partners decreased from 77 to 69% and those with two or more sexual partners from 26 to 21%. However, non-use of condoms increased from 62 to 79%. Comparison groups of non-attenders showed higher levels of risk behaviour (59-62% sharing syringes, 86-88% with sexual partners). Overall, changes in HIV risk behaviour show small but encouraging trends and support arguments that injectors can be helped to change their behaviour, which could be of cumulative importance in reducing the spread of HIV.
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