Impact of the 2014 CDC HIV testing guidelines on detection of acute HIV infections

Abstract

Background: The Centers for Disease Control and Prevention (CDC) issued updated guidelines for HIV testing in 2014. These guidelines recommend screening using an HIV-1/2 antigen/antibody (Ag/Ab) test and create the ability to identify algorithm-defined acute HIV infections (AHI). The guidelines also recommend laboratory confirmation of preliminary positive point of care (POC) rapid HIV test results and specimens from high-risk individuals who test POC rapid negative. The Florida Public Health Laboratory (FPHL) switched from an antibody-only algorithm to the CDC recommended algorithm April 16, 2012.

Objectives: To analyze the FPHL HIV testing data and evaluate the impact of the CDC recommended algorithm on the identification of AHI, time to result and inconclusive HIV reports.

Study design: FPHL HIV test data, for the period January 1, 2010 through December 31, 2019, was reviewed to determine the number of AHI cases identified, the number of indeterminate HIV results and the time from specimen receipt to result for tests in the antibody-only and CDC recommended algorithms. In addition, POC rapid results were compared to laboratory-based results for AHI cases for which rapid test results were available.

Results: There was no difference in time to result between the antibody-only and CDC recommended algorithms for HIV negative specimens. The time to result for HIV-1 positive specimens decreased from an average of 5 days with the antibody-only algorithm to an average of 1 day with the CDC recommended algorithm. The average number of indeterminate results per month decreased from 6.25 per month with the antibody-only algorithm to an average of 2.5 per month using the CDC recommended algorithm. Despite HIV seropositivity decreasing by 0.5% during the study period (2012 = 3.1% [3,892/124,394]: 2019 = 2.6% [2,456/95,525]), AHI cases increased annually from a total of 4 in 2012 to over 50 in 2019 and cases were identified in 30 of 67 Florida counties. The increase in identification of AHIs is credited to educational efforts with healthcare providers to encourage further testing on individuals with risk factors for HIV and a recent POC HIV-1/2 rapid negative test result.

Conclusions: Data indicates that performing HIV testing according to the CDC recommended algorithm decreased time to result for HIV positive results, reduced the number of indeterminate results and identified algorithm-defined AHI. In addition, laboratory-based testing is warranted for high-risk individuals who test negative by POC rapid testing.

Keywords: Acute infections; HIV; HIV diagnostic algorithm; HIV treatment; Linkage to care; Testing algorithms.