PREVALENCE OF HEPATITIS-C VIRUS IN PLASMA POOLS AND THE EFFECTIVENESSOF COLD ETHANOL FRACTIONATION

Screening blood donations for antibodies against hepatitis C virus (HC V) greatly reduces the risk of transmitting HCV by transfusions. Howev er, despite such screening programs, plasma pools still contain a high percentage of HCV ribonucleic acid as determined by polymerase chain reaction. This result would not be alarming if the procedures for prod ucing blood products included steps to inactivate or remove HCV. Altho ugh this appeared to be the case for all blood products, such as coagu lation factors and most immunoglobulins, which are subjected to an ina ctivation step, the effectiveness of the cold ethanol fractionation pr ocess still needed to be determined. In validation experiments using b ovine viral diarrhea virus as a model virus for HCV, we demonstrated t hat the Cohn-Oncley cold ethanol fractionation process neither inactiv ated nor removed this virus sufficiently. Our observations may help to explain how HCV was transmitted to a number of recipients of intraven ous immunoglobulin.