Potential Use of Antigen-Based Rapid Test for SARS-CoV-2 in Respiratory Specimens in Low-Resource Settings in Egypt for Symptomatic Patients and High-Risk Contacts

Abstract

Objective Because of the rapidly emerging SARS-CoV-2 pandemic and its wide public health challenges, rapid diagnosis is essential to decrease the spread. Antigen-based rapid detection tests are available; however, insufficient data about their performance are available. Methods The lateral-flow immunochromatographic BIOCREDIT COVID-19 antigen test was evaluated using nasopharyngeal swabs in a viral transport medium from patients with confirmed infection, contacts, and exposed healthcare professionals at Fayoum University Hospital in Egypt. Test performance was determined in comparison to the SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (RT-PCR) test. Results Three hundred ten specimens from 3 categories—patients with confirmed diagnoses of COVID-19, contacts, and exposed healthcare professionals—were included; 188 specimens were RT-PCR-positive, from which 81 were detected by rapid antigen test. Overall sensitivity was 43.1%. Sensitivity was significantly higher in specimens with high viral loads. Conclusion Poor sensitivity of the BIOCREDIT COVID-19 test does not permit its use for diagnosis, and it can only be used in conjunction with RT-PCR for screening.

Comparison between Nasal and Nasopharyngeal Swabs for SARS-CoV-2 Rapid Antigen Detection in an Asymptomatic Population, and Direct Confirmation by RT-PCR from the Residual Buffer

“…Our data define a discrete range of C T values detected by NP and NA swabs applied to the Panbio Ag-RDT, consistent with the work of others for this testing platform using NP swabs ( 5 , 8 , 17 ), NA, or saliva samples ( 6 , 18 ), and for other Ag-RDTs using various specimen types ( 19 – 22 ). Others have compared the performance of Panbio NA versus NP swabs in a mixture of symptomatic and asymptomatic individuals ( 6 , 18 , 23 ), but few studies have targeted asymptomatic populations directly using Panbio ( 13 ) or other Ag-RDTs ( 24 , 25 ).…”

Diagnostic Utility of Antigen Detection Rapid Diagnostic Tests for Covid- 19: A Systematic Review and Meta-Analysis

“…Eleven studies (55%) evaluated nasopharyngeal swabs (5,6,8,(12)(13)(14)(15)(16)(17)(18)(19)(20). Three of included studies investigated various types of samples with just one assay (18,27,28), whereas other two articles examined one type of sample with different assays to comparing sensitivity and specificity (7,9).…”

Diagnosing SARS-CoV-2 with Antigen Testing, Transcription-Mediated Amplification and Real-Time PCR

“…To identify optimized strategies of antigen-based rapid testing for SARS-CoV-2, numerous studies [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ] have been performed and partly summarized in additional reviews [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ] after those first, quite disillusioning trials [ 3 ]. Despite persisting sensitivity issues and resulting in quite variable diagnostic reliability [ 57 ], antigen-testing was broadly used in the reaction to the second SARS-CoV-2 wave in many countries [ 58 ].…”