Hepatitis B virus (HBV) infection remains to be a serious public health problem in China. There used to be a high prevalence of HBV infection in China, which resulted in a large number of HBV susceptible and post-infected population. Single anti-HBc positive usually indicates post HBV infection and its prevalence is particularly high among people over 40 years old, some of whom may be occult hepatitis B virus infection (OBI). The clinical diagnosis of OBI is difficult and easily missed. Since OBI may cause chronic liver disease progression and even lead to cirrhosis and hepatocellular carcinoma eventually, and more importantly, patients with OBI may leed to HBV reactivation when the immune function decreases or immunosuppressive therapy is performed, the accurate identify of OBI is of particular importance. Moreover, OBI is the potential source of HBV infection, which may transmit through blood transfusion, organ transplantation and mother-to-child transmission. In view of this situation, we reviewed the mechanism, prevalence and definition of OBI, and proposed a determination system for replication-competent HBV DNA based on our understanding of the updated OBI definition. It is expected to be beneficial for OBI diagnosis, treatment and management.
乙型肝炎病毒（HBV）感染是我国重大的公共卫生问题，我国曾经是HBV感染高流行区，而且存在一定比例的HBV易感染人群和既往感染，单项抗-HBc阳性人群，特别是在40岁以上人群中比例较高，其中一些人可能为HBV隐匿性感染者（OBI）。OBI临床诊断较困难，但这种隐匿感染却可使疾病慢性进展，最终导致肝硬化，甚至肝细胞癌的发生。在免疫机能下降或进行免疫抑制治疗时可能导致OBI患者HBV的复燃。而且，OBI患者是潜在的HBV传染源，可通过输血、器官移植和母婴密切接触等方式进行传播。针对这一现状，我们对OBI的发生机制、流行趋势和定义的演变进行探讨，并提出我们对OBI定义的理解以及检测方法的改进，希望对OBI人群的诊疗及管理和HBV的防控有所益处。.
Keywords: Hepatitis B virus; Integration; Occult infection; Replication.