Screening Tests Compared to Detect Acute HIV Infection

A large team of scientists led by those at the US Centers for Disease Control and Prevention (Atlanta, GA, USA) evaluated the performance of the HIV antigen/antibody (Ag/Ab) combination assay in 86,836 participants in a high-prevalence population from seven sexually transmitted infection clinics and five community-based programs in New York, California, and North Carolina. The multisite, prospective, within-individual comparison study conducted between September 2011 and October 2013 and participants were 12 years or older and seeking HIV testing, without known HIV infection.

All participants with a negative rapid HIV tests OraQuick ADVANCE Rapid HIV-1/2 Antibody Test (OraSure Technologies; Bethlehem, PA, USA) or Clearview HIV 1/2 STAT-PAK assay (Alere; Waltham, MA, USA) were tested for acute HIV infection with the index test, a laboratory-based, fourth-generation immunoassay, Architect HIV Ag/Ab Combo Assay (Abbott Diagnostics; Abbott Park, IL, USA) and pooled human immunodeficiency virus 1 (HIV-1) RNA testing. HIV RNA testing was the reference standard, with positive reference standard result defined as detectable HIV-1 RNA on an individual RNA test. The main outcomes and measures were the number and proportion with acute HIV infections detected.

The investigators found that the HIV Ag/Ab combination assay in place of rapid HIV testing increased the absolute HIV diagnostic yield by 0.15% and diagnosed 82% of the acute HIV infections detectable by pooled RNA testing. Compared with rapid HIV testing alone, HIV Ag/Ab combination testing increased the relative HIV diagnostic yield (both established and acute HIV infections) by 10.4% and pooled HIV RNA testing increased the relative HIV diagnostic yield by 12.4%.

The authors concluded that in a high-prevalence population, HIV screening using an HIV Ag/Ab combination assay following a negative rapid test detected 82% of acute HIV infections detectable by pooled HIV RNA testing, with a positive predictive value of 59%. Further studies are needed to evaluate this strategy in lower-prevalence populations and in persons using pre-exposure prophylaxis for HIV prevention. The study was published on February 16, 2016, in the Journal of the American Medical Association. 

Related Links:
US Centers for Disease Control and Prevention
OraSure Technologies
Alere