PLoS ONE (Jan 2023)

Diagnostic accuracy of the Panbio COVID-19 antigen rapid test device for SARS-CoV-2 detection in Kenya, 2021: A field evaluation.

  • Jack Karuga Irungu,
  • Peninah Munyua,
  • Caroline Ochieng,
  • Bonventure Juma,
  • Patrick Amoth,
  • Francis Kuria,
  • John Kiiru,
  • Lyndah Makayotto,
  • Ahmed Abade,
  • Marc Bulterys,
  • Elizabeth Hunsperger,
  • Gideon O Emukule,
  • Clayton Onyango,
  • Taraz Samandari,
  • Beth A Tippett Barr,
  • Victor Akelo,
  • Herman Weyenga,
  • Patrick K Munywoki,
  • Godfrey Bigogo,
  • Nancy A Otieno,
  • Jackton Azenga Kisivuli,
  • Edwin Ochieng,
  • Rufus Nyaga,
  • Noah Hull,
  • Amy Herman-Roloff,
  • Rashid Aman

DOI
https://doi.org/10.1371/journal.pone.0277657
Journal volume & issue
Vol. 18, no. 1
p. e0277657

Abstract

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BackgroundAccurate and timely diagnosis is essential in limiting the spread of SARS-CoV-2 infection. The reference standard, rRT-PCR, requires specialized laboratories, costly reagents, and a long turnaround time. Antigen RDTs provide a feasible alternative to rRT-PCR since they are quick, relatively inexpensive, and do not require a laboratory. The WHO requires that Ag RDTs have a sensitivity ≥80% and specificity ≥97%.MethodsThis evaluation was conducted at 11 health facilities in Kenya between March and July 2021. We enrolled persons of any age with respiratory symptoms and asymptomatic contacts of confirmed COVID-19 cases. We collected demographic and clinical information and two nasopharyngeal specimens from each participant for Ag RDT testing and rRT-PCR. We calculated the diagnostic performance of the Panbio™ Ag RDT against the US Centers for Disease Control and Prevention's (CDC) rRT-PCR test.ResultsWe evaluated the Ag RDT in 2,245 individuals where 551 (24.5%, 95% CI: 22.8-26.3%) tested positive by rRT-PCR. Overall sensitivity of the Ag RDT was 46.6% (95% CI: 42.4-50.9%), specificity 98.5% (95% CI: 97.8-99.0%), PPV 90.8% (95% CI: 86.8-93.9%) and NPV 85.0% (95% CI: 83.4-86.6%). Among symptomatic individuals, sensitivity was 60.6% (95% CI: 54.3-66.7%) and specificity was 98.1% (95% CI: 96.7-99.0%). Among asymptomatic individuals, sensitivity was 34.7% (95% CI 29.3-40.4%) and specificity was 98.7% (95% CI: 97.8-99.3%). In persons with onset of symptoms 7 days (157/876, 17.9%). The highest sensitivity was 87.0% (95% CI: 80.9-91.8%) in symptomatic individuals with cycle threshold (Ct) values ≤30.ConclusionThe overall sensitivity and NPV of the Panbio™ Ag RDT were much lower than expected. The specificity of the Ag RDT was high and satisfactory; therefore, a positive result may not require confirmation by rRT-PCR. The kit may be useful as a rapid screening tool only for symptomatic patients in high-risk settings with limited access to rRT-PCR. A negative result should be interpreted based on clinical and epidemiological information and may require retesting by rRT-PCR.