EVALUATION ERASMUS MC
1) Department of Viroscience, Erasmus MC, Rotterdam, the Netherlands
2) Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands.
3) Department of Intensive Care, Erasmus MC, Rotterdam, the Netherlands
4) Center for Infectious Disease Control, RIVM, Bilthoven, The Netherlands
Abstract
The world is entering a new era of the COVID-19 pandemic in which there is an increasing call for reliable antibody testing. To support decision making on the deployment of serology for either population screening or diagnostics, we present a comprehensive comparison of serological COVID-19 assays. We show that the assay detecting total immunoglobulins against the receptor binding domain of SARS CoV-2, had optimal characteristics for antibody detection in different stages of disease.
EVALUATION SWEDEN
Tove Hoffman, Karolina Nissen, Janina Krambrich, Bengt Rönnberg, Dario Akaberi, Mouna Esmaeilzadeh, Erik Salaneck, Johanna Lindahl & Åke Lundkvist
Abstract
COVID-19 is the most rapidly growing pandemic in modern times, and the need for serological testing is most urgent. Although the diagnostics of acute patients by RT-PCR is both efficient and specific, we are also crucially in need of serological tools for investigating antibody responses and assessing individual and potential herd immunity. We evaluated a commercially available test developed for rapid (within 15 minutes) detection of SARS-CoV-2-specific IgM and IgG by 29 PCR-confirmed COVID-19 cases and 124 negative controls. The results revealed a sensitivity of 69% and 93.1% for IgM and IgG, respectively, based solely on PCR-positivity due to the absence of a serological gold standard. The assay specificities were shown to be 100% for IgM and 99.2% for IgG. This indicates that the test is suitable for assessing previous virus exposure.n.
EVALUATION FRANSICUS
1) Department of Medical Microbiology and Infection Control, Franciscus Gasthuis & Vlietland, Rotterdam, the Netherlands
2) Department of Epidemiology, Julius Centre for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, the Netherlands
3) Department of Clinical Chemistry and Haematology, Franciscus Gasthuis & Vlietland, Rotterdam, the Netherlands
Abstract
To assess the diagnostic performance of rapid lateral flow immunochromatographic assays (LFAs) compared with an ELISA and nucleic acid amplification tests (NATs) in individuals with suspected coronavirus disease 2019 (COVID-19).
Methods: Patients presenting to a Dutch teaching hospital were eligible between 17 March and 10 April 2020, when they had respiratory symptoms that were suspected for COVID-19. The performances of six different LFAs were evaluated in plasma samples obtained on corresponding respiratory sample dates of NATs testing. Subsequently, the best performing LFA was evaluated in 228 patients and in 50 sera of a historical patient control group.
Results: In the pilot analysis, sensitivity characteristics of LFA were heterogeneous, ranging from 2/20 (10%; 95% CI 0%e23%) to 11/20 (55%; 95% CI 33%e77%). In the total cohort, Orient Gene Biotech COVID-19 IgG/IgM Rapid Test LFA had a sensitivity of 43/99 (43%; 95% CI 34%e53%) and specificity of 126/129 (98%; 95% CI 95%e100%). Sensitivity increased to 31/52 (60%; 95% CI 46%e73%) in patients with at least 7 days of symptoms, and to 21/33 (64%; 95% CI 47%e80%) in patients with C-reactive protein (CRP) !100 mg/L. Sensitivity and specificity of Wantai SARS-CoV-2 Ab ELISA was 59/95 (62%; 95% CI 52%e72%) and 125/128 (98%; 95% CI 95%e100%) in all patients, respectively, but sensitivity increased to 38/48 (79%; 95% CI 68% e91%) in patients with at least 7 days of symptoms.
Conclusions: There is large variability in diagnostic test performance between rapid LFAs, but overall limited sensitivity and high specificity in acutely admitted patients. Sensitivity improved in patients with longer existing symptoms or high CRP.