Clinical performance of the Luminex NxTAG CoV Extended Panel for SARS-CoV-2 detection in nasopharyngeal specimens of COVID-19 patients in Hong Kong.

In December 2019, the coronavirus disease 2019 (COVID-19) pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) was first reported in the Hubei Province of China and later spread all over the world. There was an urgent need of a high-throughput molecular testing for screening the COVID-19 patients in the community. The Luminex NxTAG CoV Extended Panel is a high-throughput FDA emergency use authorized molecular diagnostic assay for SARS-CoV-2 detection. This system targets three genes (ORF1ab, N and E gene) of SARS-CoV-2, ORF1ab region of SARS-CoV and ORF5 region of MERS-CoV.In this study, we evaluated the diagnostic performance of this system with nasopharyngeal swab specimens of 214 suspected COVID-19 patients in Hong Kong. The results were compared with our routine COVID-19 RT-PCR protocol with LightMix SarbecoV E-gene kit and an in-house RdRp/Hel RT-PCR assay. The NxTAG CoV Extended panel demonstrated a 97.8% sensitivity and 100% specificity to SARS-CoV-2 in nasopharyngeal specimens. On low viral load specimens, the sensitivity of the NxTAG panel could still maintain at 85.71%. High agreement was observed between the NxTAG panel and the routine COVID-19 RT-PCR protocol (kappa value = 0.98). Overall the E gene target of the NxTAG panel demonstrated the highest sensitivity among the three SARS-CoV-2 targets while the N gene targets demonstrated the least.In conclusion, the NxTAG CoV Extended Panel is simple to use and it has high diagnostic sensitivity and specificity to SARS-CoV-2 in nasopharyngeal specimens. we recommend this diagnostic system for high-throughput COVID-19 screening in the community.