| Drug Misuse Statistics Scotland 2002 |
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Blood-borne viruses |
Key Points
In 2001, 357 cases of Hepatitis B infection were reported by laboratories to SCIEH; a decrease from 2000 when 360 cases were reported (Chart A5.1, Table A5.1). In 1999, 386 cases were reported, the highest annual total since 1986. In 2001, 69 of the 357 reports mentioned injecting drug use as the patient's principal risk factor but it is likely that the majority of cases acquired their infection through injecting practices.
Nineteen of the 69 (28 per cent) injecting-related cases in 2001 were from Grampian, this was a decrease from that in 2000 (58 per cent). In 2001, the incidence of Hepatitis B infection associated with injecting drug use in Greater Glasgow increased from 20 cases in both 1999 and 2000 to 29 cases in 2001. In Argyll & Clyde, a decrease in the number of injecting-related reports from 17 in 1998 and 11 in 1999 and 7 in 2000, to 4 in 2001 continues to be seen; this observation reflects the impact of interventions which were introduced to control the epidemic of Hepatitis B among injectors from Port Glasgow.
Following the identification of several cases of Hepatitis B infection in Scotland's prisons, the Scottish Prison Service introduced routine Hepatitis B vaccination within the prison setting, an initiative that became fully established in 1999. It is hoped that this measure and increased efforts to vaccinate injectors in the community will help to control the spread of Hepatitis B infection that has risen to levels approaching those seen in the mid-1980s. The Hepatitis B virus, however, is less virulent than HIV and Hepatitis C. Accordingly, it is important that we do not lose sight of the root problem - namely, injectors sharing injecting equipment.
HIV
In 2001, the number of reported HIV-infected injectors increased slightly from 18 in 2000 to 20 in 2001 (Chart A5.2, Table A5.2); figures for 1999 and 1998 were 22 and 26 respectively.
Of the 20 in 2001, nine were from Lothian, four from Greater Glasgow and four from Tayside (Table A5.3). In 2001, 18 of 2 154 injectors tested (0.8 per cent) were antibody positive (Table A5.6); this compares with a prevalence of between 2 per cent and 3.7 per cent during 1989 and 1993, a constant prevalence of around 1.5 per cent during 1994-1997 (some data not shown), and a prevalence of 0.9 per cent, 0.6 per cent and 0.7 per cent in 1998, 1999 and 2000 respectively.
The incidence of HIV among injectors in Scotland is low in comparison to when infection was first introduced into the country's injecting populations in 1983. Interventions such as needle/syringe exchange and methadone maintenance programmes have been effective in making HIV transmission among injectors in Scotland a relatively rare occurrence. Indeed, apart from the outbreak of HIV among injector-inmates at HMP Glenochil in 1993, transmission among injectors in the 1990s has been sporadic not only in Scotland but elsewhere in the UK. There are signs, however, that the potential for a resurgence of HIV among injectors in Scotland is increasing (see sections on Hepatitis B above and C below).
To the end of 2001, 1 266 HIV infected injecting drug users had been reported by HIV testing laboratories to SCIEH (Table A5.3); 617 (49 per cent) were known to have died. The number of HIV-infected injecting drug users in clinical care, as indicated by the fact that they underwent CD4 count testing to assess their immunological status and thus stage of HIV disease they had reached, was at its lowest level in 2001 (Table A5.5). The majority of cases (234) resided in Lothian.
The impact of combination antiretroviral therapy (introduced in Scotland during 1996) on HIV disease progression is demonstrated by the recent reduction in AIDS cases registered among injecting drug users. During 1993-1995, the average annual number of AIDS registrations was 54; in 1997, 1998, 1999, 2000 and 2001, the number of registrations were 36, 18, 14, 11 and 16 respectively (Chart A5.3, Table A5.2).
To the end of 2001, 13 535 persons in Scotland had been diagnosed as having Hepatitis C infection (Chart A5.4, Table A5.7); information on laboratory request forms indicated that 8 153 (60 per cent) were injecting drug users but it is likely that the majority of the 4 431 (33 per cent) for whom no risk information was available, also acquired their HCV through injecting practices.
A total of 1 737 persons received their diagnosis in 2001; this compares with 1 889 in 2000, 1 961 in 1999, 2 004 in 1998 and 1 142 in 1995. 37 per cent of the 13 535 cases resided in Greater Glasgow, 15 per cent in Lothian, 12 per cent in Grampian and 8 per cent in Tayside.
Statistical models to estimate the total number of HCV infected persons in Scotland are being developed but preliminary work suggests that the overall figure is likely to be around 40 000. The rate of progression to moderate hepatitis (a stage of disease which when reached makes people eligible for drug treatment) within 20 years of infection is estimated to be 60 - 70 per cent. Therefore, since very large numbers were infected prior to 1990 several thousand injectors who have stopped injecting will be eligible for therapy over the next 10 - 15 years.
Ribavirin and Interferon therapy, combined, leads to sustained clearance of HCV infection from the circulation in about 50 per cent of treated cases; infected injectors who continue to inject, however, are ineligible for treatment. While drug treatment will be used increasingly in the management of HCV infected persons, it is essential the prevention remains the principal goal. There is evidence to indicate that the incidence of HCV among injectors has declined during the era of needle/syringe exchange, methadone maintenance therapy and other harm reduction initiatives. Nevertheless, in many parts of Scotland, infections are still occurring; in Glasgow, for example, surveys indicated that the annual incidence of HCV among the city's injectors during 1999-2001 was 20-30 per cent. The prevention of this infection among injectors - particularly in the absence of an HCV vaccine _ is one of Scotland's greatest public health challenges. In recognition of this, the Scottish Executive in association with HEBS and SCIEH are preparing awareness campaigns aimed at the general population and persons who have ever injected drugs.
In Scotland: