Transmission of antiretroviral-drug-resistant HIV-1 variants

Background Resistance of HIV-1 to antiretroviral drugs is the main cause of antiretroviral-treatment failure. We assessed the transmission of drug-res istant variants among individuals with primary HIV-1 infection. Methods Population-based sequencing of the viral reverse transcriptase and protease genes derived from plasma viral RNA was done in 82 consecutive ind ividuals with documented primary HIV-1 infection from January, 1996, to Jul y, 1998. Phenotypic resistance to protease inhibitors was assessed by recom binant virus assay in individuals with two or more mutations associated wit h resistance to protease inhibitors. Findings Zidovudine-resistance mutations were detected in seven (9%) of 82 individuals. Mutations associated with resistance to other reverse-transcri ptase inhibitors (RTls) were detected in two individuals. Primary-resistanc e mutations associated with protease inhibitors (V82A, L90M) were detected in three (4%) of 70 individuals; two of these had also RTI-resistance mutat ions. Decreased sensitivity to three or four protease inhibitors was seen i n three individuals, one of whom was infected with HIV-1 variants that harb oured 12 mutations associated with resistance to multiple RTI and protease inhibitors. Interpretation To introduce the best antiretroviral treatment, resistance t esting should be done in recently HIV-1-infected individuals.