Analysis of the diagnostic accuracy of rapid antigenic tests for detection of SARS-CoV-2 in hospital outbreak situation

Abstract

The reverse transcriptase polymerase chain reaction (RT-PCR) continues to be the reference diagnostic method for the confirmation of COVID-19 cases; however, rapid antigen detection tests (RADT) have recently been developed. The purpose of the study is to assess the performance of rapid antigen-based COVID-19 testing in the context of hospital outbreaks. This was an observational, cross-sectional study. The study period was from October 2020 to January 2021. The “Panbio COVID-19 AG” RADT (Abbott) was performed and TaqPath COVID-19 test RT-PCR. The samples were obtained from hospitalised patients in suspected outbreak situations at the Ramón y Cajal Hospital. A hospital outbreak was defined as the presence of 3 or more epidemiologically linked cases. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the RADT were calculated using RT-PCR as a reference. A total of 17 hospital outbreaks were detected in 11 hospital units during the study period, in which 34 RT-PCR and RADT screenings were performed. We obtained 541 samples, which were analysed with RT-PCR and a further 541 analysed with RADT. Six RADT tests gave conflicting results with the RT-PCR, 5 of them with a negative RADT and positive RT-PCR and one with positive RADT and a negative RT-PCR. The sensitivity of the RADT was 83.3% (65.3–94.4%) and the specificity was 99.8% (98.9–100%). The PPV was 96.2% (80.4–99.9%) and the NPV was 99% (97.7–99.7%). The RADT shows good diagnostic performance in patients on non-COVID-19 hospital wards, in the context of an outbreak.

Update of European Society of Clinical Microbiology and Infectious Diseases coronavirus disease 2019 guidelines: diagnostic testing for severe acute respiratory syndrome coronavirus 2

“… In asymptomatic patients ≥12 years old without risk factors for severe COVID-19, we suggest the use of laboratory-based NAAT versus rapid antigen testing for the diagnosis of COVID-19. Weak against Low [ 11 , 20 , 49 , 54 , 55 , 65 , 70 , 71 , 77 , 83 , 89 , 94 , 22 , 111 , 113 , 121 , 128 , 130 , 137 , [143] , [144] , [145] , [146] , 24 , [147] , [148] , [149] , 158 , [160] , [161] , [162] , [163] , [164] , [165] , 28 , [166] , [167] , [168] , [169] , [170] , [171] , [172] , [173] , [174] , [175] , 34 , 176 , 40 , 43 , 44 , 46 ] 3 In asymptomatic people of any age with any risk factor(s) for severe COVID-19 (including age <3 or ≥65 years) should rapid antigen tests be used, as compared to laboratory-based ...…”

“… In asymptomatic people, we suggest the use of laboratory-based NAAT in nasopharyngeal samples versus rapid antigen testing in nasopharyngeal samples for the diagnosis of COVID-19. Weak against Low [ 11 , 18 , 38 , 43 , 44 , 46 , 47 , 49 , 50 , [54] , [55] , [56] , 20 , 57 , 65 , 67 , 68 , 70 , 71 , 77 , 81 , 83 , 86 , 22 , 87 , 90 , 92 , 94 , 99 , 102 , 113 , 155 , 158 , 160 , 24 , [161] , [162] , [163] , 165 , 168 , 170 , [172] , [173] , [174] , [175] , 28 , [176] , [177] , [178] , [179] , [180] , [181] , [182] , [183] , [29] , [30] ...…”

Performance and application evaluation of SARS‐CoV‐2 antigen assay

“…The positive predictive value (PPV) was 96.2%, and the negative predictive value (NPV) was 99%. 33 Thus, healthcare providers must always be aware of the low sensitivity of antigen detection and consider conducting confirmatory SARS-CoV-2 nucleic acid detection, as false-negative results may lead to the failure of infection control and preventive measures and delays in diagnosis, isolation, and treatment. 28 In summary, screening of SARS-CoV-2 antigen reagent in a highrisk population is ideal, but it is still unavoidable to miss diagnosis when screening patients with SARS-CoV-2 antigen reagent in asymptomatic populations in low prevalence areas of COVID-19 due to the limitation of the methodology itself.…”

“…The sensitivity of the SARS‐CoV‐2 antigen assay was 83.3%, and the specificity was 99.8%. The positive predictive value (PPV) was 96.2%, and the negative predictive value (NPV) was 99% 33 . Thus, healthcare providers must always be aware of the low sensitivity of antigen detection and consider conducting confirmatory SARS‐CoV‐2 nucleic acid detection, as false‐negative results may lead to the failure of infection control and preventive measures and delays in diagnosis, isolation, and treatment 28 …”

Association Between Rapid Antigen Detection Tests and Real-Time Reverse Transcription–Polymerase Chain Reaction Assay for SARS-CoV-2: A Systematic Review and Meta-Analyses

“…Thus, the World Health Organization (WHO) recommended simple and rapid antigen detection tests (RADTs) in communities to serve the purpose of detection and contact tracing, as well as outbreak investigations [ 10 ]. This technique does not need trained experts and professional instruments and can offer results within 15 min, making it possible to identify those potentially infected with COVID-19 on time [ 11 ]. However, the WHO suggests a minimum of 80% sensitivity and 97% specificity to adopt RADTs [ 12 ], since their performance is inconsistent in diverse settings according to published research [ 13 ].…”