title: Occult hepatitis B among Iranian hepatitis C patients.
abstract: BACKGROUND
  Occult hepatitis B is defined as presence of HBV DNA in tissue or serum without hepatitis B surface antigen. The aim of this study is to determine frequency of occult hepatitis B among hepatitis C patients in Tehran and compare the route of transmission and liver enzymes between positive and negative HBV DNA patients.
  
  
  METHODS
  In a cross sectional study, serum of 103 hepatitis C cases (79.6% men and 20.4% women) were analyzed for s, x and core genes via a nested polymerase chain reaction technique.
  
  
  RESULTS
  HBV DNA was detectable in serum of 20 patients (19.4%). No significant difference in age, sex and route of transmission were seen in HBV DNA positive and negative patients. In HBV DNA positive and negative groups, mean of AST was 73, 47 (p < 0.05) and mean of ALT was 76 and 36 respectively (p < 0.05).
  
  
  CONCLUSIONS
  Occult hepatitis B was observed in a considerable number of hepatitis C patients in Tehran. It was associated with elevation in liver enzyme but was not related to route of transmission.
authors.affiliation: Assistant Professor, Department of Internal Medicine, Isfahan University of Medical Science, Isfahan, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Shavakhi
authors.forename: Babak
authors.initials: B
authors.lastname: Norinayer
authors.forename: Fateme Sadat
authors.initials: FS
authors.lastname: Esteghamat
authors.forename: Mohamad
authors.initials: M
authors.lastname: Seghatoleslami
authors.forename: Mahsa
authors.initials: M
authors.lastname: Khodadustan
authors.forename: Mohamad Hosein
authors.initials: MH
authors.lastname: Somi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Masoodi
authors.forename: Mohamad Reza
authors.initials: MR
authors.lastname: Zali