title: Total numbers of undiagnosed carriers of hepatitis C and B viruses in Japan estimated by age- and area-specific prevalence on the national scale.
abstract: OBJECTIVE
  To estimate total numbers of undiagnosed carriers of hepatitis C virus (HCV) and hepatitis B virus (HBV) in Japan.
  
  
  METHODS
  Area- and age-specific prevalence of HCV as well as HBV was determined in the first-time blood donors [20-39 years (n = 2,429,364)] and examinees of periodical health check-ups [40-74 years (6,204,968 for HCV and 6,228,967 for HBV)] in Japan. Prevalence in adolescents [5-19 years (79,256 for HCV and 68,792 for HBV)] was determined in a single prefecture, and that of HCV in the elderly (≥ 75 years) was estimated by the exponential model. HBV infection was determined by the detection of hepatitis B surface antigen, and HCV infection by either the algorithm or assuming persistent infection in 70% of the individuals with antibody to HCV.
  
  
  RESULTS
  Of the total population of 127,285,653 in 2005, 807,903 (95% CI 679,886-974,292) were estimated to be infected with HCV at a carrier rate of 0.63%, and 903,145 (837,189-969,572) with HBV at that of 0.71%.
  
  
  CONCLUSIONS
  Accurate estimation of undiagnosed HCV and HBV carriers in the general population would help to predict the future burden of liver disease, and take appropriate measures for improving healthcare.
authors: Department of Epidemiology, Infectious Disease Control and Prevention, Hiroshima University Graduate School of Biomedical Sciences, Japan. jun-tanaka @ hiroshima-u.ac.jp
authors: Junko
authors: J
authors: Tanaka
authors: Tomiko
authors: T
authors: Koyama
authors: Masaaki
authors: M
authors: Mizui
authors: Shigeru
authors: S
authors: Uchida
authors: Keiko
authors: K
authors: Katayama
authors: Junko
authors: J
authors: Matsuo
authors: Tomoyuki
authors: T
authors: Akita
authors: Ayumu
authors: A
authors: Nakashima
authors: Yuzo
authors: Y
authors: Miyakawa
authors: Hiroshi
authors: H
authors: Yoshizawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001782:Blood Donors; D002353:Carrier State / Q000453:epidemiology* / Q000821:virology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005843:Geography; D006509:Hepatitis B / Q000453:epidemiology*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006526:Hepatitis C / Q000453:epidemiology*; D018937:Hepatitis C Antibodies / Q000097:blood; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015995:Prevalence; D055815:Young Adult
chemical_list: D006514:Hepatitis B Surface Antigens; D018937:Hepatitis C Antibodies