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

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 > or =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.

Pathways into receiving a prescription for diamorphine (heroin) for the treatment of opiate dependence in the United kingdom.

In the UK, few doctors prescribe diamorphine for the treatment of opiate dependence to a small number of patients. A retrospective case note review of patients receiving diamorphine in 2000 was conducted in the UK to determine how and why these patients came to receive a prescription for diamorphine. Patient eligibility criteria were examined together with doctors' stated reasons for initiating a diamorphine (heroin) prescription. Two hundred and ten sets of patients' case notes were reviewed at 27 of the 42 (64%) drug clinics in England and Wales where diamorphine was prescribed by the doctor. There appeared to be a general consensus among the few doctors who had prescribed diamorphine that it was a treatment of last resort, for those with long histories of heroin use and injecting, and those who had not responded sufficiently well to previous other treatments. However, there was also a small number of patients initiated on diamorphine without ever having previously received opiate treatments and some because they were experiencing problems injecting methadone. This reflects the UK history of the individual doctor's clinical autonomy in deciding when diamorphine is appropriate and the previous lack of nationally agreed patient eligibility criteria.

Estimates of injecting drug users at the national and local level in developing and transitional countries, and gender and age distribution.

OBJECTIVE: To present and update available national and subnational estimates of injecting drug users (IDUs) in developing/transitional countries, and provide indicative estimates of gender and age distribution. METHODS: Literature review of both grey and published literature including updates from previously reported estimates on estimates of IDU population and data sources giving age and gender breakdowns. The scope area was developing/transitional countries and the reference period was 1998-2005. RESULTS: Estimates of IDU numbers were available in 105 countries and 243 subnational areas. The largest IDU populations were reported from Brazil, China, India, and Russia (0.8 m, 1.9 m, 1.1 m, and 1.6 m respectively). Subnational areas with the largest IDU populations (35,000-79,000) are: Warsaw (Poland); Barnadul, Irtkustk, Nizhny-Novgorod, Penza, Voronez, St Petersburg, and Volgograd (Russia); New Delhi and Mumbai (India); Jakarta (Indonesia), and Bangkok (Thailand). By region, Eastern Europe and Central Asia have the largest IDU prevalence (median 0.65%) (min 0.3%; max 2.2%; Q1 0.39%; Q3 1.32%) [corrected] followed by Asia and Pacific: 0.24% (min 0.004%; max 1.47%; Q1 0.14%; Q3 1.47%) [corrected] In the Middle East and Africa the median value equals 0.2% (min 0.0003%; max 0.35%; Q1 0.11%; Q3 0.23%) [corrected] and in Latin America and the Caribbean: 0.12% (min 0.11%; max 0.69%; Q1 0.04%; Q3 0.13%) [corrected] Subnational areas with the highest IDU prevalence among adults (8-14.9%) were Shymkent (Kazakhstan), Balti (Moldova), Astrakhan, Barnadul, Irtkustk, Khabarovsk, Kaliningrad, Naberezhnyje Chelny, Penza, Togliatti, Volgograd, Voronez, and Yaroslavl (Russia), Dushanbe (Tajikistan), Ashgabad (Turkmenistan), Ivano-Frankivsk and Pavlograd (Ukraine) and Imphal, Manipur (India). 66% (297/447) of the IDU estimates were reported without technical information. Data on the IDU age/gender distributions are also scarce or unavailable for many countries. In 11 Eastern European and Central Asian countries the age group 50% of the total. The proportion of IDU men was 70%-90% in Eastern Europe and Central Asia, and there was a marked absence of data on women outside this region. CONCLUSION: Unfortunately data on IDU prevalence available to national and international policymakers is of an unknown and probably yet to be tested quality. This study provide baseline figures but steps need to be taken now to improve the reporting and assessment of these critical data.

Patients receiving a prescription for diamorphine (heroin) in the United Kingdom.

The United Kingdom is unusual internationally in that it is one of few countries able to prescribe diamorphine for the treatment of opiate dependence. Prescribing diamorphine has been part of the UK response to drug problems since the 1920s. Despite this, little is known about who receives diamorphine and how treatment is delivered. This study aims to describe the characteristics and treatment regimes of opiate-dependent drug users receiving a prescription for diamorphine in the United Kingdom in 2000, and report on their status in 2002. A retrospective case-note review was conducted in England and Wales. Two hundred and ten (72%; 210/292) patients' sets of case-notes were reviewed at 27 of the 42 (64%) drug clinics where diamorphine was prescribed by the doctor. Patients had been receiving a prescription for diamorphine for a median length of six years. The majority were unemployed white males, with a median age of 44 years. Illicit drug use and criminal activity, while low, had not been eliminated totally. The majority were prescribed ampoules and few had significant health problems. In some cases patients had been transferred to injectable diamorphine from injectable methadone to reduce injection related problems. There were wide variations in dose. The majority of patients had no serious drug, health or social problems. Diamorphine prescribing was a long-term commitment. The experience from the United Kingdom has been one of long-term prescribing with the aim of retaining patients in treatment and reducing the harms caused by illicit drug use. Prospective studies are needed to determine the long-term consequences of receiving a diamorphine prescription.

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

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.

Comorbidity of substance misuse and mental illness in community mental health and substance misuse services.

BACKGROUND: Improved management of mental illness and substance misuse comorbidity is a National Health Service priority, but little is known about its prevalence and current management. AIMS: To measure the prevalence of comorbidity among patients of community mental health teams (CMHTs) and substance misuse services, and to assess the potential for joint management. METHOD: Cross-sectional prevalence survey in four urban UK centres. RESULTS: Of CMHT patients, 44% (95% CI 38.1-49.9) reported past-year problem drug use and/or harmful alcohol use; 75% (95% CI 68.2-80.2) of drug service and 85% of alcohol service patients (95% CI 74.2-93.1) had a past-year psychiatric disorder. Most comorbidity patients appear ineligible for cross-referral between services. Large proportions are not identified by services and receive no specialist intervention. CONCLUSIONS: Comorbidity is highly prevalent in CMHT, drug and alcohol treatment populations, but may be difficult to manage by cross-referral psychiatric and substance misuse services as currently configured and resourced.

Prevalence of hepatitis C among injection drug users in England and Wales: is harm reduction working?

OBJECTIVES: This study sought to establish the prevalence of hepatitis C antibodies (anti-HCV) and hepatitis B antibodies (anti-HBc) among injection drug users in England and Wales. METHODS: A voluntary cross-sectional survey collected oral fluid samples and behavioral information; 2203 injectors were recruited through drug agencies, and 758 were recruited in the community. RESULTS: Prevalence was 30% for anti-HCV, 21% for anti-HBc, and 0.9% for HIV antibodies. Anti-HCV prevalence rates were significantly greater among those with longer injecting careers, those in older age groups, those residing in London, those recruited in drug agencies, those positive for anti-HBc, and those with a previous voluntary HIV test. CONCLUSIONS: Anti-HCV prevalence rates among injectors in England and Wales, where comprehensive harm reduction programs exist, are lower than rates in other industrialized countries.

Results of a screening survey for co-morbid substance misuse amongst patients in treatment for psychotic disorders: prevalence and service needs in an inner London borough.

BACKGROUND: There is great concern in the UK, and other countries, about the clinical management of psychosis and substance misuse co-morbidity. However, relatively little is known about the UK prevalence and management of co-morbidity. METHOD: We implemented a screening survey of patients who were in treatment with an inner London adult mental health service and measured the prevalence of substance misuse amongst 851 psychotic patients. Caseworkers reported substance misuse and assessed clinical management arrangements. RESULTS: Current prevalence of substance misuse was 24.4% (95% CI: 21.3-27.1). Rates of co-morbidity were higher in males (31% vs 16%, chi2 1df=26.0, P < 0.001) and patients over 51 (chi2 3df=50.1, P < 0.001). Adjusted odds of co-morbidity in patients under 51 were 0.19 (95% CI: 0.10-0.34) and 0.47 for females (95% CI: 0.32-0.69). Substance misuse interventions were provided to 20% of co-morbid patients--Only 5% were compliant. CONCLUSIONS: The findings suggest substance misuse may be highly prevalent amongst psychotic patients. Most co-morbid patients do not receive appropriate treatment. The development of evidence-based interventions should be a priority.

Pharmacy-based needle exchange (PBNX) schemes in south east England: a survey of service providers.

AIMS: To describe the activities of service providers with regard to (i) the business operation and policies defining pharmacy-based needle exchange (PBNX) in South East England; (ii) the day-to-day work of PBNX outlets from the provider perspective; and (iii) problems encountered by PBNX providers. DESIGN: (i) Postal self-completion questionnaire to all participating PBNX community pharmacies in South East England; and (ii) postal self-completion questionnaire to needle exchange coordinators. SETTING: Community pharmacy needle exchanges. PARTICIPANTS: Pharmacists in charge of needle exchange; and needle exchange coordinators. FINDINGS: Data were collected (i) from 381/440 (86.7%) participating community pharmacists, and (ii) 32/36 (88.9%) of coordinators. The study found that PBNX was reaching injecting drug users (many of whom used PBNX regularly), and providing a wide range of injecting equipment. Although pharmacists reported that problems such as shoplifting occurred relatively frequently, more serious problems such as violence were relatively rare. However, PBNX pharmacists reported needing further training for themselves and their staff. Suggested improvements included better advertising of services and improving returns rates for used injecting equipment. CONCLUSION: Needle exchange can reasonably be provided by non-specialist health care professionals such as community pharmacists. However, attention should to be paid to the educational needs of service providers who also require adequate support.

Measuring injecting risk behaviour in the second decade of harm reduction: a survey of injecting drug users in England.

AIMS: To measure risk behaviour among injecting drug users (IDUs) using the Injecting Risk Questionnaire (IRQ). METHODS: Data were analysed from the first multi-site survey of injecting risk behaviour among IDUs not in contact with drug services in England. A total of 1214 IDUs were recruited from community settings in seven sites. FINDINGS: Fifty-two per cent reported sharing injecting equipment in the previous 4 weeks in response to a single question on sharing. This rose to 78% when asked more detailed and multiple questions on injecting risk practices. Levels of injecting risk behaviour did not differ substantially by gender, age, length of injecting career, main drug of injection, previous treatment contact or geographical location. However, sharing partners were restricted to a median of two others. CONCLUSION: These data raise questions concerning the extent to which levels of injecting risk behaviour have increased over recent years, or the extent to which previous monitoring systems underestimated levels of risk. None the less, the data confirm that the promotion of safer injecting continues to be an important public health issue with regard to reducing blood-borne infections.

Surveillance of problem drug use in the UK: a review of a Regional Drug Misuse Database.

BACKGROUND: We report detailed findings of the first systematic validation of a Regional Drug Misuse Database (RDMD); such databases constitute the main investment in routine drug statistics in the UK by the Department of Health. METHODS: A retrospective case-finding study in a stratified random sample of one in three specialist drug agencies was carried out. Agency records of clients attending during 1994 were matched with reports (episodes) to the North Thames RDMD to assess the level of under-reporting, and the relationship between RDMD reports (episodes) and the number of problem drug users in contact with agencies. Under-ascertainment of cases was estimated using two-sample capture-recapture. RESULTS: Under-reporting was associated with agency records missing full date of birth or initials (attributers), and agency type. Compared with drug dependency units (DDU) the odds of under-reporting were 3-18 times higher by the other specialist drug agencies. Even after excluding episodes with missing attributers the odds ratio (OR) of not being reported was significantly higher among needle exchanges (OR 2.7), non-statutory community based drug teams (OR 3.2), statutory community based drug teams (OR 4.9) and residential rehabilitation units (OR 8.7) compared with DDUs. Overall database episodes represented 60 per cent of the number of clients attending specialist agencies as a result of a mixture of under-reporting and the proportion of clients retained in treatment, which also varied by agency type. A total of 727 individuals (16 per cent) had never been reported. CONCLUSIONS: Surveillance of drug misuse through RDMDs does not yet fulfil its objectives. It is essential that a system of following up reports is introduced to improve their utility, and to contribute to the monitoring of the UK Government's new drugs strategy, and wider European surveillance.

HIV prevalence and risk behaviour among female injecting drug users in London, 1990 to 1996.

OBJECTIVE: To describe trends in HIV prevalence among female injecting drug users (IDU) in London between 1990 and 1996. DESIGN: HIV prevalence and risk behaviour were measured yearly between 1990 and 1993, and in 1996, in point prevalence HIV surveys of IDU recruited from both drug-treatment and community-based settings within Greater London. Sample sizes were 173 in 1990, 111 in 1991, 128 in 1992, 146 in 1993 and 200 in 1996. METHODS: Each survey used structured questionnaires and common sampling and interview strategies. Oral fluid specimens were collected for testing for antibodies to HIV (anti-HIV). Multiple logistic regression was used to assess the trend in HIV prevalence. RESULTS: The percentage of female IDU testing positive for antibodies to HIV showed a marked decline over the study period, from 15.0% in 1990 to 1.0% in 1996 (P < 0.001). This trend was independent of all other variables examined. Each year, higher HIV prevalences were found among IDU recruited from community settings compared with treatment agencies. CONCLUSIONS: These results concur with those of IDU recruited from treatment sites, although the yearly estimates in this study are higher. London benefits from low prevalence of HIV infection among IDU, coupled with behaviour change facilitated by early intervention. Continued surveillance of injectors recruited from both community and treatment settings is necessary in order properly to assess HIV prevalence among IDU.

Estimating the prevalence of problem drug use in inner London: a discussion of three capture-recapture studies.

AIMS: To provide an evidence base of estimates of the prevalence of problem drug use in inner London. DESIGN: Re-analysis of three capture-recapture studies using subjects aged 15-49 years, that aim to estimate the hidden population from analysing the overlaps between three data sources. SETTING: Newham (1995) Camden and Islington (C&I) (1993/4) and Lambeth, Southwark and Lewisham (LSL) (1992). PARTICIPANTS: Each study collected data from three sources of problem drug users including: the Regional Drug Misuse Database, specialist drug agencies, HIV tests, social services, police arrests and court records. In LSL opiate users were analysed separately. The studies identified 1832 individuals in LSL, 543 in Newham, and 1321 in C&I. MEASUREMENTS: Poisson models were fitted to the data testing different interactions between the data sources representing potential dependencies. The simplest model was selected on the basis of its AIC score and log-likelihood ratio tests. FINDINGS: The number of hidden problem drug users were estimated to be 12,500 (95% CI 9600-16,100) in LSL with 4400 (3200-6100) opiate users; 7000 (5000-10,000) in C&I and 3800 (2000-7200) in Newham. The prevalence of problem drug use in those aged 15-49 was estimated to be 3.1% (2.5-3.9%) in LSL with 1.3% (1.0-1.6%) opiate users; and 3.6% (2.7-4.9%) and 3.3% (1.9-5.7%) in C&I and Newham, respectively. CONCLUSIONS: Despite the inherent problems with capture-recapture methods, our three studies establish an evidence base for estimates of problem drug use in London. It is important that a larger study is carried out in London.