Wir haben soeben einige #COVI19 #Antigentests entsorgt, weil die FlĂŒssigkeit in den Röhrchen gelblich und auf weniger als die HĂ€lfte geschrumpft war. Das Ablaufdatum liegt weit im der Zukunft (JĂ€nner 2024). Der Hersteller ist #Newgene Bioengineering.
Since autumn 2020, rapid antigen tests (RATs) have been implemented in several countries as an important pillar of the national testing strategy to rapidly screen for infections on site during the SARS-CoV-2 pandemic. The current surge in infection rates around the globe is driven by the variant of concern (VoC) omicron (B.1.1.529). Here, we evaluated the performance of nine SARS-CoV-2 RATs in a single-centre laboratory study. We examined a total of 115 SARS-CoV-2 PCR-negative and 166 SARS-CoV-2 PCR-positive respiratory swab samples (101 omicron, 65 delta (B.1.617.2)) collected from October 2021 until January 2022 as well as cell culture-expanded clinical isolates of both VoCs. In an assessment of the analytical sensitivity in clinical specimen, the 50% limit of detection (LoD50) ranged from 1.77âĂâ106 to 7.03âĂâ107 RNA copies subjected to the RAT for omicron compared to 1.32âĂâ105 to 2.05âĂâ106 for delta. To score positive in these point-of-care tests, up to 10-fold (LoD50) or 101-fold (LoD95) higher virus loads were required for omicron- compared to delta-containing samples. The rates of true positive test results for omicron samples in the highest virus load category (Ct valuesâ<â25) ranged between 31.4 and 77.8%, while they dropped to 0â8.3% for samples with intermediate Ct values (25â30). Of note, testing of expanded virus stocks suggested a comparable RAT sensitivity of both VoCs, questioning the predictive value of this type of in vitro-studies for clinical performance. Given their importance for national test strategies in the current omicron wave, awareness must be increased for the reduced detection rate of omicron infections by RATs and a short list of suitable RATs that fulfill the minimal requirements of performance should be rapidly disclosed.
Black Metal StuđșđŠđźđ±
Jogi HofmĂŒller (he/him)
NDR|inoffiziell
Ludwig W. Mieth
R0ux
R0ux
Deutsche Welle (inoffiziell)