Andreas Osterman, Irina Badell, Christopher Dächert, Nikolas Schneider, Anna-Yasemin Kaufmann, Gamze Naz Öztan, Melanie Huber, Patricia M Späth, Marcel Stern, Hanna Autenrieth, Maximilian Muenchhoff, Alexander Graf, Stefan Krebs, Helmut Blum, Ludwig Czibere, Jürgen Durner, Lars Kaderali, Hanna-Mari Baldauf, Oliver T Keppler
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引用次数: 0
Abstract
During 2022, the COVID-19 pandemic has been dominated by the variant of concern (VoC) Omicron (B.1.1.529) and its rapidly emerging subvariants, including Omicron-BA.1 and -BA.2. Rapid antigen tests (RATs) are part of national testing strategies to identify SARS-CoV-2 infections on site in a community setting or to support layman's diagnostics at home. We and others have recently demonstrated an impaired RAT detection of infections caused by Omicron-BA.1 compared to Delta. Here, we evaluated the performance of five SARS-CoV-2 RATs in a single-centre laboratory study examining a total of 140 SARS-CoV-2 PCR-positive respiratory swab samples, 70 Omicron-BA.1 and 70 Omicron-BA.2, as well as 52 SARS-CoV-2 PCR-negative swabs collected from March 8th until April 10th, 2022. One test did not meet minimal criteria for specificity. In an assessment of the analytical sensitivity in clinical specimen, the 50% limit of detection (LoD50) ranged from 4.2 × 104 to 9.2 × 105 RNA copies subjected to the RAT for Omicron-BA.1 compared to 1.3 × 105 to 1.5 × 106 for Omicron-BA.2. Overall, intra-assay differences for the detection of Omicron-BA.1-containing and Omicron-BA.2-containing samples were non-significant, while a marked overall heterogeneity among the five RATs was observed. To score positive in these point-of-care tests, up to 22-fold (LoD50) or 68-fold (LoD95) higher viral loads were required for the worst performing compared to the best performing RAT. The rates of true-positive test results for these Omicron subvariant-containing samples in the highest viral load category (Ct values < 25) ranged between 44.7 and 91.1%, while they dropped to 8.7 to 22.7% for samples with intermediate Ct values (25-30). In light of recent reports on the emergence of two novel Omicron-BA.2 subvariants, Omicron-BA.2.75 and BJ.1, awareness must be increased for the overall reduced detection rate and marked differences in RAT performance for these Omicron subvariants.
期刊介绍:
Medical Microbiology and Immunology (MMIM) publishes key findings on all aspects of the interrelationship between infectious agents and the immune system of their hosts. The journal´s main focus is original research work on intrinsic, innate or adaptive immune responses to viral, bacterial, fungal and parasitic (protozoan and helminthic) infections and on the virulence of the respective infectious pathogens.
MMIM covers basic, translational as well as clinical research in infectious diseases and infectious disease immunology. Basic research using cell cultures, organoid, and animal models are welcome, provided that the models have a clinical correlate and address a relevant medical question.
The journal also considers manuscripts on the epidemiology of infectious diseases, including the emergence and epidemic spreading of pathogens and the development of resistance to anti-infective therapies, and on novel vaccines and other innovative measurements of prevention.
The following categories of manuscripts will not be considered for publication in MMIM:
submissions of preliminary work, of merely descriptive data sets without investigation of mechanisms or of limited global interest,
manuscripts on existing or novel anti-infective compounds, which focus on pharmaceutical or pharmacological aspects of the drugs,
manuscripts on existing or modified vaccines, unless they report on experimental or clinical efficacy studies or provide new immunological information on their mode of action,
manuscripts on the diagnostics of infectious diseases, unless they offer a novel concept to solve a pending diagnostic problem,
case reports or case series, unless they are embedded in a study that focuses on the anti-infectious immune response and/or on the virulence of a pathogen.