Ali Judd

Incidence of hepatitis C virus and HIV among new injecting drug users in London: prospective cohort study

In England, the low prevalence of HIV among injecting drug users during the 1990s was attributed in part to the introduction of harm reduction interventions in the late 1980s. Also, the prevalence of hepatitis C virus in the late 1990s was thought to be relatively low compared with other countries, at around 40% overall and 15% among those who had been injecting drugs for less than six years.1 We carried out a prospective cohort study of new injecting drug users in London to estimate the incidence of hepatitis C virus and HIV. In 2001, we recruited from community settings mainly in London, but also in Brighton, 428 injecting drug users who were aged below 30 years or had been injecting for six years or fewer. All had injected in the previous four weeks and could provide addresses for follow up. They completed interviewer administered questionnaires and provided oral fluid specimens and optionally dried capillary blood spots for testing for antibodies to hepatitis C virus and HIV using published methods.2 3 They were followed up 12 months later. …

Explosive spread and high prevalence of Hiv infection among injecting drug users in Togliatti City, Russia

ObjectiveTo establish the prevalence of antibodies to HIV (anti-HIV) and associated risk factors among injecting drug users (IDU) in Togliatti City, Samara Oblast, Russian Federation. DesignAn unlinked anonymous cross-sectional community recruited survey with oral fluid sample collection. MethodsBetween September and October 2001, 426 IDU were recruited by trained fieldworkers. Participants completed an interviewer administered questionnaire, and oral fluid samples were tested for anti-HIV. Univariate and multivariate analyses compared potential risk factors for anti-HIV. ResultsAnti-HIV prevalence was 56% (234/418). Three-quarters of anti-HIV-positive IDU (74%) were unaware of their positive status. In an adjusted model, the odds of HIV infection were higher among IDU who had ever injected home-produced drugs, who reported injecting with used needles and syringes in the past 4 weeks, and who were living in one particular district of the city (Komsomolksii). ConclusionThe high prevalence of HIV, and a recent increase in HIV detected through routine screening tests since 2000, suggests that an explosive epidemic has occurred among IDU in Togliatti City. In the face of currently inadequate HIV prevention coverage among IDU, this has urgent implications for maximizing the distribution of sterile injecting equipment as well as for enhancing sexual risk reduction. Recognizing that it is likely that similar explosive epidemics are taking place in other Russian cities, we recommend community-wide HIV prevention coverage supported by city and state policies oriented to harm reduction.

Drug-related mortality and fatal overdose risk: Pilot cohort study of heroin users recruited from specialist drug treatment sites in London

Fatal overdose and drug-related mortality are key harms associated with heroin use, especially injecting drug use (IDU), and are a significant contribution to premature mortality among young adults. Routine mortality statistics tend to underreport the number of overdose deaths and do not reflect the wider causes of death associated with heroin use. Cohort studies could provide evidence for interpreting trends in routine mortality statistics and monitoring the effectiveness of strategies that aim to reduce drug-related deaths. We aimed to conduct a retrospective mortality cohort study of heroin users recruited from an anonymous reporting system from specialist drug clinics. Our focus was to test whether (1) specialist agencies would agree to participate with a mortality cohort study, (2) a sample could be recruited to achieve credible estimates of the mortality rate, and (3) ethical considerations could be met. In total, 881 heroin users were recruited from 15 specialist drug agencies. The overall mortality rate of the cohort of heroin users was 1.6 (95% confidence interval [CI], 1.1 to 2.2.) per 100 person-years. Mortality was higher among males, heroin users older than 30 years, and injectors, but not significantly higher after adjustment in a Cox proportional hazard model. Among the 33 deaths, 17 (52%) were certified from a heroin/methadone or opiate overdose, 4 (12%) from drug misuse, 4 (12%) unascertained, and 8 (24%) unrelated to acute toxic effects of drug use. Overall, the overdose mortality rate was estimated to be at least 1.0 per 100 person-years. The standardized mortality ratio (SMR) was 17 times higher for female and male heroin users in the cohort compared to mortality in the non-heroin-using London population aged 15–59 years. The pilot study showed that these studies are feasible and ethical, and that specialist drug agencies could have a vital role to play in the monitoring of drug-related mortality.

Increasing the uptake of hepatitis C virus testing among injecting drug users in specialist drug treatment and prison settings by using dried blood spots for diagnostic testing: a cluster randomized controlled trial

Summary.  The objective of this study was to assess whether introducing dried blood spot testing can increase hepatitis C virus (HCV) diagnostic testing. A cluster randomized controlled trial was conducted. Sites were matched into pairs, with one site in each pair randomly allocated to receive the intervention (training and use of dried blood spot). Data were collected from all sites for 6 months before and 6 months after the start of the intervention. The participants were 22 specialist drug clinics and six prisons in England and Wales. The main outcome measure of this study was percentage point difference in individuals tested for HCV (the difference between the percentage of patients tested 6 months after and 6 months before the introduction of dried blood spot tests). Before the trial, 8% of patients at control and intervention sites had been tested for HCV, with 16 sites testing less than 5% of their caseload. The average percentage point difference between intervention and control sites was 14.5% (95% CI 1.3–28%, paired t‐test, P = 0.03); with 13 of the 14 pairs contributing to the positive effect of the intervention (Wilcoxon matched‐pairs signed‐rank‐test, P = 0.002). The size of the difference between intervention and control sites varied considerably. The study provides preliminary supporting evidence that dried blood spot testing may increase the uptake of HCV diagnostic testing, by increasing the opportunity for patients to be offered testing. Additional trials with a larger number of sites are justified, ideally in the context of drug and treatment policies that gave clearer priority (and targets) to infection control and testing.

Modelling emerging HIV epidemics: the role of injecting drug use and sexual transmission in the Russian Federation, China and India

Abstract Emerging epidemics of HIV in Russia, India and China will largely determine the future course of the HIV pandemic. Injecting drug use has been a major source of new infections in these countries. The evolving role of injecting drug use and sexual transmission in driving these emerging epidemics is investigated using a mathematical model. HIV prevalence projections based on behavioural data for urban Russia result in a wide range of possible outcomes, reflecting uncertainty in estimates of adult sexual behaviour. Surveys of adult sexual behaviour in all the three countries are limited, and represent a research priority if the futures of these emerging epidemics are to be better understood. Analysis of behavioural correlates with adult HIV prevalence reveal the central role of unsafe sex in driving HIV prevalence, even among injecting drug users. However, needle sharing can also play a very significant role, particularly when the potential for heterosexual transmission is limited. These emerging epidemics are more likely to cross higher prevalence thresholds when there is extensive sexual mixing between sex workers and the general population, and to a certain extent between injecting drug users and non-users. Both types of sexual mixing have been documented in Russia, India and China.

Prevalence of, and risk factors for, hepatitis C virus infection among recent initiates to injecting in London and Glasgow: cross sectional analysis.

Summary.  Our aim was to compare the prevalence of antibody to hepatitis C virus (anti‐HCV) among recently initiated injecting drug users (IDUs) in London and Glasgow, and to identify risk factors which could explain differences in prevalence between the cities. Complementary studies of community recruited IDUs who had initiated injection drug use since 1996 were conducted during 2001–2002. Data on HCV risk behaviours were gathered using structured questionnaires with identical core questions and respondents were asked to provide an oral fluid specimen which was tested anonymously for anti‐HCV but was linked to the questionnaire. Sensitivities of the anti‐HCV assays for oral fluid were 92–96%. Prevalence of anti‐HCV was 35% (122/354) in London and 57% (207/366) in Glasgow (P < 0.001). Multifactorially, factors significantly associated with raised odds of anti‐HCV positivity were increasing length of injecting career, daily injection, polydrug use, having had a needlestick injury, and having served a prison sentence. In addition lower odds of anti‐HCV positivity were associated with non‐injection use of crack cocaine and recruitment from drug agencies. After adjustment for these factors, the increased odds of anti‐HCV associated with being a Glasgow IDU were diminished but remained significant. HCV continues to be transmitted among the IDU population of both cities at high rates despite the availability of syringe exchange and methadone maintenance. Effectiveness of harm reduction interventions may be compromised by inadequate coverage and failure to reduce sufficiently the frequency of sharing different types of injecting equipment, as well as the high background prevalence of HCV, and its high infectivity. Comprehensive action is urgently required to reduce the incidence of HCV among injectors.

HIV prevalence among injecting drug users in England and Wales 1990 to 2003: evidence for increased transmission in recent years.

Objective:To describe trends in HIV prevalence among injecting drug users in England and Wales between 1990 and 2003. Methods:Analysis of surveillance data from voluntary unlinked anonymous cross-sectional surveys collecting oral fluid samples and behavioural information from injecting drug users recruited from both drug agency (n = 24 304) and community settings (n = 3628). Results:HIV prevalence in England and Wales declined from 5.9% in 1990 to 0.6% in 1996 and then remained stable until 1999, after which it increased to 1.4% in 2003. Few HIV infections were detected among short-term injectors between 1994 and 1999, but in recent years prevalence among this group has increased. Other factors associated with higher odds of HIV infection were being recruited in London and from community settings, and ever having had a voluntary confidential HIV test. Incidence estimated through a force of infection model was 2.8% per annum among those injecting for less than a year in London between 1998 and 2003. Conclusions:These data suggest that incidence and prevalence of HIV may have increased, whereas other indicators suggest an increase in risk behaviour. It is critical that harm reduction measures are reinvigorated, and evolve in response to changes in drug use risk behaviours and policy.

Twenty years of selective hepatitis B vaccination: is hepatitis B declining among injecting drug users in England and Wales?

Summary.  Injection drug use is a common route of infection for the hepatitis B virus (HBV) in the UK. The aim of this study was to establish the prevalence and force of infection for HBV among injecting drug users (IDUs) recruited from multiple community and drug agency settings in England and Wales between 1990 and 2004. Cross‐sectional studies of IDUs in and out of contact with drug agencies were conducted throughout the 15‐year period. Oral fluid samples were tested for antibodies to the hepatitis B core antigen (anti‐HBc). Logistic regression was used to investigate associations between risk factors and anti‐HBc positivity and force of infection models were explored. In total, 2527 injectors were recruited from community settings, and 29 386 from drug agencies. Anti‐HBc prevalence was 31% (95% CI 30.7–31.8%). It declined in the early 1990s from around 50% in 1992 to 25% in 1999, after which it increased slightly. It was also higher in those who had injected for longer, older IDUs, those recruited in London and North West England, and those reporting having a previous voluntary confidential HIV test. The force of infection models suggested that the incidence of infection increased in 1999–2004 compared with 1993–1998, and was higher in new injectors compared with those injecting for ≥1 year. In conclusion, findings suggest ongoing HBV transmission in recent years despite an overall decline in prevalence in the early and mid‐1990s, and highlight the importance of targeting vaccination programmes at new IDUs who have high incidence rates of infection.

How Strong Is the Evidence that Illicit Drug Use by Young People Is an Important Cause of Psychological or Social Harm? Methodological and Policy Implications of a Systematic Review of Longitudinal, General Population Studies.

Recreational use of illicit drugs (i.e. use not associated with a diagnosed drug problem) may cause psychological and social harm. A recent systematic review found that evidence for this was equivocal. Extensive evidence was only available in relation to cannabis use. This was relatively consistently associated with lower educational attainment and greater use of other drugs. However whether this association was causal was not clear. Cannabis use was less consistently associated with mental illness and antisocial behaviour. Causal relations between cannabis use and psychosocial harm could plausibly be mediated through either neurophysiological effects of cannabis or through social mechanisms related to use of an illegal substance. These different mechanisms might have different implications for harm-reduction policy. Alternatively associations may arise through non-causal pathways such as reverse causation, bias and confounding. In this latter situation, even effective reduction of cannabis use would be unlikely to be an effective harm-reduction policy in relation to psychosocial outcomes. Research strategies that could clarify these questions are discussed, as are the implications of these considerations for harm-reduction policy.