scholarly journals Evaluation of a Rapid Kit for Detection of IgM against Leptospira in Human

2019 ◽  
Vol 2019 ◽  
pp. 1-4 ◽  
Author(s):  
Mohan Rao ◽  
Fairuz Amran ◽  
Nadia Aqilla
Keyword(s):  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Clinical Manifestations ◽  
Rapid Test ◽  
Febrile Illness ◽  
High Sensitivity ◽  
Confirmatory Test ◽  
Standard Laboratory ◽  
Test Efficiency ◽  
Sensitivity Specificity

Introduction. Leptospirosis is an acute febrile illness, known for its protean clinical manifestations and the challenge in differentiating from other infectious diseases. Standardized confirmatory test is antibody dependent and not accessible by the suburban community. This study measures efficiency of an immune-chromatographic assay, Leptocheck WB, in detecting acute leptospirosis. Methods. A total of 142 sera were used for kit evaluation. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated by comparing rapid kit results with gold standard laboratory, microscopic agglutination test (MAT). Results. We found this rapid kit to have a sensitivity and specificity of 66.6% and 78.9%, respectively, whereas the PPV and NPV of the kit appeared to be 73.3% and 73.2%, respectively. Discussion. Test efficiency of this rapid kit is reasonable. It is specific in detecting leptospiral antibody and assures clinician of accurate diagnosis by having higher PPV and NPV. It is prompt and efficient in comparison with conventional methods in assisting differential diagnosis. High sensitivity and specificity leptospirosis rapid test is indeed a crucial measure to assist the diagnosis of acute undifferentiated febrile illnesses.

scholarly journals Designing and Interpreting COVID-19 Diagnostics: Mathematics, Visual Logistics, and Low Prevalence

2020 ◽  
Author(s):  
Gerald J. Kost
Keyword(s):  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Clinical Performance ◽  
Geometric Mean ◽  
High Sensitivity ◽  
False Positives ◽  
Predictive Values ◽  
Minimum Requirements ◽  
Sensitivity Specificity ◽  
Low Prevalence

ABSTRACT Context. Coronavirus infectious disease-19 (COVID-19) diagnostics require understanding of how predictive values depend on sensitivity, specificity, and especially, low prevalence. Clear expectations, high sensitivity and specificity, and manufacturer disclosure will facilitate excellence of tests. Objectives. To derive mathematical equations for designing and interpreting COVID-19 tests, assess Food and Drug Administration (FDA) Emergency Use Authorization and Health Canada minimum requirements, establish sensitivity and specificity tiers, and enhance clinical performance in low prevalence settings. Design. PubMed and other sources generated articles on COVID-19 testing and prevalence. EndNote X9.1 consolidated references. Mathematica and open access software helped prove equations, perform recursive calculations, graph multivariate relationships, and visualize patterns, including a new relationship, predictive value geometric mean-squared. Results. Derived equations were used to illustrate shortcomings of COVID-19 diagnostics in low prevalence. Visual logistics helped establish sensitivity/specificity tiers. FDA/Canada's 90% sensitivity, 95% specificity minimum requirements generate excessive false positives at low prevalence. False positives exceed true positives at <5.3% prevalence, or if sensitivity is improved to 100% and specificity to 98%, at <2% prevalence. Recursive testing improves predictive value. Three tiers emerged from these results. With 100% sensitivity, physicians can select desired predictive values, then input local prevalence, to determine suitable specificity. Conclusions. Understanding low prevalence impact will help healthcare providers meet COVID-19 needs for effective testing. Laypersons should receive clinical performance disclosure when submitting specimens. Home testing needs to meet the same high standards as other tests. In the long run, it will be more cost-effective to improve COVID-19 POC tests rather than repeat testing multiple times.

scholarly journals Evaluation of HSG and SIS Diagnostic Value in Comparison to Hysteroscopy to Detect Intrauterine Abnormalities in Infertile Women in Iran

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Nazari L ◽  
◽  
Boroujeni PT ◽  
Keyword(s):  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Gold Standard ◽  
Uterine Cavity ◽  
High Sensitivity ◽  
Diagnostic Odds Ratio ◽  
Diagnostic Value ◽  
Infertile Women ◽  
Intrauterine Abnormalities ◽  
Sensitivity Specificity

Objective: Hysteroscopy is the gold standard in evaluation of uterine cavity. However, being invasive and its possible adverse effects have reduced popularity of hysteroscopy and clinicians have always been looking for a valid alternative for hysteroscopy. In the current study, we aimed to compare diagnostic value of Saline induced Sonography with HSG in diagnosis of intrauterine abnormalities. Material and Method: We performed a retrospective study on 81 infertile women who underwent hysteroscopy, SIS, and HSG at Taleghani infertility center during their IVF treatment course. Polyp, fibroids, adhesion and septate uterus were considered as abnormality. We reported agreement percent, Kappa, sensitivity, specificity, Area Under Curve, Diagnostic Odds Ratio, Positive Predictive Value, and Negative Predictive value for both SIS and HSG. Results: Total agreement between SIS and hysteroscopy was 85.1, while it was 23.4 for HSG. We also observed considerably higher Kappa for SIS (80.1%) than HSG (15.5%). Overall sensitivity and specificity of SIS for diagnosis of all type of anomaly including both uterine abnormalities and Acquired uterine pathologies was 90.1% (95% CI= 80.7, 95.9) and 90.0% (95% CI= 55.5, 99.7). Meanwhile overall sensitivity and specificity of Hysterosalpingography where hysteroscopy was considered as the gold standard was 54.9 (42.7, 66.8) and 50.0 (18.7, 81.3). Conclusion: SIS is more sensitive tools than HSG for diagnosis of intrauterine abnormalities and could be considered one of the best alternative of hysteroscopy. It provides more accurate detail diagnostic information with high sensitivity and specificity.

scholarly journals Use of β-D-glucan in diagnosis of suspected Pneumocystis jirovecii pneumonia in adults with HIV infection

2021 ◽  
pp. 095646242110222
Author(s):  
Thomas Juniper ◽  
Chris P Eades ◽  
Eliza Gil ◽  
Harriet Fodder ◽  
Killian Quinn ◽  
...  
Keyword(s):  
Predictive Value ◽  
Diagnostic Tests ◽  
Elevated Serum ◽  
Clinical Information ◽  
High Sensitivity ◽  
Pneumocystis Pneumonia ◽  
Pneumocystis Jirovecii Pneumonia ◽  
Alternative Diagnosis ◽  
Positive Threshold ◽  
Sensitivity Specificity

Objectives: An elevated serum (1-3)-β-D-glucan (BDG) concentration has high sensitivity for a diagnosis of Pneumocystis pneumonia (PCP) in people with HIV (PWH). At the current manufacturer-recommended positive threshold of 80 pg/mL (Fungitell), specificity for PCP is variable and other diagnostic tests are required. We evaluated the utility of serum BDG for diagnosis of suspected PCP in PWH at three inner-London hospitals to determine BDG concentrations for diagnosis and exclusion of PCP. Methods: From clinical case records, we abstracted demographic and clinical information and categorised patients as having confirmed or probable PCP, or an alternative diagnosis. We calculated sensitivity, specificity and positive predictive value (PPV) of serum BDG concentrations >400 pg/mL and negative predictive value (NPV) of BDG <80 pg/mL. Results: 76 patients were included; 29 had laboratory-confirmed PCP, 17 had probable PCP and 30 had an alternative diagnosis. Serum BDG >400 pg/mL had a sensitivity of 83%, specificity of 97% and PPV 97% for diagnosis of PCP; BDG <80 pg/mL had 100% NPV for exclusion of PCP. Conclusions: In PWH with suspected PCP, BDG <80 pg/mL excludes a diagnosis of PCP, whereas BDG concentrations >400 pg/mL effectively confirm the diagnosis. Values 80–400 pg/mL should prompt additional diagnostic tests.

scholarly journals Influenza colloidal gold method and blood routine tests combination for rapid diagnosis of influenza: a decision tree-based analysis

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Xiaoguang Li ◽  
Jing Chen ◽  
Fei Lin ◽  
Wei Wang ◽  
Jie Xu ◽  
...  
Keyword(s):  
Decision Tree ◽  
Predictive Value ◽  
Colloidal Gold ◽  
Influenza A ◽  
Clinical Manifestations ◽  
Rapid Test ◽  
Test Results ◽  
Tree Model ◽  
Routine Blood ◽  
Test Result

AbstractRapid influenza diagnosis can facilitate targeted treatment and reduce antibiotic misuse. However, diagnosis efficacy remains unclear. This study examined the efficacy of a colloidal gold rapid test for rapid influenza diagnosis. Clinical characteristics of 520 patients with influenza-like illness presenting at a fever outpatient clinic during two influenza seasons (2017–2018; 2018–2019) were evaluated. The clinical manifestations and results of routine blood, colloidal gold, and nucleic acid tests were used to construct a decision tree with three layers, nine nodes, and five terminal nodes. The combined positive predictive value of a positive colloidal gold test result and monocyte level within 10.95–12.55% was 88.2%. The combined negative predictive value of a negative colloidal gold test result and white blood cell count > 9.075 × 109/L was 84.9%. The decision-tree model showed the satisfactory accuracy of an early influenza diagnosis based on colloidal gold and routine blood test results.

A Negative Antinuclear Antibody Does Not Indicate Autoantibody Negativity in Myositis: Role of Anticytoplasmic Antibody as a Screening Test for Antisynthetase Syndrome

2016 ◽  
Vol 44 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Rohit Aggarwal ◽  
Namrata Dhillon ◽  
Noreen Fertig ◽  
Diane Koontz ◽  
Zengbiao Qi ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Predictive Value ◽  
Antinuclear Antibody ◽  
High Sensitivity ◽  
Epithelial Cell Line ◽  
Antisynthetase Syndrome ◽  
Control Groups ◽  
Serum Samples ◽  
Cytoplasmic Staining ◽  
Sensitivity Specificity

Objective.To evaluate the utility of anticytoplasmic autoantibody (anti-CytAb) in antisynthetase antibody–positive (anti-SynAb+) patients.Methods.Anti-SynAb+ patients were evaluated for antinuclear antibody (ANA) and anti-CytAb [cytoplasmic staining on indirect immunofluorescence (IIF)] positivity. Anti-SynAb+ patients included those possessing anti-Jo1 and other antisynthetase autoantibodies. Control groups included scleroderma, systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis, and healthy subjects. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy of anti-CytAb, and ANA were assessed. Anti-CytAb and ANA testing was done by IIF on human epithelial cell line 2, both reported on each serum sample without knowledge of the clinical diagnosis or final anti-SynAb results.Results.Anti-SynAb+ patients (n = 202; Jo1, n = 122; non-Jo1, n = 80) between 1985–2013 with available serum samples were assessed. Anti-CytAb showed high sensitivity (72%), specificity (89%), NPV (95%), and accuracy (86%), but only modest PPV (54%) for anti-SynAb positivity. In contrast, ANA showed only modest sensitivity (50%) and poor specificity (6%), PPV (9%), NPV (41%), and accuracy (12%). Positive anti-CytAb was significantly greater in the anti-SynAb+ patients than ANA positivity (72% vs 50%, p < 0.001), and 81/99 (82%) ANA-negative patients in the anti-SynAb+ cohort had positive anti-CytAb. In contrast, the control groups showed high rates for ANA positivity (93.5%), but very low rates for anti-CytAb positivity (11.5%). Combining anti-CytAb or Jo1 positivity showed high sensitivity (92%) and specificity (89%) for identification of anti-SynAb+ patients.Conclusion.Assessing patients for anti-CytAb serves as an excellent screen for anti-SynAb+ patients using simple IIF. Cytoplasmic staining should be assessed and reported for patients suspected of having antisynthetase syndrome and a negative ANA should not be used to exclude this diagnosis.

Incorporating diffusion-weighted imaging in a diagnostic algorithm for multiparametric MR mammography

2021 ◽  
pp. 028418512110418
Author(s):  
Katerina Vassiou ◽  
Michael Fanariotis ◽  
Ioannis Tsougos ◽  
Ioannis Fezoulidis
Keyword(s):  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Region Of Interest ◽  
Diagnostic Algorithm ◽  
Breast Lesions ◽  
Adc Value ◽  
Diffusion Weighted ◽  
Adc Values ◽  
Single Formula ◽  
Sensitivity Specificity

Background Apparent diffusion coefficient (ADC) measurements are not incorporated in BI-RADS classification. Purpose To assess the probability of malignancy of breast lesions at magnetic resonance mammography (MRM) at 3 T, by combining ADC measurements with the BI-RADS score, in order to improve the specificity of MRM. Material and Methods A total of 296 biopsy-proven breast lesions were included in this prospective study. MRM was performed at 3 T, using a standard protocol with dynamic sequence (DCE-MRI) and an extra echo-planar diffusion-weighted sequence. A freehand region of interest was drawn inside the lesion, and ADC values were calculated. Each lesion was categorized according to the BI-RADS classification. Logistic regression analysis was employed to predict the probability of malignancy of a lesion. The model combined the BI-RADS classification and the ADC value. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were calculated. Results In total, 153 malignant and 143 benign lesions were analyzed; 257 lesions were masses and 39 lesions were non-mass-like enhancements. The sensitivity and specificity of the combined method were 96% and 86%, respectively, in contrast to 95% and 81% with BI-RADS classification alone. Conclusion We propose a method of assessing the probability of malignancy in breast lesions by combining BI-RADS score and ADC values into a single formula, increasing sensitivity and specificity compared to BI-RADS classification alone.

scholarly journals Quantifying the bias associated with use of discrepant analysis

1998 ◽  
Vol 44 (1) ◽  
pp. 108-115 ◽  
Author(s):  
Harvey B Lipman ◽  
J Rex Astles
Keyword(s):  
Positive Predictive Value ◽  
Laboratory Test ◽  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Comparison Method ◽  
Confirmatory Test ◽  
Analytical Sensitivity ◽  
Performance Parameters ◽  
Alternative Approaches ◽  
Biased Estimates

Abstract Discrepant analysis is a widely used technique for estimating the performance parameters of a laboratory test. In discrepant analysis, each specimen is initially tested with the candidate test and a comparison method, and when the results of the two tests disagree, a confirmatory test is used to resolve the discrepancy. Discrepant analysis usually produces biased estimates. This report quantifies this bias and shows that it is usually positive, leading to overestimation of the performance parameters of a laboratory test. The direction and magnitude of the bias are predictably influenced by the analytical sensitivity and specificity of the candidate test, comparison method, and confirmatory test. The proportion of abnormal specimens tested also affects the magnitude of the bias, particularly the estimates of analytical sensitivity and positive predictive value when this proportion is low. Alternative approaches are suggested.

scholarly journals XPERT MYCOBACTERIUM TUBERCULOSIS/RIFAMPICIN ASSAY: A BOON IN TUBERCULOSIS DIAGNOSTICS

2016 ◽  
Vol 9 (5) ◽  
pp. 225 ◽  
Author(s):  
Sevitha Bhat ◽  
Kavya Ramamurthy ◽  
Shalini Shenoy ◽  
Aseem Rangnekar
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Predictive Value ◽  
High Sensitivity ◽  
Mortality And Morbidity ◽  
Indicator Tube ◽  
Promising Tool ◽  
Causes Of Mortality ◽  
Conventional Microscopy ◽  
Tb Diagnostics ◽  
Sensitivity Specificity

ABSTRACTObjectives: Mycobacterium tuberculosis (MTB) remains one of the most significant causes of mortality and morbidity in developing countriesespecially India. India has the highest burden of TB, with an estimated incidence figure of 2.1 million cases out of the 9 million cases of TB globally.Diagnosis of TB relies on conventional microscopy and culture with drawbacks related to sensitivity, specificity, turn around time (TAT). The aim ofthis study was to evaluate the performance of Xpert MTB/rifampicin (RIF) assay (GX) for MTB detection in pulmonary and extrapulmonary clinicalsamples.Methods: A total of 209 clinical specimens (182: pulmonary and 27: extrapulmonary) were processed using auramine smear, culture by mycobacteriagrowth indicator tube and GenXpert.Results: The sensitivity of GenXpert was 62.63% for pulmonary and 55% for extrapulmonary samples. The sensitivity and specificity of GX were100% for the smear positive cases. The sensitivity, specificity, positive predictive value, and negative predictive value of the GX for smear negativecases were 67.8%, 97.5%, 90.4%, and 89.6%, respectively. RIF resistance was detected in 3.8% the samples.Conclusion: GenXpert, with short TAT, high sensitivity, specificity and less technical expertise required is a promising tool in TB diagnostics for thefuture.Keywords: GenXpert, Tuberculosis diagnosis, Molecular method, Rifampicin resistance.

scholarly journals SAT-422 Evaluation of the Siemens Thyroid Stimulating Immunoglobulin (TSI) Assay for Diagnosis and Prognosis of Graves’ Disease

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Heather Paul ◽  
Nadia Moledina ◽  
Jason Robinson ◽  
Alex Chin ◽  
Gregory A Kline ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Predictive Value ◽  
False Negative ◽  
Thyroid Stimulating Hormone ◽  
Clinical Findings ◽  
Graves Disease ◽  
Sample Collection ◽  
Primary Analysis ◽  
Sensitivity Specificity ◽  
Stimulating Hormone

Abstract Background: Hyperthyroidism due to Graves’ disease (GD) is an autoimmune condition caused by thyroid stimulating hormone receptor (TSHR) autoantibodies. Autoantibodies to the TSHR can stimulate or block thyroid hormone production, therefore testing specifically for stimulating antibodies would be beneficial for diagnosis of GD. Objectives: The primary objective of the first phase of this trial is to assess the diagnostic capability of the Siemens Thyroid Stimulating Immunoglobulin (TSI) immunoassay in diagnosing GD and to compare it with the Roche TSH Receptor Antibody (TRAb) assay. Design and Methods: Two hundred patients with suspected GD are being enrolled in this single-center multiphase prospective cohort study. Consenting patients undergo biochemical testing including thyroid stimulating hormone (TSH), free T3 (FT3) and T4 (FT4), TRAb and TSI measurements. GD diagnosis was confirmed by endocrinologists that were blinded to TSI results. Results: To date, 85 patients were included in the analysis, of which 66 were diagnosed with GD. For the primary analysis, all patients taking anti-thyroid drugs (ATD) at time of sample collection (n=14) were removed. The respective sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) for TSI was 98, 84, 94 and 94%, which were comparable to those generated by TRAb (98, 95, 95, and 98%). In patients with clinical findings of GD (ie. orbitopathy or goiter, n=33), both the TSI and TRAb assays had identical sensitivity and specificity at 96% and 80% respectively. In patients without orbitopathy or goiter (n=38), the TSI assay had perfect sensitivity and excellent specificity of 100% and 86% respectively (TRAb had 100% sensitivity and specificity). Sensitivity, specificity, NPV, and PPV were slightly lower for both TSI and TRAb in patients treated with ATDs compared to patients without treatment (TSI: 85, 84, 62, 95%; TRAb: 91, 95, 75, 98%). Of ten patients with GD and false negative TSI results, nine were on ATDs. Of this subset, four patients had discordant results between TSI (negative) and TRAb (positive). Notably, one of these patients had normalization of their FT3 and FT4 on the day of sample collection. Discussion and Conclusion: Based on our preliminary results, TSI is an excellent marker for diagnosing GD, particularly in untreated GD patients. The performance of the TSI assay has been comparable to the TRAb assay and correlates well with clinical findings. Discordant false negative results were only seen in patients on ATD. One potential explanation is that the TSI assay is detecting a decrease in stimulating autoantibodies when there is normalization of FT3 and FT4. Importantly, all discordant samples will be tested by a TSI bioassay to confirm diagnosis. Further patient enrollment is occurring, and prognostic assessment of these assays will soon be possible.

scholarly journals Role of MRI in the Diagnosis of Injury to the Lisfranc Ligament Complex

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0029
Author(s):  
Christopher Kreulen ◽  
Eric Giza ◽  
Eva Escobedo ◽  
Cyrus Bateni ◽  
Michael Doherty
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
High Sensitivity ◽  
Lisfranc Injury ◽  
Radiology Reports ◽  
Lisfranc Ligament ◽  
Sensitivity Specificity

Category: Sports Introduction/Purpose: Subtle Lisfranc ligamentous injuries are difficult to diagnose and magnetic resonance is becoming a useful tool. The purpose of this study is to evaluate the efficacy of magnetic resonance (MR) imaging for the diagnosis of injuries of the Lisfranc ligament complex. Methods: The radiology database was searched between Jan 1, 2010 and Mar 10, 2015 to identify patients over the age of 18 years who had MR imaging of the foot for suspected injury of the Lisfranc ligament complex. MR images were reviewed by 2 fellowship trained musculoskeletal radiologists, whom were blinded to the original radiology reports. Findings were categorized as: no injury or injury present. Injury was deemed to be present if 2 of the 3 components of C1-M2 ligament showed disruption or signal alterations on T1 and T2 weighted images. Disagreements were resolved by consensus. Correlation was made with surgical findings whenever performed. In patients not undergoing surgery, the presence or absence of injury was determined by clinical examination performed by an orthopedic surgeon and follow-up. Sensitivity, specificity, positive predictive value(PPV), and negative predictive value (NPV) of MR for diagnosis of Lisfranc ligament complex injury was determined. Results: Of 60 patients, 9 were excluded due to a lack of follow-up. Lisfranc injury was determined to be present on MR in 26 patients and 18 underwent surgery. Injury was confirmed in 16, and 2 were intact. 2 patients underwent closed reduction and were clinically determined to be injured. 6 of the injured 26 patients were sprained and not injured/torn on clinical evaluation. Of the 25 patients determined to have no injury on MR, 24 were intact clinically. 1 patient had a Lisfranc injury on follow-up. Sensitivity, specificity, PPV and NPV of MR for detection of significant Lisfranc injury were 94.7% (CI: 73.9% to 99.9%), 75% (CI: 56.6% to 88.5%), 69.2% (CI: 55% to 80.5%) and 96% (CI: 77.9% to 99.4%) respectively. Conclusion: MR has a high sensitivity and negative predictive value for diagnosis of injury to the Lisfranc ligament complex. MR of the foot should be considered in patients with clinical suspicion of injury to the Lisfranc ligament complex, and it is highly accurate in excluding such injuries.

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