scholarly journals Rapid and Laboratory SARS-CoV-2 Antibody Testing in High-Risk Hospital Associated Cohorts of Unknown COVID-19 Exposure, a Validation and Epidemiological Study After the First Wave of the Pandemic

2021 ◽  
Vol 8 ◽  
Author(s):  
Brendan O'Kelly ◽  
Ronan McLaughlin ◽  
Roseann O'Doherty ◽  
Hailey Carroll ◽  
Roisin Murray ◽  
...  
Keyword(s):  
High Risk ◽  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Antibody Testing ◽  
Single Center Study ◽  
Risk Patients ◽  
Study Participants ◽  
Antibody Tests ◽  
Abbott Architect ◽  
Laboratory Assay

Objective: We aimed to use SARS-CoV-2 antibody tests to assess the asymptomatic seroprevalence of individuals in high-risk hospital cohorts who's previous COVID-19 exposure is unknown; staff, and patients requiring haemodialysis or chemotherapy after the first wave.Methods: In a single Center, study participants had five SARS-CoV-2 antibody tests done simultaneously; one rapid diagnostic test (RDT) (Superbio Colloidal Gold IgM/IgG), and four laboratory tests (Roche Elecsys® Anti-SARS-CoV-2 IgG [RE], Abbott Architect i2000SR IgG [AAr], Abbott Alinity IgG [AAl], and Abbott Architect IgM CMIA). To determine seroprevalence, only positive test results on laboratory assay were considered true positives.Results: There were 157 participants, of whom 103 (65.6%) were female with a median age of 50 years (range 19–90). The IgG component of the RDT showed a high number of false positives (n = 18), was inferior to the laboratory assays (p < 0.001 RDT vs. AAl/AAr, p < 0.001 RDT vs. RE), and had reduced specificity (85.5% vs. AAl/AAr, 87.2% vs. RE). Sero-concordance was 97.5% between IgG laboratory assays (RE vs. AAl/AAr). Specificity of the IgM component of the RDT compared to Abbott IgM CMIA was 95.4%. Ten participants had positivity in at least one laboratory assay, seven (9.9%) of which were seen in HCWs. Two (4.1%) hematology/oncology (H/O) patients and a single (2.7%) haemodialysis (HD) were asymptomatically seropositive. Asymptomatic seroprevalence of HCWs compared to patients was not significant (p = 0.105).Conclusion: HCWs (9.9%) had higher, although non-significant asymptomatic seroprevalence of SARS-CoV-2 antibodies compared to high-risk patients (H/O 4.1%, HD 2.7%). An IgM/IgG rapid diagnostic test was inferior to laboratory assays. Sero-concordance of 97.5% was found between IgG laboratory assays, RE vs. AAl/AAr.

scholarly journals Prediction of Heparin Induced Thrombocytopenia (HIT) Using a Combination of 4Ts Score and Screening Immune Assays

2020 ◽  
Vol 26 ◽  
pp. 107602962096285
Author(s):  
Rajat Thawani ◽  
Srikant Nannapaneni ◽  
Vivek Kumar ◽  
Phone Oo ◽  
Michael Simon ◽  
...  
Keyword(s):  
High Risk ◽  
Community Hospital ◽  
Antibody Test ◽  
Elisa Test ◽  
Platelet Factor ◽  
Heparin Induced Thrombocytopenia ◽  
T Score ◽  
Risk Patients ◽  
Immune Assays ◽  
Antibody Tests

Clinical assessment (4Ts) followed by testing for Heparin/platelet factor 4 (HPF4) antibody in intermediate and high risk patients is the standard algorithm of pretest for Heparin induced thrombocytopenia (HIT), and the diagnosis is confirmed by serotonin releasing assay (SRA) in those who have positive antibodies. We conducted a retrospective analysis in a cohort of patients treated in a community hospital who had HIT antibody test by either ELISA or a rapid Particle Immunofiltration Assay (PIFA), regardless of their 4Ts scores. Among 224 patients, 17 had HIT. The PPV for those with a 4 T score ≥4 was 10.4%, which misdianosed 3 patients with HIT who tested positive for antibodies. Combining 4 T score ≥4 AND positive HIT antibody showed a PPV of 20.3% and a sensitivity of 70.6%, misdiagnosing 5 HIT patients. Using 4Ts ≥4 OR positive HIT antibody showed 100% sensitivity and 100% negative predictive value (NPV). The ELISA test had 100% sensitivity and 100% NPV, while the PIFA test missed 2 HIT patients, with sensitivity of 60% and NPV of 96.7%. Our results suggest that SRA testing should be conducted if a patient presents with a 4 T score ≥4 OR a positive HIT antibody, and antibody tests should be conducted for every patient suspected of HIT.

scholarly journals Erratum

2003 ◽  
Vol 10 (1) ◽  
pp. A-6-A-6
Keyword(s):  
Clinical Study ◽  
High Risk ◽  
Single Center ◽  
Peripheral Vascular ◽  
December Issue ◽  
Abdominal Aortic ◽  
Single Center Study ◽  
Risk Patients ◽  
Study Manager ◽  
Center Study

Regarding “Outcome of Abdominal Aortic Endografting in High-Risk Patients: A 4-Year Single-Center Study,” which appeared in the December issue (2002;9:736–742), Dr. Simona Zannetti is employed by Medtronic as a Clinical Study Manager for Medtronic Europe, Peripheral Vascular Division. This information did not appear with the original article.

Outcome of Abdominal Aortic Endografting in High-Risk Patients: A 4-Year Single-Center Study

2002 ◽  
Vol 9 (6) ◽  
pp. 736-742 ◽  
Author(s):  
Fabio Verzini ◽  
Piergiorgio Cao ◽  
Simona Zannetti ◽  
Gianbattista Parlani ◽  
Paola De Rango ◽  
...  
Keyword(s):  
High Risk ◽  
Rank Test ◽  
Actuarial Survival ◽  
High Risk Patients ◽  
Endoluminal Repair ◽  
Abdominal Aortic ◽  
Single Center Study ◽  
Individualized Approach ◽  
Risk Patients ◽  
Patients Experience

Purpose: To evaluate feasibility, safety, and effectiveness of endovascular abdominal aortic aneurysm (AAA) repair in patients whose fitness for surgery is questionable. Methods: Between April 1997 and December 2001, 389 consecutive patients underwent endovascular AAA repair. Of these, 51 (13.1%) were ASA grade IV. The perioperative and late outcomes of this group were compared to the remaining 338 patients with ASA grades <IV. Failure of AAA exclusion was defined as late conversion to open repair, AAA rupture, increased aneurysm diameter, or persisting graft-related endoleak. Gender, age, ASA grade IV, EUROSTAR class E, and AAA diameter were examined by logistic regression analysis for their influence on perioperative death, survival, and failure of AAA exclusion. Results: Four (7.8%) perioperative deaths occurred in the ASA IV group compared to 1 (0.3%) in the ASA <IV group (p=0.001). Median follow-up was 22 months (range 1–56). Failure of AAA exclusion occurred in 3 (5.9%) patients in ASA IV group and in 25 (7.4%) in ASA <IV group (p>0.05). Actuarial survival at 30 months was 62.9% in ASA IV group and 88.0% in ASA <IV group (p=0.001, log-rank test). There were no independent predictors for failure of AAA exclusion; ASA IV was independently associated with perioperative mortality (HR 17.8; 95% CI 1.6 to 188; p=0.016). Conclusions: Endovascular AAA repair in ASA IV patients is feasible and effective in preventing AAA rupture in the mid term. High-risk patients experience a worse prognosis than their good-risk counterparts. An individualized approach in selecting high-risk patients for endoluminal repair is mandatory.

Is Color-Flow Duplex a Good Diagnostic Test for Detection of Isolated Calf Vein Thrombosis in High-Risk Patients?

Angiology ◽  
2000 ◽  
Vol 51 (9) ◽  
pp. 705-710 ◽  
Author(s):  
Hiroatsu Sugimoto ◽  
Tracey Richardson ◽  
Marshall W. Webster ◽  
Michel S. Makaroun ◽  
Mark K. Eskandari
Keyword(s):  
High Risk ◽  
Diagnostic Test ◽  
Color Flow ◽  
High Risk Patients ◽  
Vein Thrombosis ◽  
Risk Patients ◽  
Calf Vein ◽  
Good Diagnostic Test

scholarly journals Diagnostic Performance between Histidine-Rich Protein 2 (HRP-2), a Rapid Malaria Diagnostic Test and Microscopic-Based Staining Techniques for Diagnosis of Malaria

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Jean Baptiste Niyibizi ◽  
Emmanuel Kamana Gatera
Keyword(s):  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Health Centre ◽  
Malaria Diagnosis ◽  
High Specificity ◽  
Cross Sectional Study ◽  
Diagnostic Challenge ◽  
Cross Sectional ◽  
Predictive Values ◽  
Study Participants

Malaria presents a diagnostic challenge in most tropical countries such as Rwanda. Microscopy remains the gold standard for diagnosing malaria, but it is labor intensive and depends upon the skill of the examiner. Malaria rapid diagnostic tests (RDTs) have been developed as an easy, convenient alternative to microscopy. This cross-sectional study was conducted at Rukara Health Center which is located in Eastern Province, Kayonza district, Rwanda. One hundred and fifty suspected cases of malaria, who attended Rukara Health Centre, during the period, from 21st June to 30th July 2018, were included in this study. HRP-2 RDTs (CareStart™ Malaria HRP-2 (Access Bio, Inc., Somerset, New Jersey, USA)), for malaria were performed. Thick smears were prepared and Giemsa-stained as recommended; then slides were observed under microscopy and reported quantitatively; RDTs were reported qualitatively (positive or negative). Both RDTs and thick smear results were recorded on data collection sheet. This study included a total of 150 study participants, 87 (58%) females and 63 (42%) males. The patients included in the study did not receive any antimalarial drug. The mean age of the study participants was 31.6 ± 12.4 with the majority of participants being between 25 and 44 years and the minority being above 65 years. The sensitivity of RDT (HRP-2) was calculated and found to be 95.0%, whereas the sensitivity of Giemsa microscopy was 100%. The specificity of RDT (HRP-2) was calculated and found to be 59.2%, whereas the specificity of Giemsa microscopy was 100%. Negative and positive predictive values of RDT are 85.4% and 82.7%, respectively. Negative and positive predictive values of Giemsa microscopy were both 100%. According to the results of the current study, the sensitivity, specificity, and both positive and negative predictive values of Giemsa microscopy are higher than those of histidine-rich protein 2-based rapid diagnostic test for malaria. The results obtained in histidine-rich protein 2-based rapid diagnostic test for malaria parasites should be confirmed with tests with high specificity. Further studies should determine the most appropriate type of rapid diagnostic test of malaria diagnosis to be used in combination with Giemsa microscopy. In addition, sensitivity and specificity of RDT (HRP-2) and Giemsa microscopy should be assessed against molecular biology techniques.

scholarly journals Evaluation of the Abbott Architect, Roche Elecsys and Virtus S1 SARS-CoV-2 antibody tests in community-managed COVID-19 cases

2020 ◽  
Author(s):  
Sebastian L. Johnston ◽  
Paul F McKay ◽  
Tatiana Kebadze ◽  
Kai Hu ◽  
Karnyart Samnuan ◽  
...  
Keyword(s):  
Antibody Test ◽  
Research Centre ◽  
Strong Positive Correlation ◽  
True Positive ◽  
Antibody Testing ◽  
Serum Samples ◽  
True Negative ◽  
Health And Social Care ◽  
Antibody Tests ◽  
Abbott Architect

AbstractBackgroundAntibody testing can help define how protective immunity to SARS-CoV-2 is and how long this immunity lasts. Many antibody tests have been evaluated in hospitalised rather than community based COVID-19 cases. Virtus Respiratory Research Ltd (Virtus) has developed its own quantitative IgM and IgG SARS CoV-2 antibody assay. We report its validation and performance characteristics and compare its performance with the Abbott Architect and Roche Elecsys assays in community COVID cases.MethodsWe developed a quantitative antibody test to detect IgM and IgG to the SARS-CoV-2 S1 spike protein (the Virtus test) and validated this test in 107 “true positive” sera from 106 community-managed and 1 hospitalised COVID-19 cases and 208 “true negative” serum samples. We validated the Virtus test against a neutralising antibody test. We determined sensitivities of the Abbott test in the 107 true positive samples and the Roche test in a subset of 75 true positive samples.ResultsThe Virtus quantitative test was positive in 93 of 107 (87%) community cases of COVID-19 and both IgM and IgG levels correlated strongly with neutralising antibody titres (r=0.75 for IgM, r=0.71 for IgG, P<0.0001 for both antibodies). The specificity of the Virtus test was 98.6% for low level antibody positives, 99.5% for moderate positives and 100% for high or very high positives. The Abbott test had a sensitivity of 68%. In the 75 sample subset, the Virtus test was positive in 91%, the Roche test in 69%.ConclusionsThe Abbott and Roche tests had sensitives of 68% and 69% respectively in this community set of COVID-19 sera, while the Virtus test had sensitivities of 87% and 91% in the same sample sets. The strong positive correlation with virus neutralization suggests a positive Virtus quantitative antibody test is likely predictive of protective against recurrent COVID-19.FundingThe development of the Virtus test and sample testing with all antibody tests was funded by Virtus Respiratory Research Ltd. The research studies providing 111 of the 208 of the “true negative” samples was supported by MRC Grant numbers MR/M025330/1 and G1100238 and by the National Institute of Health Research (NIHR) Imperial Biomedical Research Centre (BRC), SLJ is a NIHR Emeritus Senior Investigator and is funded in part by European Research Council Advanced Grant 788575 and the Asthma UK Clinical Chair (grant CH11SJ). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

scholarly journals Diagnostic performance of an ultrasensitive HRP2-based malaria rapid diagnostic test kit used in surveys of afebrile people living in Southern Ghana

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Festus K. Acquah ◽  
Dickson Donu ◽  
Evans K. Obboh ◽  
Dorcas Bredu ◽  
Bernice Mawuli ◽  
...  
Keyword(s):  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Diagnostic Performance ◽  
Venous Blood ◽  
Malaria Rapid Diagnostic Test ◽  
Treatment Interventions ◽  
Enhanced Sensitivity ◽  
Test Kit ◽  
Blood Smears ◽  
Study Participants

Abstract Background The Alere™ Malaria Ag P.f Ultra-sensitive RDT (UsmRDT) kit is an HRP2-based malaria rapid diagnostic test (RDT) with enhanced sensitivity relative to the SD Bioline Malaria Ag P.f RDT (mRDT) kit. However, the diagnostic performance of the UsmRDT kit has not been evaluated in Ghana. Methods A total of 740 afebrile participants aged between 3 and 88 years old were recruited from the Central and Greater Accra Regions of Ghana during the off-peak malaria season. Axillary body temperature was measured, and a volume of 1 ml venous blood was drawn from each participant. Prior to separating the blood into plasma and packed cell pellets via centrifugation, the blood was spotted onto one UsmRDT and one mRDT kit and also used to prepare thick and thin blood smears as well as filter paper blood spots. Plasmodium falciparum specific polymerase chain reaction (PCR) was performed on gDNA extracted from 100 µl of the whole blood. Results The overall positivity rate for microscopy, PCR, UsmRDT and mRDT kit were 20.4%, 40.8%, 31.3% and 30.8%, respectively. Overall, the UsmRDT identified 9.3% (28/302) more PCR positive samples than the mRDT kits. All samples that were negative by the UsmRDT kit were also negative by the mRDT kit. Overall, the sensitivity and specificity of the UsmRDT was 73% (221/302) and 89% (388/436), respectively, while that for the mRDT kit was 58% and 90%, respectively. Conclusion Although the UsmRDT kit was not as sensitive as PCR at detecting asymptomatic P. falciparum carriage, it correctly identified P. falciparum in 9.3% of the study participants that were not captured by the mRDT kit. In malaria endemic settings, the UsmRDT would provide an added advantage by identifying more asymptomatic P. falciparum carriers than the mRDT kit for targeted treatment interventions.

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