Occult Hepatitis B Infection

Abstract

Occult hepatitis B infection is a unique disease entity defined by detectable hepatitis B virus DNA in the sera and/or livers in subjects who are negative for HBsAg. OBI can be classified by serology. It can also be classified according to the medical history of the subjects. Majority of subjects with OBI have had chronic hepatitis B infection with subsequent loss of HBsAg during the natural history of disease or as a result of antiviral treatment. There are still challenges in diagnosing this condition in many service-based laboratories. The prevalence of OBI was estimated to be ranging from <1 to 18% in general population. The HBV usually replicates at an extremely low level due to various postulated mechanisms. The clinical significance of OBI is particularly prominent in three main areas: (1) transmission of HBV through blood and organ donations, (2) development of chronic liver diseases and liver-related mortality and (3) HBV reactivation during immunosuppressive therapy. With the use of more potent immunosuppressive therapies including B-cell depleting agents, the disease manifestations become more apparent which require more research to establish clinical management guidelines.