title: Molecular and serological detection of occult hepatitis B virus among healthy hepatitis B surface antigen-negative blood donors in Malaysia.
abstract: BACKGROUND
  Occult hepatitis B infections are becoming a major global threat, but the available data on its prevalence in various parts of the world are often divergent.
  
  
  OBJECTIVE
  This study aimed to detect occult hepatitis B virus in hepatitis B surface antigen-negative serum using anti-HBc as a marker of previous infection.
  
  
  METHODS
  A total of 1000 randomly selected hepatitis B surface antigen-negative sera from blood donors were tested for hepatitis B core antibody and hepatitis B surface antibody using an ELISA and nested polymerase chain reaction was done using primers specific to the surface gene (S-gene).
  
  
  RESULTS
  Of the 1000 samples 55 (5.5%) were found to be reactive, of which 87.3% (48/55) were positive for hepatitis B surface antibody, indicating immunity as a result of previous infection however, that does not exclude active infection with escaped mutant HBV. Nested PCR results showed the presence of hepatitis B viral DNA in all the 55 samples that were positive for core protein, which is in agreement with the hepatitis B surface antibody result.
  
  
  CONCLUSIONS
  This study reveals the 5.5% prevalence of occult hepatitis B among Malaysian blood donors as well as the reliability of using hepatitis B core antibody in screening for occult hepatitis B infection in low endemic, low socioeconomic settings.
authors.affiliation: Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia; Medical Microbiology and Parasitology, Faculty of Basic Medical Sciences, College of Health Sciences, Usmanu Danfodiyo University Sokoto, 840232 Sokoto State, Nigeria.
authors.forename: Shuaibu A
authors.initials: SA
authors.lastname: Hudu
authors.affiliation: Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia; Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen.
authors.forename: Nabil S
authors.initials: NS
authors.lastname: Harmal
authors.affiliation: Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia.
authors.forename: Mohammed I
authors.initials: MI
authors.lastname: Saeed
authors.affiliation: Department of Basic Health Sciences, Faculty of Pharmacy, Northern Border Universiti, 91911 Rafha, Saudi Arabia.
authors.forename: Ahmad S
authors.initials: AS
authors.lastname: Alshrari
authors.affiliation: Department of Clinical Science, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Malaysia.
authors.forename: Yasmin A
authors.initials: YA
authors.lastname: Malik
authors.affiliation: Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia.
authors.forename: Mohd T
authors.initials: MT
authors.lastname: Niazlin
authors.affiliation: National Blood Centre Malaysia, Jalan Tun Razak Kuala Lumpur, 504000 Malaysia.
authors.forename: Roshida
authors.initials: R
authors.lastname: Hassan
authors.affiliation: Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia.
authors.forename: Zamberi
authors.initials: Z
authors.lastname: Sekawi
mesh_terms: D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay; D006509:Hepatitis B / Q000175:diagnosis* / Q000453:epidemiology; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood* / Q000235:genetics; D006515:Hepatitis B virus / Q000302:isolation & purification*; D006801:Humans; D008296:Malaysia / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D015995:Prevalence
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens
keywords: Hepatitis B; core antibody; occult hepatitis B infection; polymerase chain reaction; surface antigen