Quantitative analysis of hepatitis B virus DNA in saliva and semen of chronically infected homosexual men.

Serum, saliva, and semen from fifteen homosexual men who were chronic surface antigen (HBsAg) carriers were quantitatively assayed for hepatitis B virus (HBV) DNA by Southern analysis. HBV DNA (2 pg/ml-42,000 pg/ml) was detected in 11 carriers and correlated with endogenous DNA polymerase activity and e antigen (HBeAg) titer greater than or equal to 1:640. Viral DNA was detected in the saliva, at concentrations indicating a virus titer of 10(5)-10(7)/ml, of eight carriers and in semen from three patients (10(6)-10(7) virions/ml). HBV DNA in saliva and semen had electrophoretic mobilities similar to those in serum HBV DNA, but HBV DNA was present at much lower concentrations (10(-2)-10(-4) that of serum DNA). Results of isopycnic centrifugation suggested that DNA in saliva and semen was virion associated. These data provide an indication of the quantity of virus present in the semen and saliva of HBV carriers and the relative frequency with which shedding of high titers of virus (greater than 10(5) virions/ml) occurs in these secretions.