title: Risk Factors of Hepatitis C Virus Infection in Drug Users From Eleven Methadone Maintenance Treatment Clinics in Xi'an, China.
abstract: BACKGROUND
  Hepatitis C virus (HCV) infection rates in drug users vary among different regions of China. Drug users who are unaware of their HCV serostatus tend to engage in more risky behaviors.
  
  
  OBJECTIVE
  This prospective study aimed to assess risk factors of HCV infection in drug users among 11 methadone maintenance treatment (MMT) clinics in Xi'an, China.
  
  
  METHODS
  Baseline characteristics and drug use information of patients were collected upon enrollment in the study and anti-HCV tests were performed within one month after the enrollment. Data on daily medication, monthly random urine morphine test results, illicit drug use and MMT retention time were recorded during a 5-year follow-up.
  
  
  RESULTS
  Of 10243 patients, 58.0% had positive results for anti-HCV. Injection drug use, longer duration of drug abuse, older age, female gender, unmarried status and unemployment were independent risk factors of HCV infection. Urine test positivity rate was lower (14.8% vs. 16.7%, χ(2) = 100.235, P < 0.05), but MMT retention rate was higher (log-rank χ(2) = 4.397, P < 0.05) in the anti-HCV positive group than anti-HCV negative one. However, multivariate regression revealed no significant association between anti-HCV serostatus and either MMT retention time or illicit drug use.
  
  
  CONCLUSIONS
  The major risk factor of HCV infection was injection drug use. The patient's awareness of his or her HCV status had a minor effect in reduction of illicit drug use and improvement in MMT retention. Therefore, adequate counseling is necessary for drug users in MMT clinics in Xi'an.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, China ; Xi'an Center for Disease Control and Prevention, Xi'an, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiaoli
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Lirong
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Xueliang
authors.affiliation: Xi'an Center for Disease Control and Prevention, Xi'an, China.
authors.forename: Li
authors.initials: L
authors.lastname: Jinsong
authors.affiliation: Xi'an Center for Disease Control and Prevention, Xi'an, China.
authors.forename: Li
authors.initials: L
authors.lastname: Hengxin
authors.affiliation: Methadone Maintenance Therapy Clinic, Xi'an Mental Health Center, Xi'an, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Wei
keywords: Drug User; Injection; Maintenance; Methadone; Treatment