[Hepatitis B infections in families of carriers].

To examine the transmission of hepatitis B virus in families of carriers of hepatitis B surface antigen epidemiologic and serologic data were obtained on 209 household contacts of 106 carriers. 97 relatives (46.4%) showed signs of infection, 39 became chronic carriers too. Brothers and sisters are at the highest risk of infection within the families. Household contacts of chronic carriers should be considered a high-priority group to receive the hepatitis B vaccine.