Levels of viraemia in subjects with serological markers of past or chronic hepatitis B virus infection.

Subjects with serological markers for a past HBV infection may still have HBV DNA in their serum, but the levels of viraemia in such cases are not known. In the present study, of 63 consecutive HBsAg-negative, anti-HBc-positive serum samples with or without anti-HBs, 20 were HBV DNA-positive as analysed by a highly sensitive quantitative PCR, the Cobas Amplicor HBV Monitor test. However, all of these 20 samples had viraemia levels below 1000 copies/ml, compared with median viraemia levels of 10(8.6) and 10(4.3) copies/ml, respectively, in 98 HBeAg-positive and 124 HBeAg-negative HBsAg carriers. There was no difference in viraemia between subjects with anti-HBc alone compared with both anti-HBs and anti-HBc, nor between those with or without hepatitis C virus antibodies. The findings indicate that HBsAg-negative subjects may retain a low infectivity. Their risk for progressive liver damage is probably low, but this deserves further study.