Performance of the Bio-Rad Geenius HIV1/2 Supplemental Assay in Detecting "Recent" HIV Infection and Calculating Population Incidence

J Acquir Immune Defic Syndr. 2016 Dec 15;73(5):581-588. doi: 10.1097/QAI.0000000000001146.


Objective: HIV seroconversion biomarkers are being used in cross-sectional studies for HIV incidence estimation. Bio-Rad Geenius HIV-1/2 Supplemental Assay is an immunochromatographic single-use assay that measures antibodies (Ab) against multiple HIV-1/2 antigens. The objective of this study was to determine whether the Geenius assay could additionally be used for recency estimation.

Design: This assay was developed for HIV-1/2 confirmation; however, quantitative data acquired give information on increasing concentration and diversity of antibody responses over time during seroconversion. A quantitative threshold of recent HIV infection was proposed to determine "recent" or "nonrecent" HIV infection; performance using this cutoff was evaluated.

Methods: We tested 2500 highly characterized specimens from research subjects in the United States, Brazil, and Africa with well-defined durations of HIV infection. Regression and frequency estimation were used to estimate assay properties relevant to HIV incidence measurement: mean duration of recent infection (MDRI), false-recent rate, and assay reproducibility and robustness.

Results: Using the manufacturer's proposed cutoff index of 1.5 to identify "recent" infection, the assay has an estimated false-recent rate of 4.1% (95% CI: 2.2 to 7.0) and MDRI of 179 days (155 to 201) in specimens from treatment-naive subjects, presenting performance challenges similar to other incidence assays. Lower index cutoffs associated with lower MDRI gave a lower rate of false-recent results.

Conclusions: These data suggest that with additional interpretive analysis of the band intensities using an algorithm and cutoff, the Geenius HIV-1/2 Supplemental Assay can be used to identify recent HIV infection in addition to confirming the presence of HIV-1 and HIV-2 antibodies.

Publication types

  • Evaluation Study

MeSH terms

  • Africa
  • Algorithms
  • Brazil
  • Chromatography, Affinity / methods*
  • Diagnostic Tests, Routine / methods*
  • HIV Antibodies / blood*
  • HIV Infections / diagnosis*
  • HIV Infections / epidemiology*
  • HIV Infections / virology
  • HIV-1 / immunology*
  • HIV-2 / immunology*
  • Incidence
  • Models, Theoretical
  • Retrospective Studies
  • United States


  • HIV Antibodies