Evaluation of current rapid HIV test algorithms in Rakai, Uganda

Abstract

Rapid HIV tests are a crucial component of HIV diagnosis in resource limited settings. In Uganda, the Ministry of Health allows for both serial and parallel HIV rapid testing using Determine, Stat-Pak and Uni-Gold. In serial testing, a non-reactive result on Determine ends testing. The performance of serial and parallel algorithms with Determine and Stat-Pak test kits was assessed. A cross-sectional diagnostic test accuracy evaluation using three rapid HIV test kits as per the recommended parallel test algorithm was followed by EIA-WB testing with estimates of the performance of serial testing algorithm. In 2520 participants tested by parallel rapid algorithms, 0.6% had weakly reactive result. Parallel testing had 99.7% sensitivity and 99.8% specificity. If Stat-Pak was used as the first screening test for a serial algorithm, the sensitivity was 99.6% and specificity 99.7%. However, if Determine was used as the screening test, sensitivity was 97.3% and specificity 99.9%. Serial testing with Stat-Pak as the initial screening test performed as well as parallel testing, but Determine was a less sensitive screen. Serial testing could be cost saving.

To err is human, to correct is public health: a systematic review examining poor quality testing and misdiagnosis of HIV status

“…Most studies were carried out in Africa ( n  = 48) [5,7,10–14,16,22–25,29,30,32–34,36,37,39,41,43,44,46,47,49,51,52,54–59,61–65,67–72,74,75], followed by in the Americas ( n  = 7) [28,31,42,50,53,60,66], Asia ( n  = 4) [8,35,45,73] and Europe ( n  = 1) [48]. There were also four multi-country/regional studies [26,27,38,40].…”

“…Thirty-seven studies reported using a suboptimal testing strategy that differed from the WHO recommendations [5,8,11–14,16,22–30,32–34,36–39,42–44,49,51,53,59,62,64–66,68,72,75]. Suboptimal testing strategies included using a highly specific first-line test and highly sensitive second-line test [14,33,39,55], using a single RDT for HIV-positive diagnoses [11,66,72], using a high prevalence testing strategy in a low prevalence setting [16,49], using a parallel testing algorithms and a tiebreaker testing strategy (where a third assay is used to resolve discrepant test results and rule in HIV infection) [5,12,13,16,24,25,27–30,32,34,36,37,68].…”

“…Errors identified included users having difficulty with specimen collection [14,28,68], performing RDTs [31,73], interpreting test results [10,24,27,30,32,40,42,48,62,65,66,74], reading test results too early [7] and not using the correct reagents/buffer [7]. …”

“…Fourteen studies reported challenges related to weak reactive test results, particularly difficulty with interpretation [8,10,24,27,30,32,36,38,40,42,44,48,62,74]. A study, which assessed the proficiency of laboratory technicians, found that specimens with very weak levels of HIV-1/2 antibodies were less accurately reported [40].…”

Misdiagnosis of HIV infection during a South African community‐based survey: implications for rapid HIV testing

“…Studies of laboratory-based comparisons of RDT test kit performance have demonstrated lower than expected sensitivities with both Determine and UniGold test kits in certain settings. Gawalingo et al reported a sensitivity of 97.3% for a serial algorithm which used Determine as the screening test [27]. Kosack et al demonstrated a sensitivity of 96.2% for UniGold in a head-to-head comparison of eight RDT kits in the laboratory [28].…”