Background: Synergism between tuberculosis and HIV is responsible for the increased morbidity-mortality rate in AIDS patients. Objective: To delineate the profile of patients with tuberculosis and AIDS in the city of Rio Grande by relating demographic, clinical and laboratory data. Method: The sample comprised all cases of tuberculosis defined by identification of Mycobacterium tuberculosis that occurred in the AIDS Service of the University Hospital/FURG between September, 1997 and December, 2000, which added to a total of 31 patients confirmed as definite cases of AIDS. Using the Ogawa-Kudoh culture method and the Kinyoun bacilloscopy, 33 clinical pulmonary and extrapulmonary specimens were analyzed. Identification of M. tuberculosis was made by the usual phenotype methods. The method of proportions was chosen to establish resistance of isolated strains. Results: The mean age was of 33.8±9.9 years, with a man/woman ratio of 2.87:1 and 80.7% of Caucasians. All patients (n=31) exhibited overall or specific clinical manifestations of turberculosis at the time of suspicion diagnosis. In 20 of the cases risk factors were observed: use of injected drugs, alcoholism, malnutrition, imprisonment. Pulmonary disease occurred in 19 cases, extrapulmonary in 10 and the association of both in two. Lymph node commitment was more frequent among those with extrapulmonary disease. The isolated strains (33) were identified as M. tuberculosis and 28 were tested and showed sensibility to Isoniazid and Rifampin. Conclusion: In AIDS patients, tuberculosis appeared with various clinical manifestations, jeopardizing both men and women of less favored social conditions while at a fully productive stage of their lives.

Keywords: Tuberculosis/epidemiology. Tuberculosis/complications. Acquired immunodeficiency syndorme/tuberculosis. Mycobacterium tuberculosis/indicators of morbidity and mortality.

Background: Tuberculosis is an ancient disease, which still remains one of the major ills faced by mankind in the 21st century. In recent decades, new technologies employing the knowledge gained from molecular biology studies have allowed for more accurate detection of tuberculosis and increased investigation of the etiology and epidemiology of the disease. Aim: Evaluating the degree of similarity among strains of Mycobacterium tuberculosis provided by the Phthisiology Sector of Centro de Saúde Navegantes (Navegantes Health Clinic) in Porto Alegre, RS, Brazil. Method: A retrospective study was performed involving RFLP typing of 55 sputum samples from outpatients examined at the Centro de Saúde Navegantes. The results of the genotyping were correlated to the conventional epidemiology data. Results: A single pattern was seen in 39 (70.9%) of the isolates, whereas 16 isolates (29.1%) showed clustering patterns and were grouped into 8 clusters of 2 patients each. An epidemiological link was found for 6 (37.5%) of the 16 patients in the clusters. Conclusion: The appropriate combination of conventional epidemiology and genotyping of M. tuberculosis contributes to a better understanding of the dynamics of tuberculosis transmission even when such a study is performed in a single, isolated health clinic.

Keywords: Mycobacterium tuberculosis. Transmission. Polymorphism, Restriction Fragment Length. Epidemiology.

Background: Knowledge of the rates of drug resistance is one of the pillars of tuberculosis control program evaluation. Data from low-resource countries are scarce and results are delayed due to the techniques employed. There is therefore an urgent need for evaluation of faster and less onerous testing methods. Objective: To compare the performance of rapid colorimetric assays for phenotyping that employ oxidationreduction indicators to determine the susceptibility profile of Mycobacterium tuberculosis with the gold-standard proportion method on Lowenstein-Jensen Medium. Method: We analyzed 166 M. tuberculosis strains of known susceptibility. Minimal inhibition concentrations for isoniazid and rifampicin were determined in microplates, using a liquid medium and Alamar Blue and tetrazolium bromide indicators. To measure agreement the Kappa value was used. Cutoff values between sensitive and resistant strains were defined as 0.2µg/mL and 1.0µg/mL for isoniazid and rifampicin, respectively. Results: There was 100% concordance between Alamar Blue and tetrazolium bromide methods in the determination of minimal inhibition concentrations. Agreement between the colorimetric method and the Lowenstein-Jensen was 95% for isoniazid and rifampicin. Using the colorimetric method, results were obtained within 7 days, in contrast to the 28 days required for the conventional method. Conclusions: Assays to determine minimal inhibition concentrations in liquid medium and employing oxidationreduction indicators proved to be rapid and inexpensive. This method has the potential to become a faster, alternative method for determining susceptibility of M. tuberculosis strains in developing countries.

Keywords: Mycobacterium tubercolis. Disease susceptibility. Isoniazid/therapeutic use. Rifampin/therapeutic use.

Objective: To describe the prevalence of multidrug-resistant tuberculosis (MDR-TB) among tuberculosis patients in a major Brazilian city, evaluated via the Second National Survey on Antituberculosis Drug Resistance, as well as the social, demographic, and clinical characteristics of those patients. Methods: Clinical samples were collected from tuberculosis patients seen between 2006 to 2007 at three hospitals and five primary health care clinics participating in the survey in the city of Porto Alegre, Brazil. The samples were subjected to drug susceptibility testing. The species of mycobacteria was confirmed using biochemical methods. Results: Of the 299 patients included, 221 (73.9%) were men and 77 (27.3%) had a history of tuberculosis. The mean age was 36 years. Of the 252 patients who underwent HIV testing, 66 (26.2%) tested positive. The prevalence of MDR-TB in the sample as a whole was 4.7% (95% CI: 2.3-7.1), whereas it was 2.2% (95% CI: 0.3-4.2) among the new cases of tuberculosis and 12.0% (95% CI: 4.5-19.5) among the patients with a history of tuberculosis treatment. The multivariate analysis showed that a history of tuberculosis and a longer time to diagnosis were both associated with MDR-TB. Conclusions: If our results are corroborated by other studies conducted in Brazil, a history of tuberculosis treatment and a longer time to diagnosis could be used as predictors of MDR-TB.

Keywords: Tuberculosis/diagnosis; Drug resistance; HIV.