Detection of Acute HIV Infection in Two Evaluations of a New HIV Diagnostic Testing Algorithm — United States, 2011–2013

The highly infectious phase of acute human immunodeficiency virus (HIV) infection, defined as the interval between the appearance of HIV RNA in plasma and the detection of HIV-1-specific antibodies, contributes disproportionately to HIV transmission. The current HIV diagnostic algorithm consists of a repeatedly reactive immunoassay (IA), followed by a supplemental test, such as the Western blot (WB) or indirect immunofluorescence assay (IFA). Because current laboratory IAs detect HIV infection earlier than supplemental tests, reactive IA results and negative supplemental test results very early in the course of HIV infection have been erroneously interpreted as negative. To address this problem, CDC has been evaluating a new HIV diagnostic algorithm. This report describes two evaluations of this algorithm. An HIV screening program at a Phoenix, Arizona emergency department (ED) identified 37 undiagnosed HIV infections during July 2011-February 2013. Of these, 12 (32.4%) were acute HIV infections. An ongoing HIV testing study in three sites identified 99 cases with reactive IA and negative supplemental test results; 55 (55.6%) had acute HIV infection. CDC and many health departments recognize that confirmatory supplemental tests can give false-negative results early in the course of HIV infection. This problem can be resolved by testing for HIV RNA after a reactive IA result and negative supplemental test result

Use of an Acute Seroconversion Panel To Evaluate a Third-Generation Enzyme-Linked Immunoassay for Detection of Human Immunodeficiency Virus-Specific Antibodies Relative to Multiple Other Assays

A human immunodeficiency virus type 1 (HIV-1)/HIV-2 antibody screening assay, the Genetic Systems HIV-1/HIV-2 PLUS O EIA, was compared to several established screening or confirmatory tests using an acute HIV seroconversion panel. The HIV-1/HIV-2 PLUS O EIA showed an improved sensitivity over all tested antibody screening methods, and detected antibody in 7 of 19 specimens found to be negative by a first-generation EIA but positive for the presence of HIV RNA

Assessment of Rapid Tests for Detection of Human Immunodeficiency Virus-Specific Antibodies in Recently Infected Individuals▿

We have evaluated four current Food and Drug Administration-cleared rapid tests for human immunodeficiency virus (HIV)-specific antibodies with a panel of specimens from recently infected individuals. Recent infection was detected by RNA-based screening coupled with enzyme immunoassay-based testing. We found that the sensitivities of the various rapid tests vary greatly with regard to their ability to detect HIV-specific antibodies in recently infected individuals

Performance of rapid point-of-care and laboratory tests for acute and established HIV infection in San Francisco.

BackgroundCurrent laboratory and point-of-care tests for HIV detect different analytes and use different sample types. Some have fast turnaround times (MethodsWe analyzed 21,234 consecutive HIV tests with venous blood obtained by San Francisco HIV testing programs from 2003 to 2008. For a subset, oral fluid (n = 6446) or fingerstick blood (n = 8127) samples were also obtained for rapid testing. In all cases, HIV status was determined using an HIV antibody-plus-RNA test algorithm. We assessed how the screening antibody tests performed individually versus the gold standard of the full algorithm. We then evaluated the potential ability of other tests (including new tests) to detect more cases, by re-testing all specimens that had negative/discrepant antibody results on initial screening.FindingsThe antibody-RNA algorithm identified 58 acute and 703 established HIV infection cases. 1(st)-generation (Vironostika) and 3(rd)-generation (Genetic Systems) immunoassays had 92 and 96 percent sensitivity, respectively. The Oraquick rapid test had clinical sensitivity of only 86 percent on oral fluid samples, but 92 percent on finger-stick blood. Newer 4(th)-generation, antigen-antibody combo rapid immunoassay (ARCHITECT) detected HIV in 87 percent of all the acute cases that had been missed by one of the previous screening assays. A point-of-care 4(th) generation antigen-antibody combo rapid test (Determine) detected about 54 percent of such acute cases.ConclusionsOur study suggests that some rapid antibody blood tests will give similar case detection to laboratory antibody tests, but that oral fluid testing greatly reduces ability to detect HIV. New 4(th)-generation combo tests can detect the majority of acute infections detectable by HIV RNA but with rapid results. Using these tests as a primary screening assay in high-risk HIV testing programs could reduce or eliminate the need for HIV RNA testing