Covid-19 Cartridge
Background
Several nucleic acid amplification assays have been developed for the diagnosis of SARS‐CoV‐2 infection and there is a need to assess the performance of their tests relative to others. The aim of this study was to compare the performance characteristics of the Biosewoom Real-Q 2019-nCoV Cartridge assay targeting the E and RdRP genes with the Daan Gene 2019-nCoV kit targeting the N gene and ORF1ab in the diagnosis of SARS-CoV-2.
Methods
We performed a diagnostic comparison study by testing nasopharyngeal specimens for SARS-CoV-2 using the two reverse transcription polymerase chain reaction (RT-PCR) assays. The trial agreement was assessed using overall percent agreement, negative percent agreement, positive percent agreement, and Cohen’s kappa coefficient.
Results
A total of 48 nasopharyngeal samples were analyzed using the two assays. One sample was invalid and three showed inconclusive results with Real‐Q; therefore, 44 were included for comparative analysis. Overall, the percentage agreement between trials was 93.2% (95% CI 81.3%–98.6%), the percentage positive agreement (PPA) was 86.4% (95% CI 65 .1%–97.1%) and the negative percentage agreement (NPA) was 100%. (95% CI 84.6%-100%). The kappa coefficient was 0.86 (95% CI 0.72-1.01). Three samples (6.8%) were positive with the Daan gene kit and negative with Real-Q. The fluorescence intensity for the Real-Q reporter dyes was low.
Conclusion
The two kits showed high levels of agreement in their detection of SARS-CoV-2 despite having different genetic targets. The Biosewoom kit can be improved by addressing the fluorescence intensity of the target dyes, and information was provided to the manufacturer.
Keywords: coronavirus, COVID-19, PCR, SARS-CoV-2, Zimbabwe
