High Diagnostic Accuracy of a Novel Lateral Flow Assay for the Point-of-Care Detection of SARS-CoV-2

Abstract

Highly accurate lateral flow immunochromatographic tests (LFTs) are an important public health tool to tackle the ongoing COVID-19 pandemic. The aim of this study was to assess the comparative diagnostic performance of the novel ND COVID-19 LFT under real-world conditions. A total of 400 nasopharyngeal swab specimens with a wide range of viral loads were tested in both reverse-transcription polymerase chain reaction and ND LFT. The overall sensitivity and specificity were 85% (95% CI: 76.7–90.7%) and 100% (95% CI: 98.7–100%), respectively. There was a clear association between the false-negative rate and sample viral load: the sensitivity parameters for specimens with cycle threshold values of <25 (>3.95 × 106 copies/mL) and ≥30 (≤1.29 × 105 copies/mL) were 100% and 50%, respectively. The performance was maximized in testing samples with viral loads ≥1.29 × 105 copies/mL. These findings suggest that the ND LFT is sufficiently accurate and useful for mass population screening programs, especially in high-prevalence and resource-constrained settings or during periods when the epidemic curve is rising. Other public health implications were also discussed.

Challenges in the Detection of SARS-CoV-2: Evolution of the Lateral Flow Immunoassay as a Valuable Tool for Viral Diagnosis

“…Individuals with mild or asymptomatic symptoms or who exceed this time could have a low viral load [ 111 ]. In this disease period, LFIAs detect at least a Ct value < 25 (~100,000 RNA copies/mL), which is sufficiently accurate and helpful for mass population screening programs [ 112 , 113 ]. The WHO recommends using LFIAs, which meet the minimum performance requirements of ≥80% sensitivity and ≥97% specificity.…”

A Protein Microarray-Based Respiratory Viral Antigen Testing Platform for COVID-19 Surveillance

“…Various forms of antigen-based tests against SARS-CoV-2 [ 6 , 7 ] are available including point-of-care lateral flow assays (LFA) that are better suited for screening. For example, Giberti et al examined the ND COVID-19 Ag test (NDFOS; Seoul, Republic of Korea), a lateral flow immunochromatographic test to detect both SARS-CoV-2 nucleocapsid protein (NP) and spike protein, using a total of 400 nasopharyngeal specimens, which confirmed its sensitivity of specificity as 85% and 100%, respectively [ 8 ]. Whereas, Thapa et al developed a novel handheld thermo-photonic LFA reader, which enabled to quantify the LFA test results [ 9 ].…”