Incidence and Risk Factors for Hepatitis C Virus Infection among Illicit Drug Users in Italy
So far, only three small outdated studies have investigated hepatitis C virus (HCV) incidence and risk factors among illicit drug users (DUs) in Italy. Thus, during 2007–2010, we conducted a prospective cohort study among DUs attending 17 Italian rehabilitation centers serving urban areas. Two hundred eighty-four HCV-uninfected DUs were prospectively followed by interview and anti-HCV antibody and RNA testing every 6 months. Incidence was calculated using the person-years method. Infection predictors were assessed by time-dependent Cox analysis. Participants were mostly male (83.4%), under opioid substitution therapy (OST) (78.9%), non-injecting DUs (67.9%), and with a mean age of 30.8. Ninety-one of 224 DUs initially under OST interrupted treatment during the follow-up. Overall HCV incidence was 5.83/100 person-years at risk (PYAR) [95% confidence intervals (CI), 3.63–9.38]. The incidence did not significantly differ according the participants’ sociodemographic characteristics or the degree of urbanization of the towns involved in the study. The incidence was higher for DUs under than for those not under OST (6.23 vs 4.50/100 PYAR; p = 0.681). Incidence was also higher for those with than for those without OST interruption (7.17 vs 5.04/100 PYAR; p = 0.55). However, all these differences were non-significant. At last follow-up visit, a significant decrease in frequency of sharing equipment for preparation/using drugs (by injection or not) was observed by analyzing either the whole cohort or DUs under OST only. Anti-HCV seroconversion resulted independently associated with sharing drug preparation/use equipment, backloading, having a HCV-positive sexual partner, or household and (marginally) intravenous injection. In this study, HCV incidence was non-negligible and OST seemed to lack effectiveness in reducing it. In Italy, implementation of combined harm reduction interventions and antiviral treatment of chronically infected DUs would be needed.
KeywordsHepatitis C virus Illicit drug use Incidence Opioid substitution treatment Risk factors Seroconversion
The authors thank F. D’angelo e F. Marzolini for secretarial and technical assistance.
Spada and Rezza are with the Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy; Garbuglia and Capobianchi are with the Laboratory of Virology, National Institute for Infectious Diseases “Lazzaro Spallanzani,” IRCCS, Rome, Italy; Lombardo and Menniti Ippolito are with the National Centre of Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità, Rome, Italy; Zuccaro is with the Medical Affairs Department, MSD Italia, Rome, Italy; Cupellaro is with the Local Health Unit of Latina, Latina, Italy; Capone, Nicosia, and Folgori are with the ReiThera S.r.l, Rome Italy; Nicosia and Cortese are with Keires AG, Basel, Switzerland; Nicosia is with CEINGE, Naples, Italy; Nicosia is with the Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy; Mele is with the Calabria Association of Hepatology, Reggio Calabria, Italy.
Other members of the collaborative study group are the following persons and institutions:
Carlo De Mei (Drug Dependency Service of Latina); Angela Coia (Drug Dependency Service of Priverno, Latina); Vittorio Santi (Drug Dependency Service of Formia, Latina); Marco Masci (Drug Dependency Service of Terracina, Latina); Anna Maria Cioce (Drug Dependency Service of Aprilia, Latina); Vincenzo Mellace, Egidio Battaglia, Franco Montesano (Drug Dependency Service of Soverato, Catanzaro); Vincenzo Biancolilli (Drug Dependency Service of Benevento); Pasquale Farina (Drug Dependency Service of Anzio, Roma); Marco Cuccuini (Drug Dependency Service of Terni); Giuliano Dozzini (Drug Dependency Service of Foligno, Perugia); Antonio De Luna (Drug Dependency Service of Battipaglia, Salerno); Raffaele Lovaste, Silvana Chiasera (Drug Dependency Service of Trento); Antonia Cinquegrana, EnricoElba, Elisabetta Secchi (Drug Dependency Service of Brescia); Umberto Nizzoli, Angela Zannini (Drug Dependency Service of Reggio Emilia); Henri Margaron, Lucia Mancino (Drug Dependency Service of Livorno); Salvatore De Masi (Public Health Care Districts of Livorno); Salvatore Lobello, Andrea Vendramin (Drug Dependency Service of Padova).
This study was supported in part by grants from the Isituto Superiore di Sanità-National Institute of Health Collaborative Programme (“Novel strategies toward developing a prophylactic and therapeutic vaccine against hepatitis C virus”; fasc. 30F3.
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