Bloodborne virus infections among drug users in Ireland: a retrospective cross-sectional survey of screening, prevalence, incidence and hepatitis B immunisation uptake.

BACKGROUND: Injecting drug users are at high-risk of bloodborne virus infections including hepatitis C (HCV), hepatitis B (HBV) and HIV. AIMS: To document screening for and immunisation against bloodborne viruses and to determine the known prevalence and incidence of these infections. METHODS: A cross-sectional survey of clients attending 21 specialist addiction treatment clinics in one health board area in greater Dublin. Data collected on demographic characteristics, serology for HCV, HBV and HIV and immunisation against HBV. RESULTS: A total of 316 (88%) had been tested for anti-HCV antibody, 244 (68%) had been tested for anti hepatitis B core antibody (anti-HBc), 299 (84%) had been tested for hepatitis B surface antigen (HBsAg) and 307 (86%) had been tested for anti-HIV antibody. The prevalence of anti-HCV, anti-HBc, HBsAg, and anti-HIV were: 66%, 17%, 2% and 11% respectively. The incidence of HCV, HBV and HIV infections were: 24.5, 9.0 and 3.4 per hundred person years respectively. Eighty-one per cent of those in whom it was indicated, had started a targeted HBV immunisation programme in the clinics. CONCLUSION: The proportion of clients screened for HCV, HBV and HIV infection has increased since the introduction of a screening protocol in 1998. Targeted vaccination for opiate users against hepatitis B is more successful than previously shown in Ireland. The prevalence and incidence of bloodborne viruses remains high among opiate users attending addiction treatment services, despite an increase in availability of harm reduction interventions