title: Individual and couple-level risk factors for hepatitis C infection among heterosexual drug users: a multilevel dyadic analysis.
abstract: BACKGROUND
  Hepatitis C virus (HCV) is the most common bloodborne pathogen in the United States and is a leading cause of liver-related morbidity and mortality. Although it is known that HCV is most commonly transmitted among injection drug users, the role of sexual transmission in the spread of HCV remains controversial because of inconsistent findings across studies involving heterosexual couples.
  
  
  METHODS
  A novel multilevel modeling technique designed to overcome the limitations of previous research was performed to assess multiple risk factors for HCV while partitioning the source of risk at the individual and couple level. The analysis was performed on risk exposure and HCV screening data obtained from 265 drug-using couples in East Harlem, New York City.
  
  
  RESULTS
  In multivariable analysis, significant individual risk factors for HCV included a history of injection drug use, tattooing, and older age. At the couple level, HCV infection tended to cluster within couples, and this interdependence was accounted for by couples' drug-injection behavior. Individual and couple-level sexual behavior was not associated with HCV infection.
  
  
  CONCLUSIONS
  Our results are consistent with prior research indicating that sexual contact plays little role in HCV transmission. Rather, couples' injection behavior appears to account for the clustering of HCV within heterosexual dyads.
authors.affiliation: National Development and Research Institutes, New York, NY 10010, USA. mcmahon@ndri.org
authors.forename: James M
authors.initials: JM
authors.lastname: McMahon
authors.forename: Enrique R
authors.initials: ER
authors.lastname: Pouget
authors.forename: Stephanie
authors.initials: S
authors.lastname: Tortu
mesh_terms: D000328:Adult; D005191:Family Characteristics; D005260:Female; D016174:Hepacivirus / Q000276:immunology* / Q000302:isolation & purification; D006526:Hepatitis C / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D018937:Hepatitis C Antibodies / Q000097:blood*; D020010:Heterosexuality; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009519:New York City / Q000453:epidemiology; D012307:Risk Factors; D012309:Risk-Taking; D012725:Sexual Behavior; D015819:Substance Abuse, Intravenous / Q000150:complications*
chemical_list: D018937:Hepatitis C Antibodies