Prevalence of occult hepatitis B virus infection among hepatopathy patients and healthy people in China.

Objective: To investigate the prevalence of occult hepatitis B virus (HBV) infection among hepatopathy patients and healthy people in China.

Methods: The HBV DNA in 653 sera samples collected from cryptogenic chronic liver disease patients (159), hepatitis B surface antigen (HBsAg) negative hepatocellular carcinoma (HCC) patients (135) and HBsAg-negative healthy people (359) were tested by nested PCR using specific primers of the X region of the HBV genome. We performed real-time PCR to determine the levels of serum HBV-DNA.

Results: Prevalence of occult HBV infection was 28.3% (45/159), 70.4% (95/135) and 10.6% (38/359) in cryptogenic chronic liver disease patients, HBsAg-negative HCC patients and HBsAg-negative healthy people, respectively. The prevalence of occult HBV infection in IgG anti-HBc-positive subjects was 100% (45/45), 86.7% (85/98) and 33.3% (14/42) in cryptogenic chronic liver disease patients, HBsAg-negative HCC patients and HBsAg-negative healthy people, respectively. In all cases, viral loads were low (<10(4)viral copies/mL).

Conclusion: The prevalence of occult HBV infection was significantly high among hepatopathy patients and healthy people in China. Thus, more meticulous attention should be given to prevent HBV transmission by blood transfusion or organ transplantation in endemic areas, and further studies on clinical implication and mechanism of occult HBV infection are required.