Objectives: To evaluate clinical, laboratorial, epidemiological, and therapeutic aspects of patients presenting with multiresistant tuberculosis (MRTB). Patients and methods: From January 1993 to December 1994, a prospective, non-randomized study of patients presenting MRTB, characterized by failures under treatment schemes E-1 and E-3 according to the classification of the Brazilian Ministry of Health, and resistance to isoniazid and rifampicin was carried out. Clinical and laboratorial aspects were considered: age, gender, ethnical group, duration of condition, cavity occurrences in conventional X-rays, resistance to drugs by the indirect method according to Canetti's et al. proportional criteria; epidemiological aspects such as risk predictor factors for multiresistance and treatment results. This study consisted in two alternative chemotherapy courses combining an aminoglycoside, amikacin (Group A), or S, if sensitive (Group B), ofloxacin, clofazimine, in addition to other drugs, such as thiacetazone, ethambutol, or pyrazinamide, according to the sensitivity or to the prior limited use for a minimum of twelve months. Patients with unilateral radiologic lesions, functional possibilities, and who have accepted the indication were submitted to surgery (Group C). Treatment was at the outpatient clinic, self-administered, or under indirect supervision, with hospital admission allowed for clinical reasons, for a limited time, or when surgery was indicated. Patients with prior alternative treatment, those infected with HIV, pregnant patients, and those with renal failure were excluded from the study. Evaluation extended to twelve months after completion of treatment. Results: 70 patients with mean age of 37 years, 42 male, 44 caucasian, and 26 non-caucasian (two orientals), average duration of the condition of four years, and bilateral cavitary lesions in 55 (78.6%). Resistance to two drugs in 28.6%, 51.4% to three drugs, and 20% to four drugs. The most frequent risk predictor factor for MRTB was abandonment (54.3%) followed by recurrence after cure with treatment scheme E1 and failure at retreatment (14.3%), intolerance to drugs (11.4%), contact with MRTB (8.6%). The risk predictor factor could not be determined in 11%, acquired multiresistance being considered in 80%, and primary multiresistance in only 8.6% of the patients. Cure was observed in 25 patients of Group A (n = 39), 11 patients of Group B (n = 24), and 3 of Group C (n = 7). Only two discontinued treatment (A) and only two died during treatment (C). In the control period, three patients had recurrences (1 in A, and 2 in B), and 7 died (3 in A, 2 in B, and 2 in C). The effectiveness of Group A was 67.6% (25/37) at completion of treatment, and 64.9% during the post-treatment control. The effectiveness of Group B was 45.8% (11/24) at completion of treatment, and 37.5% during the post-treatment control. The effectiveness of Group C was 42.8% (3/7) at completion of treatment and during the post-treatment control. After twelve months, effectiveness at treatment completion in Group A fell from 64.1% to 61.5%, in Group B, it fell from 45.8% to 37.5%, and it remained unchanged in 42.8% in Group C, where the four cases of failure died. Drug discontinuation due to adverse effects occurred late in two cases, and other adverse effects were noted, but did not foster discontinuation of treatment.

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

Keywords: Mycobacterium tuberculosis. Diagnostic. Automated systems.

Background: The appearance of tuberculosis/human immunodeficiency virus co-infection and the growing number of diseases caused by nontuberculous mycobacteria, as well as the confusion that these can cause in relation to emerging multidrug-resistant strains, require more accurate and rapid laboratory results, not only in the isolation of strains but also in their identification. Objective: A comparative study evaluating a new tool of molecular identification, which uses a genetic probe based on the 16S rDNA sequence of the Mycobacterium tuberculosis gene (Gen-Probe Accuprobe® Gen Probe, Inc.), and the classic methodology. Method: Fifty-five Mycobacterium strains, isolated from the sputum of patients treated at a tuberculosis reference clinic, were selected for study. Subcultures were performed in three tubes: one submitted to genetic identification, one analyzed through classical tests (production and accumulation of niacin; growth in the Lowenstein-Jensen medium with the inhibitor agents p-nitrobenzoic acid and thiophene-2-carboxylic acid hydrazide added), and one held in reserve. Results: The probe identified 51 cases as belonging to the M. tuberculosis complex (one associated with M. kansasii) and the other 4 as nontuberculous mycobacteria, later identified as M. kansasii (3) and M. avium (1). Using traditional methods, 47 samples were identified as belonging to the M. tuberculosis complex, 4 were classified as fitting the profile of nontuberculous mycobacteria (in agreement with the genetic probe results), and 4 were unidentified, 1 of which presented the exact characteristics that 2 mycobacterium species have in common. Conclusion: The benefits of the molecular biology technique justify its implementation and routine use, in combination with classical methods, in a high-traffic clinic where complex cases of tuberculosis are treated.

Keywords: Mycobacterium tuberculosis. Molecular probe techniques.