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

Abstract

Background: Accurate and timely diagnosis is essential in limiting the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Real-time reverse transcription-polymerase chain reaction (rRT-PCR), the reference standard, requires specialized laboratories, costly reagents, and a long turnaround time. Antigen rapid diagnostic tests (Ag 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%. Methods: This 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. Results: We 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 <5 days (594/876, 67.8%), sensitivity was 67.1% (95% CI: 59.2-74.3%), and 53.3% (95% CI: 40.0-66.3%) among those 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. Conclusion: The 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 for only symptomatic patients in high-risk settings with limited access to RT-PCR. A negative result should be interpreted based on clinical and epidemiological information and may require retesting by rRT-PCR.

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

“… In patients with signs and symptoms compatible with COVID-19, we suggest the use of laboratory based NAAT in nasopharyngeal samples versus rapid antigen detection testing in nasopharyngeal samples for the diagnosis of COVID-19. Weak against Very low [ 4 , 5 , 16 , 106 , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , 6 , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , 8 , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , 10 , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , 11 , [56] , [57] , [58] , [59] , [60] , [61] , [62] , [63] ...…”

“… In patients with signs and symptoms compatible with COVID-19 of equal or less than 7 days-onset, we suggest the use of rapid antigen detection testing versus laboratory-based NAAT for the diagnosis of COVID-19. Weak for Very low [ 3 , 7 , 39 , 41 , 46 , 53 , 60 , 61 , 63 , 65 , 73 , 78 , 9 , 79 , 83 , [91] , [92] , [93] , 96 , 97 , 100 , 101 , 104 , 11 , 106 , 108 , 109 , 114 , 118 , 119 , 126 , [129] , [130] , [131] , 13 , [132] , [133] , [134] , [135] , [136] , 14 , 17 , 21 , 36 , 37 ] 16 In patients with signs and symptoms compatible with COVID-19 of more than 7 days-onset , should rapid antigen detection testing be used, compared with standard NAAT (commercial and/or in house) for diagnosis of COVID-19? In patients with signs and symptoms compatible with COVID-19 of more than 7 days-onset, we suggest the use of laboratory-based NAAT versus rapid antigen detection testing for the diagnosis of COVID-19.…”

“… In patients ≥ 12 years old with signs and symptoms compatible with COVID-19, we suggest the use of laboratory-based NAAT versus rapid antigen detection testing for the diagnosis of COVID-19. Weak against Low [ 4 , 6 , 25 , 28 , 33 , 34 , 37 , [41] , [42] , [43] , [44] , 46 , 7 , 48 , 49 , [53] , [54] , [55] , [62] , [63] , [64] , 70 , 71 , 10 , 77 , 82 , 83 , 90 , 94 , 108 , 109 , 111 , 113 , 115 , 11 , 116 , 119 , 123 , 128 , 130 , 133 , [135] , [136] , [137] , 140 , 17 , [143] , [144] , [145] , [146] , [147] , [148] , [149] , [150] , [151] , ...…”

“… 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] ...…”