PERFORMANCE OF NASAL SARS-COV-2 ANTIGEN-RAPID DIAGNOSTIC TEST (AG RDT) IN KOGABWILHAN II FOREFRONT HOSPITAL INDRAPURA (RSLKI) SURABAYA INDONESIA

Abstract

Due to the limited access of nucleic-acid-amplification-tests (NAAT) in Indonesia, Antigen-Rapid Diagnostic Tests (Ag-RDT) are performed to directly detect SARS-CoV-2 proteins secreted by replicating virus in respiratory track. Most Ag-RDT expect nasopharyngeal (NP) sampling conducted by qualified healthcare professionals. Nasal (NS) sampling would enlarge the scale of antigen testing strategies. This study aimed to evaluate the performance of nasal SARS-CoV-2 Ag RDT with local condition in KOGABWILHAN II Forefront Hospital Indrapura (RSLKI) Surabaya Indonesia. A total of 150 from 172 patients between 25^th May and 7^th June 2021 were enrolled according to purposive consecutive sampling method. A NS Ag-RDT and a NP Polymerase-Chain-Reaction (PCR) sampling were obtained by a qualified laboratory technicians according to the recommended standard procedure. The antigen kit was used according to Bioquick^TM Ag-Rapid Test Device (Nasal)’s instructions. PCR testing was performed according to the manufacturer's guidelines on mBioCoV-19 RT-PCR Kit (Biofarma, Bandung, Indonesia). Diagnostic value were calculated for NS Ag-RDT compared to the NP PCR test. A total of 81 patients (54%) were males and a total of 69 (46%) patients were females. The median age was 32.5 years (minimum 13 years, maximum 66 years). The clinical manifestations showed asymptomatic in 61 patients (40.7%), mild in 86 patients (57.3%), moderate in 3 patients (2.0%), and no patient with severe symptoms. The difference < 7 days between the first PCR positive with Ag RDT testing was found in 125 patients (83.3%) and > 7 days in 25 patients (16.7%). Ag-RDT diagnostic value in samples with PCR CT-value < 25 showed sensitivity 85.2%, specificity 97.3%, positive predictive value (PPV) 92.0%, negative predictive value (NPV) 94.7%, and accuracy 94.0%. In conclusion, a professional nasal Ag-RDT had an acceptable performance.