scholarly journals Developing RT-LAMP Assays for Detection of SARS-CoV-2 in Saliva

2021 ◽  
Author(s):  
Xin Huang ◽  
Gongyu Tang ◽  
Nahed Ismail ◽  
Xiaowei Wang
Keyword(s):  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Reliable Method ◽  
Rapid Test ◽  
Rna Isolation ◽  
Current Crisis ◽  
Design Algorithm ◽  
Assay Performance ◽  
Total Agreement ◽  
S Genes

The coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has killed millions of people worldwide. The current crisis has created an unprecedented demand for rapid test of SARS-CoV-2 infection. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a fast and convenient method to amplify and identify the transcripts of a targeted pathogen. However, the sensitivity and specificity of RT-LAMP were generally regarded as inferior when compared with the gold standard RT-qPCR. To address this issue, we combined bioinformatic and experimental analyses to improve the assay performance for COVID-19 diagnosis. First, we developed an improved algorithm to design LAMP primers targeting the nucleocapsid (N), membrane (M), and spike (S) genes of SARS-CoV-2. Next, we rigorously validated these new assays for their efficacy and specificity. Further, we demonstrated that multiplexed RT-LAMP assays could directly detect as low as a few copies of SARS-CoV-2 RNA in saliva, without the need of RNA isolation. Importantly, further testing using saliva samples from COVID-19 patients indicated that the new RT-LAMP assays were in total agreement in sensitivity and specificity with standard RT-qPCR. In summary, our new LAMP primer design algorithm along with the validated assays provide a fast and reliable method for the diagnosis of COVID-19 cases.

scholarly journals Evaluation of Mycobacterium tuberculosis lipoarabinomannan antigen assay and rapid serology blood test for the diagnosis of bovine tuberculosis in Ethiopia

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Aboma Zewude ◽  
Temesgen Mohammed ◽  
Lemma Terfassa ◽  
W. Garrett Hunt ◽  
Xueliang Pan ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Bovine Tuberculosis ◽  
Blood Test ◽  
Point Of Care ◽  
Rapid Test ◽  
Tuberculin Test ◽  
Receiver Operating Curve ◽  
Diagnostic Tools ◽  
Ifn Γ

Abstract Background Bovine tuberculosis (bTB) is prevalent in dairy cattle in Ethiopia. Currently used diagnostic tools such as the single intradermal comparative tuberculin test (SICTT) are time consuming and labor intensive. A rapid, easy-to-use and cost-effective diagnostic test would greatly contribute to the control of bTB in developing countries like Ethiopia. In the present study, two point-of-care diagnostic tests were evaluated for the detection of bTB: LIONEX® Animal TB Rapid test, a membrane-based test for the detection of antibodies to Mycobacterium bovis in blood and ALERE® Determine TB Lipoarabinomannan (LAM) Ag, an immunoassay for the detection of lipoarabinomannan (LAM) antigen (Ag) of mycobacteria in urine. A combination of the SICTT and gamma interferon (IFN-γ) test was used as the gold standard for the validation of these point-of-care tests, as it was not feasible to slaughter the study animals to carry out the historical gold standard of mycobacterial culture. A total of 175 heads of cattle having three different bTB infection categories (positive SICTT, negative SICTT, and unknown SICTT status) were used for this study. Result The sensitivity and specificity of TB LAM Ag were 72.2% (95% CI = 62.2, 80.4) and 98.8% (95% CI = 93.6, 99.7), respectively, while the sensitivity and specificity of the LIONEX Animal TB rapid test assay were 54% (95% CI = 44.1 64.3) and 98.8% (95% CI = 93.6, 99.7) respectively. The agreement between TB LAM Ag and SICTT was higher (κ = 0.85; 95% CI = 0.65–0.94) than between TB LAM Ag and IFN-γ (κ = 0.67; 95% CI = 0.52–0.81). The agreement between LIONEX Animals TB Rapid blood test and SICTT was substantial, (κ = 0.63; 95% CI = 0.49–0.77) while the agreement between LIONEX Animal TB rapid blood test and IFN-γ test was moderate (κ = 0.53; 95% CI = 0.40–0.67). Analysis of receiver operating curve (ROC) indicated that the area under the ROC curve (AUC) for TB LAM Ag was 0.85 (95% CI = 0.79–0.91) while it was 0.76 (95% CI; =0.69–0.83) for LIONEX Animal TB rapid test assay. Conclusion This study showed that TB LAM Ag had a better diagnostic performance and could potentially be used as ancillary either to SICTT or IFN-γ test for diagnosis of bTB.

Evaluation of a Multiplex Fully Automated Treponemal and Nontreponemal (Rapid Plasma Reagin) Assay

2019 ◽  
Vol 152 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Sophie Arbefeville ◽  
Maureen Lynch ◽  
Patricia Ferrieri
Keyword(s):  
Sensitivity And Specificity ◽  
Immunoglobulin G ◽  
Gold Standard ◽  
Treponema Pallidum ◽  
Immunoglobulin M ◽  
Rapid Plasma Reagin ◽  
Agglutination Assay ◽  
Assay Performance ◽  
Card Test ◽  
Particle Agglutination

ABSTRACTObjectivesIn June 2017, Bio-Rad Laboratories received US Food and Drug Administration clearance for its BioPlex 2200 Syphilis Total & RPR (rapid plasma reagin) assay. It is the first fully automated treponemal/nontreponemal multiplex flow immunoassay, simultaneously detecting Treponema pallidum and reagin antibodies and an RPR titer. We compared the performance of the BioPlex Syphilis Total & RPR assay with the LIAISON Treponema Assay and the manual BD Macro-Vue RPR 18-mm Circle Test.MethodsIn total, 314 serum specimens were tested for treponemal immunoglobulin G/immunoglobulin M and RPR with the LIAISON Treponema Assay, the BioPlex 2200 Syphilis Total & RPR assay, and the manual BD Macro-Vue RPR card test. All discordant results were further tested with the T pallidum particle agglutination assay from Fujirebio Diagnostics.ResultsThe overall percent agreement for the BioPlex assay for treponemal antibodies with the LIAISON Treponema Assay was 96.1%. Sensitivity and specificity for the BioPlex RPR assay were 90.5% and 97.2%, respectively (the manual RPR assay was considered the gold standard).ConclusionsThe BioPlex 2200 Syphilis Total & RPR assay performance was comparable to the LIAISON Treponema Assay and the manual RPR test. Compared with the manual RPR, the automation of RPR testing offered labor savings, objective result reporting, and improved workflow.

Association between endometritis and urocystitis in culled sows

2002 ◽  
Vol 50 (4) ◽  
pp. 413-423 ◽  
Author(s):  
I. Biksi ◽  
N. Takács ◽  
F. Vetési ◽  
Keyword(s):  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Positive Association ◽  
Urogenital Tract

Slaughterhouse sampling and examination of urogenital tracts of 499 sows and gilts culled for reproductive reasons from 21 Hungarian herds were performed over a 6-year period. The aim was to estimate the prevalence of different urogenital tract lesions, and to provide sensitivity and specificity estimates for macroscopic and bacteriological examinations in the diagnosis of urocystitis and endometritis. Furthermore, the association between endometritis and urocystitis was assessed. The prevalence of main lesions of the urogenital tract was similar to that reported in other studies. The 'sensitivity' of macroscopic and bacteriological methods was determined statistically by taking histopathology as the 'Gold Standard'. As a result, the 'sensitivity' of macroscopic methods for the diagnosis of endometritis and urocystitis was ≤ 18.1% and 47.9%, respectively, while the 'sensitivity' of bacteriology for the diagnosis of the same conditions was ≤ 31.8% and 63.0%, respectively. The presumed positive association between urocystitis and endometritis was confirmed; it was not confounded by parity. Animals affected by urocystitis had a 3.5 times higher odds to simultaneously have endometritis than animals without urocystitis.

scholarly journals Investigation of the rapid immunochromatographic test performance in the diagnosis of syphilis; comparison of four serological methods

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Huseyin Agah Terzi ◽  
Ozlem Aydemir ◽  
Engin Karakece ◽  
Huseyin Hatipoglu ◽  
Mehmet Olmez ◽  
...  
Keyword(s):  
Test Performance ◽  
Gold Standard ◽  
Treponema Pallidum ◽  
Rapid Test ◽  
Immunochromatographic Test ◽  
Rapid Plasma Reagin ◽  
Serum Samples ◽  
Hemagglutination Assay ◽  
Predictive Values ◽  
Sensitivity Specificity

AbstractObjectivesTo test the performance of the newly available rapid test for syphilis, we compared it with Treponema pallidum hemagglutination assay (TPHA). Additionally, we investigated the performance of rapid plasma reagin (RPR) and chemiluminescence microparticle immunoassays (CMIA) at our laboratory using TPHA as a gold standard.MethodsThe serum samples of 595 patients with the pre-diagnosis of syphilis were studied by four serological methods. The sensitivity, specificity, and predictive values of RPR, CMIA, and syphilis rapid test were assessed by utilizing TPHA as a gold standard for the diagnosis of syphilis.ResultsOf the patients, 6.2% (37/595) had positive RPR, 5.5% (33/595) had positive CMIA, 5.5% (33/595) had a positive rapid immunochromatographic method and 5% (30/595) had positive TPHA. When TPHA results were taken as the reference, the sensitivity of the rapid test for syphilis was 100%, the specificity was 99.5%, PPV was 90.9%, and NPV was 100.0%.ConclusionsIt was observed that the rapid test for syphilis used in the study was quite successful, its cost was appropriate, and the test was very fast and easy to apply. At the same time, the agreement between syphilis rapid test and TPHA was found to be excellent.

scholarly journals The role of magnetic resonance cholangiopancreatography and diffusion-weighted imaging for the differential diagnosis of obstructive biliary disorders

2017 ◽  
Vol 21 (1) ◽  
Author(s):  
Zeynep Cetiner-Alpay ◽  
Fatma Kulali ◽  
Aslihan Semiz-Oysu ◽  
Yasar Bukte ◽  
Kamil Ozdil
Keyword(s):  
Magnetic Resonance ◽  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Diffusion Weighted Imaging ◽  
Magnetic Resonance Cholangiopancreatography ◽  
Malignant Tumours ◽  
Diagnostic Efficacy ◽  
Diffusion Weighted ◽  
Sensitivity Specificity ◽  
And Diffusion

Background: Although endoscopic retrograde cholangiopancreatography (ERCP) is accepted as the gold standard, there is a place for magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted imaging (DWI) in the diagnosis of obstructive biliary disorders.Aim: To compare the findings of MRCP with ERCP in patients with obstructive biliary disorders and to investigate the diagnostic efficacy of MRCP combined with DWI.Study design: Retrospective, analytic, cross-sectional study.Methods: The MRCP images of 126 patients who underwent both MRCP and ERCP owing to biliary obstruction were reviewed. Nine patients were excluded because of incomplete diagnostic workup or a long period (>3 months) between MRCP and ERCP. Ninety-two patients underwent DWI, which was also evaluated. The sensitivity, specificity and accuracy of MRCP and DWI were analysed.Results: The sensitivity, specificity and accuracy of MRCP according to ERCP results as the gold standard was 97%, 71% and 93% for assessment of biliary dilatation; 100%, 94.7% and 97.5% for the diagnosis of choledocholithiasis; 93.7%, 100% and 99% for the identification of benign strictures; 100%, 100% and 100% for the diagnosis of malignant tumours; and 100%, 100% and 100% for the detection of complicated hydatid cysts; respectively. The sensitivity and specificity of DWI for the diagnosis of malignant tumour was 100%. In the detection of choledocholithiasis, the sensitivity and specificity of DWI was 70.8% and 100%.Conclusions: MRCP is an alternative, non-invasive, diagnostic modality, comparable with ERCP for the evaluation of pancreaticobiliary diseases. DWI can be helpful for diagnosis of choledocholithiasis and tumours.

scholarly journals A20 DIAGNOSTIC ACCURACY OF A LOW COST, WIDELY AVAILABLE TEST STRIP FOR PREDICTING A POSITIVE FECAL CALPROTECTIN TEST

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 210-212
Author(s):  
R Trasolini ◽  
S Wong ◽  
B Salh
Keyword(s):  
Sample Size ◽  
Likelihood Ratio ◽  
Gold Standard ◽  
Low Cost ◽  
Positive Likelihood Ratio ◽  
Negative Likelihood Ratio ◽  
Rapid Test ◽  
Test Strip ◽  
Fecal Calprotectin ◽  
Type I

Abstract Background Fecal calprotectin is a non-invasive test of colonic inflammation used for monitoring inflammatory bowel disease activity and for risk stratifying non-specific colonic symptoms. Calprotectin is a leukocyte specific enzyme. A similar test, leukocyte esterase is used to detect leukocytes in urine and is widely available as a low-cost point-of-care test strip. We hypothesize that an unmodified version of the urine test strip would be highly accurate in predicting a positive fecal calprotectin test in a real world sample of patients. Aims To explore a low cost, rapid alternative to the fecal calprotectin test Methods All inpatient and outpatient stool samples tested for calprotectin by the Vancouver General Hospital laboratory from February 2020 to November 2020 were included prospectively. Samples were simultaneously tested for fecal leukocyte esterase using an unmodified Roche Cobas Chemstrip urinalysis test strip by central lab personnel. An identical aliquot was sent to LifeLabs for calprotectin as per standard protocol. All samples were suspended in buffer using established laboratory protocols prior to testing. Fecal leukocyte esterase results were reported as 0–4+ based on visual interpretation, calprotectin results were reported as mcg/g of stool. REB review and approval was obtained prior to data collection. Sensitivity, Specificity and AUROC were calculated using Microsoft Excel and JROCFIT. Results 26 samples were collected. Using a fecal calprotectin greater than 120 mcg/g as a gold standard an AUROC of 0.89 (SE= .06) was calculated. A leukocyte esterase reading of 2+ or greater had the best test characteristics based on ROC curve analysis. Using this cutoff, 21/26 samples were concordant, giving an accuracy of 80.8%, sensitivity of 90.9% and specificity of 73.3%. Positive likelihood ratio was 8.07 and negative likelihood ratio was 0.29. Assuming an AUROC of 0.8, the sample size N=26 is 90% powered (β=0.9) to predict the true AUROC within 0.1 with a type I error rate of .05 (α<.05). Conclusions This study suggests application of a prepared stool sample to a urinalysis test strip gives a result highly predictive of a positive fecal calprotectin test. Further results are being collected prospectively to improve the robustness of these preliminary data. Secondary outcomes including comparison to endoscopy and biopsy results where available are planned if an adequate sample size can be accrued. Future studies justifying independent clinical use of leukocyte esterase would require a common gold standard comparator such as endoscopy. Fecal calprotectin testing is not universally insured and is not available as a rapid test strip. Use of fecal leukocyte esterase may reduce costs and shorten time to results if proven to be independently reliable. Funding Agencies None

Child Abuse

PEDIATRICS ◽  
1990 ◽  
Vol 86 (5) ◽  
pp. 805-806
Author(s):  
ALLAN R. DE JONG ◽  
MIMI ROSE
Keyword(s):  
Sexual Abuse ◽  
Child Abuse ◽  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Child Protective Services ◽  
Iron Pyrite ◽  
Protective Services ◽  
Physical Evidence

In Reply.— We thank Dr Smith for his interesting perspective regarding screening for child abuse. We had hoped our article would help physicians focus on the verbal evidence of abuse and show how insensitive the physical evidence is in predicting which child had been abused sexually. To apply the principles of sensitivity and specificity to the assessment of child abuse or sexual abuse, we must have a gold standard which characterizes these problems. Neither a child protective services decision nor a legal determination of "no proven abuse" can be used as a gold standard, unless we can accept a "gold standard" made of iron pyrite.

scholarly journals Rapid Diagnosis of Malaria by Antigen Detection

2009 ◽  
Vol 3 (1) ◽  
pp. 14-16
Author(s):  
Mesbah Uddin Ahmed ◽  
Md Akram Hossain ◽  
AKM Shamsuzzaman ◽  
Md Murshed Alam ◽  
Abdul Hossain Khan ◽  
...  
Keyword(s):  
Thin Films ◽  
Sensitivity And Specificity ◽  
Standard Method ◽  
Gold Standard ◽  
Rapid Diagnosis ◽  
Healthy Controls ◽  
Immunochromatographic Test ◽  
Gold Standard Method ◽  
Malaria Antigen ◽  
Age And Sex

The study was conducted to evaluate the sensitivity and specificity of Immunochromatographic test (ICT) for antigen, using microscopy as the "gold standard" method for diagnosis of malaria. A total of 98 clinically suspected malaria patients and another 30 age and sex-matched healthy controls were included in this study. Thick and thin films were also prepared and examined under microscope as well as Immunochromatographic test (ICT) was performed for malaria antigen. Sensitivity and specificity of ICT for antigen were 93.22% and 94.87% respectively. Keywords: Detection of malaria antigen, Immunochromatographic test   doi: 10.3329/bjmm.v3i1.2965 Bangladesh J Med Microbiol 2009; 03 (01): 14-16

scholarly journals ULTRASONOGRAPHY IN OBSTRUCTIVE JAUNDICE

2012 ◽  
Vol 19 (04) ◽  
pp. 436-441
Author(s):  
ASMA AFZAL KIANI ◽  
RANA HASSAN JAVAID ◽  
ABDUL GHAFFAR ◽  
Shamrez Khan
Keyword(s):  
Obstructive Jaundice ◽  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Biliary Obstruction ◽  
Pancreatic Head ◽  
Histological Diagnosis ◽  
Imaging Procedure ◽  
Preoperative Ultrasonography ◽  
Initial Imaging

Objective: To evaluate the validity of ultrasonography in patients who have obstructive jaundice. Design: Descriptive study.Place and duration of study: The study was carried out from September 2006 to May 2008 in department of Radiology Combined MilitaryHospital Quetta. Patients and Methods: A total of 30 patients; 14 male and 16 female underwent operation for obstructive jaundice. All of themhad preoperative ultrasonography. The site and nature of biliary obstruction were noted and the accuracy was determined with per-operativefindings / histological diagnosis as gold standard. Results: The cause of obstructive jaundice identified by ultrasonography with reasonablesensitivity of 90% and specificity of 90% for choledocholithiasis and sensitivity of 55.5% and specificity of 95.2% for pancreatic head tumours.Conclusions: Ultrasonography should be the first and best initial imaging procedure in patients who have obstructive jaundice and showsreasonable sensitivity and specificity to identify causes of obstruction in obstructive jaundice.

scholarly journals Diagnostic Accuracy of Three-dimensional Ultrasonography in Detection of Endometrial Lesions compared with Hysteroscopy in Infertile Women

2016 ◽  
Vol 10 (4) ◽  
pp. 393-397
Author(s):  
Firoozeh Ahmadi ◽  
Farnaz Akhbari ◽  
Fatemeh Niknejad ◽  
Hadieh Haghighi ◽  
Zahra Ghahremani ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Gold Standard ◽  
Three Dimensional ◽  
Assessment Method ◽  
Diagnostic Efficiency ◽  
Infertile Women ◽  
Reliable Assessment ◽  
Uterine Anomalies

ABSTRACT Introduction Two of the most frequent procedures performed on infertile women are two-dimensional ultrasound (2DUS) and three-dimensional ultrasound (3DUS). Hysteroscopy is considered as the gold standard for evaluation of acquired endometrial lesions in infertile women; however, 3DUS is used as a noninvasive, less expensive, and reliable assessment method for evaluation of the intrauterine lesions in infertile women. We aimed to compare the diagnostic efficiency between 3DUS and hysteroscopy in the detection of lesions (polyps, submucous leiomyoma, and synechiae) in infertile women. Materials and methods In this prospective observational study, infertile women (n = 155) with indication of hysteroscopy were scheduled to undergo 3DUS prior to hysteroscopy from September 2010 to 2011. Women with suspected congenital uterine anomalies were excluded. The sensitivity and specificity values of 3DUS were compared with those of hysteroscopy. Hysteroscopy was used as the gold standard for diagnosis of intrauterine lesions in infertile women. Results Of the 155 women, 50 were found to have an intracavitary abnormality, 36 had polyps, 12 had myomas, and 7 had synechiae on hysteroscopic findings. Examination with 3DUS in the diagnosis of intrauterine lesions reached an accuracy of 94%, and 92.15 and 96.9% of sensitivity and specificity respectively. Positive predictive value (PPV) was 83.9%, and a negative predictive value (NPV) was 91.3% (LR+ = 10.75, LR+ = 0.065). Conclusion According to our results, 3DUS has a reliable diagnostic accuracy for intrauterine lesions, and it may limit unnecessary hysteroscopy in patients with normal results. How to cite this article Ahmadi F, Haghighi H, Ghahremani Z, Niknejad F, Akhbari F, Ramezanali F, Chehrazi M. Diagnostic Accuracy of Three-dimensional Ultrasonography in Detection of Endometrial Lesions compared with Hysteroscopy in Infertile Women. Donald School J Ultrasound Obstet Gynecol 2016;10(4):393-397.

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