Evaluation of the Omicron variant by RT-PCR and rapid antigen testing (ExacTest™ COVID-19 Antigen Rapid Test)

Öz

Purpose: The present study aims to compare the results of the COVID-19 rapid antigen test (ExacTest™ COVID-19 Antigen Rapid Test) and real-time polymerase chain reaction (RT-PCR) test in samples of people suspected of coronavirus disease (COVID-19).
Materials and methods: Among the samples submitted between January 2022 and March 2022 with suspicion of COVID-19, 299 samples subject to simultaneous COVID-19 RADT (Rapid Antigen Detection Test) and RT-PCR were evaluated retrospectively. The Real-Time PCR test was studied with the DS CORONEX COVID-19 Multiplex Real time-qPCR Test Kit (DS Nano and Biotechnology Product Tracing and Tracking Co., Turkey) and the rapid antigen test was studied by the immunochromatographic method with ExacTest™ COVID-19 Antigen Rapid Test Cassette kit (General Diagnostica inc., California, USA). Ag-RDT test results were evaluated with the fluorescent immunoassay analyzer (FIATEST Analyzer, Hangzhou Alltest Biotech Co., Ltd. China).
Results: RT-PCR test was positive in 53 (17.7%) samples. The RADT's sensitivity was found 88.7 (95% Cl 77.0-95.7), specificity 98.0 (95% Cl 95.3-99.3), positive predictive value 90.4 (95% Cl 79.7-95.8), negative predictive value 97.6 (95% Cl 95.0-98.8), and accuracy 96.3 (95% Cl 93.5-98.2). Sample sensitivities of patients under and over 18 years of age have been identified as 75 (95% Cl 19.4-99.4) and 89.8 (95% Cl 77.8-96.6), respectively. The sensitivity of patients with and without symptoms was 95.5 (95% Cl 77.2-99.9) and 83.9 (95% Cl 66.3-94.6), respectively. For samples with a cycle threshold (Ct) of <20, 20-<25, 25-<30 and 30-<35, the concordance of testing was 100%, 92.9%, 78.9% and 80%, respectively.
Conclusion: The rapid antigen kit studied complies with the use criteria recommended by the World Health Organization and is quite useful for the rapid diagnosis of symptomatic patients in COVID-19.

Anahtar Kelimeler

• COVID-19
• RT-PCR
• RADT
• immunochromatography method

Omicron varyantının RT-PCR ve hızlı antijen testi (ExacTest™ COVID-19 Antijen Hızlı Testi) ile değerlendirilmesi

Öz

Amaç: Çalışmamızda, koronavirüs hastalığı (COVID-19) şüphesi olan kişilerin örneklerinde COVID-19 hızlı antijen testi (ExacTest™ COVID-19 Antigen Rapid Test) ve gerçek zamanlı polimeraz zincir reaksiyonu (RT-PCR) testi sonuçlarının karşılaştırılması amaçlanmıştır.
Gereç ve yöntem: Ocak 2022-Mart 2022 tarihleri arasında COVID-19 şüphesi ile gönderilen örneklerde eş zamanlı COVID-19 RADT (Rapid Antigen Detection Test) ve RT-PCR çalışılan 299 örnek retrospektif olarak değerlendirilmiştir. Real-Time PCR testi, DS CORONEX COVID-19 Multiplex Real Time-qPCR Test Kiti (DS Nano and Biotechnology Product Tracing and Tracking Co.,Türkiye) ile ve hızlı antijen testi immünokromatografi yöntemi ile ExacTest™ COVID-19 Antigen Rapid Test Cassette (General Diagnostica inc., California, USA) kitiyle çalışılmıştır. RADT testi sonuçları floresan immünoassay analiz cihazı (FIATEST Analyzer, Hangzhou Alltest Bıotech Co.,Ltd. China) ile değerlendirildi.
Bulgular: RT-PCR testi 53 (%17,7) örnekte pozitif olarak saptanmıştır. RADT duyarlılığı 88,7 (%95 Cl 77,0-95,7), özgüllüğü 98,0 (%95 Cl 95,3-99,3), pozitif öngörü değeri 90,4 (%95 Cl 79,7-95,8), negatif öngörü değeri 97,6 (%95 Cl 95,0-98,8) ve doğruluğu 96,3 (%95 Cl 93,5-98,2) olarak bulunmuştur. 18 yaş altı ve 18 yaş ve üstü hastaların örnek duyarlılıkları sırasıyla 75 (%95 Cl 19,4-99,4), 89,8 (%95 Cl 77,8-96,6) olarak tespit edilmiştir. Semptomu olan ve olmayan hastaların duyarlılığı sırasıyla 95,5 (%95 Cl 77,2-99,9), 83,9 (%95 Cl 66,3-94,6) olarak saptanmıştır. Döngü eşiği (Ct) <20, 20-<25, 25-<30, 30-<35 olan örneklerde testin uyumu sırasıyla %100, %92,9, %78,9, %80 olarak bulunmuştur.
Sonuç: Çalışılan hızlı antijen kiti dünya sağlık örgütünün önerdiği kullanılabilirlik kriterleri ile uyumludur ve semptomatik hastaların COVID-19 tanısında hızlı sonuç alınması açısından oldukça yararlıdır.

Anahtar Kelimeler

• COVID-19
• RT-PCR
• RADT
• immünokromatografi yöntemi

Kaynakça

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