Avaliação comparativa da metodologia automatizada BACTEC MGIT 960 e a manual com o meio de cultura sólido Lowenstein-Jensen para o diagnóstico da tuberculose em amostras clínicas

Abstract

Tuberculosis (TB) and an infectious disease caused by Mycobacterium tuberculosis that afflicted mankind since antiquity with reports of up to about 5,000 BC Despite the high efficiency of treatment, TB remains a major health problem. In 2011, an estimated 8.7 million incident cases of TB worldwide. Among the main measures for tuberculosis control are early diagnosis and proper treatment of the disease. Thus, the active search should be performed continuously for all healthcare services (primary, secondary and tertiary). The study aimed to evaluate the benefits of automated methodology for the diagnosis of tuberculosis in different clinical specimens in relation to the methodology manual. This is a descriptive study and experimental evaluation of two diagnostic tests (manual and automated) for which several samples were analyzed. The survey was conducted from July to September 2011. The samples were provided by patients of 15 health units of the State, which needed to confirm or culture tuberculosis control. In the 1520 samples, smear, 188 (12.37%) samples were positive and 1,332 (87.63%) negative. In cultures on solid media (LJ), a manual methodology, 254 (16.71%) samples were positive, 1.156 (76.05%) and 110 negative (7.24%) were contaminated. In automated methodology (MGIT), the result was 258 (16.97%) positive, 1,149 (75.59%) and 113 negative contaminated (7.43%). The median time to positivity in the manual method was 31.95 days, with a mean deviation of 15.01 and automated methodology was 16.53 days, with a standard deviation of 12.39. It was possible to demonstrate concordance between the methods and various advantages that automated methodology presents compared to manual in the laboratory routine. Among them is the decreased time to detection of the disease, representing a breakthrough in the initial treatment of patients, which, in the case of TB, may mean to decrease the number of cases, since people no longer be bacillary patients.