title: Serological characterization of occult hepatitis B virus infection among blood donors in India.
abstract: BACKGROUND
  Discovery of hepatitis B infections characterized by the presence of viral genome without detectable HBsAg (Occult Hepatitis; OBI) has initiated a considerable amount of research in this regard. Our study is a serological and molecular characterization of OBI among the donors who donated at our blood bank during the study period.
  
  
  METHODS
  During the study period HBsAg ELISA non reactive ID-NAT reactive donors samples were screened for presence of antibody against HBc, HBs and HBe. Molecular analysis of these NAT yield samples was undertaken for detection of the viral load and genotyping.
  
  
  RESULTS
  We studied 28,134 HBsAg ELISA non reactive donor samples. On testing them with ID-NAT, HBV DNA was detected in 25 samples. Eighteen samples out of these 25 NAT yield were further worked up. The 66.6% of the NAT yield samples (12 out of 18) were reactive for antibody against HBc. The 25% (3 out of 12) of these NAT yield samples having antibody against core antigen also had antibody against HBs. The 27.7% (5 out of 18) of NAT yield detected by ID-NAT did not have any detectable serological marker in blood. Four out of 12 core antibody positive NAT yield samples had genotype A HBV infection.
  
  
  CONCLUSIONS
  As per our study molecular detection of HBV DNA by ID-NAT, we were able to analyze 18 HBV NAT yield cases among 28,134 HBsAg ELISA non reactive donors. Out of 18, 12 donors were OBI whereas the rest (6) were in window period (WP yield) of HBV infection. One out of every 3.6 NAT yield detected by ID-NAT was non reactive for all serological markers.
authors.affiliation: Blood Bank, Post Graduate Institute of Medical Education and Research (PGIMER), Dr Ram Manohar Lohia Hospital, New Delhi, India. Electronic address: veenadoda@gmail.com.
authors.forename: Veena
authors.initials: V
authors.lastname: Doda
authors.affiliation: Blood Bank, Post Graduate Institute of Medical Education and Research (PGIMER), Dr Ram Manohar Lohia Hospital, New Delhi, India.
authors.forename: Satyam
authors.initials: S
authors.lastname: Arora
authors.affiliation: Blood Bank, Post Graduate Institute of Medical Education and Research (PGIMER), Dr Ram Manohar Lohia Hospital, New Delhi, India.
authors.forename: Tapannidhi
authors.initials: T
authors.lastname: Kirtania
mesh_terms: D001782:Blood Donors; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D006509:Hepatitis B / Q000097:blood*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006515:Hepatitis B virus; D006801:Humans; D007194:India; D008297:Male
chemical_list: D004279:DNA, Viral; D006510:Hepatitis B Antibodies
keywords: Blood bank; Hepatitis B; NAT; OBI; TTI