Incidence and risk factors for hepatitis C seroconversion in injecting drug users in Australia
Maher, L and Jalaludin, B and Chant, KG and Jayasuriya, R and Sladden, T and Kaldor, JM and Sargent, PL, Incidence and risk factors for hepatitis C seroconversion in injecting drug users in Australia, Addiction, 101, (10) pp. 1499-1508. ISSN 1360-0443 (2006) [Refereed Article]
Copyright 2006 The Authors. Journal compilation Society for the Study of Addiction
To determine the incidence of hepatitis C virus (HCV) infection and identify risk factors for seroconversion.
Prospective cohort study. Participants were recruited through direct approaches, street-based outreach,
methadone and sexual health clinics and needle and syringe programmes.
Urban, regional and rural settings
in New South Wales, Australia.
Injecting drug users (IDUs) (
584) were screened and tested for
exposure to HCV. Between 1999 and 2002 antibody HCV negative IDUs (
368) were enrolled and followed-up every
3–6 months until seroconversion or study completion.
Interviewer-administered baseline and follow-
up questionnaires consisted of 131 items and included demographics, drug use and risk behaviour. Approximately
10 cc of whole blood was drawn at each visit. Specimens were stored at
70C and serology performed using one or
two third-generation enzyme-linked immunosorbent assays and polymerase chain reaction testing.
seroconversions were observed and incidence was 30.8 per 100 person-years, with incidence in IDUs injecting
1 year, 133 per 100 person-years. Independent predictors of seroconversion were female gender, duration of injecting,
injecting cocaine, shared use of filters and recruitment strategy.
Women, new initiates and IDUs
recruited via outreach appear to be at increased risk of infection. Results confirm the significance of cocaine injection
as a risk factor and provide the first evidence outside North America of the link between shared use of drug preparation
equipment and incident HCV infection. Prevention efforts should attempt to raise awareness of the risks associated
with drug sharing and, in particular, the role of potentially contaminated syringes in HCV infection.
Hepatitis C, drug use, risk factors, seroconversion