scholarly journals Humoral Immune Response to SARS-CoV-2

2020 ◽  
Vol 154 (5) ◽  
pp. 610-619 ◽  
Author(s):  
Pauline H Herroelen ◽  
Geert A Martens ◽  
Dieter De Smet ◽  
Koen Swaerts ◽  
An-Sofie Decavele

Abstract Objectives Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serology tests are clinically useful to document prior SARS-CoV-2 infections. Data are urgently needed to select assays with optimal sensitivity at acceptable specificity for antibody detection. Methods A comparative evaluation was performed of 7 commercial SARS-CoV-2 serology assays on 171 sera from 135 subjects with polymerase chain reaction–confirmed SARS-CoV-2 infection (71 hospitalized patients and 64 paucisymptomatic individuals). Kinetics of IgA/IgM/IgG seroconversion to viral N and S protein epitopes were studied from 0 to 54 days after onset of symptoms. Cross-reactivity was verified on 57 prepandemic samples. Results Wantai SARS-COV-2 Ab ELISA and Orient Gene COVID-19 IgG/IgM Rapid Test showed superior overall sensitivity for detection of SARS-CoV-2 antibodies. Elecsys Anti-SARS-CoV-2 assay and EUROIMMUN Anti-SARS-CoV-2 combined IgG/IgA showed acceptable sensitivity (>95%) vs the consensus result of all assays from 10 days post onset of symptoms. Wantai SARS-COV-2 Ab ELISA, Elecsys Anti-SARS-CoV-2 assay, and Innovita 2019-nCoV Ab rapid test showed least cross-reactivity, resulting in an optimal analytical specificity greater than 98%. Conclusions Wantai SARS-COV-2 Ab ELISA and Elecsys Anti-SARS-CoV-2 assays are suitable for sensitive and specific detection of SARS-CoV-2 antibodies from 10 days after onset of symptoms.

Author(s):  
Clarence W Chan ◽  
Sajid Shahul ◽  
Cheyenne Coleman ◽  
Vera Tesic ◽  
Kyle Parker ◽  
...  

Abstract Objectives To evaluate the analytical and clinical performance of the Truvian Easy Check coronavirus disease 2019 (COVID-19) IgM/IgG anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody test. Serologic assays have become increasingly available for surveillance through the Food and Drug Administration emergency use authorization in the ongoing COVID-19 global pandemic. However, widespread application of serologic assays has been curbed by reports of faulty or inaccurate tests. Therefore, rapid COVID-19 antibody tests need to be thoroughly validated prior to their implementation. Methods The Easy Check device was analytically evaluated and its performance was compared with the Roche Elecsys anti-SARS-CoV-2 antibody assay. The test was further characterized for cross-reactivity using sera obtained from patients infected by other viruses. Clinical performance was analyzed with polymerase chain reaction-confirmed samples and a 2015 prepandemic reference sample set. Results The Easy Check device showed excellent analytical performance and compares well with the Roche Elecsys antibody assay, with an overall concordance of 98.6%. Clinical performance showed a sensitivity of 96.6%, a specificity of 98.2%, and an overall accuracy of 98.1%. Conclusions The Easy Check device is a simple, reliable, and rapid test for detection of SARS-CoV-2 seropositivity, and its performance compares favorably against the automated Roche Elecsys antibody assay.


2019 ◽  
Vol 43 (3) ◽  
pp. 173-176
Author(s):  
Chang-Hun Park

Abstract Background Infections caused by carbapenem-resistant Enterobacterales (CREs) are an emerging problem associated with high rates of morbidity and mortality. CREs are divided into two categories (carbapenemase-producing [CP] CRE and non-CP CRE). The most prevalent carbapenemase produced by Enterobacterales is Klebsiella pneumoniae carbapenemase (KPC) in Korea. Rapid identification of CREs is clinically important in infection control precaution. We compared the performance of two chromogenic media (chromID CARBA agar and CHROMagar KPC agar) for non-CP CREs or CP CREs with blaGES-5, blaNDM-1 or blaVIM-2 in a Korean hospital. Methods The study was carried out during a 3-month period from April to June 2017 during the surveillance program for CRE colonization. Antimicrobial susceptibility testing (AST) and polymerase chain reaction (PCR) were performed at the Korean Centers for Disease Control and Prevention. Results A total of 45 rectal swabs from 42 hospitalized patients were examined. Sensitivity of both chromID CARBA and CHROMagar KPC were 100% for CP CREs; and 50% and 100% for non-CP CREs, respectively. Specificity of chromID CARBA and CHROMagar KPC were 89.2% and 70.3% for CP CRE, respectively; and 76.9% and 66.7% for non-CP CRE, respectively. Conclusions The CHROMagar KPC is useful to monitor non-CP and CP CREs. The chromID CARBA is efficient for rapid detection of CP CREs requiring high contact precaution.


Author(s):  
Jurai Wongsawat ◽  
Patama Suttha ◽  
Sumalee Chanama ◽  
Somkid Srisopa ◽  
Nichapa Yonchoho ◽  
...  

Information is limited regarding differential serological responses after acute Zika virus (ZIKV) infections and prevalence of cross-reactivity with anti-dengue virus (DENV) assays comparing children and adults. Early convalescent sera from a cohort of suspected mild DENV cases between December 2016 and September 2018 at Bamrasnaradura Infectious Diseases Institute in Thailand were tested for nonstructural protein 1 (NS1)–based anti-ZIKV IgM and IgG ELISAs (Euroimmun), and in-house anti-DENV IgM- and IgG-capture ELISAs. ZIKV cases were identified by positive real-time reverse transcriptase-polymerase chain reaction on urine. Sera from 26 (10 children and 16 adults) ZIKV and 237 (153 children and 74 adults) non-ZIKA cases collected at the median duration of 18 days (interquartile range [IQR] 18,19) post-onset of symptoms were tested. Comparing pediatric ZIKV to adult ZIKV cases, the mean anti-ZIKV IgM ratio was higher (2.12 versus 1.27 units, respectively; P = 0.07), whereas mean anti-ZIKV IgG ratio was lower (3.13 versus 4.24 units, respectively; P = 0.03). Sensitivity of anti-ZIKV IgM and specificity of anti-ZIKV IgG in pediatric ZIKV were higher than in adult ZIKV cases (80.0% versus 43.7% and 79.1% versus 43.2%, respectively). No cross-reactivity with anti-DENV IgM- and IgG-capture ELISA were reported in pediatric ZIKV cases in our study, whereas 25% and 12.5% were found in adult ZIKV cases, respectively. Age-related ZIKV serological differences have been observed. Positive NS1-based anti-ZIKV IgM and IgG ELISA at the early convalescent phase could be useful for ZIKV diagnosis in children, even in a dengue endemic setting.


Author(s):  
Ika Yasma Yanti ◽  
Dalima Ari Wahono Astrawinata

Toxigenic Clostridium difficile infection, causing a Pseudo Membrane Colitis (PMC) and Clostridium Difficile Associated Diarrhea(CDAD) has increased sharply. The largest risk factor is the use of antibiotics. The purpose of this study was to know how to determinethe prevalence and characteristics of subjects with Toxigenic Clostridium difficile and to assess the ability of the toxin rapid test comparedto real-time PCR. Ninety adult subjects with antibiotic therapy more than two (2) weeks were enrolled in this study. The results of toxinrapid test and real-time PCR were presented in a 2x2 table, statistical test used was Chi square. The prevalence of Toxigenic Clostridiumdifficile based on the toxin rapid test and by real-time PCR was 27.3% and 37.5%, respectively. There were significant differences betweenstool consistency and number of antibiotics used with the detection of Toxigenic Clostridium difficile. There was a relationship betweenthe duration of antibiotic therapy with the detection of Toxigenic Clostridium difficile using real-time PCR (p=0.010, RR=2.116). Thesensitivity, specificity, PPV, NPV, PLR and NLR rapid test against real-time PCR were 69.7%; 98.2%; 95.8%; 84.4%; 39.2 and 0.31,respectively. This study concluded that the prevalence of Clostridium difficile in RSCM was higher compared to that in Malaysia, Thailandand India; the subjects with antibiotic therapy for more than four (4) weeks had a double risk to have Toxigenic Clostridium difficilethan subjects with antibiotic therapy for less than that time (4 weeks). Thus, in this study, toxin rapid test could be used as a tool todetect Toxigenic Clostridium difficile.


1999 ◽  
Vol 103 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Salim Bounou ◽  
Suha H. Jabaji-Hare ◽  
Richard Hogue ◽  
Pierre M. Charest

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