The importance of virus-B as a cause of acute hepatitis in South African Blacks was determined by examining the serum of 147 patients during the acute stage of the illness for the presence of hepatitis-B antigen (HBAg). The antigen was found in 54% of 63 children and 65% of 83 adults with this disease. It is suggested that the relative predominance of virus-B hepatitis in Blacks is related to the high HBAg carrier rate in this population. The majority of patients with virus-B hepatitis did not give a history of parenteral exposure to the infectious agent, emphasising the importance of non·parenteral spread of virus-B.S. Afr. Med. J., 48, 1837 (1974)
