scholarly journals Sensitivity, specificity and predictive values of molecular and serological tests for COVID-19. A longitudinal study in emergency room.

2020 ◽  
Author(s):  
Zeno Bisoffi ◽  
ELENA POMARI ◽  
Michela Deiana ◽  
Chiara Piubelli ◽  
Niccolo Ronzoni ◽  
...  
Keyword(s):  
Emergency Room ◽  
Diagnostic Tests ◽  
Latent Class ◽  
Single Gene ◽  
High Specificity ◽  
Elisa Test ◽  
Serological Tests ◽  
Predictive Values ◽  
Molecular Tests ◽  
Sensitivity Specificity

Accuracy of diagnostic tests is essential for suspected cases of Coronavirus Disease 2019 (COVID-19). This study aimed to assess the sensitivity, specificity and positive and negative predictive value (PPV and NPV) of molecular and serological tests for the diagnosis of SARS-CoV-2 infection. A total of 346 consenting, adult patients were enrolled at the emergency room of IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Italy. We evaluated three RT-PCR methods including six different gene targets; five serologic rapid diagnostic tests (RDT); one ELISA test. The final classification of infected/not infected patients was performed using Latent Class Analysis in combination with clinical re-assessment of incongruous cases and was the basis for the main analysis of accuracy. Of 346 patients consecutively enrolled, 85 (24.6%) were classified as infected. The molecular test with the highest sensitivity, specificity, PPV and NPV was RQ-SARS-nCoV-2 with 91.8% (C.I. 83.8-96.6), 100% (C.I. 98.6-100.0), 100.0% (C.I. 95.4-100.0) and 97.4% (C.I. 94.7-98.9) respectively, followed by CDC 2019-nCoV with 76.2% (C.I. 65.7-84.8), 99.6% (C.I. 97.9-100.0), 98.5% (C.I. 91.7-100.0) and 92.9% (C.I. 89.2-95.6) and by in-house test targeting E-RdRp with 61.2% (C.I. 50.0-71.6), 99.6% (C.I. 97.9-100.0), 98.1% (C.I. 89.9-100.0) and 88.7% (C.I. 84.6-92.1). The analyses on single gene targets found the highest sensitivity for S and RdRp of the RQ-SARS-nCoV-2 (both with sensitivity 94.1%, C.I. 86.8-98.1). The in-house RdRp had the lowest sensitivity (62.4%, C.I. 51.2-72.6). The specificity ranged from 99.2% (C.I. 97.3-99.9) for in-house RdRp and N2 to 95.0% (C.I. 91.6-97.3) for E. The PPV ranged from 97.1% (C.I. 89.8-99.6) of N2 to 85.4% (C.I. 76.3-92.00) of E, and the NPV from 98.1% (C.I. 95.5-99.4) of gene S to 89.0% (C.I. 84.8-92.4) of in-house RdRp. All serological tests had <50% sensitivity and low PPV and NPV. One RDT (VivaDiag IgM) had high specificity (98.5%, with PPV 84.0%), but poor sensitivity (24.7%). Molecular tests for SARS-CoV-2 infection showed excellent specificity, but significant differences in sensitivity. As expected, serological tests have limited utility in a clinical context.

scholarly journals Sensitivity, Specificity and Predictive Values of Molecular and Serological Tests for COVID-19: A Longitudinal Study in Emergency Room

Diagnostics ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 669 ◽  
Author(s):  
Zeno Bisoffi ◽  
Elena Pomari ◽  
Michela Deiana ◽  
Chiara Piubelli ◽  
Niccolò Ronzoni ◽  
...  
Keyword(s):  
Emergency Room ◽  
Latent Class ◽  
Single Gene ◽  
Molecular Test ◽  
Clinical Context ◽  
Serological Tests ◽  
Predictive Values ◽  
Molecular Tests ◽  
Sensitivity Specificity

Background: We assessed the sensitivity, specificity and positive and negative predictive value (PPV and NPV) of molecular and serological tests for the diagnosis of SARS-CoV-2 infection. Methods: A total of 346 patients were enrolled in the emergency room. We evaluated three Reverse Transcriptase-real time PCRs (RT-PCRs) including six different gene targets, five serologic rapid diagnostic tests (RDT) and one ELISA. The final classification of infected/non-infected patients was performed using Latent Class Analysis combined with clinical re-assessment of incongruous cases. Results: Out of these, 24.6% of patients were classified as infected. The molecular test RQ-SARS-nCoV-2 showed the highest performance with 91.8% sensitivity, 100% specificity, 100.0% PPV and 97.4% NPV respectively. Considering the single gene targets, S and RdRp of RQ-SARS-nCoV-2 had the highest sensitivity (94.1%). The in-house RdRp presented the lowest sensitivity (62.4%). The specificity ranged from 99.2% for in-house RdRp and N2 to 95.0% for E. The PPV ranged from 97.1% of N2 to 85.4% of E and the NPV from 98.1% of S to 89.0% of in-house RdRp. All serological tests had < 50% sensitivity and low PPV and NPV. VivaDiag IgM (RDT) had 98.5% specificity, with 84.0% PPV, but 24.7% sensitivity. Conclusion: Molecular tests for SARS-CoV-2 infection showed excellent specificity, but significant differences in sensitivity. Serological tests have limited utility in a clinical context.

scholarly journals COVID-19 Seroprevalence among Healthcare Workers of a Large COVID-19 Hospital in Rome Reveals Strengths and Limits of Two Different Serological Tests

2021 ◽  
Vol 18 (5) ◽  
pp. 2650
Author(s):  
Giuseppe Vetrugno ◽  
Daniele Ignazio La Milia ◽  
Floriana D’Ambrosio ◽  
Marcello Di Pumpo ◽  
Roberta Pastorino ◽  
...  
Keyword(s):  
Blood Test ◽  
Healthcare Workers ◽  
Point Of Care ◽  
Venous Blood ◽  
Administrative Staff ◽  
Serological Tests ◽  
Predictive Values ◽  
Work From Home ◽  
Significant Difference ◽  
Sensitivity Specificity

Healthcare workers are at the forefront against COVID-19, worldwide. Since Fondazione Policlinico Universitario A. Gemelli (FPG) IRCCS was enlisted as a COVID-19 hospital, the healthcare workers deployed to COVID-19 wards were separated from those with limited/no exposure, whereas the administrative staff were designated to work from home. Between 4 June and 3 July 2020, an investigation was conducted to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin (IgG) antibodies among the employees of the FPG using point-of-care (POC) and venous blood tests. Sensitivity, specificity, and predictive values were determined with reverse-transcription polymerase chain reaction on nasal/oropharyngeal swabs as the diagnostic gold standard. The participants enrolled amounted to 4777. Seroprevalence was 3.66% using the POC test and 1.19% using the venous blood test, with a significant difference (p < 0.05). The POC test sensitivity and specificity were, respectively, 63.64% (95% confidence interval (CI): 62.20% to 65.04%) and 96.64% (95% CI: 96.05% to 97.13%), while those of the venous blood test were, respectively, 78.79% (95% CI: 77.58% to 79.94%) and 99.36% (95% CI: 99.07% to 99.55%). Among the low-risk populations, the POC test’s predictive values were 58.33% (positive) and 98.23% (negative), whereas those of the venous blood test were 92.86% (positive) and 98.53% (negative). According to our study, these serological tests cannot be a valid alternative to diagnose COVID-19 infection in progress.

Validity of hearTest Smartphone-Based Audiometry for Hearing Screening in Workers Exposed to Noise

2020 ◽  
Author(s):  
Luma Cordeiro Rodrigues ◽  
Silvia Ferrite ◽  
Ana Paula Corona
Keyword(s):  
Hearing Loss ◽  
High Specificity ◽  
Hearing Screening ◽  
Youden Index ◽  
Hearing Level ◽  
Predictive Values ◽  
Auditory Thresholds ◽  
The Mean ◽  
Low Sensitivity ◽  
Sensitivity Specificity

Abstract Purpose This article investigates the validity of a smartphone-based audiometry for hearing screening to identify hearing loss in workers exposed to noise. Research Design This is a validation study comparing hearing screening with the hearTest to conventional audiometry. The study population included all workers who attended the Brazilian Social Service of Industry to undergo periodic examinations. Sensitivity, specificity, the Youden index, and positive (PPV) and negative predictive values (NPV) for hearing screening obtained by the hearTest were estimated according to three definitions of hearing loss: any threshold greater than 25 dB hearing level (HL), the mean auditory thresholds for 0.5, 1, 2, and 4 kHz greater than 25 dB HL, and the mean thresholds for 3, 4, and 6 kHz greater than 25 dB HL. Note that 95% confidence intervals were calculated for all measurements. Results A total of 232 workers participated in the study. Hearing screening with the hearTest presented good sensitivity (93.8%), specificity (83.9%), and Youden index (77.7%) values, a NPV (97.2%), and a low PPV (69.0%) for the identification of hearing loss defined as any auditory threshold greater than 25 dB HL. For the other definitions of hearing loss, we observed high specificity, PPV and NPV, as well as low sensitivity and Youden index. Conclusion The hearTest is an accurate hearing screening tool to identify hearing loss in workers exposed to noise, including those with noise-induced hearing loss, although it does not replace conventional audiometry.

Multi-Slice Computed Tomographic Angiography for Stenosis Detection in Forearm Hemodialysis Arteriovenous Fistulas

2008 ◽  
Vol 9 (4) ◽  
pp. 278-284 ◽  
Author(s):  
P.P.G.M. Rooijens ◽  
G.P Serafino ◽  
D. Vroegindeweij ◽  
R. Dammers ◽  
T.I. Yo ◽  
...  
Keyword(s):  
High Specificity ◽  
Computed Tomographic Angiography ◽  
Observer Agreement ◽  
Predictive Values ◽  
Computed Tomographic ◽  
Arteriovenous Fistulas ◽  
Blinded Manner ◽  
Sensitivity Specificity ◽  
Tomographic Angiography ◽  
Diameter Reduction

Purpose A method of diagnosing the extent and severity of arteriovenous fistula (AVF) stenoses is multi-slice computed tomographic angiography (MS-CTA). The aim of this prospective study was to assess the accuracy of MS-CTA for the detection and grading of stenoses in AVF in comparison to digital subtraction angiography (DSA), which was used as the gold standard of reference. Methods Fifteen hemodialysis (HD) patients with dysfunctioning forearm AVF were included. These AVFs were evaluated by both DSA and MS-CTA and were read in a prospective, blinded manner by two radiologists experienced in vascular imaging. Results ROC analysis revealed areas under the curve of 0.90 ± 0.07 for observer I and 0.87 ± 0.08 for observer II at a stenosis cut-off level of ≥50% diameter reduction. The combined results for MS-CTA showed sensitivity, specificity and positive and negative predictive values of 82%, 98%, 82% and 98% for stenoses ≥50% and 71%, 99%, 77% and 98% for stenoses ≥75%. Inter-observer agreement for the detection of stenoses ≥50% diameter reduction was 0.70 and 1.0, for MS-CTA and DSA, respectively. Conclusion MS-CTA can provide good visualization of forearm HD access AVF and has moderate sensitivity, but high specificity for the detection of flow-limiting stenoses.

scholarly journals Increased detection of schistosomiasis with Kato-Katz and SWAP-IgG-ELISA in a Northeastern Brazil low-intensity transmission area

2012 ◽  
Vol 45 (4) ◽  
pp. 510-513 ◽  
Author(s):  
Teiliane Rodrigues Carneiro ◽  
Marta Cristhiany Cunha Pinheiro ◽  
Sara Menezes de Oliveira ◽  
Ana Lúcia de Paula Hanemann ◽  
José Ajax Nogueira Queiroz ◽  
...  
Keyword(s):  
Serological Test ◽  
Laboratory Diagnosis ◽  
Elisa Test ◽  
Northeastern Brazil ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Tests ◽  
Predictive Values ◽  
Transmission Area ◽  
Elisa Technique ◽  
Endemic Areas

INTRODUCTION: The laboratory diagnosis of schistosomiasis is based mainly on the detection of parasite eggs in stool samples through the Kato-Katz (KK) technique, reading one slide by test. However, a widely known limitation of parasitological methods is reduced sensitivity, particularly in low endemic areas. METHODS: To increase sensitivity, we conducted further slide readings from the same stool sample using the parasitological method associated with a serological test. We used the KK method (three slides) and the IgG anti-Schistosoma mansoni-enzyme-linked immunosorbent assay (ELISA) technique to diagnose schistosomiasis in low endemic areas in the Brazilian State of Ceará. Fecal samples and sera from 250 individuals were analyzed. RESULTS: Sixteen percent and 47.2% of samples were positive in parasitological tests and serological tests, respectively. Parasitological methods showed that 32 (80%) individuals tested positive on the first slide, 6 (15%) on the second slide, and 2 (5%) on the third. The performance of the ELISA test in the diagnosis, using the KK method as diagnostic reference, showed a negative predictive value of 100%, with specificity and positive predictive values of 62.8% and 33.9%, respectively. CONCLUSIONS: In this study, the increase from one to three slides analyzed per sample using the KK technique was shown to be a useful procedure for increasing the diagnostic sensitivity of this technique.

scholarly journals Clinical Performance of the Spot Vision Photo Screener before and after Induction of Cycloplegia in Children

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Konuralp Yakar
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Clinical Performance ◽  
High Specificity ◽  
Screening Criteria ◽  
Predictive Values ◽  
Before And After ◽  
Sensitivity Specificity ◽  
Vision Screener

Aim. To compare the clinical performance of the Spot Vision Screener used to detect amblyopia risk factors (ARFs) in children before and after induction of cycloplegia; the children were referred because they met the screening criteria of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS). Methods. The Spot Vision Screener and a standard autorefractometer were used to examine 200 eyes of 100 children aged 3–10 years, before and after cycloplegia induction, in terms of ARFs. Sensitivity, specificity, and positive and negative predictive values for the detection of significant refractive errors were measured using the AAPOS referral criteria. It was explored that Spot Screener data were affected by cycloplegia. The extent of agreement between cycloplegic/noncycloplegic photoscreening data and cycloplegic autorefraction measurements was assessed using Wilcoxon and Spearman correlation analyses. Results. The Spot’s sensitivity was improved from 60.9% to 85.3% and specificity from 94.9% to 87.4% with cycloplegia compared to cycloplegic standard autorefractometer results. The positive predictive value of Spot was 75.7%, and the negative predictive value was 90.4% without cycloplegia. With cycloplegia, the positive predictive value of Spot was 63.6% and the negative predictive value was 95.8%. Conclusions. The Spot Screener afforded moderate sensitivity and high specificity prior to cycloplegia. The sensitivity and negative predictive value improved after induction of cycloplegia. Examiners should be aware of the effects of cycloplegia on their findings.

scholarly journals Bayesian evaluation of three serological tests for the diagnosis of bovine brucellosis in Bangladesh

2019 ◽  
Vol 147 ◽  
Author(s):  
A. K. M. A. Rahman ◽  
S. Smit ◽  
B. Devleesschauwer ◽  
P. Kostoulas ◽  
E. Abatih ◽  
...  
Keyword(s):  
Latent Class ◽  
Latent Class Model ◽  
Dairy Farm ◽  
Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bovine Brucellosis ◽  
Class Model ◽  
Serological Tests ◽  
Predictive Values ◽  
Conditional Dependence

AbstractWe evaluated the performance of three serological tests – an immunoglobulin G indirect enzyme linked immunosorbent assay (iELISA), a Rose Bengal test and a slow agglutination test (SAT) – for the diagnosis of bovine brucellosis in Bangladesh. Cattle sera (n = 1360) sourced from Mymensingh district (MD) and a Government owned dairy farm (GF) were tested in parallel. We used a Bayesian latent class model that adjusted for the conditional dependence among the three tests and assumed constant diagnostic accuracy of the three tests in both populations. The sensitivity and specificity of the three tests varied from 84.6% to 93.7%, respectively. The true prevalences of bovine brucellosis in MD and the GF were 0.6% and 20.4%, respectively. Parallel interpretation of iELISA and SAT yielded the highest negative predictive values: 99.9% in MD and 99.6% in the GF; whereas serial interpretation of both iELISA and SAT produced the highest positive predictive value (PPV): 99.9% in the GF and also high PPV (98.9%) in MD. We recommend the use of both iELISA and SAT together and serial interpretation for culling and parallel interpretation for import decisions. Removal of brucellosis positive cattle will contribute to the control of brucellosis as a public health risk in Bangladesh.

scholarly journals Prevalence of asymptomatic SARS-CoV-2-positive individuals in the general population of northern Italy and evaluation of a diagnostic serological ELISA test: a cross-sectional study protocol

BMJ Open ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. e040036
Author(s):  
Massimo Guerriero ◽  
Zeno Bisoffi ◽  
Albino Poli ◽  
Claudio Micheletto ◽  
Carlo Pomari
Keyword(s):  
General Population ◽  
Study Protocol ◽  
Latent Class ◽  
Serological Test ◽  
Statistical Technique ◽  
Elisa Test ◽  
Nasopharyngeal Swab ◽  
Cross Sectional ◽  
Predictive Values ◽  
Study Results

IntroductionAs of 30 April 2020, the novel betacoronavirus SARS-CoV-2 had infected more than 3 172 000 individuals, killing over 224 000 people and spreading to more than 200 countries. Italy was the most affected country in Europe and the third most affected in the world in terms of the number of cases. Therefore, the aims of this study are: (1) to estimate the prevalence of asymptomatic SARS-CoV-2-positive individuals among the general population of Verona; (2) to assess the accuracy (sensitivity, specificity and predictive values) of an ELISA serological test for the screening of SARS-CoV-2.Methods and analysisThe study will be carried out on a random sample of subjects aged at least 10 years from the general population of Verona. Participants will undergo the measurement of vital parameters (oxygen saturation measured by oximeter, respiratory rate and body temperature detected by laser thermometer), the administration of a COVID-19-related symptoms questionnaire, the collection of a blood sample and a nasopharyngeal swab. Our evaluation will include the statistical technique of Latent Class Analysis, which will be the basis for the estimation of prevalence.Ethics and disseminationThe study protocol has been approved by the Ethics Committee of Verona and Rovigo provinces on 15 April 2020 (internal protocol number 2641CESC). The study results will be submitted for publication in international, peer-reviewed journals and the complete dataset will be deposited in a public repository. Most relevant data will be made available to policy-makers as well as disseminated to stakeholders and to the community.

Neutrophil CD64 Index as a superior biomarker for early diagnosis of infection in febrile patients in the hematology department

2017 ◽  
Vol 55 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Shu-Dao Xiong ◽  
Lian-Fang Pu ◽  
Hui-Ping Wang ◽  
Lin-Hui Hu ◽  
Yang-Yang Ding ◽  
...  
Keyword(s):  
High Specificity ◽  
Likelihood Ratios ◽  
Predictive Values ◽  
Combined Analysis ◽  
Reactive Protein ◽  
Neutrophil Cd64 ◽  
Special Value ◽  
Diagnostic Values ◽  
Neutropenic Patients ◽  
Sensitivity Specificity

Abstract Background: In the hematology department, the availability of biomarkers for early detection of infection is difficult to obtain. The present study aimed to compare the diagnostic values of neutrophil CD64 Index, procalcitonin (PCT), interleukin-6 (IL-6) and C-reactive protein (CRP) and to determine whether the combined analysis of these biomarkers offer stronger predictive power in the diagnosis for the infection of febrile patients. Methods: Neutrophil CD64 Index, PCT, IL-6 and CRP levels were determined in 356 febrile patients in the hematology ward from May 2013 to May 2015. Sensitivity, specificity, positive and negative likelihood ratios, positive and negative predictive values, receiver operating characteristic (ROC) areas under the curve (AUC), and logistic regression analysis were determined to evaluate the diagnostic values of these biomarkers. Results: The levels of the four biomarkers were higher in the infection patients (p<0.001), and the PCT and IL-6 were higher in the patients with positive microbial blood culture (p<0.01). The neutrophil CD64 Index, PCT, IL-6, CRP had AUCs of 0.95, 0.83, 0.75 and 0.73, respectively. The best cut-off value of the neutrophil CD64 Index to detect infections was 5.06, with high specificity (87.5%) and sensitivity (88.4%). Furthermore, neutrophil CD64 Index, PCT and IL-6 offered the best combination of diagnosis with sensitivity of 93.9% and an AUC of 0.95. In addition, the neutrophil CD64 Index may have a special value to assist the physician to diagnose infection in the neutropenic patients with fever. Conclusions: The neutrophil CD64 Index is useful for early identification of infections in febrile patients in the hematology department. The combined analysis of the CD64 Index, PCT and IL-6 could further improve its sensitivity.

scholarly journals Accuracy of diagnostic tests for respiratory syncytial virus infection within a paediatric hospital population in Kilifi County, Kenya

2020 ◽  
Vol 5 ◽  
pp. 155
Author(s):  
Marshal M. Mweu ◽  
Nickson Murunga ◽  
Juliet W. Otieno ◽  
D. James Nokes
Keyword(s):  
Respiratory Syncytial Virus ◽  
Diagnostic Tests ◽  
Latent Class ◽  
Respiratory Illness ◽  
Acute Respiratory Illness ◽  
Predictive Values ◽  
Paediatric Hospital ◽  
Rsv Infection ◽  
Hospital Population ◽  
Syncytial Virus

Background: Respiratory syncytial virus (RSV)-induced lower respiratory tract disease is a prominent cause of hospitalisation among children aged <5 years in developing countries. Accurate and rapid diagnostic tests are central to informing effective patient management and surveillance efforts geared towards quantifying RSV disease burden. This study sought to estimate the sensitivity (Se), specificity (Sp) (along with the associated factors) and predictive values of a direct immunofluorescence test (IFAT), and two real-time reverse transcription polymerase chain reaction (rRT-PCR) assays for RSV infection within a paediatric hospital population: a multiplex rRT-PCR (MPX) and Fast-Track Diagnostics® (FTD) Respiratory Pathogens 33 (Resp-33) rRT-PCR. Methods: The study enlisted 1458 paediatrics aged ≤59 months admitted with acute respiratory illness at the Kilifi County Hospital between August 2011 and December 2013. A Bayesian latent class modelling framework was employed to infer the tests’ estimates based on the patients’ diagnostic data from the three tests. Results: The tests posted statistically similar Se estimates: IFAT (93.7%, [90.7; 95.0]), FTD (97.8%, [94.6; 99.4]) and MPX (97.5%, [94.2; 99.3]). As for Sp, FTD registered a lower estimate (97.4%, [96.2; 98.2]) than MPX (99.7%, [99.0; 100.0]) but similar to IFAT (99.0%, [98.2; 99.6]). The negative and positive predictive values were strong (>91%) and closely mimicked the pattern given by the Se and Sp values respectively. None of the examined covariates (age, sex and pneumonia status) significantly influenced the accuracy of the tests. Conclusions: The evaluation found little to choose between the three diagnostic tests. Nonetheless, with its relative affordability, the conventional IFAT continues to hold promise for use in patient care and surveillance activities for RSV infection within settings where children are hospitalised with severe acute respiratory illness.

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