ABSTRACT
Introdução: o Teste Cutâneo Tuberculínico (TCT) tem sido utilizado como diagnóstico para a Tuberculose Infecção Latente (TBIL). Os profissionais de saúde, principalmente os que trabalham com assistência a pacientes com tuberculose (TB), têm risco elevado de contrair a doença ou a TBIL. Normas de biossegurança e qualificação da equipe de trabalho são fundamentais para o controle da Tb entre os profissionais de saúde. Atualmente testes diagnósticos mais específicos para a TBIL têm sido utilizados como alternativa para o padronizado TCT, dentre eles o QuantiFERON-TB Gold (QTF®). Objetivo: comparar e avaliar os resultados obtidos no QTF® e Teste Cutâneo Tuberculínico dos profissionais de saúde de um centro de referência terciário para Tuberculose. Metodologia: o projeto foi aprovado pelo Comitê de Ética em Pesquisa da Fundação Bahiana Desenvolvimento Científico e pelo Comitê de Ética em Pesquisa da instituição hospitalar. Foi utilizado o banco de dados do setor de medicina ocupacional da Instituição e os 87 voluntários que atenderam aos critérios do estudo foram categorizados e distribuídos em dois grupos: TCT negativo (<5mm) e TCT positivo (>5mm). Foi realizada coleta de sangue para o teste QTF®. Resultados: dos 47 profissionais de saúde TCT negativo 53,2% tiveram resultado QTF negativo. Dos 40 profissionais TCT positivo, 67,5% apresentaram resultado QTF® positivo. O grau de concordância do índice kappa foi de 0,24. Conclusão: O QTF® não mostrou uma especificidade superior quando comparado ao TCT.
Introduction: tuberculin Skin test (TST) is a test used to Latent tuberculosis Infection (LTBI) diagnosis. Health professional, principally those that work with tuberculosis (TB) patients, have a high risk of contract and developing the disease or LTBI. Biosecurity norms and professional qualification are fundamentals to TB control in care centers. Actually some diagnosis tests with higher specificity of LTBI are used as an alternative to the TST, such as QuantiFERON-TB Gold (QTF®). Objective: to compare and evaluate the results obtained in the Quantiferon-TB Gold® and TST, of health professionals from a tertiary referral center for Tuberculosis. Methodology: the project was approved by a Research Ethics Committee of FBDC, and by the CEP of the hospital institution. The data base of the occupational medicine sector and the health professionals were categorized and distributed in two groups: Negative Tuberculin test and Positive Tuberculin test. The 93 volunteers who met the criteria and agreed to participate, signed the consent form, with subsequent data collection. A blood collection was also performed to perform Quantiferon-TB Gold® test. Results: of the 47 PS negative Tuberculin test, 53.2% had negative Quantiferon-TB Gold® results and 46.8% positive. Of the health professional positive Tuberculin test, 32.5% presented negative Quantiferon-TB Gold® result and 67.5% positive. Conclusion: quantiferon-TB Gold® did not show superior specificity when compared to Tuberculin test on this coorte.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Tuberculin Test , Interferon-gamma , Health Personnel , Latent Tuberculosis , Cross-Sectional Studies , Retrospective Studies , Observational StudyABSTRACT
ABSTRACT Introduction Latent tuberculosis infection diagnosis based on the release of interferon-gamma in cultures of peripheral blood cells stimulated with Mycobacterium tuberculosis antigens has replaced the tuberculin skin test in many countries with low tuberculosis prevalence. The IFN-γ production can be influenced by genetic polymorphisms, of which the IFNG + 874 (rs62559044) locus is the most studied. We investigated the possible influence of the IFNG + 874 A/T polymorphism on interferon-gamma test performance. Methods Patients diagnosed with pulmonary tuberculosis (75), volunteers with positive tuberculin skin test (70) and healthy volunteers with negative tuberculin skin test and no history of contact with tuberculosis (57) were evaluated regarding the IFNG + 874 genotype and the IFN-γ levels in whole blood cultures performed using an interferon-gamma commercial kit (QuantiFERON-TB® Gold In-Tube). Results IFN-γ production was not influenced by the IFNG + 874 genotype, regardless of antigen or mitogen-based stimulation, which suggests that other genes may influence IFN-γ production in response to mycobacteria. The IFNG + 874 polymorphism was found to exert no influence over QFT-IT test sensitivity in our study. Conclusions The IFNG + 874 polymorphism was not shown to influence QuantiFERON-TB® Gold In-Tube test performance in an admixed population from northeastern Brazil.
Subject(s)
Humans , Male , Female , Polymorphism, Genetic/genetics , Tuberculosis, Pulmonary/diagnosis , Interferon-gamma/genetics , Interferon-gamma Release Tests/methods , Mycobacterium tuberculosis/genetics , Brazil , Tuberculin Test , Case-Control Studies , Reproducibility of Results , Sensitivity and Specificity , Interferon-gamma/metabolism , Statistics, Nonparametric , Genotyping Techniques , Gene Frequency , GenotypeABSTRACT
ABSTRACT Objective: To evaluate the impact of the use of the molecular test for Mycobacterium tuberculosis and its resistance to rifampin (Xpert MTB/RIF), under routine conditions, at a referral hospital in the Brazilian state of Bahia. Methods: This was a descriptive study using the database of the Mycobacteriology Laboratory of the Octávio Mangabeira Specialized Hospital, in the city of Salvador, and georeferencing software. We evaluated 3,877 sputum samples collected from symptomatic respiratory patients, under routine conditions, between June of 2014 and March of 2015. All of the samples were submitted to sputum smear microscopy and the Xpert MTB/RIF test. Patients were stratified by gender, age, and geolocation. Results: Among the 3,877 sputum samples evaluated, the Xpert MTB/RIF test detected M. tuberculosis in 678 (17.5%), of which 60 (8.8%) showed resistance to rifampin. The Xpert MTB/RIF test detected M. tuberculosis in 254 patients who tested negative for sputum smear microscopy, thus increasing the diagnostic power by 59.9%. Conclusions: The use of the Xpert MTB/RIF test, under routine conditions, significantly increased the detection of cases of tuberculosis among sputum smear-negative patients.
RESUMO Objetivo: Avaliar o impacto do teste rápido molecular automatizado Xpert MTB/RIF, utilizado para a detecção de Mycobacterium tuberculosis e sua resistência à rifampicina, em condições de rotina, em um hospital de referência no estado da Bahia. Métodos: Estudo descritivo retrospectivo utilizando o banco de dados do Laboratório de Micobacteriologia do Hospital Especializado Octávio Mangabeira, localizado na cidade de Salvador, e um programa de georreferenciamento. Entre junho de 2014 e março de 2015, foram incluídas no estudo 3.877 amostras de escarro coletadas de pacientes sintomáticos respiratórios em condições de rotina. Todas as amostras coletadas foram submetidas tanto à baciloscopia quanto a Xpert MTB/RIF. Os pacientes foram estratificados por sexo, idade e georreferenciamento. Resultados: Das 3.877 amostras de escarro analisadas, Xpert MTB/RIF detectou a presença de M. tuberculosis em 678 pacientes (17,5%). Desses, 60 (8,8%) apresentaram resistência à rifampicina. O Xpert MTB/RIF detectou 254 pacientes com baciloscopia negativa, representando um acréscimo diagnóstico de 59,9%. Conclusões: A implantação do Xpert MTB/RIF, sob condições de rotina, teve um impacto significativo no aumento da detecção de casos de tuberculose em pacientes com baciloscopia negativa.