scholarly journals Development of in-house serological methods for diagnosis and surveillance of chikungunya

2017 ◽  
Vol 41 ◽  
pp. 1 ◽  
Author(s):  
Ángel Balmaseda ◽  
Saira Saborío Galo ◽  
Karla González ◽  
Yolanda Téllez ◽  
Nadezna García ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
Epidemiological Surveillance ◽  
Diagnostic Systems ◽  
Serum Samples ◽  
Hyperimmune Serum ◽  
Predictive Values ◽  
Processing Times ◽  
Igm Elisa ◽  
Sensitivity Specificity ◽  
Research Demands

Objective.To develop and evaluate serological methods for chikungunya diagnosis and research in Nicaragua.Methods.Two IgM ELISA capture systems (MAC-ELISA) for diagnosis of acute chikungunya virus (CHIKV) infections, and two Inhibition ELISA Methods (IEM) to measure total antibodies against CHIKV were developed using monoclonal antibodies (mAbs) and hyperimmune serum at the National Virology Laboratory of Nicaragua in 2014–2015. The sensitivity, specificity, predictive values, and agreement of the MAC-ELISAs were obtained by comparing the results of 198 samples (116 positive; 82 negative) with the Centers for Disease Control and Prevention’s IgM ELISA (Atlanta, Georgia, United States; CDC-MAC-ELISA). For clinical evaluation of the four serological techniques, 260 paired acute and convalescent phase serum samples of suspected chikungunya cases were used.Results.All four assays were standardized by determining the optimal concentrations of the different reagents. Processing times were substantially reduced compared to the CDC-MAC-ELISA. For the MAC-ELISA systems, a sensitivity of 96.6% and 97.4%, and a specificity of 98.8% and 91.5% were obtained using mAb and hyperimmune serum, respectively, compared with the CDC method. Clinical evaluation of the four serological techniques versus the CDC real-time RT-PCR assay resulted in a sensitivity of 95.7% and a specificity of 88.8%–95.9%.Conclusion.Two MAC-ELISA and two IEM systems were standardized, demonstrating very good quality for chikungunya diagnosis and research demands. This will achieve more efficient epidemiological surveillance in Nicaragua, the first country in Central America to produce its own reagents for serological diagnosis of CHIKV. The methods evaluated here can be applied in other countries and will contribute to sustainable diagnostic systems to combat the disease.

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 Accuracy of ICD-9 coding for Clostridium difficile infections: a retrospective cohort

2006 ◽  
Vol 135 (6) ◽  
pp. 1010-1013 ◽  
Author(s):  
D. B. SCHEURER ◽  
L. S. HICKS ◽  
E. F. COOK ◽  
J. L. SCHNIPPER
Keyword(s):  
Clostridium Difficile ◽  
Administrative Data ◽  
Epidemiological Surveillance ◽  
Administrative Database ◽  
Test Results ◽  
Micro Data ◽  
Cytotoxic Assay ◽  
Predictive Values ◽  
Sensitivity Specificity ◽  
Microbiological Data

SUMMARYClostridium difficile (C. diff) is a major nosocomial problem. Epidemiological surveillance of the disease can be accomplished by microbiological or administrative data. Microbiological tracking is problematic since it does not always translate into clinical disease, and it is not always available. Tracking by administrative data is attractive, but ICD-9 code accuracy for C. diff is unknown. By using a large administrative database of hospitalized patients with C. diff (by ICD-9 code or cytotoxic assay), this study found that the sensitivity, specificity, positive, and negative predictive values of ICD-9 coding were 71%, 99%, 87%, and 96% respectively (using micro data as the gold standard). When only using symptomatic patients the sensitivity increased to 82% and when only using symptomatic patients whose test results were available at discharge, the sensitivity increased to 88%. C. diff ICD-9 codes closely approximate true C. diff infection, especially in symptomatic patients whose test results are available at the time of discharge, and can therefore be used as a reasonable alternative to microbiological data for tracking purposes.

A unique antiphospholipid assay recognizing phospholipid mixture compared with criteria antiphospholipid immunoassays in lupus patients

Lupus ◽  
2016 ◽  
Vol 26 (6) ◽  
pp. 606-615 ◽  
Author(s):  
Y Zuo ◽  
R Willis ◽  
E Papalardo ◽  
M Petri ◽  
E N Harris ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Clinical Manifestations ◽  
Case Series ◽  
Likelihood Ratios ◽  
Serum Samples ◽  
Predictive Values ◽  
Pregnancy Morbidity ◽  
Commercial Kits ◽  
Sensitivity Specificity

Background While essential for the classification of antiphospholipid syndrome (APS), anticardiolipin (aCL) assays lack specificity and anti-β2glycoproteinI (anti-β2GPI) assays lack sensitivity in this regard. Our aim was to perform a comparative analysis of the APhL ELISA assay (IgG/IgM) and criteria antiphospholipid (aPL) immunoassays in identifying APS-related clinical manifestations in a large group of patients with systemic lupus erythematosus (SLE). Methods Serum samples from 1178 patients from the Hopkins ( n = 543), LUMINA ( n = 588) and Jamaican SLE cohorts ( n = 47) were examined for IgG/IgM positivity in aCL (in-house), anti-β2GPI (two commercial kits) and APhL (Louisville APL) ELISA assays. Correlation of assay positivity with clinical manifestations and sensitivity, specificity, positive and negative predictive values and likelihood ratios were evaluated. A case series analysis was also performed in patients for whom there was isolated positivity in the specific aPL assays. Results The prevalence of aCL positivity was 34.9%, anti-β2GPI kit A was 22.6%, APhL was 11.5% and anti-β2GPI kit B was 7.6% in the study population. Anti-β2GPI kit B, aCL and APhL assays were correlated with venous thrombosis, while only APhL was significantly correlated with arterial thrombosis and consistently correlated with pregnancy-related morbidity. No significant correlations were noted for anti-β2GPI kit A. Sensitivity was greatest for aCL assays followed by anti-β2GPI kit A, APhL and anti-β2GPI kit B, while specificity was greatest and equal for anti-β2GPI kit B and APhL assays. Conclusions Overall, APhL antibodies, especially IgG, represent a promising biomarker for the classification of APS patients in the context of autoimmunity and in risk assessment with regards to pregnancy morbidity and thrombotic manifestations.

scholarly journals Threshold value of the anti-HCV test in the diagnosis of HCV infection

2019 ◽  
Vol 13 (10) ◽  
pp. 914-919
Author(s):  
Özlem Kirişci ◽  
Ahmet Calıskan
Keyword(s):  
Roc Analysis ◽  
Threshold Value ◽  
Hcv Infection ◽  
Nucleic Acid Amplification ◽  
High Rate ◽  
Hcv Rna ◽  
Serum Samples ◽  
Predictive Values ◽  
Pcr Method ◽  
Sensitivity Specificity

Introduction: In the diagnosis of hepatitis C virus (HCV) infection, the first step is screening for anti-HCV antibodies, and positive results are generally confirmed with nucleic acid amplification tests. Recent studies have reported that more compatible results have been obtained with the HCV RNA test using signal to cut-off (S/Co) values >1, which are the routine reactivity threshold for the anti-HCV enzyme immunoassay (EIA) test. The aim of this study was to determine the most appropriate S/Co value for the anti-HCV test, predicting HCV infection. Methodology: Comparisons were made between results of 559 patients who underwent anti-HCV with ECLIA method and HCV RNA tests with real-time polymerase chain reaction (PCR) method. By accepting the HCV-RNA test as the gold standard for HCV infection, the sensitivity, specificity and predictive values of the ECLIA test were determined and statistical “receiver operating characteristic” (ROC) analysis was applied to determine the most appropriate threshold. Results: Between January 2013 and April 2018, a total of 81,203 serum samples were examined. Of 559 anti-HCV positive patients, HCV RNA positivity was determined in 214 (38.2 %). According to the ROC analysis results, the most appropriate S/Co value was determined as 12.27, at which sensitivity was 94.4 %, and specificity 97.4 %. The positive and negative predictive values were calculated at the high rate of 95.7% and 96.6% respectively. Conclusions: The results of this study investigating the anti-HCV reactivity values which could be used in the diagnosis of HCV infection determined the most appropriate value to be 12.27.

scholarly journals Clinical Relevance of Thyroid-Stimulating Autoantibodies in Pediatric Graves' Disease—A Multicenter Study

2014 ◽  
Vol 99 (5) ◽  
pp. 1648-1655 ◽  
Author(s):  
T. Diana ◽  
R. S. Brown ◽  
A. Bossowski ◽  
M. Segni ◽  
M. Niedziela ◽  
...  
Keyword(s):  
Multicenter Study ◽  
Clinical Relevance ◽  
Graves Disease ◽  
Healthy Children ◽  
Serum Samples ◽  
Camp Response Element ◽  
Cross Sectional ◽  
Predictive Values ◽  
Graves Orbitopathy ◽  
Sensitivity Specificity

Context and Objective: The incidence of TSH receptor (TSHR) stimulating autoantibodies (TSAbs) in pediatric Graves' disease (GD) is controversial. This large, multicenter study evaluated the clinical relevance of TSAbs in children with GD both with Graves' orbitopathy (GO) and without orbital disease. Design: We conducted a cross-sectional retrospective study. Setting: Sera were collected in seven American and European academic referral centers and evaluated in a central laboratory. Patients and Samples: A total of 422 serum samples from 157 children with GD, 101 control individuals with other thyroid and nonthyroid autoimmune diseases, and 50 healthy children were studied. Main Outcome Measures: TSAbs were measured using a novel, chimeric TSHR bioassay and a cAMP response element-dependent luciferase. TSH binding-inhibitory Ig (TBII) and parameters of thyroid function were also determined. Results: In 82 untreated children with GD, sensitivity, specificity, and positive and negative predictive values for TSAb and TBII were: 100 and 92.68% (P = .031), 100 and 100%, 100 and 100%, and 100 and 96.15%, respectively. TSAb and TBII were present in 147 (94%) and 138 (87.9%) of the 157 children with GD (P < .039), respectively; and in 247 (94%) and 233 (89%) of the 263 samples from this group (P < .0075), respectively. In children with GD and GO, TSAb and TBII were noted in 100 and 96% (P < .001), respectively. Hyperthyroid children with GD and GO showed markedly higher TSAb levels compared to those with thyroidal GD only (P < .0001). No significant differences were noted for TBII between the two groups. After a 3-year (median) medical treatment, the decrease of TSAb levels was 69% in GD vs 20% in GD and GO (P < .001). All 31 samples of euthyroid children with GO were TSAb positive; in contrast, only 24 were TBII positive (P = .016). All children with Hashimoto's thyroiditis, nonautoimmune hyperthyroidism, type 1 diabetes, and juvenile arthritis and the healthy controls were TSAb and TBII negative. Conclusions: Serum TSAb level is a sensitive, specific, and reproducible biomarker for pediatric GD and correlates well with disease severity and extrathyroidal manifestations.

scholarly journals Comparison between clinical and videofluoroscopic evaluation of swallowing in children with suspected dysphagia

CoDAS ◽  
2015 ◽  
Vol 27 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Lenice de Fatima da Silva-Munhoz ◽  
Karina Elena Bernardis Bühler ◽  
Suelly Cecilia Olivan Limongi
Keyword(s):  
Clinical Sign ◽  
Clinical Evaluation ◽  
Clinical Assessment ◽  
Clinical Signs ◽  
Signs And Symptoms ◽  
Predictive Values ◽  
Thin Fluid ◽  
Laryngeal Penetration ◽  
Clinical Signs And Symptoms ◽  
Sensitivity Specificity

Purpose: To verify the accuracy of clinical evaluation compared with videofluoroscopic swallowing studies in the detection of isolated laryngeal penetration and laryngeal aspiration in children with suspected dysphagia; to identify clinical signs and symptoms associated with isolated laryngeal penetration and laryngeal aspiration; and to determine the sensitivity and specificity of the clinical signs and symptoms identified. Methods: Retrospective analysis of data from clinical and videofluoroscopic evaluations carried out in 55 children from 1 month to 7 years and 11 months old. For clinical assessment, the Protocol for Clinical Assessment of Pediatric Dysphagia was used. The sensitivity, specificity, and positive and negative predictive values of clinical evaluation were analyzed. For statistical analysis, the Fisher's exact and χ2 tests were used. Results: Clinical evaluation showed, in general, a sensitivity of 86% and a specificity of 32%. For isolated laryngeal penetration, clinical evaluation showed a sensitivity of 88%. For laryngeal aspiration, clinical evaluation showed a sensitivity of 86%. However, the specificity values were low for both alterations. There was no association between clinical evaluation and videofluoroscopic findings. Choking was the only clinical sign associated with isolated laryngeal penetration thin fluid and showed a sensitivity of 53% and a specificity of 77%. Conclusions: Clinical evaluation was sensible to detect isolated laryngeal penetration and laryngeal aspiration in children with suspected dysphagia. However, it showed a low specificity. Choking was the only clinical sign associated with isolated laryngeal penetration of thin fluid. More prospective studies are needed to confirm these findings in this population.

scholarly journals Absorption of non-specific antibodies with Salmonella Enteritidis and Salmonella Typhimurium suspensions from tested serum samples as a useful method in serodiagnosis of salmonellosis carried out by ELISA for epidemiological surveillance

2019 ◽  
pp. 13-21
Author(s):  
Waldemar Rastawicki ◽  
Natalia Rokosz-Chudziak ◽  
Karolina Śmietańska ◽  
Urszula Roguska
Keyword(s):  
Salmonella Enteritidis ◽  
Humoral Response ◽  
Stool Culture ◽  
Epidemiological Surveillance ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Igm Elisa ◽  
Cost Efficient ◽  
D Antigen ◽  
Positive Results

Introduction: Diagnosis of salmonellosis is usually made by stool culture however in many laboratories ELISA for the detection of human serum antibodies against mixture of LPS antigens of the two predominant serovars of Salmonella was developed. We present the method of absorbing non-specific antibodies with S. Enteritidis (serovars D) and S. Typhimurium (serovars B) suspensions from serum samples as a useful method in serodiagnosis of salmonellosis carried out by ELISA. This simple, cost-efficient and effective method of absorption may be used in the epidemiological investigations. Methods: We used in-house ELISA three different antigens: LPS of the S. Enteritidis, LPS of the S. Typhimurium and 1:1 mixture of LPS of both serovars. Serum samples collected from 14 patients with salmonellosis, were absorbed with 20% bacterial suspensions obtained from S. Enteritidis, S. Typhimurium and mixture of both serovars (serovars B+D). The non-absorbed sera and sera after particular absorptions were tested separately in ELISA with all three antigens. Results: The all 14 non-absorbed serum samples showed a high positive results in the IgA, IgG and IgM ELISA with all three LPS antigens. Absorption of the 13 from 14 tested samples with the Salmonella B suspension resulted in a significant decrease in the level of antibodies to Salmonella B antigen, but only a very slight decrease in the levels of Salmonella B + D and Salmonella D antigen. On the other hand, the absorption of the same sera with Salmonella D suspension, caused a significant decrease in the level of antibodies for serovars D, B and B + D antigens. Such a test result clearly shows that the 13 serum samples were obtained from patients with an infection caused by S. Enteritidis (serogroup D). A opposite picture of the humoral response was obtained in the case of one serum sample obtained from a subject with an infection caused by S. Typhimurium (serogroup B). Conclusions: The presented work demonstrates the usefulness of absorption of non-specific antibodies with S. Enteritidis and S. Typhimurium suspensions in serodiagnosis of salmonellosis carried out by ELISA.

scholarly journals Evaluation of dengue NS1 antigen detection for diagnosis in public health laboratories, São Paulo State, 2009

2011 ◽  
Vol 53 (6) ◽  
pp. 315-320 ◽  
Author(s):  
Ivani Bisordi ◽  
Iray Maria Rocco ◽  
Akemi Suzuki ◽  
Gizelda Katz ◽  
Vivian Regina Silveira ◽  
...  
Keyword(s):  
Public Health ◽  
Virus Isolation ◽  
High Sensitivity ◽  
Kappa Index ◽  
Predictive Values ◽  
Paulo State ◽  
Igm Elisa ◽  
Ns1 Antigen ◽  
Sensitivity Specificity ◽  
Sera Samples

The present work evaluated the diagnostic accuracy of detection of Dengue NS1 antigen employing two NS1 assays, an immunochromatographic assay and ELISA, in the diagnostic routine of Public Health laboratories. The results obtained with NS1 assay were compared with virus isolation and, in a subpopulation of cases, they were compared with the IgM-ELISA results obtained with convalescent samples. A total of 2,321 sera samples were analyzed by one of two NS1 techniques from March to October 2009. The samples were divided into five groups: groups I, II and III included samples tested by NS1 and virus isolation, and groups IV and V included patients with a first sample tested by NS1 and a second sample tested by IgM-ELISA. Sensitivity, specificity, positive and negative predictive values, Kappa Index and Kappa Concordance were calculated. The results showed that NS1 testing in groups I, II and III had high sensitivity (98.0%, 99.5% and 99.3%), and predictive values and Kappa index between 0.9 - 1.0. Groups IV and V only had Kappa Concordance calculated, since the samples were analyzed according to the presence of NS1 antigen or IgM antibody. Concordance of 92.1% was observed when comparing the results of NS1-negative samples with IgM-ELISA. Based on the findings, it is possible to suggest that the tests for NS1 detection may be important tools for monitoring the introduction and spread of Dengue serotypes.

scholarly journals Applicability of the Platelia EIA® Aspergillus test for the diagnosis of aspergilosis in penguins

2019 ◽  
Vol 79 (2) ◽  
pp. 169-173 ◽  
Author(s):  
A. L. Cabana ◽  
M. O. Xavier ◽  
J. F. Mendes ◽  
A. J. Teles ◽  
A. M. Martins ◽  
...  
Keyword(s):  
Roc Curve ◽  
Clinical Sample ◽  
Sandwich Elisa ◽  
Area Under The Curve ◽  
Control Group ◽  
Serum Samples ◽  
Predictive Values ◽  
Average Value ◽  
Magellanic Penguins ◽  
Sensitivity Specificity

Abstract Even today, an effective diagnostic test for aspergillosis in penguins is unknown, being the gold standard post-mortem examinations. The fungal antigen galactomannan (GM) has been used as a biomarker of disease in humans and is detected by the Platelia Aspergillus EIA (BioRad)®, a commercial kit based on the sandwich ELISA technique. It is standardized for use in neutropenic patients, however studies have demonstrated its usefulness also possible for birds. The aim of our study was to evaluate the effectiveness of Platelia Aspergillus EIA® test (BioRad-US) in the diagnosis of aspergillosis in Magellanic penguins, determining sensitivity, specificity, and positive and negative predictive values for different cut-off points. Were included in the study, blood serum samples (n = 29) Magellanic penguins in captivity that died by aspergillosis. Detection of GM was performed following manufacturer's instructions and the GM index was obtained by dividing the average value of OD of the duplicate of the clinical sample by duplicate OD of the average value of the cut-off sample provided by the kit. Through information database results were obtained for the presence of anti-Aspergillus fumigatus antibodies detected by agar gel immunodiffusion (AGID) for all serum samples. Results were analyzed using chi-square test and Kruskal-Wallis from SPSS 20.0, IBM®. ROC curve was obtained and from this, rates of sensitivity, specificity, positive and negative predictive values were also calculated based on four different cutoff points (0.5, 1.0, 1.5 and 2.0). The serum GM index did not differ between animals of the case and control group (pkw =0.097). In determining the ROC curve for serum GM detection the value of area under the curve was 0.635. From the values determined by the coordinate of the curve, four different cut points (0.5, 1.0, 1.5 and 2.0) were analyzed, resulting in sensitivity rates ranging from 86.2 to 34.5% % and specificity between 87% and 26.1%. By comparing the serum GM index in group case as the presence or absence of antibodies detected by AGID was found p=0.503. The detection of GM the Platelia Aspergillus EIA® test seems is not be useful for the diagnosis of aspergillosis in naturally infected penguins.

Diagnosis of toxoplasmosis in pregnancy. Evaluation of latex–protein complexes by immnunoagglutination

Parasitology ◽  
2017 ◽  
Vol 144 (8) ◽  
pp. 1073-1078 ◽  
Author(s):  
LEANDRO E. PERETTI ◽  
VERÓNICA D. G. GONZALEZ ◽  
IVÁN S. MARCIPAR ◽  
LUIS M. GUGLIOTTA
Keyword(s):  
Pregnant Women ◽  
Protein Complexes ◽  
Physical Adsorption ◽  
Area Under The Curve ◽  
Serum Samples ◽  
Predictive Values ◽  
Latex Particles ◽  
Receiver Operating Characteristic Curves ◽  
Acute Toxoplasmosis ◽  
Sensitivity Specificity

SUMMARYThe aim of this work was to obtain a reagent based on latex particles for ruling out acute toxoplasmosis in pregnant women by immunoagglutination (IA). Latex–protein complexes (LPC) were previously synthesized coupling the recombinant protein ofToxoplasma gondiiP22Ag and the homogenate of the parasite to latex particles with different size, chemical functionality and charge density. LPC were tested in IA assays against a panel of 72 pregnant women serum samples. Results were analysed through receiver operating characteristic curves, determining area under the curve (AUC), sensitivity, specificity positive and negative predictive values (PPV and NPV, respectively). It was observed that the antigenicity of proteins was not affected during sensitization by either physical adsorption or covalent coupling. The best results in the sense of maximizing discrimination of low avidity sera from chronic ones were observed for the IA test based on latex particles with carboxyl functionality and the recombinant P22Ag, obtaining an AUC of 0·94, a sensitivity of 100% and a NPV of 100%. In this way, the proposed test could be useful for the toxoplasmosis diagnosis in pregnant women, with the advantages of being cheap, rapid and easy to be implemented.

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