Acute HIV Screening With Combo Assay Ups Diagnostic Yield

Use of an HIV antigen/antibody (Ag/Ab) combination assay increases the diagnostic yield by more than 10 percent compared with rapid HIV testing in a high-prevalence population, while pooled RNA testing further increases the diagnostic yield, according to a study published in the Feb. 16 issue of the Journal of the American Medical Association. Because rapid testing detected HIV infection in only 87 percent of HIV-infected participants, the authors say alternative strategies that can detect acute infection should be considered in high-prevalence, U.S. populations. Acute HIV infection is defined as the interval between the appearance of HIV RNA and detection of HIV-specific antibodies and can be diagnosed with HIV RNA assays (the reference standard) or the p24 antigen. The U.S. Centers for Disease Control and Prevention (CDC) recommends an HIV diagnostic algorithm that uses HIV immunoassays that detect both the p24 antigen and anti-HIV antibody (fourth generation Ag/Ab combo assay) as the initial screening test. But, they are not as sensitive as pooled HIV RNA tests, which are not widely used because there is only one U.S. Food and Drug Administration-approved assay and the protocol is complex. This prospective trial (September 2011 through October 2013) included seven sexually transmitted infection clinics […]