scholarly journals The diagnostic efficiency of some serological tests for bovine brucellosis

1978 ◽  
Vol 80 (3) ◽  
pp. 373-384 ◽  
Author(s):  
R. J. Chappel ◽  
D. J. McNaught ◽  
J. A. Bourke ◽  
G. S. Allan
Keyword(s):  
False Positive ◽  
False Negative ◽  
Diagnostic System ◽  
Diagnostic Value ◽  
Diagnostic Efficiency ◽  
Bovine Brucellosis ◽  
Serological Tests ◽  
Probable Infection ◽  
Serum Agglutination

SummaryResults obtained from 1887 sera using three serological tests for bovine brucellosis were compared with a serological classification of sera described as the ‘probable infection status’. Sera showing apparent false positive and apparent false negative reactions were identified, and were subjected to supplementary testing as appropriate.The serum agglutination test (SAT) gave 35% apparent false negative reactions and 5% apparent false positives. The complement fixation test (CFT) gave 12% apparent false negative reactions using warm fixation (CFTW) and at least 5% using cold fixation (CFTC). The routine diagnostic system used in Victoria, in which the CFTW is supplemented by the CFTC and the SAT, gave 9% apparent false negative reactions and 2% apparent false positive reactions. The radioimmunoassay gave 1% or 6% apparent false negative reactions, depending the minimum diagnostic value used.Atypical reactions in the CFT sometimes caused difficulties in diagnosis.

scholarly journals A quantitative comparison of the sensitivity of serological tests for bovine brucellosis to different antibody classes

1976 ◽  
Vol 76 (2) ◽  
pp. 287-298 ◽  
Author(s):  
G. S. Allan ◽  
R. J. Chappel ◽  
P. Williamson ◽  
D. J. McNaught
Keyword(s):  
Complement Fixation Test ◽  
Complement Fixation ◽  
Quantitative Comparison ◽  
Agglutination Test ◽  
Bovine Brucellosis ◽  
Serological Tests ◽  
Plate Test ◽  
Specific Antibodies ◽  
The Rose ◽  
Serum Agglutination

SUMMARYBrucella-specific antibodies of different immunoglobulin classes were quantitatively evaluated with respect to their efficiency in serological tests for bovine brucellosis.IgM reacted more efficiently than IgG1and IgG2in both the Rose Bengal plate test and serum agglutination test. The complement fixation test was found to be slightly more sensitive to IgM than to IgG1and did not react to IgG2.IgM was, however, partly inactivated when heated at 60°C. in the presence of serum.

Value of alkaline phosphatase, 5'-nucleotidase, gamma-glutamyltransferase, and glutamate dehydrogenase activity measurements (single and combined) in serum in diagnosis of metastasis to the liver.

1977 ◽  
Vol 23 (11) ◽  
pp. 2034-2038 ◽  
Author(s):  
N K Kim ◽  
W G Yasmineh ◽  
E F Freier ◽  
A I Goldman ◽  
A Theologides
Keyword(s):  
Alkaline Phosphatase ◽  
Liver Metastases ◽  
Glutamate Dehydrogenase ◽  
False Positive ◽  
Serum Alkaline Phosphatase ◽  
False Negative ◽  
Diagnostic Value ◽  
Gamma Glutamyltransferase ◽  
Activity Measurements ◽  
Positive Results

Abstract We assessed, in 98 patients with cancer, the diagnostic value of measuring serum alkaline phosphatase, 5'-nucleotidase, gamma-glutamyltransferase, and glutamate dehydrogenase activities as an aid to detection of liver metastases. All four enzymes showed diagnostic value, but 5'-nucleotidase appeared to have the greatest. It showed the lowest false-positive results (7.4%) with the highest predictive value of a positive test (85.7%) and agreement (81.3%).. gamma-Glutamyltransferase showed the lowest proportion of false-negative results (2.8%), but was the least specific 35% false-positive results). Analysis of various test combinations showed that the best agreement (77.5%) was obtained when the patients were divided into those who had no or only one abnormal test result, and those who had two or more abnormal test results. However, this was not better than the agreement for 5' nucleotidase alone (81.3%). The agreement of 5'-nucleotidase and gamma-glutamyltransferase (i.e., both tests were positive or negative) was excellent (91.4%), but such agreement included only 67% of the patients with liver metastases.

scholarly journals Efficacy of Several Serological Tests and Antigens for Diagnosis of Bovine Brucellosis in the Presence of False-Positive Serological Results Due to Yersinia enterocolitica O:9

2005 ◽  
Vol 12 (1) ◽  
pp. 141-151 ◽  
Author(s):  
P. M. Muñoz ◽  
C. M. Marín ◽  
D. Monreal ◽  
D. González ◽  
B. Garin-Bastuji ◽  
...  
Keyword(s):  
Yersinia Enterocolitica ◽  
False Positive ◽  
Lipid A ◽  
Protein Complexes ◽  
Serological Test ◽  
Bovine Brucellosis ◽  
Serological Tests ◽  
Cytosolic Proteins ◽  
Membrane Protein Complexes ◽  
Sensitivity Specificity

ABSTRACT Yersinia enterocolitica O:9 bears a smooth lipopolysaccharide (S-LPS) of Brucella sp. O-chain A + C/Y epitopic structure and is a cause of false-positive serological reactions (FPSR) in standard tests for cattle brucellosis. Brucella S-LPS, cross-reacting S-LPSs representing several O-chain epitope combinations, Brucella core lipid A epitopes (rough LPS), Brucella abortus S-LPS-derived polysaccharide, native hapten polysaccharide, rough LPS group 3 outer membrane protein complexes, recombinant BP26, and cytosolic proteins were tested in enzyme-linked immunosorbent assays (ELISA) and precipitation tests to detect cattle brucellosis (sensitivity) and to differentiate it from FPSR (specificity). No single serological test and antigen combination showed 100% sensitivity and specificity simultaneously. Immunoprecipitation tests with native hapten polysaccharide, counterimmunoelectrophoresis with cytosolic proteins, and a chaotropic ELISA with Brucella S-LPS were 100% specific but less sensitive than the Rose Bengal test, complement fixation, and indirect ELISA with Brucella S-LPSs and native hapten or S-LPS-derived polysaccharides. A competitive ELISA with Brucella S-LPS and M84 C/Y-specific monoclonal antibody was not 100% specific and was less sensitive than other tests. ELISA with Brucella suis bv. 2 S-LPS (deficient in C epitopes), Escherichia hermannii S-LPSs [lacking the contiguous α-(1-2)-linked perosamine residues characteristic of Y. enterocolitica S-LPS], BP26 recombinant protein, and Brucella cytosolic fractions did not provide adequate sensitivity/specificity ratios. Although no serological test and antigen combination fully resolved the diagnosis of bovine brucellosis in the presence of FPSR, some are simple and practical alternatives to the brucellin skin test currently recommended for differential diagnosis.

Antigenic components of Taenia saginata and their relevance to the diagnosis of bovine cysticercosis by immunoelectrophoresis

1979 ◽  
Vol 53 (4) ◽  
pp. 293-299 ◽  
Author(s):  
S. Geerts ◽  
V. Kumar ◽  
N. Aerts
Keyword(s):  
Post Infection ◽  
False Positive ◽  
False Negative ◽  
Diagnostic Value ◽  
Evolutionary Stage ◽  
Taenia Saginata ◽  
Hyperimmune Serum ◽  
False Positive Reaction ◽  
Bovine Cysticercosis ◽  
Cross Absorption

ABSTRACT22 antigenic components of Taenia saginata proglottides were detected by immunoelectrophoretic (IEP) study. Cross-absorption of the Hyperimmune serum, raised in rabbits against T. saginata, with heterologous and host antigens showed that two thirds of these components were not specific for the cestode. Among the calves experimentally infected with T. saginata eggs, 3 precipitation patterns in IEP were identified depending on the evolutionary stage of the infection. The hydrosoluable extract of T. Saginata was used as antigen. A short precipitating arc present near the antigen well and appearing 3 to 4 weeks post-infection of the calves and a long precipitating arc extending towards the anodic end of the slide and appearing in later stages of infection were found of high diagnostic value. No false-positive reaction or cross-reaction were found. Among the calves harbouring less than 50 cysticerci, false-negative reactions were seen.

scholarly journals Identification of etiological agents of selected bacterial and viral infections based on serological tests

2018 ◽  
Vol 72 ◽  
pp. 1162-1178
Author(s):  
Aleksandra Lewandowicz-Uszyńska ◽  
Piotr Naporowski ◽  
Gerard Pasternak ◽  
Danuta Witkowska
Keyword(s):  
False Positive ◽  
Cellular Response ◽  
Bacterial Infections ◽  
Viral Infections ◽  
False Negative ◽  
Main Role ◽  
Serological Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Positive Results

The human immune system’s response to infection is closely related with the type of pathogen. First, a rapid, metabolically inexpensive and non-specific innate immunity is induced, then a specific acquired immunity is activated. In bacterial infections caused by intracellular pathogens, the main role is played by cellular response. In infections caused by bacterial extracellular pathogens, a crucial role is played by antibodies. The clinical symptoms of bacterial and viral infections very often are similar, which is why diagnosing them based only on medical history and physical examination is insufficient. To identify the etiological factors of infections differentiating media, biochemical tests, molecular methods and serological tests are used. The detection of microorganisms or their genetic material can be performed within a short time after the occurrence of an infection. The detection of antibodies is possible only in the appropriate time called the serological window. In a serological diagnostic of infections there are problems with an appropriate interpretation of obtained results. Cross-reactivity can give false positive results for the diagnosis of Chlamydophila pneumonia infection. The problem with the detection of Borrelia burgdorferi infection can be caused by a simultaneous coinfection with different spirochetes, syphilis, mononucleosis or HIV. In serological diagnostics of bacterial infections, the administration of antibiotics to patients before taking serum samples can be responsible for false negative results. Another reason for such results can be a weak humoral response in infected patients. In viral infections, false positive results can be caused by a coinfection of different viruses, especially from the same family or by bacterial or protozoal coinfections or by autoimmune diseases. False-negative results in viral infections often are caused by the early phase of an infection. To properly recognize an etiological factor of infection it is necessary to use an appropriate method, precision of test and collect samples at the appropriate time.

Diagnostic Value of Routine Liver Scanning in Ecchinococcus Disease of the Liver; a Comparison of Scintigraphic and Surgical Findings in 100 Consecutive Cases

1970 ◽  
Vol 09 (01) ◽  
pp. 05-16
Author(s):  
D. Ikkos ◽  
S. Gonticas ◽  
P. Gatsou
Keyword(s):  
False Positive ◽  
False Negative ◽  
Diagnostic Value ◽  
Pathological Findings ◽  
Hydatid Cysts ◽  
Liver Scanning

SummaryThe diagnostic value of liver scanning for hydatid cysts of the liver was examined by comparing the preoperative scintigrams and the surgical findings in 100 consecutive cases operated upon for hydatid cysts of the liver. False results were found in 10 cases (false positive in 1 and false negative in 9 cases). In the remaining 90 cases the scans had demonstrated the presence of pathological findings supporting the diagnosis of hydatid cysts. In 66 of these 90 cases the number, location and size of the cyst(s) were accurately defined by the scan, while in the remaining 24 cases there was a discrepancy between the scan and the surgical findings as to the number of the cysts. The effect of the number and location of the cysts on the accuracy of the scan diagnosis was analyzed.

scholarly journals The false classification of extinction risk in noisy environments

2014 ◽  
Vol 281 (1787) ◽  
pp. 20132935 ◽  
Author(s):  
B. M. Connors ◽  
A. B. Cooper ◽  
R. M. Peterman ◽  
N. K. Dulvy
Keyword(s):  
False Positive ◽  
Extinction Risk ◽  
False Negative ◽  
False Alarms ◽  
Observation Error ◽  
Noisy Environments ◽  
Stochastic Variation ◽  
Process Noise ◽  
Autocorrelated Process

Abundance trends are the basis for many classifications of threat and recovery status, but they can be a challenge to interpret because of observation error, stochastic variation in abundance (process noise) and temporal autocorrelation in that process noise. To measure the frequency of incorrectly detecting a decline (false-positive or false alarm) and failing to detect a true decline (false-negative), we simulated stable and declining abundance time series across several magnitudes of observation error and autocorrelated process noise. We then empirically estimated the magnitude of observation error and autocorrelated process noise across a broad range of taxa and mapped these estimates onto the simulated parameter space. Based on the taxa we examined, at low classification thresholds (30% decline in abundance) and short observation windows (10 years), false alarms would be expected to occur, on average, about 40% of the time assuming density-independent dynamics, whereas false-negatives would be expected to occur about 60% of the time. However, false alarms and failures to detect true declines were reduced at higher classification thresholds (50% or 80% declines), longer observation windows (20, 40, 60 years), and assuming density-dependent dynamics. The lowest false-positive and false-negative rates are likely to occur for large-bodied, long-lived animal species.

scholarly journals Comparison of the results of some serological tests for bovine brucellosis

1978 ◽  
Vol 80 (3) ◽  
pp. 365-371 ◽  
Author(s):  
R. J. Chappel ◽  
D. J. McNaught ◽  
J. A. Bourke ◽  
G. S. Allan
Keyword(s):  
Rose Bengal ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Agglutination Test ◽  
Bovine Brucellosis ◽  
Serological Tests ◽  
Plate Test ◽  
Comparison Of The Results ◽  
The Rose ◽  
Serum Agglutination

SummaryA total of 1887 bovine sera positive to the Rose Bengal plate test were subjected to other serological tests for bovine brucellosis: the complement fixation test using warm fixation (CFTW), the serum agglutination test (SAT) and the radioimmunoassay (RIA).The SAT was generally much less sensitive than the CFTW. Many sera, however, gave positive reactions in the SAT but no reaction in the CFTW or the RIA. These SAT reactions were attributed to IgM antibody.Comparison between the results of the CFTW and the RIA led to the conclusion that 200 ng could be used as a minimum diagnostic reaction in the RIA.

scholarly journals "Multimodal" Imaging Performance and Clinical Application of Coronavirus Disease 2019 (COVID-19)

2020 ◽  
Author(s):  
Guohong Li ◽  
Qijian Zhou ◽  
Jintian Li ◽  
Lin Zhu ◽  
Yan Chen ◽  
...  
Keyword(s):  
Ct Scan ◽  
False Negative ◽  
Diagnostic Value ◽  
Ground Glass ◽  
Digital Tomosynthesis ◽  
Diagnostic Efficiency ◽  
Imaging Methods ◽  
Examination Methods ◽  
Equal Capacity ◽  
Novel Coronavirus

Abstract Background: To investigate the diagnostic value of three different examination methods of chest radiography (CXR), digital tomosynthesis (DTS) and Computed tomography (CT) scan on the diagnosis of novel coronavirus pneumonia (COVID-19).Methods: A retrospective analysis of three examination methods of chest: CXR, DTS, and CT scan of COVID-19 pneumonia patients diagnosed in our hospital from January, 23, 2020 to February, 29, 2020. And we compared three different imaging methods to COVID-19 display ability of pneumonia intrapulmonary lesions.Results: A total of 37 patients diagnosed as COVID-19 by nucleic acid testing were included. The CXR group (10/37) and DTS group (21/28) of 37 patients with COVID-19 pneumonia showed significant differences in intrapulmonary ground glass opacities (P<0.05); DTS group (21/28) and CT group (25/27) showed no statistically significant differences in intrapulmonary ground glass opacities (P> 0.05). Conclusion: Comparison of the three imaging methods of COVID-19 pneumonia, the diagnostic efficiency of CXR is low, which is easy to be false negative and miss lesions; diagnostic resolutions of DTS are higher than CXR, which can improve the ability to display the fine structure of intrapulmonary lesions; CT scan shows the intrapulmonary of COVID-19 pneumonia low-density ground glass opacities and internal structures have equal capacity compared with DTS. Therefore, DTS and CT are the best choices for the image diagnosis of COVID-19 pneumonia.

scholarly journals Intercurrence of Paratuberculosis in Intradermal Tuberculin Test Reactive Cattle

2020 ◽  
Vol 48 ◽  
Author(s):  
Mariana Assunção De Souza ◽  
Nicolle Pereira Soares ◽  
Alessandra Aparecida Medeiros-Ronchi ◽  
Brendhal Almeida Silva ◽  
Pedro Paulo Feitosa De Albuquerque ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
False Positive ◽  
False Negative ◽  
Complex Mixture ◽  
Pathological Finding ◽  
Intradermal Test ◽  
Mesenteric Lymph Nodes ◽  
Serological Tests ◽  
Mesenteric Lymph ◽  
False Positive Reactions

Background: Bovine tuberculosis control programs are based on a standard diagnostic method, the intradermal test with purified protein derivatives, which is used to identify and eliminate diseased animals. Currently none of the tests available allow complete differentiation between infected and uninfected animals. The main limitations of the tests available are related to diagnostic sensitivity and specificity, which results in false positive reactions due to the existence of cross infections, and also false negative, inherent to the state of energy of some animals. The aim of this work was to study the intercurrence of paratuberculosis in tuberculosis reactive cattle by the comparative cervical test.Materials, Methods & Results: Three hundred and thirty four cattle were evaluated using the comparative cervical test (CCT) and serology for tuberculosis (TB) and paratuberculosis (PTB) ELISA IDEXX®. All of the animals testing positive by CCT were euthanized and necropsied. Fragments of lymph node, lung and intestine were collected and analyzed using histopathological techniques, with staining by Hematoxylin-Eosin (HE). Samples of lung and lymph nodes (retropharyngeal, submandibular, cervical and mediastinal) of the animals testing positive by CCT were evaluated using qPRC for M. bovis, and intestinal and mesenteric lymph nodes using PCR for PTB. Of the 334 cattle evaluated using the comparative cervical test, 16 were considered positive. No lesions suggestive of tuberculosis were found in the macroscopic inspection of the carcasses. The most evident anatomical and pathological finding was a thickening of intestinal mucosa, found in 12 of the 16 cattle submitted to necropsy. No microscopic lesions suggestive of TB were identified nor was the presence of M. bovis detected by qPCR. The main histopathological findings were observed in the small intestine and mesenteric lymph nodes and identified as enteritis, lymphangitis, lymphangiectasia and granulomatous lymphadenitis. In the intestine the changes are characterized by dilated and inflamed lymphatic vessels and intense inflammatory infiltrate on the mucosa and submucosa. Of the 334 serum samples evaluated, the M. bovis ELISA Antibody Test (IDEXX®) identified 17 positive animals. All the cattle considered positive by M. bovis ELISA were considered negative by CCT. In the samples from nine animals (9/16), DNA from M. avium subsp. paratuberculosis (MAP) was identified and in twelve carcasses (12/16) lesions characteristic of PTB were found, which were subsequently confirmed by histopathological techniques. In another nine animals of the herd anti-MAP antibodies were detected. None of those that tested positive by PTB ELISA were reactive by CCT.Discussion: Animals considered positive by TB ELISA that were not positive in the intradermal test does not mischaracterize the clinical picture of the disease. Considering the inverse relationship between cell-mediated and humoral responses to M. bovis, the intradermal test and the serological tests are designed to measure different immunological responses, which develop during different stages of infection. The progress of the cellular immunological response to humoral immunity occurs in the most advanced stages of tuberculosis. Of the 16 cattle considered positive by CCT, 12 animals presented macroscopic and histological lesions suggestive of PTB and DNA from MAP was detected in nine. Although it is the official test for the control of TB in different countries, the intradermal test with PPD has presented limitations, primarily related to specificity. M. avium subsp. Paratuberculosis is considered the main cause of false positive reactions in the intradermal test. The PPD bacterial extract is a complex mixture of proteins, lipids, sugars and nucleic acids, and many of these components are also shared by numerous species of mycobacteria (tuberculous or not). 

Sign in / Sign up

Export Citation Format

Share Document