ABSTRACT
OBJECTIVES: To evaluate pre-analytical challenges related to high-volume central laboratory SARS-CoV-2 antigen testing with a prototype qualitative SARS-CoV-2 antigen immunoassay run on the automated Abbott ARCHITECT instrument. METHODS: Contrived positive and negative specimens and de-identified nasal and nasopharyngeal specimens in transport media were used to evaluate specimen and reagent on-board stability, assay analytical performance and interference, and clinical performance. RESULTS: TCID50/mL values were similar for specimens in various transport media. Inactivated positive clinical specimens and viral lysate (USA-WA1/2020) were positive on the prototype immunoassay. Within-laboratory imprecision was ≤0.10 SD (<1.00 S/C) with a ≤10% CV (≥1.00 S/C). Assay reagents were stable on board the instrument for 14 days. No high-dose hook effect was observed with a SARS-CoV-2 stock of Ct 13.0 (RLU>1.0 × 106). No interference was observed from mucin, whole blood, 12 drugs, and more than 20 cross-reactants. While specimen stability was limited at room temperature for specimens with or without viral inactivation, a single freeze/thaw cycle or long-term storage (>30 days) at -20 °C did not adversely impact specimen stability or assay performance. Specificity of the prototype SARS-CoV-2 antigen immunoassay was ≥98.5% and sensitivity was ≥89.5% across two ARCHITECT instruments. Assay sensitivity was inversely correlated with Ct and was similar to that reported for the Roche Elecsys® SARS-CoV-2 Ag immunoassay. CONCLUSIONS: The prototype SARS-CoV-2 antigen ARCHITECT immunoassay is sensitive and specific for detection of SARS-CoV-2 in nasal and nasopharyngeal specimens. Endogenous proteases in mucus may degrade the target antigen, which limits specimen storage and transport times and complicates assay workflow.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , COVID-19/diagnosis , Sensitivity and Specificity , COVID-19 Testing , ImmunoassayABSTRACT
This second annual edition of MycoNews starts with a message from IMA President Wieland Meyer regarding the steps being taken to legally incorporate the Association in Switzerland. News is provided on progress in the arrangements for IMC12 (Amsterdam 2022), release of the State of World's Plants and Fungi report, mycology under the Coronavirus pandemic, and two new biodiversity initiatives in The Netherlands. Reports are presented from the: 1st International Symposium on Tropical African Mycology (Benin 2019); Recent Advances in the Biodiversity, Biology, and Biotechnology of Fungi (Pondicherry 2019); the 4th International Malassezia Workshop (virtual 2020); Dutch Design Week (2020), and UK Fungus Day (2020). An honour awarded to Francis Martin is recorded. Birthday greetings from IMA go to John Walker, José Dianese, Richard Harris, Tomasz Majewski, David Malloch, and John Sheard. Tributes are paid to the passing of John Peberdy, Anthony Trinci, and Balamuri Vittal. This contribution continues with news of 10 new mycological books published in 2019 or 2020 and concludes with a letter on the appropriateness of adopting the term 'Funga'.