Optimizing early infant diagnosis at delivery rooms with HIV-1 Abbott RealTime-PCR using phosphate buffered saline to complement low plasma volumes

•Early infant diagnosis is critical to improve the care of newborns living with HIV-1.•Neonate samples are difficult to collect and not uncommonly have small volumes.•Automated RNA quantification systems require minimal plasma volume.•Available plasma can be adjusted with phosphate buffered saline.•Dilution does not change the specificity of the test and allows HIV-1 diagnosis. Improving the early identification of HIV-1-infected newborns with birth testing is critical to comprehensive early infant diagnosis and care for newborns living with HIV-1. Automated RNA quantification systems are valuable diagnostic tools, but the volume of plasma that viral load platforms require makes their widespread use for young children difficult. Seventy-nine plasma samples with different viral load ranges were evaluated in parallel with the use of 1x PBS, pH 7.4, to supplement the required volume at dilutions factors from 1:2 to 1:50. Viral load quantification assays were evaluated using ABBOTT Molecular platforms, USA. Using 1x PBS, at 1:10 dilution (70 µL plasma in 630 µL 1x PBS), a sensitivity of 100% and 100% specificity were obtained for detecting a viremia above 400 copies/mL (Kappa of 0.96, p