[Epidemiologic significance of different categories of carriers of hepatitis B surface antigen (HBsAg). I. Role of reconvalescent HBsAg-positive viral hepatitis in the spread of infection].

133 convalescents, formerly hospitalized for HBsAG-positive viral hepatitis and discharged still with HBsAG in the blood serum, and 982 persons (665 children and 317 adults) having contacts with the convalescents in families and organized groups have been subjected to many-year complex observation, including epidemiological, clinical and laboratory examinations. As a result, chronic HBsAG carriers with the antigen persisting in their blood for a year or longer have been found to be epidemiologically more dangerous in conditions of inartificial infection. Most often children, especially those with prolonged persistence of HBsAG in the blood accompanied by the development of chronic infectious process in the liver, are the source of hepatitis B infection. Among their contact the greatest number of persons (mostly children) with the manifest form of the infection and with certain signs of hepatitis B can be found. Of these signs, the presence of HBsAG in the blood serum and increased activity of fructose-1-phosphate aldolase are most frequently detected in persons having contacts with HGsaG carriers.