Testing of blood donors for human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) RNA by nucleic acid amplification was introduced in mid-1999. This identified donations made during the window period before seroconversion.
In this study, doctors from the United States analyzed all antibody-nonreactive donations that were confirmed positive for HIV-1 and HCV RNA during the first 3 years of nucleic acid screening.
Donations were confirmed positive on nucleic acid–amplification testing of "minipools" (pools of 16 to 24 donations).
A total of 37,164,054 units were screened. Of these, 12 were found to be positive for HIV-1 RNA; only 2 of which were detected by HIV-1 p24 antigen testing.
For HCV 39,721,404 units were screened. Of these, 170 were confirmed to be positive for HCV RNA.
|Nucleic acid–amplification testing has prevented the transmission of 56 HCV infections annually.|
|New England Journal of Medicine|
The team found that the rates of positive HCV and HIV-1 nucleic acid–amplification tests were 3.3 and 4.1 times higher for first-time donors than donors who gave blood repeatedly.
Follow-up studies of 67 HCV RNA–positive donors demonstrated that seroconversion occurred a median of 35 days after the index donation.
Dr Susan Stramer and colleagues concluded, "Minipool nucleic acid–amplification testing has helped prevent the transmission of approximately 5 HIV-1 infections and 56 HCV infections annually and has reduced the residual risk of transfusion-transmitted HIV-1 and HCV to approximately 1 in 2 million blood units."