Infection rate of HBV in the high-risk population, such as dentists and the patients undertaking hemodialysis, was not higher than those in general population. The occurrence of the subclinical infection state might be resulted from hypo-responsiveness of humoral and cellular immunity to HBsAg. Of 257 cases of liver biopsy, 44% of them were diagnosed as chronic hepatitis of various categories. No relationship was found between the expression patterns of viral antigens and the inflammatory activity in the liver. The infection state was quite stable. HBeAg/anti-HBe seroconversion was not a turning point from replicative to nonreplicative phase of the virus. The individuals with intrahepatic integrated HBV DNA might be the genome carriers with sero-negative HBsAg. The above results illustrate the characteristics of hyporesponsive HBV infection in hyperendemic area in China.

32P-HBV-DNA was used as a probe to determine HBV-DNA by molecular hybridization in the sera of 186 chronic asymptomatic HBsAg carriers (ASC). The result of HBV-DNA determination correlated closely with that of the HBeAg/anti-HBe system.The viral DNA was detected in 51(82.2%)of 62 HBeAg (+) cases but only in 1 of 103 anti-HBe ( + ) cases. The prevalence of HBV-DNA was directly proportional to the P/N ratio of RIA for HBeAg. When the P/N was above 8.1. its detection rate was 95.0%; when P/N below 5.0. it was only 12.5%. HBV-DNA determined by molecular hybridization was deemed to be a more direct proof of viral replication in ASC.