Mini-pool screening by nucleic acid testing for hepatitis B virus, hepatitis C virus, and HIV: preliminary results


Department of Transfusion Medicine, University of Ulm; and Head, Molecular Virus Diagnostics Section, German Red Cross Blood Transfusion Service of Baden-Württemberg, Helmholtzstrasse 10, 89081 Ulm, Germany


BACKGROUND: The purpose of this study was to evaluate the feasibility of nucleic acid testing (NAT) of mini-pools as a blood donation screening test.

STUDY DESIGN AND METHODS: The stepwise implementation of NAT of mini-pools began in January 1997. Since March 1997, all blood donations collected by the German Red Cross Blood Transfusion Service of Baden-Wurttemberg were tested for hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV nucleic acids. An extra barcoded serum sample is collected from each blood donor for NAT-based screening, which is performed only on hepatitis B surface antigen-, anti-HCV-, anti-HIV-, and anti-Treponema pallidum-seronegative donations. Samples are pooled to a maximum of 96. Positive results are resolved through intersecting subpools (a chessboard design). NAT-based screening does not include a virus concentration step before nucleic acid extraction.

RESULTS: By the end of October 1997, 331, 783 donations in 3,779 pools had been screened. As yet, no viremic but seronegative blood donor has been found for the three markers.

CONCLUSION: It is feasible to incorporate NAT-based screening of mini-pools into the routine virus diagnostics of a large blood transfusion service. It remains to be determined whether screening blood donations by NAT will indeed increase the safety of blood supply.