Evaluation of SARS-CoV-2 antigen-based rapid diagnostic kits in Pakistan: formulation of COVID-19 national testing strategy

Umar Saeed,Zubair Aftab,Azhar Rasheed,Sara Rizwan Uppal,Zahra Zahid Piracha,Hafsah Zaheer,Rizwan Uppal

doi:10.1186/s12985-021-01505-3

Abstract

Rapid diagnosis of SARS-CoV-2 during pandemic enables timely treatment and prevention of COVID-19. Evaluating the accuracy and reliability of rapid diagnostic testing kits is crucial for surveillance and diagnosis of SARS-CoV-2 infections in general population, injection drug users, multi-transfused populations, healthcare workers, prisoners, barbers and other high risk populations. The aim of this study was to evaluate performance and effectiveness of nasopharyngeal swab (NSP) and saliva based rapid antigen detection testing kits in comparison with USFDA approved triple target gold standard real-time polymerase chain reaction. A cross-sectional study was conducted on 33,000 COVID-19 suspected patients. From RT-PCR positive patients, nasopharyngeal swab (NSP) and saliva samples were obtained for evaluation of rapid COVID-19 testing kits (RDT). 100/33,000 (0.3%) of specimens were RT-PCR positive for SARS-CoV-2. Among RT-PCR positive, 62% were males, 34% were females, and 4% were children. The NSP-RDT (Lepu Medical China) analysis revealed 53% reactivity among males, 58% reactivity among females, and 25% reactivity among children. However saliva based RDT (Lepu Medical China) analysis showed 21% reactivity among males and 23% among females, and no reactivity in children. False negative results were significantly more pronounced in saliva based RDT as compared to NSP-RDT. The sensitivity of these NSP-RDT and saliva based RDT were 52% and 21% respectively. The RDTs evaluated in this study showed limited sensitivities in comparison to gold standard RT-PCR, indicating that there is a dire need in Pakistan for development of suitable testing to improve accurate COVID-19 diagnosis in line with national demands.

Highlights

Severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), belonged to Betacoronavirus genera and preferentially infects cells in respiratory tract [1, 2], but its organotropism including brain, conjunctiva, pharynx, lungs, heart, liver and kidneys remains poorly understood [3, 4]
100 reverse-transcription polymerase chain reaction (RT-PCR) positive cases were pre-selected for evaluation of COVID-19 antigen kits
The nasopharyngeal swab (NSP)-rapid COVID-19 testing kits (RDT) analysis revealed a reactive result for SARS-CoV-2 antigen in 52% patients, while remaining 48% were declared non-reactive

Summary

Introduction

Severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), belonged to Betacoronavirus genera and preferentially infects cells in respiratory tract [1, 2], but its organotropism including brain, conjunctiva, pharynx, lungs, heart, liver and kidneys remains poorly understood [3, 4]. According to World Health Organization (WHO) Emergencies Preparedness Response Report published in 2004, 8096 people around the world were diagnosed with 774 deaths [7]. In December 2019, SARS-CoV-2, a novel coronavirus from same family of SARS-CoV and Middle East Respiratory Syndrome (MERS) coronavirus emerged causing coronavirus disease 2019 (COVID-19) pandemic [8, 9]. The global number of SARS-CoV-2 positive cases were 43,820,929 and have been climbing vigorously.

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