The prevalence and long term outcome of occult hepatitis B virus infections in community based populations

Features of occult hepatitis B infection in community‐based populations have yet to be described. In this study we documented: (1) the prevalence and demographics, (2) associated serology and viral loads, and (3) clinical outcomes of occult hepatitis B infection in community‐based populations. Hepatitis B surface antigen (HBsAg)‐negative sera collected from three Northern Canadian communities (HBsAg prevalences: 11–12%) in 1983–1985 were tested for HBV‐DNA by nested stage polymerase chain reaction. Of 706 HBsAg negative sera, 9 (1.3%) were HBV‐DNA positive. The median age of occult hepatitis B infected patients at the time of sampling was 9.8 years (range 3.1–50.4 years) and six (67%) were female. Two (22%) individuals were anti‐HBs positive (in the absence of prior vaccination). Viral loads were undetectable in all but two samples (2.40 and 2.86 log₁₀ IU/ml). Only one of the five (20%) patients who were assessed clinically, remained HBV‐DNA positive at 25–30 year follow‐up. There was no clinical, biochemical or radiologic evidence of chronic hepatitis, cirrhosis or hepatocellular carcinoma in these individuals or on review of the charts from the remaining four infected patients. The results of this study suggest that in community‐based populations: (1) occult hepatitis B infection is not as common as HBsAg positive infection, (2) the majority of infected subjects are young females, (3) a minority are anti‐HBs positive, (4) viral loads are either undetectable or low, and (5) in the absence of concurrent liver disease, occult hepatitis B infection does not appear to be associated with long term adverse clinical outcomes. J. Med. Virol. 84:1369–1375, 2012. © 2012 Wiley Periodicals, Inc.