Objective: To describe the outcomes of retreatment in tuberculosis patients receiving the regimen known, in Brazil, as regimen 3 (streptomycin, ethambutol, ethionamide, and pyrazinamide for 3 months + ethambutol and ethionamide for 9 months) after treatment failure with the basic regimen (rifampin, isoniazid, and pyrazinamide for 2 months + rifampin and isoniazid for 4 months). Methods: A descriptive, uncontrolled, historical cohort study involving adult tuberculosis patients treated with regimen 3. We evaluated adverse drug effects, recurrence, treatment outcomes, and associated factors. Results: The study included 229 patients. The overall cure rate was 62%. For the patients who used the medications regularly and those who did not, the cure rate was 88% and 31%, respectively. Adverse events occurred in 95 patients (41.5%), and most of those events were related to the gastrointestinal tract. In the five-year follow-up period, relapse occurred in 17 cases (12.0%). Conclusions: Overall, the outcomes of treatment with regimen 3 were unsatisfactory, in part because this regimen was administered to a selected population of patients at high risk for noncompliance with treatment, as well as because it presents high rates of adverse effects, especially those related to the gastrointestinal tract, which might be caused by ethionamide. However, for those who took the medications regularly, the cure rate was satisfactory. The recurrence rate was higher than that recommended in international consensus guidelines, which might be attributable to the short (12-month) treatment period. We believe that regimen 3, extended to 18 months, represents an option for patients with proven treatment compliance.

Keywords: Tuberculosis, pulmonary/therapy; Treatment outcome; Retreatment.

Objective: To compare clinical, radiological, and laboratory characteristics of individuals with pulmonary tuberculosis co-infected or not with HIV. Methods: A cross-sectional study, in which signs and symptoms were assessed by anamnesis and physical examination in patients hospitalized with pulmonary tuberculosis. The results of sputum smear microscopy and culture for Mycobacterium tuberculosis, as well as hemoglobin levels and CD4+ T-cell counts, were obtained from medical records, and chest X-ray reports were consulted. Results: We included 50 pulmonary tuberculosis patients, who were divided into two groups (HIV-positive and HIV-negative; n = 25 per group). The mean age of the participants was 38.4 ± 10.5 years; 46 (92%) were males; and 27 (54%) were White. Expectoration was presented by 21 (84%) and 13 (52%) of the patients in the HIV-negative and HIV-positive groups, respectively (p = 0.016). Radiological findings of cavitation were present in 10 (43%) and 2 (10%) of the patients in the HIV-negative and HIV-positive groups, respectively (p = 0.016), whereas an interstitial pattern was observed in 18 (78%) and 8 (40%), respectively (p = 0.012). The mean hemoglobin level was 11.1 ± 2.9 g/dL and 9.3 ± 2.2 g/dL in the HIV-negative and HIV-positive groups, respectively (p = 0.015). Conclusions: In our sample of tuberculosis patients, expectoration was less prevalent, hemoglobin levels were lower, and cavitation was less common, as was an interstitial pattern, among those co-infected with HIV than among those without HIV co-infection.

Keywords: HIV; Tuberculosis; Acquired immunodeficiency syndrome.

Objective: To compare inpatient and outpatient treatment of tuberculosis, in terms of outcomes, in the city of São Paulo, Brazil, as well to determine which variables are most frequently associated with hospitalization. Methods: A prospective, longitudinal study carried out between January and December of 2007, at two large hospitals and at outpatient clinics, in two regions of the city of São Paulo. For inpatients, data were collected with a structured questionnaire. Additional data were obtained from the São Paulo State Department of Health Tuberculosis Database. Results: Of the 474 patients included in the study, 166 were inpatients, and 308 were outpatients. The multivariate analysis showed that hospitalization for tuberculosis was associated with hospital/emergency room diagnosis of tuberculosis (OR = 55.42), with HIV co-infection (OR = 18.57), with retreatment (OR = 18.51), and with having previously sought treatment at another health care facility (OR = 12.32). For the inpatient and outpatient groups, the overall cure rates were 41.6% and 78.3%, respectively, compared with 30.4% and 58.5% for those who were co-infected with HIV, whereas the overall mortality rates were 29.5% and 2.6%, respectively, compared with 45.7% and 9.8% for those who were co-infected with HIV. Conclusions: Among inpatients, tuberculosis appears to be more severe and more difficult to diagnose, resulting in lower cure rates and higher mortality rates, than among outpatients. In addition, tuberculosis patients co-infected with HIV have less favorable outcomes.

Keywords: Tuberculosis; Hospitalization; Primary health care; Treatment outcome.

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.

Objective: To evaluate the effect that the distribution of food baskets to tuberculosis (TB) patients has on treatment outcomes at a primary health care clinic. Methods: Retrospective comparative study of the medical and social aspects of 142 patients at a primary health care clinic in the city of Duque de Caxias, Brazil. The patients were divided into two groups: the first group included 68 patients treated with standard regimens (between September of 2001 and December of 2003); and the second group included 74 patients treated with the same regimens but also receiving food baskets on a monthly basis (between January of 2004 and July of 2006). Results: The statistical comparison between the two groups revealed that the cure rate was higher in the group receiving the food baskets (87.1% vs. 69.7%), whereas the rate of noncompliance was markedly lower (12.9% vs. 30.3%). Conclusions: The results indicate that the distribution of food baskets can be a useful strategy to improve compliance with TB treatment at primary health care clinics.

Keywords: Tuberculosis; Nutritional support; Treatment outcome; Ambulatory health services.

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.

Objective: The aim of this study was to determine the prevalence of macrolide-resistant S. pneumoniae and to identify its phenotypic and genotypic characteristics. Methods: Strains of S. pneumoniae isolated in the city of Porto Alegre between May 2002 and August 2004 from samples collected from different anatomical sites were analyzed. For the agar diffusion test, disks of erythromycin, clarithromycin, azithromycin and clindamycin were used. The minimum inhibitory concentrations of erythromycin were determined for macrolide-resistant isolates by the agar dilution method. Macrolide-resistant isolates were phenotyped by agar diffusion test and genotyped by polymerase chain reaction. Results: A total of 229 pneumococcal strains were evaluated, 12 (5.2%) of which were macrolide-resistant. Among the 12 resistant strains, 9 (75%) presented the MLSB phenotype, and 3 (25%) presented the M phenotype. Polymerase chain reaction testing indicated that 8 MLSB phenotype isolates harbored the ermB gene only, whereas the mefE gene was present in all 3 M phenotype isolates. One MLSB phenotype isolate presented both genes. Conclusion: In Porto Alegre, the S. pneumoniae resistance to macrolides is still low since such resistance is due primarily to the presence of the ermB gene expressing the MLSB phenotype.

Objectives: The purpose of this study is to establish the prevalence of pulmonary thromboembolism (PTE) in autopsies and its rate of antemortem suspicion at Hospital de Clínicas de Porto Alegre (HCPA). Design: Cohort study with historical data. Setting: School hospital with 728 beds. Patients and methods: The adult autopsy reports were studied from 1985 to 1995 as well as the records of patients whose autopsies diagnosed PTE. Antemortem suspicion of PTE was considered from explicit notes on patients records, from requests of lung scan, or from full anticoagulation. Results: In the period mentioned, 9,607 deaths occurred, and 767 (7.98%) autopsies were performed. Significant PTE (> 1 pulmonary subsegment) in 30 (3.9%) patients. In 3 (10%) patients, PTE was considered the effective cause of death. Clinic suspicion was present in 5 (16.6%) patients; in 25 (83.4%) patients, there were only postmortem findings. Conclusion: PTE rates in autopsies were similar to those found in international literature. The rates of clinical suspicion were half of the ones mentioned in school hospitals in the United States and Europe. PTE was subsuspected in life in patients hospitalized at HCPA.

Keywords: Venous thromboembolism. Deep venous thrombosis. Pulmonary artery. Pulmonary infarction.

Background: Tuberculosis cure is dependent upon treatment adherence. Objective: To analyze the results of tuberculosis treatment in public health clinics in the city of Campinas, in the state of São Paulo, Brazil, during 2002. Method: From a cohort of 484 patients diagnosed with tuberculosis, we evaluated 436. Treatment outcomes were described for all patients, whether new patients or patients in retreatment, including those presenting the pulmonary form, with or without acquired immunodeficiency syndrome (AIDS) comorbidity. Results: The success rate was 68.6% (72.3% among non-AIDS patients and 57.6% among AIDS patients). Among new cases, the non-AIDS group presented a 2.2-times greater chance of presenting favorable results. In the AIDS group, no differences were observed between new patients and those in retreatment. Among the unfavorable outcomes, only lethality presented a difference (18.9% among AIDS patients and 8.0% among non-AIDS patients). In patients presenting the pulmonary form, the success rate was similar between those who were initially acid-fast bacilli positive and those who were not. Conclusion: The tuberculosis control program in Campinas presented low effectiveness. In comparison to the 2001 national cohort, success rates were higher for non-AIDS patients but lower for AIDS patients. The higher success rate among cases of tuberculosis without AIDS was primarily derived from the treatment of new cases. The unfavorable profile of tuberculosis patients co-infected with AIDS, characterized by the (18.9%) lethality and the (15.3%) noncompliance, were partially responsible for the lower success rate seen among such patients. It is notable that such high proportions of noncompliant patients were seen in a city providing easy access to treatment. In order to improve the program, medical teams should receive further training in supervised treatment, health education and techniques for interacting with patients, all of which will require considerable investment.

Keywords: Key words: Tuberculosis. Treatment Refusal. Retreatment. Acquired Immunodeficiency Syndrome. Comorbidity

Background: In recent decades, the prevalence of asthma has increased. Objectives: To determine the prevalence of asthma symptoms in children and adolescents from 2 to 14 years of age living in Porto Alegre (in the state of Rio Grande do Sul, Brazil) and to determine any potential correlations with socioeconomic profile, treatment and smoking in the home. Methods: A transversal study based on interviews of all families seeking medical attention in June of 2000. Results: The prevalence of asthma symptoms was 49.5%. In 66.8% of families, total income was less than four times the minimum wage, and in more than 50% of homes, the parents had had less than five years of schooling. In 98.5%, prophylactic asthma treatment was not used. In the 174 families studied, 38.7% of mothers and 43.7% of fathers were smokers (32.7% overall). Correlations were found between the following variables: exposure to smoking in the home and number of asthma attacks in the last year (p = 0.02; RR = 2.9; CI: 1.1 - 4.5); maternal level of education and number of attacks in the last year (p = 0.03; RR = 2.03; CI: 1.01 - 4.19); close living quarters and number of attacks in the last year among children exposed to second-hand smoke (p = 0.04; RR = 2.7; CI: 1.4 - 5.1); hospitalization and number of attacks in the last year (p = 0.004; RR = 1.46; CI: 1.15 -1.86); hospitalization and close living quarters (p = 0.03; RR = 1.47; CI: 1.15 -1.86). In children below the age of five, there was correlation between maternal smoking and number of attacks in the last year (p = 0.03; RR = 1.79; CI: 1.04 - 3.08). Conclusion: The prevalence of asthma symptoms was high. The community studied has limited socioeconomic resources, and there is therefore a lack of adequate treatment for asthma. Our results demonstrate the need for prioritized, standardized treatment programs that would give healthcare workers access to the appropriate materials and means of evaluation necessary for asthma control.

Keywords: Key words: Asthma. Prevalence. Smoking in the home. Treatment between episodes of asthma.

Objective: To estimate the prevalence of human immunodeficiency virus seropositivity among patients with active tuberculosis residing in the city of Londrina, in the state of Paraná, Brazil and treated at the Pulmonology Clinic of the 17th Regional Health Facility of the State of Paraná, and to compare those coinfected with human immunodeficiency virus to those with active tuberculosis only in terms of the clinical form of tuberculosis, sputum smear microscopy, chest X-ray and tuberculosis treatment regimen. Methods: A transversal study involving 188 active tuberculosis patients was conducted. Tuberculosis and human immunodeficiency virus infection were diagnosed based on criteria established by the Brazilian Ministry of Health. In addition to the data obtained through individual tuberculosis investigation files, clinical and epidemiological information were collected by means of questionnaires, which were completed by all participating patients. Results: The prevalence of human immunodeficiency virus seropositivity among patients with tuberculosis was 14.9%. The rate of positive sputum microscopy results was higher in the tuberculosis-only group (p = 0.0275), and the ratio for patients treatment with alternative scheme was significantly higher in the co-infected group (p = 0.042). In 32.1% of the coinfected patients, the serological diagnosis of human immunodeficiency virus infection was made simultaneously to or following that of the tuberculosis. Conclusion: The results underscore the importance of routinely testing for human immunodeficiency virus antibodies in patients diagnosed with tuberculosis.

Keywords: Tuberculosis/complications; Tuberculosis/diagnosis; Soropositivity; HIV/immunology; HIV infections/complications; HIV infections/epidemiology; HIV infections/ drug therapy; Rifampin/therapeutic use; Disease progression

Introduction: A considerable increase in asthma and atopy prevalence has been noticed worldwide through the last decades, however, in our country, epidemiological data are still insufficient. Objective: This study was carried out to determine the prevalence of asthma and atopy in a group of students, and compare these data with those found in two previous studies undertaken in Porto Alegre, Rio Grande do Sul. Methods: Asthma prevalence was identified through a questionnaire applied to 855 students from five schools of Porto Alegre. The students submitted to skin tests who presented, at least, one positive reaction were considered atopic. The signature of an informed consent from one of the parents was required for the skin test performance. Results: Prevalence was found to be 42.5% and 22% of cumulative and active asthma, respectively, with predominance in females. Atopy was identified in 50.1% of the sample. These results were significantly higher than the 6.7% (1980) and 16% (1989) of cumulative asthma, 10.9% (1989) of active asthma and 15.8% (1980) of atopy found in the two previous studies. Conclusion: A high prevalence of asthma and atopy was identified in our students. Future studies should be performed to elucidate the phenomenon herein demonstrated.

Keywords: Asthma. Epidemiology. Atopy.

The objective of this study was to determine the prevalence of HIV infection among individuals ≥ 15 years of age with a confirmed diagnosis of tuberculosis and treated at family health care clinics in the city of Fortaleza, Brazil. We evaluated a random sample of 110 patients with tuberculosis, treated at a total of 26 family health care clinics between January and May of 2009. All of the participants completed a questionnaire regarding sociodemographic and clinical data, and all underwent HIV testing. In this sample, the prevalence of tuberculosis/HIV co-infection was 3.6% (95% CI: 0.2-7.0).

Keywords: Tuberculosis; HIV seroprevalence; Primary health care.

Objective: Early tuberculosis diagnosis and treatment are determinants of better outcomes and effective disease control. Although tuberculosis should ideally be managed in a primary care setting, a proportion of patients are diagnosed in emergency facilities (EFs). We sought to describe patient characteristics by place of tuberculosis diagnosis and determine whether the place of diagnosis is associated with treatment outcomes. A secondary objective was to determine whether municipal indicators are associated with the probability of tuberculosis diagnosis in EFs. Methods: We analyzed data from the São Paulo State Tuberculosis Control Program database for the period between January of 2010 and December of 2013. Newly diagnosed patients over 15 years of age with pulmonary, extrapulmonary, or disseminated tuberculosis were included in the study. Multiple logistic regression models adjusted for potential confounders were used in order to evaluate the association between place of diagnosis and treatment outcomes. Results: Of a total of 50,295 patients, 12,696 (25%) were found to have been diagnosed in EFs. In comparison with the patients who had been diagnosed in an outpatient setting, those who had been diagnosed in EFs were younger and more socially vulnerable. Patients diagnosed in EFs were more likely to have unsuccessful treatment outcomes (adjusted OR: 1.54; 95% CI: 1.42-1.66), including loss to follow-up and death. At the municipal level, the probability of tuberculosis diagnosis in EFs was associated with low primary care coverage, inequality, and social vulnerability. In some municipalities, more than 50% of the tuberculosis cases were diagnosed in EFs. Conclusions: In the state of São Paulo, one in every four tuberculosis patients is diagnosed in EFs, a diagnosis of tuberculosis in EFs being associated with poor treatment outcomes. At the municipal level, an EF diagnosis of tuberculosis is associated with structural and socioeconomic indicators, indicating areas for improvement.

Keywords: Tuberculosis/diagnosis; Emergency treatment; Treatment outcome; Delivery of health care.

Objective: To characterize deaths from pulmonary tuberculosis, according to sociodemographic and operational variables, in the city of São Luís, Brazil, and to describe their spatial distribution. Methods: This was an exploratory ecological study based on secondary data from death certificates, obtained from the Brazilian Mortality Database, related to deaths from pulmonary tuberculosis. We included all deaths attributed to pulmonary tuberculosis that occurred in the urban area of São Luís between 2008 and 2012. We performed univariate and bivariate analyses of the sociodemographic and operational variables of the deaths investigated, as well as evaluating the spatial distribution of the events by kernel density estimation. Results: During the study period, there were 193 deaths from pulmonary tuberculosis in São Luís. The median age of the affected individuals was 52 years. Of the 193 individuals who died, 142 (73.60%) were male, 133 (68.91%) were Mulatto, 102 (53.13%) were single, and 64 (33.16%) had completed middle school. There was a significant positive association between not having received medical care prior to death and an autopsy having been performed (p = 0.001). A thematic map by density of points showed that the spatial distribution of those deaths was heterogeneous and that the density was as high as 8.12 deaths/km2. Conclusions: The sociodemographic and operational characteristics of the deaths from pulmonary tuberculosis evaluated in this study, as well as the identification of priority areas for control and surveillance of the disease, could promote public health policies aimed at reducing health inequities, allowing the optimization of resources, as well as informing decisions regarding the selection of strategies and specific interventions targeting the most vulnerable populations.

Keywords: Tuberculosis, pulmonary/mortality; Communicable disease control; Spatial analysis.

Tuberculosis remains a major public health problem deeply influenced by inequality. The present study used data from the Brazilian Tuberculosis Case Registry Database in order to compare the rates of tuberculosis treatment success, loss to follow-up, and tuberculosis mortality between the homeless population and the general population of Brazil. The likelihood of tuberculosis treatment success was reduced by approximately 50% in the homeless population. In addition, the rate of loss to follow-up was 2.9 times higher in the homeless population than in the general population, and the rate of tuberculosis mortality was 2.5 times higher in the former.

Keywords: Tuberculosis; Homeless persons; Health information systems; Health policy.

The objective of this study was to compare gender differences among tuberculosis patients in a city with a high incidence of tuberculosis. This was a cross-sectional questionnaire-based study involving 560 tuberculosis patients (373 males and 187 females). Sociodemographic and clinical data, as well as data related to diagnostic criteria and treatment outcome, were collected (from the questionnaires and medical records) and subsequently compared between the genders. The median time from symptom onset to diagnosis was 90 days. There were no differences between the genders regarding the clinical presentation, diagnostic criteria, previous noncompliance with treatment, time from symptom onset, number of medical appointments prior to diagnosis, or treatment outcome. Gender-specific approaches are not a priority in Brazil. However, regardless of patient gender, the delay in diagnosis is a major concern.

Keywords: Poverty; Tuberculosis; Income.

Background: Tuberculosis is a disease linked to poverty, unequal distribution of wealth, and urbanization, as well as the epidemics of acquired immunodeficiency syndrome epidemic and multidrug resistance. Objective: To analyze indicators of tuberculosis morbidity and mortality in the city of São José do Rio Preto, Brazil from 1985 to 2003, compared with those in the state of São Paulo and in Brazil at large, and to determine the relationship between the risk of occurrence and socioeconomic level. Method: The following official information systems were utilized: the Sistema de Informação de Mortalidade (SIM, Mortality database), the Notificação de Tuberculose (Epi-Tb, Tuberculosis Notification database), the Sistema de Informação de Agravos de Notificação (SINAN, Case-registry database), the Departamento de Informação e Informática do Sistema Único de Saúde (DATASUS, Information Department of the Brazilian Health Ministry) and the Instituto Brasileiro de Geografia e Estatística (IBGE, Brazilian Institute of Geography and Statistics database). New cases reported in 2003 in the urban area were georeferenced and analyzed. A map of the sectors, each classified as representing one of three socioeconomic classes, was drawn up, showing the respective tuberculosis incidence coefficients. Results: Comparing Brazil as a whole to the state of São Paulo, total incidence coefficients and mortality rates were similar, as were gender-related values. In the city of São José do Rio Preto the rates were consistently lower. The proportion of cases presenting tuberculosis/human immunodeficiency virus coinfection varied from 29% to 37%. In 2002, 59% and 65% of tuberculosis-only and coinfected tuberculosis patients, respectively, were under supervised treatment, with a cure rate of 81% and a treatment-abandonment rate of 1%. The risk of developing active tuberculosis was three times higher in the area presenting the lowest socioeconomic levels. Conclusion: Identification of the areas with different levels of risks for tuberculosis enables the Municipal Health Department to deal with the peculiarities of each region and to prioritize those presenting higher incidences of the disease.

Keywords: Tuberculosis. Epidemiology. Socioeconomic class. Supervised Treatment. Infection. HIV.

Objective: To describe cases of tuberculosis recurrence (TBR), stratified by temporal classification (early or late TBR), and to identify possible predictors of such recurrence. Methods: This was an analytical retrospective observational epidemiological study involving a cohort of 963 new cases of pulmonary tuberculosis, reported and treated via the Tuberculosis Control Program in the city of Carapicuíba, Brazil. The study period was from 2000 to 2010. All of the pulmonary tuberculosis patients who successfully completed the treatment (with or without confirmation of cure) were selected and followed until December 31, 2012. Results: Of the 963 cases, TBR occurred in 47 (4.88%). The mean time between the first and second tuberculosis episodes was 36.12 months. Of the 47 TBR cases, 16 (34.04%) occurred within the first 18 months after the completion of the initial treatment (early TBR) and 31 (65.96%) occurred thereafter (late TBR). There were statistically significant differences between the early and late TBR groups only regarding level of education (≤ 3 vs. > 3 years of schooling; p < 0.004) and weight gain at completion of the initial treatment (1.78 kg vs. 5.31 kg; p < 0.045)-not regarding any of the other variables studied. Conclusions: A low level of education might translate to poor treatment adherence, which impedes the killing of bacilli and facilitates their survival in a latent state, making it appear as if the treatment was effective. Minimal or no weight gain at completion of the initial treatment might be a reliable biomarker to be used by health care facilities that provide tuberculosis treatment.

Keywords: Recurrence; Tuberculosis; Risk factors.

Objective: To determine primary and acquired resistance to pyrazinamide in Mycobacterium tuberculosis strains isolated in sputum samples from patients with pulmonary tuberculosis. Methods: This was a prospective, descriptive study conducted between April and November of 2011 at a referral hospital for tuberculosis in the city of Recife, Brazil. Cultures, drug sensitivity tests, and tests of pyrazinamidase activity were conducted in a private laboratory in Recife. Results: Of the 71 patients included in the study, 37 were treatment-naïve and 34 represented cases of retreatment. Pyrazinamide-resistant strains were isolated in 14 (41.2%) of the 34 patients who had previously been treated for tuberculosis and in none of the 37 treatment-naïve patients. Of the 14 isolates, 10 (90.9%) tested negative for pyrazinamidase activity. A total of 60 isolates tested positive for pyrazinamidase activity. Of those, 56 (93.3%) were found to be sensitive to pyrazinamide. Conclusions: The high frequency of pyrazinamide-resistant strains (41.2%) in patients previously treated for tuberculosis highlights the need for drug susceptibility testing prior to the adoption of a new treatment regimen.

Keywords: Mycobacterium tuberculosis; Pyrazinamide; Tuberculosis, multidrug-resistant