HIV-1 NAT minipool during the pre-seroconversion window period: Detection of a repeat blood donor

Background: The introduction of nucleic acid amplification technology (NAT) for screening pooled or individual donations remarkably improved the safety of blood products. The size of mini-pooled NAT is considered critical for identification of HIV-1 infected donors during preseroconversion phase of infection. We describe a case of HIV-1 infection in a serologically negative repeat blood donor identified by 16 minipool (MP) NAT. Materials and Methods: The donation was tested by Roche Cobas AmpliScreen HIV-1 Test with manual extraction (MultiPrep Specimen Processing Procedure). The sensitivity of different MP sizes was observed. Serial samples of infected donor were examined with different third and fourth generation HIV-1 serological assays. Results: In the index donation viral load was 515 copies/ml corresponding to about 50 IU when diluted in 16 MP. Abbott third and fourth generation EIA tests detected the seroconversion four days later the index donation. Conclusion: The report emphasizes the relevance of a very small size of MP to really reduce the window serologic phase of current EIA test by HIV-1 NAT test. © 2005 Blackwell Publishing.