title: Detection of occult hepatitis B virus infection among blood donors in Sudan.
abstract: BACKGROUND
  Sudan is classified among countries with a high hepatitis B surface antigen (HBsAg) endemicity of more than 8%. Cross-sectional studies have showed a marked increase in the prevalence of occult hepatitis B infection (OBI) in patients with cirrhosis or hepatocellular carcinoma. In terms of OBI infectivity by transfusion, it is largely unknown whether residual risk estimates translate into true rates of infection.
  
  
  OBJECTIVE
  The current study aimed to determine the frequency of OBI among blood donors in Sudan.
  
  
  METHODS
  This study was carried out during the period between 2011 and 2012. It included 100 HBsAg-negative blood donors who attended the Central Blood Bank in Sudan. Sera collected from all donors were tested for HBsAg, antibodies against hepatitis B core antigen (anti-HBc), antibodies against hepatitis Be antigen (anti-HBe), and antibodies against hepatitis B surface antigen (anti-HBs) by enzyme-linked immunosorbant assay. Anti-HBc-positive patients were tested for hepatitis B virus (HBV)-DNA.
  
  
  RESULTS
  The anti-HBc was detected in 42% of the blood donors, among whom 90.5% were positive for HBV-DNA. Two main profiles have been detected, namely, the presence of the three genes (S, C, and X genes) together in 35.7% of the blood donors or the presence of the X gene in addition to the core gene.
  
  
  CONCLUSIONS
  With the use of HBsAg as the sole detection marker for HBV, there is a danger of HBV transmission through blood transfusion. Anti-HBc testing should be added to the routine blood donor screening test if occult hepatitis B is to be diagnosed.
authors.affiliation: aDepartment of Microbiology Medical Research Institute, University of Alexandria, Alexandria, Egypt bDepartment of Haematology, Faculty of Medicine, University of Elimam Elmahdi, Kosti cMedical Laboratory Science, University of Khartoum, Khartoum, Sudan.
authors.forename: Ola
authors.initials: O
authors.lastname: Abd El Kader Mahmoud
authors.forename: Abeer
authors.initials: A
authors.lastname: Abd El Rahim Ghazal
authors.forename: Dalia
authors.initials: D
authors.lastname: El Sayed Metwally
authors.forename: Ahmed Mohamed
authors.initials: AM
authors.lastname: Elnour
authors.forename: Ghanim Eltahir Ahmed
authors.initials: GE
authors.lastname: Yousif
mesh_terms: D001782:Blood Donors; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000097:blood; D006509:Hepatitis B / Q000175:diagnosis; D006515:Hepatitis B virus / Q000235:genetics; D006801:Humans; D008113:Liver Neoplasms; D013397:Sudan
chemical_list: D004279:DNA, Viral