SYSTEMATIC REVIEW OF ROLE OF POLYMERASE CHAIN-REACTION IN DEFINING INFECTIOUSNESS AMONG PEOPLE INFECTED WITH HEPATITIS-C VIRUS

Objective: To assess the role of polymerase chain reaction in defining infectiousness among people infected with hepatitis C virus. Design: Published studies of hepatitis C transmission were examined. Twenty ni ne studies with identified sources of hepatitis C infection who were t ested for presence of hepatitis C RNA by polymerase chain reaction wer e reviewed, including studies of vertical transmission (n = 21), trans mission after transplantation (n = 3), transfusion of blood components (n = 3), and needlestick exposure (n = 2). Subjects: All patients ide ntified in studies. Results: A total of 2022 people who had been expos ed to sources positive for antibody to hepatitis C were identified. Am ong 1148 people exposed to sources positive by polymerase chain reacti on 148 cases of transmission occurred compared with no definite case a mong 874 people exposed to negative sources. Rates of transmission fro m positive sources were 6.2% for perinatal exposure, 6.1% after needle stick exposure, 78% after solid organ or bone marrow transplantation, and 83% after transfusion of blood components. Other factors influenci ng risk of vertical transmission were coinfection with HIV and level o f hepatitis C viraemia. Conclusions: Negative results by polymerase ch ain reaction indicate an extremely low probability of transmission of hepatitis C from a person with antibody to hepatitis C.