Hepatitis B surface antigen in human subretinal fluid.

Body fluids containing hepatitis B surface antigen are considered to be potential sources of hepatitis B infection. This antigen has been detected in blood, oral secretions, synovial fluid, urine, feces, bile cerebrospinal fluid, pleural and peritoneal fluid, semen, vaginal secretions, breast milk, and tears. These fluids are probably not equally infectious, however, because the concentration of virus in a particular fluid may be low when compared to that in blood. For instance, in hepatitis B carriers whose tears were positive for hepatitis B surface antigen, the concentration of hepatitis B surface antigen in the tears averaged less than one-fifteenth the average value found in serum.