Diagnostic Accuracy of STANDARD Q COVID-19 Antigen Detection Kit in Comparison with RT-PCR Assay using Nasopharyngeal Samples in India
Published: January 1, 2022 | DOI: https://doi.org/10.7860/JCDR/2022/52286.15825
Seema Aleem, Naziya Zahoor, Asif Jeelani, SM Salim Khan
1. Senior Resident, Department of Microbiology, Government Medical College, Srinagar, Jammu and Kashmir, India.
2. Senior Resident, Department of Community Medicine, Government Medical College, Srinagar, Jammu and Kashmir, India.
3. Senior Resident, Department of Community Medicine, Government Medical College, Srinagar, Jammu and Kashmir, India.
4. Professor and Head, Department of Community Medicine, Government Medical College, Srinagar, Jammu and Kashmir, India.
Correspondence
Dr. Asif Jeelani,
House No. 27, Lane No. 1, Lal Bazar, Srinagar, Jammu and Kashmir, India.
E-mail: drasifjeelani@gmail.com
Introduction: Real-time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) can be considered to be the gold standard for diagnosis of Coronavirus Disease-2019 (COVID-19). Though it is highly accurate but has some limitations in terms of its use, which means that Rapid Antigen Tests (RAT) can support COVID-19 mitigation efforts.
Aim: To estimate sensitivity, specificity and degree of agreement of STANDARD Q COVID-19 Antigen Detection Kit in comparison to real-time quantitative RT-PCR (qRT-PCR).
Materials and Methods: This cross-sectional study was conducted at Government Medical College, Srinagar, Jammu and Kashmir, India, in April 2021. Socio-demographic and clinical information was collected on a pretested schedule after which two consecutive nasopharyngeal swabs were collected from each subject. One sample was tested using the STANDARD Q COVID-19 antigen test and the other was tested using qRT-PCR. Sensitivity and specificity were calculated using standard formulas. Cohen’s Kappa was calculated and Mann-Whitney U test was used for comparison.
Results: The study included 473 subjects with a mean age of 38.4±12.2 years. Around 1/4th (124 subjects) of subjects were symptomatic at testing with the most common symptoms being fever (57.2%), cough (50%), sore throat (43%), myalgia (25%) and diarrhoea (13%). The sensitivity, specificity, positive likelihood ratio and negative likelihood ratio were estimated to be 54.4%, 99.2%, 71.49 and 0.46, respectively. The Cohen’s Kappa between the two tests was 0.644. Cycle threshold value was significantly lower in subjects with symptoms and those with a positive rapid test among those positive on qRT-PCR.
Conclusion: The STANDARD Q COVID-19 antigen test has a reasonable sensitivity, high specificity with a substantial inter-test agreement in comparison to qRT-PCR.
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