# Evaluation of the HIV-1 Rapid Recency Assay and Limiting Antigen Avidity Enzyme Immunoassay for HIV Infection Status Interpretation in Long-Term Diagnosed Individuals in Thailand

## TL;DR

This study evaluates a rapid HIV test for identifying long-term infections in Thailand, showing it is reliable and accurate compared to a standard lab test.

## Contribution

The study demonstrates the ARRA's effectiveness as a point-of-care tool for HIV surveillance in long-term diagnosed individuals.

## Key findings

- Visual interpretation of ARRA showed 0.00% false recent rate compared to LAg-EIA.
- Strip reader interpretation had a 0.32% false recent rate.
- ARRA showed moderate agreement with LAg-EIA optical density values (Spearman’s rho = 0.434).

## Abstract

Background/Objectives: Accurate surveillance of recent HIV infections is crucial for effective epidemic control and timely intervention. The Limited Antigen Avidity Enzyme Immunoassay (LAg-EIA) allows precise differentiation between recent and long-term HIV infections. To enhance accessibility, it has been developted into a point-of-care test, the Asanté™ HIV-1 Rapid Recency® Assay (ARRA), a rapid immunoassay. This study evaluated the performance and false recent rates (FRRs) of the ARRA, interpreted both visually and via a strip reader, in comparison with the LAg-EIA. Methods: Plasma samples were collected from two groups: 634 long-term HIV-infected individuals, identified through routine diagnostic testing, who had not received antiretroviral therapy for over one year, and 224 individuals from high-risk populations. High-risk individuals, including pregnant women, female sex workers, and men who have sex with men, were selected based on behavioral and demographic risk factors. Concordance between the ARRA and LAg-EIA was assessed, and FRRs were calculated for both assays. McNemar’s test was used to evaluate agreement, while Spearman’s rho was applied to assess correlation between the two methods. Results: Visual interpretation of ARRA demonstrated perfect agreement with LAg-Avidity EIA results (FRR = 0.00%), while the strip reader misclassified two specimens as recent infections (FRR = 0.32%). McNemar’s test indicated no significant differences between the methods (p > 0.05). Moderate agreement (Spearman’s rho = 0.434) was observed between ARRA strip reader results and LAg-Avidity EIA optical density values. Among high-risk populations, ARRA misclassified one sample as recent, resulting in an inconsistency rate of 0.45%. Conclusions: This study highlights ARRA’s reliability in identifying long-term infections and its potential as a point-of-care tool. Its rapid results and ease of use make it a valuable asset for effective HIV surveillance, facilitating targeted epidemic monitoring and enhancing public health interventions.