Qualitative evaluation of the new rapid point-of-care antigen Afias Covid-19/Flu Ag Combo assay

Background: An interim guidance document by the WHO (World Health Organization) suggests the use of rapid diagnostic tests based on antigen detection as an alternative to the real-time PCR test for the diagnosis of SARS-CoV2 infection, when the molecular RT-PCR test is not available, or the turnaround time is excessive, precluding its clinical and/or public health usefulness. Rapid antigenic tests are recommended when a  minimum of  80% sensitivity and 97% specificity are ensured. Methods: Here we employ a new assay for screening applications based on lateral-flow immunofluorescence assay, with microfluidic technology (Boditech AFIAS COVID-19/Flu Ag Combo) on a point-of-care analyzer AFIAS-6 (BoditechMed. Inc.) and compare it with a reference molecular method and an alternative screening immunochromatographic method (Boditech AFIAS COVID-19 Ag). Our study was carried out on stored UTM (at -20°C) samples of patients admitted to Di Venere Hospital of Bari that were already tested with molecular methods. Results: The new AFIAS COVID-19 Flu/Ag Combo test reached a clinical sensitivity of 92% on positive samples with Ct< 30, and a clinical specificity of 97.9% on negative samples.  Sensitivity is higher than the reference immunochromatographic test AFIAS COVID-19/Ag (92.0% vs 88.0%) while specificity remains unchanged (97.9% vs 98.0%). In addition the new AFIAS Combo test confirm the same negative predictive value (NPV, 95.9%) of the rapid reference test (AFIAS COVID 19-Ag) and an agreement with the molecular test of 95.9% (Cohen's k = 0.908). Conclusions: Considering its qualitative improvement, rapidity and ease of use we suggests AFIAS Combo test as a valid alternative to the reference lateral flow test (AFIAS COVID-19 Ag) and an adequate screening test. Keywords: SARS-CoV2; COVID-19; POCT; diagnosis; screening; immunoassay; rapid antigen test.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:36

Enthalten in:

Microbiologia Medica - 36(2021), 3

Sprache:

Englisch ; Italienisch

Beteiligte Personen:

Mara Lorusso [VerfasserIn]
Edmondo Adorisio [VerfasserIn]
Giuseppe Gagliardi [VerfasserIn]
Achille Meneghini [VerfasserIn]
Domenico Lagravinese [VerfasserIn]
Mario Antonio Lerario [VerfasserIn]

Links:

doi.org [kostenfrei]
doaj.org [kostenfrei]
www.pagepressjournals.org [kostenfrei]
Journal toc [kostenfrei]

Themen:

Covid-19
Diagnosis
Immuno-assay
Microbiology
POCT
Sars-CoV-2
Screening

doi:

10.4081/mm.2021.10315

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

DOAJ064433455