ABSTRACT An inexpensive enzyme-linked immunosorbent assay method for human immunodeficiency virus type 1 quantitation, ultrasensitive p24 antigen assay (Up24), was compared with RNA viral load assay (VL). Up24 had 100% sensitivity of detection at a viral load of ≥30,000, with sensitivity of 46.4% at a viral load of <30,000 (232 specimens from 65 seropositive subjects). The assay was highly reproducible, with excellent correlation between duplicates and among three laboratories.

BACKGROUND:Delays in receipt of positive HIV test results and in entry into HIV care are common problems in clinics; in public venues, up to 33% of patients with negative results and 25% of those with positive results never learn their results.METHODS:Patients aged 18 years or older at an urban sexually transmitted disease (STD) clinic were offered rapid HIV testing between October 1999 and August 2000. Specimens were tested using the rapid Single Use Diagnostic System for HIV-1 (SUDS; Abbott/Murex, Norcross, GA), and results were confirmed by conventional enzyme immunoassay and Western blot (WB) analysis. Trained health educators performed all HIV counseling, phlebotomy, and rapid testing.RESULTS:Of 1977 eligible patients, 1581 (80%) agreed to HIV testing; of these, 1372 (87%) accepted rapid testing and 1357 (99%) received same-visit results and posttest counseling. Thirty-seven (2.7%) were HIV-positive as confirmed by WB analysis. One of these HIV-positive participants died, but the remaining 36 went to their first clinic appointment.CONCLUSION:Rapid HIV testing was acceptable and feasible in this STD clinic and facilitated entry of newly identified HIV-infected patients into health care.