First report of human immunodeficiency virus transmission via an RNA-screened blood donation


Michael P. Busch, MD, PhD, Vice President, Research, Blood Systems Research Institute, 270 Masonic Avenue, San Francisco, CA 94118, USA E-mail:


Background and Objectives  Blood banks in the USA have recently introduced minipool nucleic acid amplification testing (MP-NAT) of blood products to reduce the transmission of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) by transfusions. However, MP-NAT is limited in its ability to detect preseroconversion samples with very low viral RNA loads.

Materials and Methods  To determine whether a red blood cell unit, from an MP-NAT-negative donation, transmitted HIV when transfused to a patient, we compared the viral sequences from the blood donor and recipient. The implicated donation was also tested by commercially available NAT assays at a range of dilution factors to determine whether the infectious unit could have been detected using individual-donation NAT (ID-NAT).

Results  Phylogenetic linkage of HIV sequences in the blood donor and recipient confirmed the transmission of HIV by blood transfusion, the first such case identified since introduction of MP-NAT screening in 1999. Viral RNA was reliably detected by ID-NAT, but only inconsistently detected by MP-NAT.

Conclusions  Even following the introduction of MP-NAT, a preseroconversion donation with a viral load of ≤ 150 copies of RNA/ml went undetected and resulted in an HIV transmission. Implementation of ID-NAT will further reduce such rare transmissions, but at a considerable cost per infectious unit interdicted.