The incident rate of post transfusion hepatitis (NANB-PTH) was reduced from 8.9% to 3.9% after the introduction of C100-3 antibody screening of blood for transfusion, and has become to 0% after the introduction of PHA screening.
A retrospective study of 385 units of blood transfused to 75 patients from 1988 to 1991, however, revealed the presence of HCV transmission which had not been prevented by PHA screening. Therefore, a major task for the future is to develop a measuring system highly specific to other antigenic epitopes.
Further, retrospective study indicated that the HCV infection did not occur even in some cases in which antibodies were present. This non-infectivity appears that the donors was infected in the past, and little of the HCV infective genome was present in the blood of the donors.
