Occult hepatitis B virus infection in a North American community-based population

Background/Aims: Occult hepatitis B virus (HBV) infection [HBV-DNA detection in hepatitis B surface antigen (HBsAg)-negative individuals] may cause acute and/or chronic liver disease. The objective of this study was to document the prevalence of occult HBV in an isolated, North American Inuit community. Methods: Four hundred and eighty seven HBsAg negative sera (61% of the community population) were available for HBV-DNA testing by real time PCR. Of these, 80 (Group 1) had serologic evidence of resolved HBV infection and 407 (Group 2) were HBV-seronegative. Results: HBV-DNA was detected in 14/80 (18%) and S-variants in 12/14 (86%) samples from Group 1. In Group 2, HBV-DNA was detected in 33/407 (8.1%) and S-variants in 17/33 (52%). In all cases (Groups 1 and 2) viral loads were low (<10(5) viral copies/ml) and clinical or biochemical features did not distinguish HBV-DNA positive from negative individuals. However, S-variants were more common (P<0.0001) in older age groups. Conclusions: The results of this study indicate that in this community-based population; (1) the prevalence of occult HBV infection is 18% in those with serologic evidence of previous HBV infection and 8.1% in HBV seronegative individuals, (2) age, gender and liver biochemistry findings do not identify those with occult HBV and (3) S-variants are present in the majority of individuals with occult HBV. (C) 2005 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.