Equal susceptibility of males and females on Santa Cruz Island to the carrier state of hepatitis B surface antigen.

Various studies have shown that hepatitis B surface antigen is detected more frequently in the blood of asymptomatic males than in that of asymptomatic females. The reason for this difference might be that males are more frequently infected than females or that males more frequently become asymptomatic carriers when they are infected. The sex distribution of hepatitis B surface antigen and antibody, as measured by reversed passive hemagglutination and passive hemagglutination, was determined in a Melanesian population. The frequency of the antigen was higher among males, but the ratio of antigen to antibody was the same in both sexes. This finding indicated that the higher frequency in males was due to a higher rate of infection rather than to a greater susceptibility of the males to the chronic carrier state.