Rendimento da cultura de escarro na comparação de um sistema de diagnóstico automatizado com o meio de Lowenstein-Jensen para o diagnóstico da tuberculose pulmonar

Abstract

Background: Tuberculosis continues to be a global health problem.Objective: To evaluate an automated system designed to diagnose tuberculosis, comparing it to sputum microscopy and culture in Löwenstein-Jensen medium.Method: A comparative study using 844 sputum samples, collected between September and December of 1999 at a reference center for tuberculosis in São Paulo, Brazil, to draw distinctions between the results obtained through the use of the automated system and those obtained through sputum microscopy and culture in Löwenstein-Jensen medium.Results: Of the 844 samples evaluated, 27.1% tested positive for acid-fast bacilli, and 72.9% tested negative. In Löwenstein-Jensen culture, 34.7% were positive and 63% were negative, compared with 37.1% positivity and 56.9% negativity using the automated system. Sensitivity was 98.1% for the automated system and 91.9% for Löwenstein-Jensen culture. Specificity and positive predictive value were 100% for both methods. Negative predictive value was 98.9% for the automated system and 95.5% for Löwenstein-Jensen culture. The degree of accuracy was 99.3% for the automated system and 97% for Löwenstein-Jensen culture, and the Kappa was 0.99 for the automated system and 0.94 for Löwenstein-Jensen culture. The difference between the mean time to detection of mycobacteria using the automated system (10.5 days) and that found using Löwenstein-Jensen culture (34.7 days) was statistically significant. Conclusion:The difference between the culture yield obtained using the automated system and that achieved with Löwenstein-Jensen culture was statistically significant. Mean time to detection of mycobacteria was significantly shorter with the automated system. The higher yield provided by this new system justifies its use in a reference center for tuberculosis in São Paulo Original Article 232Almeida, EA, et al.

Análise do Programa de Controle da Tuberculose em Cáceres, Mato Grosso, antes e depois da implantação do Programa de Saúde da Família

“…(15) Despite presenting limitations, sputum smear microscopy has a good diagnostic yield in the diagnosis of TB due to its ease of application, and due to its being a simple, reliable, and low cost laboratory procedure available in the network of public health care facilities. (16,17) If sputum smear microscopy was not given sufficient importance at the time of diagnosis, a worse situation was observed at the end of the treatment, when, prior to discharge, less than 30% of the patients treated via the PSF were submitted to the test, as recommended. These results suggest that local public health care facilities should re-evaluate their strategies for monitoring TB patients during the treatment period as well as prior to discharge after proven cure.…”

Detecção de bactérias do complexo Mycobacterium tuberculosis em saliva/muco ou escarro em Centro de Referencia Ambulatorial para Tuberculose da Cidade de São Paulo: baciloscopia, cultura convencional e automatizada.

“…(BENNEDSEN et al, 1996). Com a necessidade de obter isolados para os dados epidemiológicos, estudo da sensibilidade aos antimicobacterianos e outros procedimentos que necessitam da célula bacteriana viável, além dos métodos convencionais de cultivo e isolamento aplicaram-se métodos automatizados para atender a demanda e a urgência dos resultados laboratoriais (KRITSKI et al, 2000, ALMEIDA et al, 2005 Os métodos de diagnóstico molecular apresentam ainda imperfeições principalmente no que se refere na precisão de resultados de acordo com Sarmiento, 2003. Apresentam elevada sensibilidade (95%) e especificidade (98%) em amostras com baciloscopia positiva, sendo o seu rendimento inferior em amostras com baciloscopia negativa (SARMIENTO et al, 2003).…”