Hepatitis C infection commonly complicates injecting drug use. The outcome of end stage liver disease for this cohort in Ireland has not been estimated. This study aims to:
• To estimate the prevalence of persistent hepatitis C viraemia and distribution of genotypes in a drug using cohort.
• To measure the frequency of poor prognostic co-factors.
• To extrapolate the burden of hepatitis C related disease nationally for this route of infection. A cross section survey of attendees at an East Coast Area drug treatment clinic.

Of 94 patients studied (63 male), 70 were hepatitis C antibody positive and 39 were PCR positive. 26 had genotype 1 and 11 had genotype 2 or 3. Most displayed factors associated with a poor prognosis: 72% male, 83% problem drinkers and 87% abnormal liver blood tests. Using published data, we extrapolate over 1,214 cases of cirrhosis via this route of infection nationally, leading to approximately 35, 60 and 50 cases of hepatocellular carcinoma, hepatic decompensation and liver related death respectively per annum.

A high prevalence of hepatitis C infection in injecting drug users, compounded by a high frequency of poor prognostic co-factors, means a significant burden of disease can be expected from this group.