Primary antiretroviral drug resistance in newly human immunodeficiency virus-diagnosed individuals testing anonymously and confidentially.

The purpose of this study was to determine if anonymous and confidential testers differ in recency of human immunodeficiency virus (HIV) infection at time of testing and prevalence of antiretroviral drug (ARV) resistance. We examined data from the Centers for Disease Control and Prevention-sponsored Antiretroviral Drug Resistance Testing project, which performed genotypic testing on leftover HIV diagnostic serum specimens of confidentially and anonymously tested ARV-naïve persons newly diagnosed with HIV in Colorado (n = 365 at 11 sites) and King County, Washington (n = 492 at 44 sites). The serologic testing algorithm for recent HIV seroconversion was used to classify people as likely to have been recently infected or not. Type of testing, anonymous or confidential, was not significantly associated with either timing of HIV testing by serologic testing algorithm for recent HIV seroconversion or resistance rates. Mutations conferring any level of ARV resistance were present in 17% of testers, and high-level resistance mutations were present in 10%. Anonymous testers were significantly more likely to have CD4+ counts >500 cells per mm(3) (45% vs. 28%; p = 0.018), indicative of an early infection. This study indicates that anonymous testers have demographic differences relative to confidential HIV testers but were not more likely to exhibit drug resistance. Findings related to when in the course of disease anonymous testers are tested are inconsistent, but anonymous testers had higher CD4 counts, which indicates early testing and is consistent with other studies.