RESUMO
Universal human immunodeficiency virus (HIV) screening was recommended in 2012, and major improvements in HIV testing have occurred in the past decade, but identification of HIV infected individuals remains inadequate in the United States. We report the case of a seronegative HIV-infected man who despite clinical and laboratory findings of acquired immunodeficiency syndrome,repeatedly tested nonreactive to third-generation HIV enzyme immunoassays (EIAs) and Western blot testing. Serologic diagnosis in this case required fourth-generation EIA testing due to the seronegativity of standard testing. The fourth-generation HIV EIA was positive presumably because it detects p24 HIV antigen as well as antibodies, unlike rapid HIV tests and third-generation HIV EIAs.This case highlights not only the importance of frontline providers to understand the different testing methodologies for HIV screening and their limitations but the importance of clinical suspicion as well.