Objective: To investigate the prevalence of occult HBV infection among subjects with normal serum ALT levels in South Korea.
Methods: A total of 195 serum samples were collected from subjects without a past history of alcohol abuse and with normal serum ALT levels. They were negative for HBsAg, anti-HCV, and anti-HIV. HBV-DNA was detected from sera by nested polymerase chain reaction (PCR) using specific primers of the surface antigen region of the HBV genome. We performed a quantitation assay using hybrid capture II test to determine the levels of serum HBV-DNA.
Results: HBV-DNA was detected in 31 of 195 subjects (16%). Prevalence of occult hepatitis B was significantly higher in the male subjects (23%) than in the female (8%), (P<0.05). We were able to detect HBV-DNA in 15% (7/47) even in which sera were all negative for anti-HBs and IgG anti-HBc. Serum HBV-DNA levels were as high as 10(5) copies/mL in 18 of 31 subjects (58%) with occult HBV infection.
Conclusions: The prevalence of occult HBV infection and their HBV-DNA levels were significantly high among subjects with normal serum ALT levels in South Korea. 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.