scholarly journals Serological test performance for bovine tuberculosis in cattle from herds with evidence of on-going infection in Northern Ireland

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0245655
Author(s):  
Lyanne McCallan ◽  
Cathy Brooks ◽  
Claire Barry ◽  
Catherine Couzens ◽  
Fiona J. Young ◽  
...  
Keyword(s):  
Northern Ireland ◽  
Test Performance ◽  
Bovine Tuberculosis ◽  
Serological Test ◽  
Infected Individual ◽  
Post Mortem ◽  
Serological Tests ◽  
Discriminatory Ability ◽  
Serology Test

The ability to accurately identify infected hosts is the cornerstone of effective disease control and eradication programs. In the case of bovine tuberculosis, accurately identifying infected individual animals has been challenging as all available tests exhibit limited discriminatory ability. Here we assess the utility of two serological tests (IDEXX Mycobacterium bovis Ab test and Enfer multiplex antibody assay) and assess their performance relative to skin test (Single Intradermal Comparative Cervical Tuberculin; SICCT), gamma-interferon (IFNγ) and post-mortem results in a Northern Ireland setting. Furthermore, we describe a case-study where one test was used in conjunction with statutory testing. Serological tests using samples taken prior to SICCT disclosed low proportions of animals as test positive (mean 3% positive), despite the cohort having high proportions with positive SICCT test under standard interpretation (121/921; 13%) or IFNγ (365/922; 40%) results. Furthermore, for animals with a post-mortem record (n = 286), there was a high proportion with TB visible lesions (27%) or with laboratory confirmed infection (25%). As a result, apparent sensitivities within this cohort was very low (≤15%), however the tests succeeded in achieving very high specificities (96–100%). During the case-study, 7/670 (1.04%) samples from SICCT negative animals from a large chronically infected herd were serology positive, with a further 17 animals being borderline positive (17/670; 2.54%). Nine of the borderline animals were voluntarily removed, none of which were found to be infected post-mortem (no lesions/bacteriology negative). One serology test negative animal was subsequently found to have lesions at slaughter with M. bovis confirmed in the laboratory.

scholarly journals Performance of serological antibody tests for bovine tuberculosis in cattle from infected herds in Northern Ireland

2017 ◽  
Author(s):  
L. McCallan ◽  
C. Brooks ◽  
C. Couzens ◽  
F. Young ◽  
A.W. Byrne ◽  
...  
Keyword(s):  
Northern Ireland ◽  
Skin Test ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Skin Testing ◽  
Gamma Interferon ◽  
Study Cohort ◽  
Post Mortem ◽  
Serological Tests

AbstractThe ability to accurately identify infected hosts is the cornerstone of effective disease control and eradication programs. In the case of bovine tuberculosis, caused by infection with the pathogenMycobacterium bovis, accurately identifying infected individual animals has been challenging as all available tests exhibit less than 100% discriminatory ability. Here we assess the utility of three serological tests and assess their performance relative to skin test (Single Intradermal Comparative Cervical Tuberculin; SICCT), gamma-interferon (IFNγ) and post-mortem results in a Northern Ireland setting. Furthermore, we describe a case-study where one test was used in conjunction with statutory testing.Serological tests using samples taken prior to SICCT disclosed low proportions of animals as test positive (mean 3% positive), despite the cohort having high proportions with positive SICCT test under standard interpretation (121/921; 13%) or IFNγ (365/922; 40%) results. Furthermore, for animals with a post-mortem record (n=286), there was a high proportion with TB visible lesions (27%) or with laboratory confirmed infection (25%). As a result, apparent sensitivities within this cohort was very low (≤15%), however the tests succeeded in achieving very high specificities (96-100%). During the case-study, 7/670 (1.04%) samples from SICCT negative animals from a large chronically infected herd were serology positive, with a further 10 animals being borderline positive (17/670; 2.54%). 9/17 of these animals were voluntarily removed, none of which were found to be infected (-lesions/-bacteriology) post-mortem; 1 serology test negative animal was subsequently lesion+ andM bovisconfirmed at slaughter.ImportanceEradication of bovine tuberculosis (bTB; caused byMycobacterium bovis) has remained elusive in a number of countries despite long-term coordinated test and cull programs. This can partially be explained by the limitations of available statutory tests; therefore supplementary test platforms that identify additional infected animals would be of significant utility. Overall, during our study three serological tests did not disclose a high proportion of animals as infected in high-risk cattle herds, and exhibited limited ability to disclose animals that were positive to the statutory skin test, the gamma interferon test (IFNγ), or were post-mortem confirmed withM. bovis. These serological tests could be used in a supplementary fashion to the statutory tests in particular circumstances; but may be of limited advantage where parallel use of IFNγ and skin testing is performed, as these tests together tended to disclose the majority of animals with post-mortem evidence of infection in our study cohort.

scholarly journals Diagnosis of tuberculosis in wildlife: a systematic review

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Jobin Thomas ◽  
Ana Balseiro ◽  
Christian Gortázar ◽  
María A. Risalde
Keyword(s):  
Systematic Review ◽  
Test Performance ◽  
Diagnostic Tests ◽  
Large Scale ◽  
Diagnostic Techniques ◽  
Review Literature ◽  
Meat Industry ◽  
Post Mortem ◽  
Serological Tests ◽  
Ongoing Research

AbstractAnimal tuberculosis (TB) is a multi-host disease caused by members of the Mycobacterium tuberculosis complex (MTC). Due to its impact on economy, sanitary standards of milk and meat industry, public health and conservation, TB control is an actively ongoing research subject. Several wildlife species are involved in the maintenance and transmission of TB, so that new approaches to wildlife TB diagnosis have gained relevance in recent years. Diagnosis is a paramount step for screening, epidemiological investigation, as well as for ensuring the success of control strategies such as vaccination trials. This is the first review that systematically addresses data available for the diagnosis of TB in wildlife following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The article also gives an overview of the factors related to host, environment, sampling, and diagnostic techniques which can affect test performance. After three screenings, 124 articles were considered for systematic review. Literature indicates that post-mortem examination and culture are useful methods for disease surveillance, but immunological diagnostic tests based on cellular and humoral immune response detection are gaining importance in wildlife TB diagnosis. Among them, serological tests are especially useful in wildlife because they are relatively inexpensive and easy to perform, facilitate large-scale surveillance and can be used both ante- and post-mortem. Currently available studies assessed test performance mostly in cervids, European badgers, wild suids and wild bovids. Research to improve diagnostic tests for wildlife TB diagnosis is still needed in order to reach accurate, rapid and cost-effective diagnostic techniques adequate to a broad range of target species and consistent over space and time to allow proper disease monitoring.

scholarly journals Diagnostic performance of a commercial ELISA used as a complementary test for bovine tuberculosis in two bovine herds with different disease status

2020 ◽  
Vol 72 (1) ◽  
pp. 1-8
Author(s):  
P.M. Soares Filho ◽  
A.K. Ramalho ◽  
A.M. Silva ◽  
M.A. Issa ◽  
P.M.P.C. Mota ◽  
...  
Keyword(s):  
Bovine Tuberculosis ◽  
Diagnostic Performance ◽  
Latent Class ◽  
Serological Test ◽  
Antibody Test ◽  
Latent Class Models ◽  
Lower Sensitivity ◽  
Kappa Index ◽  
Serological Tests ◽  
Test Kit

ABSTRACT Bovine tuberculosis is a worldwide spread zoonotic disease. Intradermal tuberculinizations are the most used diagnostic tests in the world. Serological tests can be an ancillary diagnosis for bovine tuberculosis. The objective of this study was to evaluate the diagnostic performance of the ELISA Mycobacterium Bovis Antibody Test Kit IDEXX ™ in infected herds, which were in different disease control stages. One hundred and twenty animals from two dairy herds of Minas Gerais state, Brazil, were subjected to the ELISA serological test and the comparative cervical tuberculin test (CCT). Diagnostic test parameters were estimated using Bayesian latent class models and concordance between tests estimated by the frequentist approach. The ELISA test presented lower sensitivity than CCT in both herds. Its sensitivity was higher in the herd in sanitation process. Specificity estimates were above 95% in both herds. Kappa index indicated low concordance or even disagreement between tests. According to the results, the ELISA IDEXX should not be used as substitution for CCT. The tests must not be associated in series. Parallel association increased diagnostic sensitivity in the herd which was in the process of sanitation.

scholarly journals Seroprevalence of anti-SARS-CoV-2 IgG antibodies in Juba, South Sudan: a population-based study

2021 ◽  
Author(s):  
Kirsten E. Wiens ◽  
Pinyi Nyimol Mawien ◽  
John Rumunu ◽  
Damien Slater ◽  
Forrest K. Jones ◽  
...  
Keyword(s):  
Test Performance ◽  
Serological Test ◽  
South Sudan ◽  
Bayesian Regression ◽  
Sub Saharan Africa ◽  
Surveillance Systems ◽  
Igg Antibody ◽  
Serological Tests ◽  
Cross Sectional ◽  
Sub Saharan

AbstractBackgroundRelatively few COVID-19 cases and deaths have been reported through much of sub-Saharan Africa, including South Sudan, although the extent of SARS-CoV-2 spread remains unclear due to weak surveillance systems and few population-representative serosurveys.MethodsWe conducted a representative household-based cross-sectional serosurvey in Juba, South Sudan. We quantified IgG antibody responses to SARS-CoV-2 spike protein receptor-binding domain and estimated seroprevalence using a Bayesian regression model accounting for test performance.ResultsWe recruited 2,214 participants from August 10 to September 11, 2020 and 22.3% had anti-SARS-CoV-2 IgG titers above levels in pre-pandemic samples. After accounting for waning antibody levels, age, and sex, we estimated that 38.5% (32.1 - 46.8) of the population had been infected with SARS-CoV-2. For each RT-PCR confirmed COVID-19 case, 104 (87-126) infections were unreported. Background antibody reactivity was higher in pre-pandemic samples from Juba compared to Boston, where the serological test was validated. The estimated proportion of the population infected ranged from 30.1% to 60.6% depending on assumptions about test performance and prevalence of clinically severe infections.ConclusionsSARS-CoV-2 has spread extensively within Juba. Validation of serological tests in sub-Saharan African populations is critical to improve our ability to use serosurveillance to understand and mitigate transmission.

scholarly journals Genetic diversity of Trypanosoma cruzi parasites infecting dogs in southern Louisiana sheds light on parasite transmission cycles and serological diagnostic performance

2020 ◽  
Vol 14 (12) ◽  
pp. e0008932
Author(s):  
Eric Dumonteil ◽  
Ardem Elmayan ◽  
Alicia Majeau ◽  
Weihong Tu ◽  
Brandy Duhon ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Trypanosoma Cruzi ◽  
Test Performance ◽  
Serological Test ◽  
Parasite Transmission ◽  
Parasite Diversity ◽  
Serological Tests ◽  
Transmission Cycle ◽  
Southern Us ◽  
Transmission Cycles

Background Chagas disease is a neglected zoonosis of growing concern in the southern US, caused by the parasite Trypanosoma cruzi. We genotyped parasites in a large cohort of PCR positive dogs to shed light on parasite transmission cycles and assess potential relationships between parasite diversity and serological test performance. Methodology/principal findings We used a metabarcoding approach based on deep sequencing of T. cruzi mini-exon marker to assess parasite diversity. Phylogenetic analysis of 178 sequences from 40 dogs confirmed the presence of T. cruzi discrete typing unit (DTU) TcI and TcIV, as well as TcII, TcV and TcVI for the first time in US dogs. Infections with multiple DTUs occurred in 38% of the dogs. These data indicate a greater genetic diversity of T. cruzi than previously detected in the US. Comparison of T. cruzi sequence diversity indicated that highly similar T. cruzi strains from these DTUs circulate in hosts and vectors in Louisiana, indicating that they are involved in a shared T. cruzi parasite transmission cycle. However, TcIV and TcV were sampled more frequently in vectors, while TcII and TcVI were sampled more frequently in dogs. Conclusions/significance These observations point to ecological host-fitting being a dominant mechanism involved in the diversification of T. cruzi-host associations. Dogs with negative, discordant or confirmed positive T. cruzi serology harbored TcI parasites with different mini-exon sequences, which strongly supports the hypothesis that parasite genetic diversity is a key factor affecting serological test performance. Thus, the identification of conserved parasite antigens should be a high priority for the improvement of current serological tests.

scholarly journals Performance of the Enferplex TB Assay with Cattle in Great Britain and Assessment of Its Suitability as a Test To Distinguish Infected and Vaccinated Animals

2010 ◽  
Vol 17 (5) ◽  
pp. 813-817 ◽  
Author(s):  
Clare Whelan ◽  
Adam O. Whelan ◽  
Eduard Shuralev ◽  
Hang Fai Kwok ◽  
Glyn Hewinson ◽  
...  
Keyword(s):  
Great Britain ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Serological Test ◽  
Relative Sensitivity ◽  
Multiplex Assay ◽  
Screening Methods ◽  
Sensitivity Range ◽  
Test Specificity ◽  
Serology Test

ABSTRACT Rapid, simple, and accurate antemortem tests for tuberculosis (TB) in cattle need to be developed in order to augment the existing screening methods. In particular, as cattle vaccines are developed, such tests would allow the continuation of test-and-slaughter policies alongside vaccination. Therefore, the development of an assay that distinguishes infected from vaccinated animals (a DIVA test) is an urgent research requirement. In this study, we assessed the performance of a novel multiplex serological test with sera collected from 96 skin-tested animals with bovine tuberculosis, 93 TB-free animals, and 39 cattle vaccinated with Mycobacterium bovis BCG. Our results indicate that the test has a relative sensitivity range of 77.0% to 86.5% at corresponding specificity levels of 100.0% to 77.6%. Comparison with the Bovigam gamma interferon antemortem test revealed that this serology test was significantly more sensitive at specificities above 97.9%, while the Bovigam test was, on average, about 10% more sensitive when the test specificity was set below 97%. Importantly, this serological multiplex assay does not react with sera from BCG-vaccinated calves and is therefore suitable as a DIVA test alongside BCG-based vaccine strategies.

scholarly journals Efficiency of slaughterhouse surveillance for the detection of bovine tuberculosis in cattle in Northern Ireland

2016 ◽  
Vol 145 (5) ◽  
pp. 995-1005 ◽  
Author(s):  
A. V. PASCUAL-LINAZA ◽  
A. W. GORDON ◽  
L. A. STRINGER ◽  
F. D. MENZIES
Keyword(s):  
Risk Factors ◽  
Logistic Regression ◽  
Northern Ireland ◽  
Bovine Tuberculosis ◽  
Post Mortem ◽  
Univariable Analysis ◽  
Eradication Programme ◽  
Risk Status ◽  
Regression Modelling ◽  
Logistic Regression Modelling

SUMMARYPost-mortem examination continues to play an important surveillance role in the bovine tuberculosis (bTB) eradication programme in Northern Ireland. It is estimated that 18–28% of new bTB herd breakdowns are disclosed by the detection of bTB lesions in animals routinely slaughtered. The purpose of this study was to compare the performance of different slaughterhouses in Northern Ireland in detecting bTB-lesioned animals at routine slaughter (LRS) and to apply the findings to maximize the sensitivity of bTB slaughterhouse surveillance. Univariate statistical analysis on cattle slaughtered in Northern Ireland during 2011–2013 revealed that the risk of LRS disclosure varied between slaughterhouses, ranging from 0·08% to 0·54%. Furthermore, the risk of confirmation of these LRS as bTB varied between slaughterhouses, ranging from 57·9% to 72·4%. Logistic regression modelling of selected risk factors found that the risk of LRS disclosure increased with age, and was higher in purchased animals, during winter months, in animals coming from high bTB incidence areas and in animals slaughtered from herds with a bTB restriction in the last 2–3 years. Adjusting for these selected factors, the risk of LRS disclosure and bTB confirmation changed very little from the univariable analysis, suggesting that differences in disclosure risks between slaughterhouses were likely to be due to factors related to the slaughterhouses, rather than to the risk status of the animals presented. Examination of procedures within these slaughterhouses is recommended to identify ways that could increase the sensitivity of their bTB surveillance.

scholarly journals Test characteristics of the tuberculin skin test and post-mortem examination for bovine tuberculosis diagnosis in cattle in Northern Ireland estimated by Bayesian latent class analysis with adjustments for covariates

2019 ◽  
Vol 147 ◽  
Author(s):  
M. J. H. O'Hagan ◽  
H. Ni ◽  
F. D. Menzies ◽  
A. V. Pascual-Linaza ◽  
A. Georgaki ◽  
...  
Keyword(s):  
Northern Ireland ◽  
Bovine Tuberculosis ◽  
Latent Class ◽  
Latent Class Model ◽  
Diagnostic Tools ◽  
Post Mortem ◽  
Standard Interpretation ◽  
Posterior Median ◽  
Post Mortem Examination ◽  
Test Characteristics

AbstractThe single intradermal comparative cervical tuberculin (SICCT) test and post-mortem examination are the main diagnostic tools for bovine tuberculosis (bTB) in cattle in the British Isles. Latent class modelling is often used to estimate the bTB test characteristics due to the absence of a gold standard. However, the reported sensitivity of especially the SICCT test has shown a lot of variation. We applied both the Hui–Walter latent class model under the Bayesian framework and the Bayesian model specified at the animal level, including various risk factors as predictors, to estimate the SICCT test and post-mortem test characteristics. Data were collected from all cattle slaughtered in abattoirs in Northern Ireland in 2015. Both models showed comparable posterior median estimation for the sensitivity of the SICCT test (88.61% and 90.56%, respectively) using standard interpretation and for post-mortem examination (53.65% and 53.79%, respectively). Both models showed almost identical posterior median estimates for the specificity (99.99% vs. 99.80% for SICCT test at standard interpretation and 99.66% vs. 99.86% for post-mortem examination). The animal-level model showed slightly narrower posterior 95% credible intervals. Notably, this study was carried out in slaughtered cattle which may not be representative for the general cattle population.

scholarly journals Opportunities for Improved Serodiagnosis of Human Tuberculosis, Bovine Tuberculosis, and Paratuberculosis

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Ashutosh Wadhwa ◽  
Graham J. Hickling ◽  
Shigetoshi Eda
Keyword(s):  
Test Performance ◽  
Bovine Tuberculosis ◽  
New Technologies ◽  
Diagnostic Methods ◽  
Nucleic Acid Amplification ◽  
Protein Antigens ◽  
Serological Tests ◽  
Lab On Chip ◽  
Mycobacterial Infections ◽  
Species Specific

Mycobacterial infections—tuberculosis (TB), bovine tuberculosis (bTB), and Johne’s disease (JD)—are major infectious diseases of both human and animals. Methods presently in use for diagnosis of mycobacterial infections include bacterial culture, nucleic acid amplification, tuberculin skin test, interferon-γassay, and serology. Serological tests have several advantages over other methods, including short turn-around time, relatively simple procedures, and low cost. However, current serodiagnostic methods for TB, bTB and JD exhibit low sensitivity and/or specificity. Recent studies that have aimed to develop improved serodiagnostic tests have mostly focused on identifying useful species-specific protein antigens. A review of recent attempts to improve diagnostic test performance indicates that the use of multiple antigens can improve the accuracy of serodiagnosis of these mycobacterial diseases. Mycobacteria also produce a variety of species-specific nonprotein molecules; however, only a few such molecules (e.g., cord factor and lipoarabinomannan) have so far been evaluated for their effectiveness as diagnostic antigens. For TB and bTB, there has been recent progress in developing laboratory-free diagnostic methods. New technologies such as microfluidics and “Lab-on-Chip” are examples of promising new technologies that can underpin development of laboratory-free diagnostic devices for these mycobacterial infections.

scholarly journals Problems and prospects of bovine tuberculosis serological diagnosis

2021 ◽  
Vol 1 (1) ◽  
pp. 33-37
Author(s):  
M. O. Baratov
Keyword(s):  
Bovine Tuberculosis ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Serological Test ◽  
Fixation Test ◽  
Antibody Activity ◽  
Post Mortem ◽  
Indirect Haemagglutination ◽  
Cell Immunity ◽  
Allergy Test

For the purposes of tuberculosis eradication on any tuberculosis-infected farm, it is necessary to identify tuberculin anergic animals, being a potential source of the infection. The purpose of this study was to analyze the role of complement fixing and haemagglutinating antibodies for the detection cattle infected with bovine tuberculosis (TB). 977 cattle of different sex and age groups on two tuberculosis-infected farms were tested thrice over time. After 35 days all tuberculin reactive cattle (132 animals; 13.5%) were subjected to complex testing using allergy and serology methods. After 40 days, (Stage 3) animals demonstrating apparent specific antibody activity and low cell immunity were tested. Allergy tests were proved to be non-informative to diagnose tuberculosis on infected farms. Complement fixing and haemagglutinating antibodies were found to be active in tuberculin anergic animals. A higher antigenicity of Ukrainian RIEVM TB antigen complex as compared to Siberian RVI one was revealed by complement fixation test as well as by indirect haemagglutination test using VIEV polysaccharide antigen; the detection rate was 68 (7.0%), 28 (2.9%) and 299 (30.6%) respectively. The correlation between seropositivity and immunoreactivity was not established. Animals, positive in complement fixation and indirect haemagglutination tests, did not react to tuberculin. Nineteen out of twenty tuberculin reactive animals showed post mortem lesions, consistent with their seropositivity during post-mortem inspection; moreover, the postmortem lesions of animals, positive in complement fixation test using Siberian RVI antigen, were consistent in all cases. The results obtained suggest a high performance of allergy test and serological test combination and a promising potential of their complex use for tuberculosis diagnosis in cattle.

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