title: Prevalence and characterization of occult hepatitis B infection among blood donors in central Saudi Arabia.
abstract: OBJECTIVE
  To evaluate the prevalence of occult hepatitis B viral infections (OBIs)  among blood donors considering the clinical and epidemiological importance of identifying OBIs.
  
  
  METHODS
  A cross-sectional study conducted at King Khalid University Hospital, Riyadh, Saudi Arabia between January 2011 and January 2012. Blood donors (n=8501) were screened for Hepatitis B virus surface antigen (HBsAg) and hepatitis B core antibodies (HBcAb). All HBsAg-negative and HBcAb-positive samples were tested further for hepatitis B surface antibodies (HBsAb), hepatitis B virus (HBV)-DNA, and HBV genotyping.
  
  
  RESULTS
  Of the 8501 serum samples tested, 56 (0.7%) were positive and 8445 (99.3%) were negative for HBsAg. Among the HBsAg-negative samples, 198 (2.3%) were positive for HBcAb and these patients were suspected to have OBIs. Among the HBcAb-positive samples, 119 (60.1%) were positive while 79 (39.9%) were negative for HBsAb. Analysis of HBV-DNA for the suspected OBIs showed that 17 out of 198 samples (8.6%) yielded positive results, and all of them were HBsAb-negative. The viral load was low (less than 20-186 IU/mL) in all OBIs. Hepatitis B virus genotyping showed that 15 out of 17 samples (88.2%) were genotype D, and the other 2 samples (11.8%) were genotype E.
  
  
  CONCLUSIONS
  The prevalence of OBIs among blood donors in Riyadh was 0.2%. Therefore, it is recommended that HBV molecular testing should be incorporated with serological assays for screening of blood donors.
authors.affiliation: Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia. E-mail. areeg@ksu.edu.sa.
authors.forename: Areej I
authors.initials: AI
authors.lastname: Alshayea
authors.forename: Gamal E
authors.initials: GE
authors.lastname: Eid
authors.forename: Malak M
authors.initials: MM
authors.lastname: El-Hazmi
authors.forename: Abdulkarim F
authors.initials: AF
authors.lastname: Alhetheel
mesh_terms: D000328:Adult; D001782:Blood Donors; D003430:Cross-Sectional Studies; D005260:Female; D006509:Hepatitis B / Q000097:blood / Q000453:epidemiology*; D006510:Hepatitis B Antibodies / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D012529:Saudi Arabia / Q000453:epidemiology; D055815:Young Adult
chemical_list: D006510:Hepatitis B Antibodies