title: Prevalence of occult hepatitis B virus infection in hemodialysis patients in Isfahan, Iran.
abstract: BACKGROUND
  The absence of a detectable hepatitis B surface antigen (HBsAg) with or without hepatitis B core antibody (anti-HBc) or hepatitis B surface antibody (anti-HBs) in the presence of hepatitis B virus-DNA (HBV-DNA) is defined as occult HBV infection. This study was aimed to evaluate the prevalence of occult HBV infection in patients receiving hemodialysis (HD) in Isfahan, Iran.
  
  
  METHODS
  This cross sectional study was done on 400 patients without acute or chronic HBV infection with end-stage renal disease undergoing regular HD. Blood samples were collected prior to the HD session, and serological markers of viral hepatitis B included HBsAg, anti-HBs and anti-HBc were measured using standard third generation commercially available enzyme immunoassays kit, then samples of positive anti-HBc and negative anti-HBs were tested for HBV DNA using quantitative real-time polymerase chain reaction techniques. Data were analyzed by SPSS usingt-test and Chi-square test.
  
  
  RESULTS
  The mean age of patients was 51.6 ± 11.2 years. Anti-HBc positive was observed in 32 (8%) of 400 studied patients with negative HBsAg. Of 32 patients with anti-HBc positive, 15 were males and 17 were females with mean age of 49.7 ± 12.6 years. Among 32 patients with anti-HBc positive, 10 patients were negative for anti-HBs. All of 10 patients were negative for HBV DNA. The prevalence of occult HBV infection was 0%.
  
  
  CONCLUSIONS
  The prevalence of occult HBV infection in HBsAg negative patients undergoing HD was 0% and look to be among the lowest worldwide. So, occult HBV infection is not a significant health problem in HD patients in this region.
authors.affiliation: Department of Gastroenterology, Isfahan Liver Disease Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Kalantari
authors.affiliation: Department of Internal Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Faezeh
authors.initials: F
authors.lastname: Ferdowsi
authors.affiliation: Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Yaran
keywords: Hemodialysis; hepatitis B core antibody; hepatitis B surface antibody; hepatitis B virus DNA; occult hepatitis B