Implementation of an interactive mobile application to pilot a rapid assay to detect HIV drug resistance mutations in Kenya

Abstract

Usability is an overlooked aspect of implementing lab-based assays, particularly novel assays in low-resource-settings. Esoteric instructions can lead to irreproducible test results and patient harm. To address these issues, we developed a software application based on "Aquarium", a laboratory-operating system run on a computer tablet that provides step-by-step digital interactive instructions, protocol management, and sample tracking. Aquarium was paired with a near point-of-care HIV drug resistance test, "OLA-Simple", that detects mutations associated with virologic failure. In this observational study we evaluated the performance of Aquarium in guiding untrained users through the multi-step laboratory protocol with little supervision. To evaluate the training by Aquarium software we conducted a feasibility study in a laboratory at Coptic Hope Center in Nairobi, Kenya. Twelve volunteers who were unfamiliar with the kit performed the test on blinded samples (2 blood specimens; 5 codons/sample). Steps guided by Aquarium included: CD4+ T-Cell separation, PCR, ligation, detection, and interpretation of test results. Participants filled out a short survey regarding their demographics and experience with the software and kit. None of the laboratory technicians had prior experience performing CD4+ separation and 7/12 had no experience performing laboratory-based molecular assays. 12/12 isolated CD4+ T cells from whole blood with yields comparable to isolations performed by trained personnel. The OLA-Simple workflow was completed by all, with genotyping results interpreted correctly by unaided-eye in 108/120 (90%) and by software in 116/120 (97%) of codons analyzed. In the surveys, participants favorably assessed the use of software guidance. The Aquarium digital instructions enabled first-time users in Kenya to complete the OLA-simple kit workflow with minimal training. Aquarium could increase the accessibility of laboratory assays in low-resource-settings and potentially standardize implementation of clinical laboratory tests.

Fig 1. OLA-Simple laboratory setup and workflow.

(A) Laboratory setup: Tablets were connected to a local server to run Aquarium software. The pre-PCR room had a refrigerator/freezer and a BSC where CD4+ separation and PCR reaction were set-up. Technicians controlled the Aquarium-based software on the tablet with a foot pedal (not shown in the picture) while performing CD4+ preparation. The post-PCR room had two designated bench areas to set up ligation and detection separately. This room also contained a thermal cycler and a scanner. (B) Tasks assigned by Aquarium for Kenyan technicians, and assessment of their performance using Aquarium-assisted OLA-Simple. The sample preparation module was separated from the amplification, ligation, detection, and interpretation module. Associated protocol code, and examples of complete runs are publicly available (https://github.com/OLA-Simple/Papers-Vrana-Panpradist-et-al-2021).

Fig 2. OLA-Simple HIVDR results and interpretations.

(A) Examples of scanned images of test strips for Samples 1 and 2 and test accuracy across each codon based on visual calls made by each participant and post-processing by image analysis software. Sample1 and Sample 2 have different mutation profiles. (B) Mutant (MUT) signal intensity of each lateral flow strip. Middle lines on the box plot indicate medians. Top and bottom lines on box plot indicate interquartile ranges. Dashed lines indicate the detection threshold for MUT signal. Both Sample 1 and Sample 2 have mutant genotype at codon Y181C. Diamonds correspond to signal from the strips of a Sample 1 that was erroneously tested in place of Sample 2.