Quantitation of human immunodeficiency virus type 1 group O load in plasmaby measuring reverse transcriptase activity

We have evaluated the use of an ultrasensitive reverse transcriptase (RT) a ctivity assay to monitor plasma viremia in two human immunodeficiency virus type I (HIV-1) group O-infected patients treated with stavudine, lamivudin e, and indinavir. After a initial decline in RT levels observed at 4 weeks of therapy, RT-based plasma viremia returned to baseline values at 28 or 44 weeks of treatment. The rebound in levels of RT activity was associated wi th the detection of phenotypic resistance to lamivudine and with the Met184 Val mutation.;Analysis of RT activity in plasma provides a sequence-indepen dent means of monitoring virus lends in HIV-1 group O-infected patients.