Abstract: | Serum specimens collected during the period from September 1970 to April 1971 from hospitalized patients and apparently healthy staff members at risk were tested for the presence of hepatitis-associated antigen (HAA) by the parallel use of three techniques: the complement fixation test, crossover-electrophoresis and immuno-electronmicroscopy.Out of a total of 204 persons investigated 63 (30.9%) were found to harbour the antigen. The HAA-positive sera originated almost exclusively from sporadic cases of acute viral hepatitis (clinically diagnosed as “infectious hepatitis” or “serum hepatitis”). The great majority of the hepatitis cases studied had a history of drug addiction. |