RESUMO
The direct methods for diagnosis of bovine brucellosis have several limitations, therefore serological tests are the basis for the diagnosis of the disease. However, a meta-analysis estimating the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) on the main tests used in bovine brucellosis control programs worldwide has not been performed. This systematic review and meta-analysis aimed to estimate the DSe, DSp and thereby accuracy of serological tests individually used in the diagnosis of bovine brucellosis. The databases CABI, Cochrane Library, PubMed/MEDLINE, SciELO, Scopus and Web of Science were used to select articles. The search resulted in 5308 studies, of which 71 were selected for systematic review using quality assessment tools and 65 studies were included in the meta-analysis. For the meta-analysis, 178 assays and 11 different serological tests were considered. To estimate DSe and DSp of the tests, studies were divided according to animal selection for the studies: (1) studies that carried out a random or consecutive selection of participants (noncasecontrol studies) and (2) all studies, including casecontrol studies. Considering only the non-case-control studies to estimate the DSe, the tests that exhibited the best and worst performance were the iELISA test (indirect enzyme immunoassay - bacterial suspension as antigen - BS) (96.5%, 95% CI: 94.1-97.9%) and 2ME (2- mercaptoethanol test) (85.0%, 95% CI: 79.6-89.1%), respectively; while for DSp, the FPA (fluorescence polarization assay) (99, 7%, 95% CI: 99.5-99.8%) and PCFIA tests (protein concentration fluorescence immunoassay) (78.5%, 95% CI: 70.0-85.1%) showed better and worse performance, respectively. Overall, our results showed an overestimation in the DSe and DSp of the eleven serological tests assessed when casecontrol studies were included in the meta-analysis, which is a concern considering its impacts on the time and costs associated with populational diagnosis of the diseases, since several of these tests are routinely used in the control and eradication programs of bovine brucellosis worldwide. Furthermore, the tests that exhibited the best DSe and DSp, iELISA (BS) and FPA, respectively, are relatively easy to perform and interpret and the test which showed the best overall accuracy was FPA.
Assuntos
Brucelose Bovina , Brucelose , Doenças dos Bovinos , Bovinos , Animais , Sensibilidade e Especificidade , Brucelose Bovina/diagnóstico , Imunoensaio de Fluorescência por Polarização/métodos , Imunoensaio de Fluorescência por Polarização/veterinária , Ensaio de Imunoadsorção Enzimática/veterinária , Ensaio de Imunoadsorção Enzimática/métodos , Testes Sorológicos/veterinária , Brucelose/diagnóstico , Brucelose/veterinária , Anticorpos AntibacterianosRESUMO
In order to show the development and scope of a serological analysis method based on fluorescence polarization assay (FPA) from a drop of blood obtained by the capillary technique, a Brucella antibody assay was performed on a group of 321 high-risk workers. The results were compared with data from the analysis of blood serum by FPA and a competitive enzyme immunoassay (ELISA-c). The number of concordance was 318 (99.06%), and discordant 3 (0.93%), which were negative in serum by fluorescence polarization (FPAs) and ELISA-c, but positive with capillary FPA (FPAc). The comparative results FPAc were: sensitivity 100%; specificity: 99.05%; positive predictive value 66.67%; negative predictive value 100.0%; false positive rate: 0.95%; false negative rate: 0%; accuracy: 98.0%; odds ratio: 203.00. The youden J for both FPA methods was 0.667. The identification was considered reliable and the correlation of both procedures, FPA and ELISA-c, was no statistically different (P > 0.05%), which allows to highly recommend the study implementation of human brucellosis with capillary blood as a preliminary method.
Assuntos
Anticorpos Antibacterianos/sangue , Brucella/imunologia , Imunoensaio de Fluorescência por Polarização/métodos , Matadouros , Adulto , Criação de Animais Domésticos , Brucelose/imunologia , Ensaio de Imunoadsorção Enzimática , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Exposição Ocupacional , Valor Preditivo dos Testes , Risco , Sensibilidade e Especificidade , Medicina VeterináriaRESUMO
A objeto de mostrar el desarrollo y alcance de un método de análisis serológico basado en la técnica de fluorescencia polarizada (FPA) a partir de una gota de sangre obtenida mediante punción capilar, se realizó la determinación de anticuerpos antibrucelosis de un conjunto de 321 personas de alto riesgo laboral. Los resultados se compararon con la data proveniente del análisis de sueros sanguíneos mediante FPA e inmunoanálisis enzimático competitivo (ELISA-c). El número de concordantes fue 318 (99,06%), los 3 discordantes (0,93%) resultaron negativos con fluorescencia polarizada en suero (FPAs) y ELISA-c, pero positivos con FPA capilar (FPAc). Los resultados comparativos de FPAc fueron: sensibilidad: 100%; especificidad: 99,05%; valor predictivo positivo: 66,67%; valor predictivo negativo: 100,0%; proporción de falsos positivos: 0,95%; proporción de falsos negativos: 0%; exactitud: 98,0%; razón de probabilidades: 203,00. La J de Youden para ambos métodos de FPA fue de 0,667. La determinación se consideró confiable y la concordancia de ambos procedimientos de FPA y ELISA-c resultó sin diferencias estadísticas (P>0,05%), lo que permite recomendar ampliamente la implementación del estudio de la brucelosis humana con sangre proveniente de punción capilar como método preliminar.
In order to show the development and scope of a serological analysis method based on fluorescence polarization assay (FPA) from a drop of blood obtained by the capillary technique, a Brucella antibody assay was performed on a group of 321 high-risk workers. The results were compared with data from the analysis of blood serum by FPA and a competitive enzyme immunoassay (ELISA-c). The number of concordance was 318 (99.06%), and discordant 3 (0.93%), which were negative in serum by fluorescence polarization (FPAs) and ELISA-c, but positive with capillary FPA (FPAc). The comparative results FPAc were: sensitivity 100%; specificity: 99.05%; positive predictive value 66.67%; negative predictive value 100.0%; false positive rate: 0.95%; false negative rate: 0%; accuracy: 98.0%; odds ratio: 203.00. The youden J for both FPA methods was 0.667. The identification was considered reliable and the correlation of both procedures, FPA and ELISA-c, was no statistically different (P> 0.05%), which allows to highly recommend the study implementation of human brucellosis with capillary blood as a preliminary method.
Assuntos
Adulto , Humanos , Anticorpos Antibacterianos/sangue , Brucella/imunologia , Imunoensaio de Fluorescência por Polarização/métodos , Matadouros , Criação de Animais Domésticos , Brucelose/imunologia , Ensaio de Imunoadsorção Enzimática , Reações Falso-Negativas , Reações Falso-Positivas , Exposição Ocupacional , Valor Preditivo dos Testes , Risco , Sensibilidade e Especificidade , Medicina VeterináriaRESUMO
The current method for goat brucellosis diagnosis is based on the World Organization for Animal Health (OIE) using the screening card test (CT), with antigen at 8% (CT8) or 3% (CT3) of cell concentrations, and the confirmatory complement fixation test (CFT). However, these tests do not differentiate antibodies induced by vaccination from those derived from field infections by Brucella species or other bacterial agents; in places like Mexico, where the prevalence of brucellosis and the vaccination rates are high, there is a considerable percentage of false positive reactions that causes significant unnecessary slaughter of animals. Furthermore, results of the fluorescence polarization assay (FPA) using the Brucella abortus O-polysaccharide (OPS) tracer in goats are poorer than those with cattle. The present study was undertaken to investigate a tracer prepared from the native hapten (NH) of the Rev. 1 strain of Brucella melitensis to improve FPA performance on goat brucellosis diagnosis. Evaluation of 48 positive samples and 96 negative samples showed that the NH tracer was more accurate (p<0.01) than the OPS tracer (97.2% vs. 93.8% accuracy, respectively). On the diagnostic performance evaluation, the NH tracer performed better (87.5% accuracy, 79.5% sensitivity, 84.3% specificity, and 163.8 performance index) than the OPS tracer (83.5%, 75.9%, 81.0%, and 156.9, respectively) using 1009 positive and 2039 negative Mexican field goat sera samples selected by test series approved by the OIE (card test 3% and CFT). We demonstrated a new application for the NH lipopolysaccharide on detecting antibodies against Brucella using the FPA, which may yield faster results (minutes vs. 24-72h) than the immunodiagnosis assays frequently used in bovine brucellosis. In addition, NH tracer produces similar or better performance results than the conventional OPS tracer, using the FPA in goat sera samples.
Assuntos
Anticorpos Antibacterianos/sangue , Brucella melitensis/imunologia , Brucelose/veterinária , Imunoensaio de Fluorescência por Polarização/veterinária , Doenças das Cabras/microbiologia , Haptenos/química , Animais , Anticorpos Antibacterianos/imunologia , Brucella abortus/imunologia , Brucella melitensis/química , Brucelose/diagnóstico , Brucelose/imunologia , Brucelose/microbiologia , Bovinos , Fluoresceína-5-Isotiocianato/química , Imunoensaio de Fluorescência por Polarização/métodos , Corantes Fluorescentes/química , Doenças das Cabras/sangue , Doenças das Cabras/diagnóstico , Doenças das Cabras/imunologia , Cabras , Haptenos/imunologia , Curva ROC , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The performance of a fluorescence polarization assay (FPA) that detects antibodies to Mycobacterium bovis in bovine sera is described. The FPA reported here is a direct binding primary screening assay using a small polypeptide derived from the M. bovis MPB70 protein. A secondary inhibition assay confirms suspect or presumed positive samples. Specificity studies involved five different veterinary laboratories testing 4461 presumed negative bovine samples. FPA specificity was 99.9%. The FPA was used to identify herd status as either M. bovis infected or non-infected. Herd surveillance studies (nine herds) were performed in Mexico and South Africa. The FPA had a specificity of 100% (two negative herds), and correctly identified six of seven infected herds. Finally, sera from 105 slaughter animals that had gross lesions in lymph nodes similar to those seen with bovine tuberculosis were tested by the FPA. Thin sections from the associated formalin-fixed paraffin-embedded samples of lymph nodes were stained using hematoxylin and eosin (H&E) for morphologic examination and using the Ziehl-Neelsen (ZN) method for detection of acid-fast bacilli. Of the 105 animals, 78 were classified as TB suspect based on lesion morphology, 21 were positive by ZN, 9 were positive by FPA and 13 were positive by PCR for the tuberculosis group of Mycobacterium. Among the 21 ZN positives, 11 (52.4%) were PCR positive. Among the 9 FPA positives, 8 (88.9%) were PCR positive. For the 13 PCR positives, 8 (61.5%) were FPA positive and 11 (84.6%) were ZN positives. These results show that use of the FPA for detection of M. bovis infection of cattle has value for bovine disease surveillance programs.
Assuntos
Anticorpos Antibacterianos/sangue , Imunoensaio de Fluorescência por Polarização/veterinária , Mycobacterium bovis/imunologia , Tuberculose Bovina/imunologia , Animais , Proteínas de Bactérias/imunologia , Bovinos , Imunoensaio de Fluorescência por Polarização/métodos , Linfonodos/microbiologia , México , Reação em Cadeia da Polimerase/veterinária , Vigilância da População/métodos , Sensibilidade e Especificidade , África do Sul , Tuberculose Bovina/microbiologiaRESUMO
Evaluation of Cyclosporin A (CyA) blood concentration is imperative in solid organ transplantation in order to achieve maximal immunosuppression with the least side effects. We compared the results of whole blood concentrations of CyA in 50 blood samples simultaneously evaluated by the fluorescent polarization immune assay (TDx) and the enzymatic competitive immune assay (EMIT 2000). There was a strong correlation between both kits for any range of CyA blood concentration (R=0.99, p<0.001). The within-run and between-days coefficient of variation were less than 4 percent for both assays. The cost for each CyA measurement was 50 percent lower for the EMIT assay when compared to the TDx assay. We concluded that the EMIT is as accurate as the TDx in measuring CyA blood concentration and has the advantage of a lower cost, as well as the possibility of widespread access to the EMIT methodology in contrast to the TDx equipment, allowing the laboratory to perform several routines within a working day
Assuntos
Humanos , Ciclosporina/sangue , Imunoensaio de Fluorescência por Polarização/métodos , Técnicas Imunoenzimáticas/métodos , Transplante de Rim , Custos e Análise de Custo , Terapia de ImunossupressãoRESUMO
Evaluation of Cyclosporin A (CyA) blood concentration is imperative in solid organ transplantation in order to achieve maximal immunosuppression with the least side effects. We compared the results of whole blood concentrations of CyA in 50 blood samples simultaneously evaluated by the fluorescent polarization immune assay (TDx) and the enzymatic competitive immune assay (EMIT 2000). There was a strong correlation between both kits for any range of CyA blood concentration (R=0.99, p<0.001). The within-run and between-days coefficient of variation were less than 4% for both assays. The cost for each CyA measurement was 50% lower for the EMIT assay when compared to the TDx assay. We concluded that the EMIT is as accurate as the TDx in measuring CyA blood concentration and has the advantage of a lower cost, as well as the possibility of widespread access to the EMIT methodology in contrast to the TDx equipment, allowing the laboratory to perform several routines within a working day.
Assuntos
Ciclosporina/sangue , Imunoensaio de Fluorescência por Polarização/métodos , Técnicas Imunoenzimáticas/métodos , Imunossupressores/sangue , Transplante de Rim , Custos e Análise de Custo , HumanosRESUMO
A homogeneous fluorescence-polarization assay (FPA) was used for the serological diagnosis of bovine brucellosis in México. The assay uses O-polysaccharide prepared from Brucella abortus lipoplysaccharide (20-30 kDa) conjugated with fluorescein isothiocyanate as a tracer. To measure the fluorescence polarization, a FPM-1 fluorescence-polarization analyzer was used with the procedure described by Nielsen et al. (1996b). A cut-off value of 90 millipolarization (mP) units was used for testing 560 bovine sera from different areas of México. (305 positive sera and 255 negative sera according to the complement fixation test; CFT.) Some were tested with the Rose Bengal plate (RB) test (n = 490) and some with the rivanol-agglutination (RIV) test (n = 190). Sensitivities were 98.3%, 99.3% and 99.0%, and specificities were 68.8%, 55.4% and 96.9%, respectively, for RB, RIV and FPA. The FPA gave a kappa coefficient of agreement with respect to CFT of 0.96, while RB and RIV (relative to the CFT) gave coefficients of 0.70 and 0.61, respectively. Finally, ROC analysis suggested a cut-off value which agreed with the one recommended in the test procedure. We concluded that FPA is a suitable test to be used instead of the CFT in Mexican conditions.