In September 2006 the Health Research Board published Overview 4 which describes what is known about blood-borne viral infections among drug users in Ireland.1 The data pertaining to injecting drug users are presented where possible, and where the data are not analysed by injecting status or where injecting status is not ascertained, the data on all drug users are presented.

The analysis presented in this Overview is based on disease notifications reported to the Health Protection Surveillance Centre (formerly known as the National Disease Surveillance Centre) during the period 1995 to 2005 and on ad hoc research studies.

The main observations and their implications are:

The number of newly diagnosed cases of HIV among injecting drug users increased in 1999 and to date has remained at a higher level than in the early nineties, while the number of new AIDS cases diagnosed decreased. Around one-tenth of injecting drug users in drug treatment are HIV positive. Age, injecting practices and sexual practices are associated with HIV status. The increase in HIV infections over the last five years requires investigation. HIV treatment is available to injecting drug users through genito-urinary medical units and infectious disease clinics in Ireland. In 2003, a study reported that a number of stable injecting drug users were suitable for treatment, but were not receiving treatment at the time of the study. Two studies demonstrated that decentralised treatment at drug treatment centre level achieved high uptake and compliance with HIV treatment.

Just under one-fifth of injecting drug users in treatment have ever been infected with hepatitis B and approximately 2% are chronic cases. Age, injecting practices and sexual practices are linked to hepatitis B status. The uptake and completion rates of hepatitis B vaccination are much higher in the HSE South Western Area (56%) and in Drug Treatment Centre Board (86%) cohorts for the period 2001 to 2003 than those reported in prisoners or at general practice in Ireland between 1998 and 2001. This possibly indicates an increase in hepatitis B vaccine coverage in recent years. There are no published data on the coverage of hepatitis B vaccine among injecting drug users outside the HSE Eastern Region. It is important to ensure that hepatitis B vaccine is administered as early as possible in a drug user’s career; therefore, needle exchange and low-threshold methadone services require facilities to deliver this intervention on a daily basis.

Around 70% of injecting drug users attending drug treatment tested positive for antibodies to the hepatitis C virus. Injecting practices and prison history are associated with hepatitis C status. There are seven specialist hepatology centres for adults and one for children in Ireland. A number of studies demonstrated low rates of access to and uptake of treatment for hepatitis C among injecting drug users. Two small studies demonstrated that a decentralised approach to initial assessment at general practice level and hepatitis C treatment at drug treatment centres achieved higher uptake and compliance rates than the current centralised approach.

Little has been published in Ireland on the prevalence of co-infection with HIV and/or hepatitis B and/or hepatitis C. The two national prison surveys in the late nineties presented data on co-infection among prisoners. These data indicated that approximately one-fifth of prisoners testing positive for hepatitis C were also infected with either hepatitis B or HIV. Up-to-date information is required.

Both HIV co-infection and, independently, high rates of alcohol consumption among those infected with hepatitis C are associated with more rapid disease progression and higher death rates.

The principles of expanded and accessible harm reduction measures are documented in both the AIDS Strategy 2000 and the Mid-Term Review of the National Drugs Strategy and will lead to synergistic actions to stem the current increase in new HIV cases among injecting drug users. The publicattion of the HSE Eastern Region's hepatitis strategy is awaited.

Newly diagnosed HIV cases are reported directly to the Health Protection Surveillance Centre (HPSC) through a case-based, extended surveillance system and staff at the HPSC collate these data on a six-monthly basis. Up to 2005, information on risk factors was not included in the data recorded on newly diagnosed cases of hepatitis B and hepatitis C, which makes it difficult to monitor the number of newly diagnosed cases of these infectious diseases among injecting drug users. It also means that Ireland has been unable to provide data to the European Monitoring Centre for Drugs and Drug Addiction on the incidence of hepatitis B and hepatitis C among injecting drug users. Action 39 of the European Union Drugs Action Plan requires member states to comply with the requirements of the key indicators to measure the drug situation. The incidence and prevalence of HIV, hepatitis B and hepatitis C among injecting drug users is one of the five key indicators. In recent years, the HPSC has improved the reporting of newly diagnosed cases of hepatitis B and hepatitis C. In 2006, hepatitis B data by risk factor status will be published.

There are a number of areas where further research is required. The data presented in this Overview indicate the need to record the risk factor status of newly diagnosed cases of hepatitis C. There is a need to set up a register to quantify the incidence and prevalence of hepatitis C among all heroin and cocaine users, including those who are in harm reduction and treatment services. The register should also permit the assessment of main risk factors, treatment uptake and outcomes. Strategies to increase uptake of and compliance with HIV and hepatitis C therapy in both prison and community settings need to be implemented and monitored. The medical consequences of and interventions required to deal with hepatitis C among injecting drug users need to be estimated. A system to monitor the national hepatitis B vaccine uptake is required to estimate coverage among prisoners, injecting drug users and sex workers. The effectiveness of needle exchange, opiate detoxification and opiate maintenance programmes in stabilising and reducing the incidence of hepatitis C needs to be quantified.

1.    Long J (2006) Blood-borne viral infections among injecting drug users in Ireland 1995 to 2005. Overview 4. Dublin: Health Research Board.