[Prevention of hepatitis B virus infection]

The incidence of the carrier of hepatitis B virus (HBV) in Japan is about ten times higher than that in U.S.A. and Western Europe. Countermeasures against HBV infection have been proposed on a national basis. The main route of HBV infection is due to contamination of blood and secretion from the carrier of HBV. The contamination would occur in many circumstances such as in the case of blood transfusion, needle accidents in hospital, vertical infection from mother to baby at the time of delivery and infection within family members. To prevent the posttransfusion hepatitis due to HBV, rapid and high sensitive measurement of HBs antigen should be introduced. Countermeasures have begun against the vertical infection from mother to baby at the time of delivery by the National Treasury. Already, a good result has been obtained. Recently the vaccination against HBV is generally performed. However, a low incidence of people have a high anti-HBs titer for a long period. The new countermeasure against this problem should be worked up as soon as possible.