title: Prevalence, risk factors and genotypes of hepatitis C virus infection among drug users, Central-Western Brazil.
abstract: OBJECTIVE
  To estimate prevalence of hepatitis C virus (HCV) infection and identify risk factors associated and circulating HCV genotypes and subtypes.
  
  
  METHODS
  Study conducted including 691 drug users attending 26 charitable, private and public drug treatment centers in Goiânia and Campo Grande, central-western Brazil, between 2005 and 2006. Sociodemographic characteristics and risk factors for HCV infection were collected during interviews. Blood samples were tested for HCV antibodies (anti-HCV). Positive samples were submitted to HCV RNA detection by PCR with primers complementary to 5' NC and NS5B regions of viral genome and genotyped by line probe assay (LiPA) and direct nucleotide sequencing followed by phylogenetic analysis. The prevalence and odds ratio were calculated with 95% confidence intervals. Risk factors were first estimated in the univariate analysis (p<0.10) and then analyzed by hierarchical logistic regression. Statistical significance was assessed at a 5% significance level.
  
  
  RESULTS
  The prevalence of anti-HCV was 6.9% (95% CI: 5.2-9.2). The multivariate analysis of risk factors revealed that age over 30 years and injecting drug use were associated with HCV infection. HCV RNA was detected in 85.4% (41/48) of anti-HCV-positive samples. Thirty-three samples were genotyped as genotype 1 by LiPA, subtypes 1a (63.4%) and 1b (17.1%), and 8 samples (19.5%) were genotype 3, subtype 3a. The phylogenetic analysis of the NS5B region showed that 17 (68%), 5 (20%), and 3 (12%) samples were subtypes 1a, 3a, and 1b, respectively.
  
  
  CONCLUSIONS
  The results show a high prevalence of HCV infection and predominance of subtype 1a among drug users in Brazil. In addition, injecting drug use was a major risk factor associated with HCV infection.
authors: Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás (UFG), Goiânia, GO, Brasil.
authors: Carmen L R
authors: CL
authors: Lopes
authors: Sheila A
authors: SA
authors: Teles
authors: Márcia P
authors: MP
authors: Espírito-Santo
authors: Elisabete
authors: E
authors: Lampe
authors: Fabiana P
authors: FP
authors: Rodrigues
authors: Ana Rita C
authors: AR
authors: Motta-Castro
authors: Thaís A
authors: TA
authors: Marinho
authors: Nádia R
authors: NR
authors: Reis
authors: Agabo M C
authors: AM
authors: Silva
authors: Regina M B
authors: RM
authors: Martins
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D055030:Drug Users / Q000706:statistics & numerical data*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D006526:Hepatitis C / Q000453:epidemiology* / Q000821:virology; D018937:Hepatitis C Antibodies; D006801:Humans; D015151:Immunoblotting; D008297:Male; D015999:Multivariate Analysis; D015995:Prevalence; D012367:RNA, Viral / Q000235:genetics; D012307:Risk Factors; D012959:Socioeconomic Factors; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*
chemical_list: D018937:Hepatitis C Antibodies; D012367:RNA, Viral