title: Identification of chronic hepatitis B and hepatitis C co-infection in British Columbia from 1991 to 2007.
abstract: OBJECTIVE
  To determine the chronic HBV/HCV co-infection identification rate in British Columbia, and examine the demographic characteristics, the order of virus identification, and trends of co-infection over time.
  
  
  METHODS
  All newly identified cases of chronic HBV/HCV co-infection between 1991 and October 2007 were extracted from the BC integrated Public Health Information System. Differences according to sex and order of hepatitis identification were evaluated using chi-square, t-tests, and ANOVA.
  
  
  RESULTS
  Of 1,815 HBV/HCV co-infected residents, 71.6% were male and the mean age at co-infection diagnosis was 40.5 years (95% CI, 40.0-41.0; range 3-85 years). Among all persons identified with HCV infection, 3.1% were identified as co-infected with HBV and 5.2% of all chronic HBV-infected were diagnosed with HCV. Annual co-infection identification rates peaked at 5.3 per 100,000 in 1996. Females were significantly younger when they were first diagnosed with a hepatitis virus (p=0.0005) at 35.2 years (95% CI, 34.0-36.5; range 3-79 years) than males at 37.9 years (95% CI, 37.0-39.7; range 4-85 years). The majority of co-infections consisted of concurrent diagnoses until 2003; since then, the number of co-infected cases identified with HBV first, HCV first and concurrent virus identification is similar.
  
  
  CONCLUSIONS
  HBV/HCV co-infection identification rates have declined since the late 1990s, but appropriate testing and identification for both viruses are important. Some co-infection cases may be prevented through HBV vaccination and harm reduction activities for those with or at risk for HCV.
authors.affiliation: British Columbia Centre for Disease Control, Vancouver, BC.
authors.forename: Lily
authors.initials: L
authors.lastname: Fang
authors.forename: Amanda
authors.initials: A
authors.lastname: Yu
authors.forename: Jane A
authors.initials: JA
authors.lastname: Buxton
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001955:British Columbia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D005260:Female; D019694:Hepatitis B, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D019698:Hepatitis C, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D006801:Humans; D008297:Male; D008875:Middle Aged; D011634:Public Health; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult