Frontline Screening for SARS-CoV-2 Infection at Emergency Department Admission by Third Generation Rapid Antigen Test: Can We Spare RT-qPCR?

Viruses

Chiara Vismara¹  Diana Fanti¹  Claudia Alteri²  Maria Antonello²  Arianna Pani²  Francesco Scaglione²  Valeria Cento²  Silvia Renica²  Massimo Puoti³  on behalf of the S.Co.Va Study Group³  Elisa Matarazzo⁴  Federica Di Ruscio⁴  Carlo Federico Perno⁵  Luna Colagrossi⁵ 

[1] Department of Chemical-Clinical and Microbiological Analyses, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milan, Italy;Department of Oncology and Hemato-Oncology, Università degli Studi di Milano, 20122 Milan, Italy;Infectious Diseases Unit, ASST Grande Ospedale Metropolitano Niguarda, 20162 Milan, Italy;Residency in Microbiology and Virology, Università degli Studi di Milano, 20122 Milan, Italy;Unit of Microbiology and Diagnostic Immunology, IRCCS Bambino Gesù Children’s Hospital, 00165 Rome, Italy;

关键词: antigenic test;    SARS-CoV-2;    rapid diagnostic test;    viral load;    subgenomic RNA;    infectivity;   

DOI  :  10.3390/v13050818

来源: DOAJ

【 摘 要 】

To complement RT-qPCR testing for diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, many countries have introduced the use of rapid antigen tests. As they generally display lower real-life performances than expected, their correct positioning as frontline screening is still controversial. Despite the lack of data from daily clinical use, third generation microfluidic assays (such as the LumiraDx SARS-CoV-2 Ag test) have recently been suggested to have similar performances to RT-qPCR and have been proposed as alternative diagnostic tools. By analyzing 960 nasopharyngeal swabs from 960 subjects at the emergency department admissions of a tertiary COVID-19 hospital, LumiraDx assay demonstrated a specificity of 97% (95% CI: 96–98), and a sensitivity of 85% (95% CI: 82–89) in comparison with RT-qPCR, which increases to 91% (95% CI: 86–95) for samples with a cycle threshold ≤ 29. Fifty false-negative LumiraDx-results were confirmed by direct quantification of genomic SARS-CoV-2 RNA through droplet-digital PCR (median (IQR) load = 5880 (1657–41,440) copies/mL). Subgenomic N and E RNAs were detected in 52% (n = 26) and 56% (n = 28) of them, respectively, supporting the presence of active viral replication. Overall, the LumiraDx test complies with the minimum performance requirements of the WHO. Yet, the risk of a misrecognition of patients with active COVID-19 persists, and the need for confirmatory RT-qPCR should not be amended.

【 授权许可】

Unknown