Evaluation of Performance of Two Rapid Tests for Detection of HIV-1 and -2 in High- and Low-Prevalence Populations in Nigeria

Abstract

The availability of reliable human immunodeficiency virus types 1 and 2 (HIV-1/2) rapid tests in resource-limited settings represents an important advancement in the accurate diagnosis of HIV infection and presents opportunities for implementation of effective prevention and treatment interventions among vulnerable populations. A study of the potential target populations for future HIV vaccine studies examined the prevalence of HIV infections at six selected sites in Nigeria and evaluated the use of two rapid diagnostic tests (RDTs) for HIV. The populations included market workers at sites adjacent to military installations and workers at highway settlements (truck stops) who may have a heightened risk of HIV exposure. Samples from 3,187 individuals who provided informed consent were tested in parallel using the Determine (DT) and Stat-Pak (SP) RDTs; discordant results were subjected to the Uni-Gold (UG) RDT as a tiebreaker. The results were compared to those of a third-generation enzyme immunoassay screen with confirmation of repeat reactive samples by HIV-1 Western blotting. One participant was HIV-2 infected, yielding positive results on both RDTs. Using the laboratory algorithm as a gold standard, we calculated sensitivities of 98.5% (confidence interval [CI], 97.1 to 99.8%) for DT and 98.1% (CI, 96.7 to 99.6%) for SP and specificities of 98.7% (CI, 98.3 −99.1%) for DT and 99.8% (CI, 99.6 to 100%) for SP. Similar results were obtained when the sites were stratified into those of higher HIV prevalence (9.4% to 22.8%) versus those of lower prevalence (3.2% to 7.3%). A parallel two-test algorithm requiring both DT and SP to be positive resulted in the highest sensitivity (98.1%; CI, 96.7 to 99.6%) and specificity (99.97%; CI, 99.9 to 100%) relative to those for the reference laboratory algorithm.

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].…”

“…And three studies reported false negative results were due to patients testing in the window period [45] or with acute or early infection [16,44]. For instance, in South Africa, 0.04% (95% CI: 0.0–0.001) and 0.3% (95% CI: 0.1–0.4) of clients with a false negative diagnosis using serology tests were later found to have acute or early HIV infection after retesting with nucleic acid testing technologies [44].…”

“…Clerical and user errors [57], early/acute infection [16,44,45], presentation late in disease stage [56] and individuals with known HIV status on ART who sought retesting, or were retested using oral fluid-based RDTs [58], were also reported as factors contributing to false negative diagnostic errors [14,16,39,44,47]. In Zimbabwe, all the reported false negative diagnoses were among children on ART who were retested with an oral fluid-based HIV RDT [58].…”

Epidemiology of Human Immunodeficiency Virus in Prospective Blood Donors and Testing Algorithm Assessment with Real-Time PCR for Optimal Blood Safety Practice

“…Stat-Pak) is used as the tie-breaker [31]. Some clinical settings prefer the use of parallel HIV testing algorithm prior confirmatory procedures [32] while others make enzyme-linked immuno-sorbent assay (ELISA) technique the starting point for HIV diagnosis [33] There is virtual lack of data on the rapid HIV antibody testing based on serial algorithm II validated with molecular techniques (such as real-time polymerase chain reaction) in HIV diagnosis especially in Ekiti state and that requires evidence-based baseline study.…”