Screening for hepatitis B virus in healthy blood donors by molecular DNA hybridization analysis.

A DNA molecular hybridization technique employing a purified adw subtype hepatitis B virus (HBV) cloned DNA of 3.2 kilobase pairs as a probe was used to screen for the presence of HBV DNA in blood samples collected from 486 apparently healthy blood donors. Eighteen of 104 (17.3%) hepatitis B surface antigen (HBsAg) carriers and 7 of 382 (1.8%) HBsAg-negative individuals had circulating HBV DNA in their sera. Among the seven individuals who were positive for HBV DNA but negative for HBsAg, three had antibodies against both HBsAg (anti-HBsAg) and hepatitis B core antigen, one had only anti-HBsAg, one had both anti-hepatitis B core antigen and anti-hepatitis B e antigen and two were negative for all the above HBV markers. The results suggest that the absence of HBsAg in otherwise apparently healthy individuals may not be enough to ensure lack of circulating HBV.