Type B hepatitis in Iran.

Hepatitis B surface antigen (HBsAg) was found in 1% of controls, 2.1% of professional blood donors, 2.0% of leprosy patients and 76.1% of acute hepatitis in Tehran and Mashhad, Iran. All HBsAg positive samples also possessed antibody to the hepatitis B core antigen and all were subtype ayw. Type B hepatitis and the HBsAg state are frequent in Iran, but most must be accounted for by "non-parenteral" or inapparent" parenteral exposure.