Low risk for hepatitis C seroconversion in methadone maintenance treatment.

OBJECTIVES

To study the risk factors for seroconversion to hepatitis C virus (HCV) infection since admission to methadone maintenance treatment (MMT) and to characterize the seronegative admitted group.

METHODS

All 657 patients admitted to our MMT clinic in Tel Aviv, Israel, between 1993 and 2008 were prospectively followed up. Those who were HCV negative (n = 271) with >1 HCV tests (n = 207) were included for seroconversion analyses.

RESULTS

Proportions of ever drug injectors, benzodiazepine abuse, and former USSR immigrants were higher among HCV sera-positive versus sera-negative patients on admission to MMT. The incidence of HCV seroconversion in MMT was 2/100 person years [py] (25 seroconversions, 1133.9 py). Seroconversion rates were higher among 44 younger patients (<30 years: 9.6/100 vs 1.4/100 py, P < 0.0005), among 103 patients with positive urine results to benzodiazepines (3.6/100 vs 1/100 py, P = 0.005), among 118 patients who injected the drugs (3.9/100 vs 1/100 py, P = 0.003), and among 43 patients who dropped out and were readmitted to the MMT (4.3/100 vs 1.7/100 py, P = 0.04). There was a trend of higher seroconversion among 61 females (P = 0.1), among 62 patients with no children (P = 0.1), and among those having hepatitis B antigen (n = 7; P = 0.09). Variables that predicted seroconversion were drug injection, benzodiazepine abuse, and being younger at admission to MMT. Being a former USSR immigrant did not predict seroconversion.

CONCLUSIONS

The HCV seroconversion rate of patients in MMT is low, also, for former USSR immigrants. The predictors for seroconversion were only admission variables (younger age at admission to MMT, ever drug injector, and having positive urine to benzodiazepines at MMT admission). Specific intervention to eliminate seroconversion is needed for these high-risk groups.