“David vs. Goliath”: A simple antigen detection test with potential to change diagnostic strategy for SARS-CoV-2

  • Jyotsna Agarwal Department of Microbiology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
  • Anupam Das Department of Microbiology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
  • Pranshu Pandey Department of Microbiology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
  • Manodeep Sen Department of Microbiology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
  • Jaya Garg Department of Microbiology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
Keywords: COVID-19, TrueNat, Rapid Antigen Test, RAT, RT-PCR

Abstract

Introduction: As regard to all pandemics, the current COVID-19 pandemic, could also have been better managed with prudent use of preventive measures coupled with rapid diagnostic tools such as rapid antigen tests, but their efficacy is under question because of projected lower sensitivity as compared to Real Time Reverse Transcriptase Polymerase Chain Reaction, which although considered gold standard has its own limitations.

Methodology: A prospective, single centre study was carried out to evaluate the performance of Standard Q COVID-19 Ag, a rapid immuno-chromatographic assay for antigen detection, against TrueNat, a chip-based, point-of-care, portable, Real-Time PCR analyzer for diagnosis of COVID-19; on 467 nasal swab samples from suspected subjects at a fever clinic in North India in month of July 2020.

Results: Of the 467 specimens tested, TrueNat showed positive result in 29 (6.2%), majority of whom were asymptomatic (72.4%) while 4/29 (13.9%) had influenza like illness and 2/29 (6.8%) presented with severe acute respiratory illness. Compared to TrueNat, Rapid antigen test gave concordance for 26 samples, while for 2 samples the result was false positive; giving an overall sensitivity of 89.7% (95% CI = 72.6- 97.8) and a specificity of 99.5%, indicating strong agreement between two methods.

Conclusion: Community prevalence plays an important role is choosing the laboratory test and result interpretation. Rapid antigen detection tests definitely have a big role to play, especially in resource limited setting, for early diagnosis as well as for source control to halt the spread.

Published
2021-07-31
How to Cite
1.
Agarwal J, Das A, Pandey P, Sen M, Garg J (2021) “David vs. Goliath”: A simple antigen detection test with potential to change diagnostic strategy for SARS-CoV-2. J Infect Dev Ctries 15:904-909. doi: 10.3855/jidc.13925
Section
Coronavirus Pandemic