Prevalence of mutations associated with reduced antiretroviral drug susceptibility among human immunodeficiency virus type 1 seroconverters in the United States, 1993-1998

To assess the prevalence of mutations associated with decreased antiretrovi ral drug susceptibility, specimens were tested from persons infected with h uman immunodeficiency virus (HIV) during 1993-1998, Subjects were drug naiv e and were attending sexually transmitted disease clinics in 6 US cities. A ll were enrolled consecutively and had tested negative for HIV during the 2 years before enrollment. Plasma specimens from patients having greater tha n or equal to 1 reverse transcriptase (RT) or primary protease mutation wer e tested phenotypically with a recombinant virus assay. Of 99 patients, 6 ( 6%) had mutations associated with zidovudine resistance, 2 (2%) had mutatio ns associated with nonnucleoside RT inhibitor resistance, and 1 (1%) had a primary protease mutation. Overall, the prevalence of resistance-associated primary mutations was 5%, although high levels of decreased drug susceptib ility (IC(50)s greater than or equal to 10 times that of a reference virus) were observed in just 1%. These findings confirm the transmission of these mutations to drug-naive persons.