Re‐reading of OraQuick HIV‐1/2 rapid antibody test results: quality assurance implications for HIV self‐testing programmes

Abstract

Introduction Scale‐up of HIV self‐testing ( HIVST ) will play a key role in meeting the United Nation's 90‐90‐90 targets. Delayed re‐reading of used HIVST devices has been used by early implementation studies to validate the performance of self‐test kits and to estimate HIV positivity among self‐testers. We investigated the stability of results on used devices under controlled conditions to assess its potential as a quality assurance approach for HIVST scale‐up. Methods 444 OraQuick ® HIV ‐1/2 rapid antibody tests were conducted using commercial plasma from two HIV ‐positive donors and HIV ‐negative plasma (high‐reactive n = 148, weak‐reactive n = 148 and non‐reactive n = 148) and incubated them for six months under four conditions (combinations of high and low temperatures and humidity). Devices were re‐read daily for one week, weekly for one subsequent month and then once a month by independent readers unaware of the previous results. We used multistage transition models to investigate rates of change in device results, and between storage conditions. Results and discussion There was a high incidence of device instability. Forty‐three (29%) of 148 initially non‐reactive results became false weak‐reactive results. These changes were observed across all incubation conditions, the earliest on Day 4 (n = 9 kits). No initially HIV ‐reactive results changed to a non‐reactive result. There were no significant associations between storage conditions and hazard of results transition. We observed substantial statistical agreement between independent re‐readers over time (agreement range: 0.74 to 0.96). Conclusions Delayed re‐reading of used OraQuick ® HIV ‐1/2 rapid antibody tests is not currently a valid methodological approach to quality assurance and monitoring as we observed a high incidence (29%) of true non‐reactive tests changing to false weak‐reactive and therefore its use may overestimate true HIV positivity.

Point-of-care serological assays for delayed SARS-CoV-2 case identification among health-care workers in the UK: a prospective multicentre cohort study

“…This effect has previously been reported with a high incidence of true non-reactive results changing to weak positive when undergoing delayed reading of rapid antibody tests for HIV. 17 We therefore strongly advise against any use of lateral flow serological assays in home testing programmes that involve non-expert reading of cassettes or return postage of samples for evaluation at extended time intervals.…”

Comparison of practicability and effectiveness between unassisted HIV self-testing and directly assisted HIV self-testing in the Democratic Republic of the Congo: A randomized feasibility trial

“…To our knowledge, this is the rst study in a French-speaking country in Africa to assess the practicability and effectiveness of UH versus DAH. A limitation of this study was that the re-reading by the research team of self-test device brought back by participants in sealed envelopes could have led to errors in interpreting the tests because other studies using the oral uid-based self-test have shown that delayed re-reading of used oral self-tests is not currently a valid methodological approach to ensure quality and monitoring and may overestimate true HIV-positivity [32]. Our protocol involving re-reading the Exacto ® HIV selftests was validated in a preliminary investigation that assessed the stability of 30 performed self-tests (15 positives and 15 negatives), and no changes in the results were found 72 h after use.…”

To thine own test be true: HIV self‐testing and the global reach for the undiagnosed

“…evaluated the OraQuick HIV‐1/2 antibody test kits for result stability post‐testing. They showed that while strongly reactive HIVST remained stable, 29% of initially non‐reactive kits converting to be weakly reactive false positive when read at least four days later, countering previous work which indicated OraQuick test kits were stable for up to a year . Re‐reading may be problematic and result in artificially inflated positivity rates; this finding led the WHO to recommend against any delayed readings of kits .…”