RESUMO
A OMS, em 2007, recomendou a implementação da cultura líquida para o diagnóstico da tuberculose (TB) e teste de sensibilidade para países de baixa e média renda. Neste estudo foi avaliado odesempenho da cultura líquida MGIT em condição de rotina após dois anos de implantação em uma rede de laboratórios públicos. Foi efetuada análise retrospectiva de dados da cultura líquida,realizadas em dez laboratórios regionais do Instituto Adolfo Lutz, de janeiro a março de 2010. Foram incluídas amostras submetidas a baciloscopia, cultura líquida MGIT automatizada ou manual eidentificação presuntiva do complexo Mycobacterium tuberculosis (CMTB). Foram detectadas 1.159 culturas positivas. Destas, 113 (9,7%) contaminaram, e 1.046 foram analisadas, sendo 850 (81,3%) CMTB, 116 (11,1%) micobactérias não tuberculosas e 6 (0,6%) Nocardia sp. A taxa de contaminação foi de 2,2% e o acréscimo da cultura para o diagnóstico da TB foi de 29,9%. A média do tempo de detecção da cultura foi de 14,7 dias (DP+/- 11,7 dias). A acurácia da identificação presuntiva foide 91,3%. A cultura líquida MGIT demonstrou ser excelente alternativa para efetuar diagnóstico da TB e das micobacterioses, em razão da rapidez possibilitando uma intervenção rápida e eficaz no tratamento.
In 2007, WHO recommended the implementation of liquid culture for tuberculosis (TB) diagnosis anddrug-susceptibility test in low and middle-income countries. This study evaluated the performanceof MGIT culture in routine condition after two years of its implementation in a public laboratoriesnetwork. This is a retrospective study, which analyzed the data on the liquid culture performed in ten regional laboratories of the Institute Adolfo Lutz, from January to March 2010. The data included clinical samples submitted to microscopy, automated or manual MGIT culture and presumptive M. tuberculosis complex (MTBC) identification by analyzing the cord formation. Culture waspositive in 1,159 samples. Of these, 113 (9.7%) contaminated, and 1,046 were analyzed, of which 850 (81.3%) were identified as MTBC, 116 (11.1%) as non-tuberculous mycobacteria and 6 (0.6%)as Nocardia sp. Contamination rate was 2.2% and the contribution of culture to the TB diagnosis was 29.9%. The detection mean time was 14.7 days (SD+/-11.7 days). The accuracy of the presumptive identification of MTBC was 91.3%. MGIT liquid culture demonstrated to be an excellent alternative for diagnosing TB and mycobacterioses, because of the rapidity of diagnosis, thus allowing an immediate and effective treatment.
Assuntos
Humanos , Fatores Corda , Mycobacterium tuberculosis , Serviços Laboratoriais de Saúde Pública , TuberculoseRESUMO
A OMS, em 2007, recomendou a implementação da cultura líquida para o diagnóstico da tuberculose (TB) e teste de sensibilidade para países de baixa e média renda. Neste estudo foi avaliado o desempenho da cultura líquida MGIT em condição de rotina após dois anosde implantação em uma rede de laboratórios públicos. Foi efetuada análise retrospectiva de dados da cultura líquida, realizadas em dez laboratórios regionais do Instituto Adolfo Lutz, de janeiro a março de 2010. Foram incluídas amostras submetidas a baciloscopia, cultura líquida MGIT automatizada ou manual e identificação presuntiva do complexo Mycobacterium tuberculosis (CMTB). Foram detectadas 1.159 culturas positivas. Destas, 113 (9,7%) contaminaram, e 1.046 foram analisadas, sendo 850 (81,3%) CMTB, 116 (11,1%) micobactérias não tuberculosas e 6 (0,6%) Nocardia sp A taxa de contaminação foi de 2,2% e o acréscimo da cultura para o diagnóstico da TB foi de 29,9%. A média do tempo de detecção da cultura foi de 14,7 dias (DP+/- 11,7 dias). A acurácia da identificação presuntiva foi de 91,3%. A cultura líquida MGIT demonstrou ser excelente alternativa para efetuar diagnóstico da TB e das micobacterioses, em razão da rapidez possibilitando uma intervenção rápida e eficaz no tratamento.
In 2007, WHO recommended the implementation of liquid culture for tuberculosis (TB) diagnosis and drug-susceptibility test in low and middle-income countries. This study evaluated the performance of MGIT culture in routine condition after two years of its implementation in a public laboratories network.This is a retrospective study, which analyzed the data on the liquid culture performed in ten regional laboratories of the Institute Adolfo Lutz, from January to March 2010. The data included clinical samples submitted to microscopy, automated or manual MGIT culture and presumptive M. tuberculosis complex (MTBC) identification by analyzing the cord formation. Culture was positive in 1,159 samples. Of these, 113 (9.7%) contaminated, and 1,046 were analyzed, of which 850 (81.3%) were identified as MTBC, 116 (11.1%) as non-tuberculous mycobacteria and 6 (0.6%) as Nocardia sp. Contamination rate was 2.2% and the contribution of culture to the TB diagnosis was 29.9%. The detection mean time was 14.7 days (SD+/-11.7 days). The accuracy of the presumptive identification of MTBC was 91.3%. MGIT liquid culture demonstrated to be an excellent alternative for diagnosing TB and mycobacterioses, because of the rapidity of diagnosis, thus allowing an immediate and effective treatment.
Assuntos
Cultura de Vírus , Fatores Corda , Mycobacterium tuberculosis , Tuberculose/diagnóstico , Técnicas de Laboratório Clínico/métodosRESUMO
A OMS, em 2007, recomendou a implementação da cultura líquida para o diagnóstico da tuberculose (TB) e teste de sensibilidade para países de baixa e média renda. Neste estudo foi avaliado o desempenho da cultura líquida MGIT em condição de rotina após dois anosde implantação em uma rede de laboratórios públicos. Foi efetuada análise retrospectiva de dados da cultura líquida, realizadas em dez laboratórios regionais do Instituto Adolfo Lutz, de janeiro a março de 2010. Foram incluídas amostras submetidas a baciloscopia, cultura líquida MGIT automatizada ou manual e identificação presuntiva do complexo Mycobacterium tuberculosis (CMTB). Foram detectadas 1.159 culturas positivas. Destas, 113 (9,7%) contaminaram, e 1.046 foram analisadas, sendo 850 (81,3%) CMTB, 116 (11,1%) micobactérias não tuberculosas e 6 (0,6%) Nocardia sp A taxa de contaminação foi de 2,2% e o acréscimo da cultura para o diagnóstico da TB foi de 29,9%. A média do tempo de detecção da cultura foi de 14,7 dias (DP+/- 11,7 dias). A acurácia da identificação presuntiva foi de 91,3%. A cultura líquida MGIT demonstrou ser excelente alternativa para efetuar diagnóstico da TB e das micobacterioses, em razão da rapidez possibilitando uma intervenção rápida e eficaz no tratamento.(AU)
In 2007, WHO recommended the implementation of liquid culture for tuberculosis (TB) diagnosis and drug-susceptibility test in low and middle-income countries. This study evaluated the performance of MGIT culture in routine condition after two years of its implementation in a public laboratories network.This is a retrospective study, which analyzed the data on the liquid culture performed in ten regional laboratories of the Institute Adolfo Lutz, from January to March 2010. The data included clinical samples submitted to microscopy, automated or manual MGIT culture and presumptive M. tuberculosis complex (MTBC) identification by analyzing the cord formation. Culture was positive in 1,159 samples. Of these, 113 (9.7%) contaminated, and 1,046 were analyzed, of which 850 (81.3%) were identified as MTBC, 116 (11.1%) as non-tuberculous mycobacteria and 6 (0.6%) as Nocardia sp. Contamination rate was 2.2% and the contribution of culture to the TB diagnosis was 29.9%. The detection mean time was 14.7 days (SD+/-11.7 days). The accuracy of the presumptive identification of MTBC was 91.3%. MGIT liquid culture demonstrated to be an excellent alternative for diagnosing TB and mycobacterioses, because of the rapidity of diagnosis, thus allowing an immediate and effective treatment.(AU)
Assuntos
Tuberculose/diagnóstico , Mycobacterium tuberculosis , Cultura de Vírus , Fatores Corda , Técnicas de Laboratório Clínico/métodosRESUMO
INTRODUCTION: World Health Organization had estimated 9.4 million tuberculosis cases on 2009, with 1.7 million of deaths as consequence of treatment and diagnosis failures. Improving diagnostic methods for the rapid and timely detection of tuberculosis patients is critical to control the disease. The aim of this study was evaluating the accuracy of the cord factor detection on the solid medium Middlebrook 7H11 thin layer agar compared to the Lowenstein Jensen medium for the rapid tuberculosis diagnosis. METHODS: Patients with suspected tuberculosis were enrolled and their sputum samples were processed for direct smear and culture on Lowenstein Jensen and BACTEC MGIT 960, from which positive tubes were subcultured on Middlebrook 7H11 thin layer agar. Statistical analysis was performed comparing culture results from Lowenstein Jensen and the thin layer agar, and their corresponding average times for detecting Mycobacterium tuberculosis. The performance of cord factor detection was evaluated determining its sensitivity, specificity, positive and negative predictive value. RESULTS: 111 out of 260 patients were positive for M. tuberculosis by Lowenstein Jensen medium with an average time ± standard deviation for its detection of 22.3 ± 8.5 days. 115 patients were positive by the MGIT system identifying the cord factor by the Middlebrook 7H11 thin layer agar which average time ± standard deviation was 5.5 ± 2.6 days. CONCLUSION: The cord factor detection by Middlebrook 7H11 thin layer agar allows early and accurate tuberculosis diagnosis during an average time of 5 days, making this rapid diagnosis particularly important in patients with negative sputum smear.