A multicentre evaluation of the Elecsys® HIV Duo assay

Abstract

Background: Fourth generation HIV assays, which detect both HIV p24 antigen and HIV antibodies are widely used in HIV screening. The combination of markers enables the fourth generation assays to shorten the window of detection, which is important in real-world testing scenarios. The Elecsys^® HIV Duo assay is a fourth generation assay, which provides an overall result based on both the detection of the p24 antigen and HIV antibodies, and lists the sub-results for the antibody and antigen units.

Objectives and study design: The performance of the Elecsys^® HIV Duo assay was assessed at five international centres and compared with other available fourth generation assays.

Results: The specificity of the Elecsys^® HIV Duo assay in 13,328 blood donor samples was 99.87% (95% confidence interval [CI] 99.80-99.93) and was 100% (95% CI 99.63-100) in 1000 routine diagnostic samples. Sensitivity was assessed in 139 seroconversion panels; the Elecsys^® HIV Duo assay detected a greater number of positive samples/number of bleeds compared with other assays investigated. An individual analysis of those seroconversion panels also shows that the Elecsys^® HIV Duo assay compared to other fourth generation assays detected HIV up to 2 days earlier than other assays. The Elecsys^® HIV Duo assay also detected 125/130 'early seroconversion' samples assessed, which was greater than the number detected with comparator fourth generation assays.

Conclusion: These results indicate that the Elecsys^® HIV Duo assay is appropriate for use in the diagnosis of HIV and for screening of blood donations and is sensitive for the early detection of HIV.

Keywords: Antibody; Antigen; HIV; Sensitivity; Specificity.