Objective: To assess the diagnostic performance of the Xpert MTB/RIF assay, a rapid molecular test for tuberculosis, comparing it with that of AFB staining and culture, in BAL fluid (BALF) samples from patients with clinically suspected pulmonary tuberculosis (PTB) who are sputum smear-negative or produce sputum samples of insufficient quantity. Methods: This was a retrospective study of 140 cases of suspected PTB in patients who were smear-negative or produced insufficient sputum samples and were evaluated at a tertiary teaching hospital in the city of Rio de Janeiro, Brazil. All of the patients underwent fiberoptic bronchoscopy with BAL. The BALF specimens were evaluated by AFB staining, mycobacterial culture, and the Xpert MTB/RIF assay. Results: Among the 140 patients, results for all three microbiological examinations were available for 73 (52.1%), of whom 22 tested positive on culture, 17 tested positive on AFB staining, and 20 tested positive on the Xpert MTB/RIF assay. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for AFB staining were 68.1%, 96.1%, 88.2%, 87.5%, and 87.6%, respectively, compared with 81.8%, 96.1%, 90.0%, 92.4%, and 91.8%, respectively, for the Xpert MTB/RIF assay. The agreement between AFB staining and culture was 82.3% (kappa = 0.46; p < 0.0001), whereas that between the Xpert MTB/RIF assay and culture was 91.8% (kappa = 0.8; p < 0.0001). Conclusions: In BALF samples, the Xpert MTB/RIF assay performs better than do traditional methods, providing a reliable alternative to sputum analysis in suspected cases of PTB. However, the rate of discordant results merits careful consideration.

Keywords: Tuberculosis; Molecular diagnostic techniques; Bronchoscopy; Bronchoalveolar lavage fluid; Mycobacterium tuberculosis.

Objective: To compare 28-day mortality rates and clinical outcomes in ICU patients with ventilator-associated pneumonia according to the diagnostic strategy used. Methods: This was a prospective randomized clinical trial. Of the 73 patients included in the study, 36 and 37 were randomized to undergo BAL or endotracheal aspiration (EA), respectively. Antibiotic therapy was based on guidelines and was adjusted according to the results of quantitative cultures. Results: The 28-day mortality rate was similar in the BAL and EA groups (25.0% and 37.8%, respectively; p = 0.353). There were no differences between the groups regarding the duration of mechanical ventilation, antibiotic therapy, secondary complications, VAP recurrence, or length of ICU and hospital stay. Initial antibiotic therapy was deemed appropriate in 28 (77.8%) and 30 (83.3%) of the patients in the BAL and EA groups, respectively (p = 0.551). The 28-day mortality rate was not associated with the appropriateness of initial therapy in the BAL and EA groups (appropriate therapy: 35.7% vs. 43.3%; p = 0.553; and inappropriate therapy: 62.5% vs. 50.0%; p = 1.000). Previous use of antibiotics did not affect the culture yield in the EA or BAL group (p = 0.130 and p = 0.484, respectively). Conclusions: In the context of this study, the management of VAP patients, based on the results of quantitative endotracheal aspirate cultures, led to similar clinical outcomes to those obtained with the results of quantitative BAL fluid cultures. (Brazilian Registry of Clinical Trials - ReBEC; identification number RBR-86DCDX [http://www.ensaiosclinicos.gov.br])

Keywords: Bronchoalveolar lavage fluid/diagnosis; Respiratory aspiration; Pneumonia, ventilator-associated.

Tuberculosis continues to be a major public health problem worldwide. The aim of the present study was to evaluate the accuracy of the Xpert MTB/RIF rapid molecular test for tuberculosis, using pulmonary samples obtained from patients treated at the Júlia Kubitschek Hospital, which is operated by the Hospital Foundation of the State of Minas Gerais, in the city of Belo Horizonte, Brazil. This was a retrospective study comparing the Xpert MTB/RIF test results with those of standard culture for Mycobacterium tuberculosis and phenotypic susceptibility tests. Although the Xpert MTB/RIF test showed high accuracy for the detection of M. tuberculosis and its resistance to rifampin, attention must be given to the clinical status of the patient, in relation to the test results, as well as to the limitations of molecular tests.

Keywords: Tuberculosis/diagnosis; Molecular diagnostic techniques; Sputum; Bronchoalveolar lavage fluid.

Objective: To evaluate the performance of nested PCR (nPCR) in detecting the Mycobacterium tuberculosis complex in blood samples of patients suspected of having TB, in order to determine its potential for use as an auxiliary tool in the laboratory diagnosis of TB in children. Methods: Detection of the M. tuberculosis complex in blood samples using as a target the insertion sequence IS6110 of the genomic DNA of the bacillus. Blood samples of 120 patients were evaluated. All of the patients were under 15 years of age at the time of their treatment at public hospitals in the city of Recife, Brazil (between January of 2003 and August of 2005). Attending physicians at the hospitals diagnosed TB based on the criteria recommended by the American Thoracic Society. The nPCR amplified a 123-bp fragment with outer oligonucleotides (IS1/IS2) and, in the subsequent reaction, using inner oligonucleotides (IS3/IS4), generating an 81-bp amplicon. Results: Active or latent TB was found in 65 patients, TB was ruled out in 28 suspected cases, and 27 patients were TB-free (controls). The sensitivity of nPCR was 26.15% and was significantly higher for the extrapulmonary form of the disease (55.56%) than for the pulmonary form (18.18%). The specificity was 92.73%. Conclusions: Despite the difficulties in diagnosing TB in children and the low number of cases evaluated in the present study, nPCR in blood samples proved to be a rapid and specific technique, albeit one with low sensitivity. In order to establish its true usefulness in the diagnosis of paucibacillary forms, especially extrapulmonary TB, further studies need to be carried out with a larger sample of children and analyzing biological specimens other than blood.

Keywords: Tuberculosis; Diagnosis; Blood; Polymerase chain reaction.

Objective: To study the clinical, radiological, and histopathological patterns of transbronchial biopsy (TBB) used in order to confirm the diagnosis in patients with clinical suspicion of interstitial lung disease (ILD) treated at a tertiary-care university hospital. Methods: We reviewed the medical records, radiology reports, and reports of transbronchial biopsies from all patients with suspected ILD who underwent TBB between January of 1999 and December of 2006 at the Hospital das Clínicas de Botucatu, located in the city of Botucatu, Brazil. Results: The study included 56 patients. Of those, 11 (19.6%) had a definitive diagnosis of idiopathic pulmonary fibrosis (IPF), the rate of which was significantly higher in the patients in which ILD was a possible diagnosis in comparison with those in which ILD was the prime suspect (p = 0.011), demonstrating the contribution of TBB to the diagnostic confirmation of these diseases. The histopathological examination of the biopsies revealed that 27.3% of the patients with IPF showed a pattern of organizing pneumonia, which suggests greater disease severity. The most common histological pattern was the indeterminate pattern, reflecting the peripheral characteristic of IPF. However, the fibrosis pattern showed high specificity and high negative predictive value. For CT scan patterns suggestive of IPF, the ROC curve showed that the best relationship between sensitivity and specificity occurred when five radiological alterations were present. Honeycombing was found to be strongly suggestive of IPF (p = 0.01). Conclusions: For ILDs, chest CT should always be performed, and TBB should be used in specific situations, according to the suspicion and distribution of lesions.

Keywords: Lung diseases, interstitial; Diagnosis, differential; Bronchoscopy.

Objective: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. Methods: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). Results: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. Conclusions: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

Keywords: Tuberculosis; Molecular diagnostic testing; Diagnostic tests, routine; Indians, South American.

Abstract Objective: The incidence of tuberculosis worldwide has emphasized the need for better assays designed to diagnose the disease, principally the extrapulmonary form. The objective of the present study was to validate the performance of an automated method for the determination of adenosine deaminase (ADA) activity in pleural fluid (PF) and cerebrospinal fluid (CSF), comparing it with a conventional method (the modified Giusti method). Methods: In total, 134 samples were selected from among those tested in our laboratory: 94 PF samples and 40 CSF samples. The ADA activity was determined using the two methods. Inter- and intra-assay precision was determined, linear regression analysis was performed, simple concordance tests were conducted, and the means of the differences were calculated. Results: The correlation coefficients for PF and CSF samples were, respectively, 0.96 and 0.95. Inter-assay precision was determined using 21 replicates at 3 different activity levels: low, medium and high. The percentage coefficient of variation (%CV) was, respectively, 5.9, 8.1 and 5.8 for PF samples, compared with 21.9, 18.6 and 13.8 for CSF samples. Intra-assay precision in %CV was 1.3 and 11.7, respectively, for PF and CSF samples. The concordance between the methods in PF and CRF samples was, respectively, 96.8% and 100%, considering the reference values for the diagnosis of TB to be 40 U/L (conventional) and 30 U/L (automated) in PF samples, versus 9 U/L (for both methods) in CSF samples. Conclusions: The results validate the use of the automated method of determining ADA activity in PF and CSF samples as an alternative to the conventional method.

Keywords: Adenosine deaminase; Tuberculosis/diagnosis; Pleural effusion; Cerebrospinal fluid.

Objective: To compare the accuracy of the amplified Mycobacterium tuberculosis direct (AMTD) test with reference methods for the laboratory diagnosis of tuberculosis in HIV-infected patients. Methods: This was a study of diagnostic accuracy comparing AMTD test results with those obtained by culture on Löwenstein-Jensen (LJ) medium and by the BACTEC Mycobacteria Growth Indicator Tube 960 (BACTEC MGIT 960) system in respiratory samples analyzed at the Bioassay and Bacteriology Laboratory of the Oswaldo Cruz Foundation Evandro Chagas Clinical Research Institute in the city of Rio de Janeiro, Brazil. Results: We analyzed respiratory samples collected from 118 patients, of whom 88 (74.4%) were male. The mean age was 36.6 ± 10.6 years. Using the AMTD test, the BACTEC MGIT 960 system, and LJ culture, we identified M. tuberculosis complex in 31.0%, 29.7%, and 27.1% of the samples, respectively. In comparison with LJ culture, the AMTD test had a sensitivity, specificity, positive predictive value, and negative predictive value of 87.5%, 89.4%, 75.7%, and 95.0%, respectively, for LJ culture, whereas, in comparison with the BACTEC MGIT 960 system, it showed values of 88.6%, 92.4%, 83.8%, and 94.8%, respectively. Conclusions: The AMTD test showed good sensitivity and specificity in the population studied, enabling the laboratory detection of M. tuberculosis complex in paucibacillary respiratory specimens.

Keywords: Molecular diagnostic techniques; Tuberculosis; HIV; Molecular probe techniques.

Objective: To determine the diagnostic sensitivity of bacteriological analyses in induced sputum (IS) for the diagnosis of pulmonary tuberculosis (TB) and to identify the clinical characteristics associated with the confirmed diagnosis, as well as to determine the diagnostic yield of bronchoscopy carried out when IS tests negative for AFB in smear microscopy. Methods: A retrospective, cross-sectional study of patients suspected of having active pulmonary TB and referred to our clinic for sputum induction. We consecutively reviewed the laboratory data of all patients submitted to sputum induction between June of 2003 and January of 2006, as well as their electronic medical records. In addition, the results of the bacteriological analysis of bronchoscopic specimens collected from the patients whose AFB tests were negative in IS were reviewed. Results: Of the 417 patients included in the study, 83 (19.9%) presented IS samples that tested positive for TB (smear microscopy or culture). In the logistic regression analysis, radiological findings of cavitation (OR = 3.8; 95% CI: 1.9-7.6) and of miliary infiltrate (OR = 3.7; 95% CI: 1.6-8.6) showed the strongest association with the diagnosis of pulmonary TB. In 134 patients, bronchoscopy was carried out after negative AFB results in IS and added 25 (64.1%) confirmed diagnoses of pulmonary TB. Conclusions: In our clinical practice, the frequency of confirmed diagnosis of pulmonary TB using IS (19.9%) was lower than that previously reported in controlled trials. Cavitation and miliary infiltrate increase the diagnostic probability of pulmonary TB using IS. The use of bronchoscopy when IS tests negative for AFB significantly increases sensitivity in the diagnosis of pulmonary TB.

Keywords: Tuberculosis, pulmonary; Diagnosis; Sputum.

Objective: To identify mycobacterial species in the sputum of patients suspected of having pulmonary tuberculosis and to determine the impact that the acquisition of this knowledge has on the therapeutic approach. Methods: We evaluated 106 patients suspected of having pulmonary tuberculosis and referred to the pulmonology department of a public hospital in the city of Teresina, Brazil. Morning sputum specimens were evaluated for the presence of mycobacteria by sputum smear microscopy and culture. We used PCR and restriction enzyme analysis of the hsp65 gene (PRA-hsp65) to identify the strains of mycobacteria isolated in culture. Results: A total of 206 sputum samples were analyzed. Patient ages ranged from 15 to 87 years, and 67% were male. There was cough in 100% of the cases. The predominant radiographic pattern was moderate disease, observed in 70%. Smear positivity was 76%, and isolation in culture occurred in 91% of the cultures. Traditional tests identified nontuberculous mycobacteria (NTM) in 9% of the isolates. The PRA-hsp65 method confirmed these data, showing seven band patterns that were able to identify the isolated species of NTM: Mycobacterium kansasii; M. abscessus 1; M. abscessus 2; M. smegmatis; M. flavescens 1; M. gordonae 5; and M. gordonae 7. All of the patients with NTM were over 60 years of age, and bronchiectasis was seen in 88% of the X-rays. There were two cases of reinfection, initially attributed to M. abscessus and M. kansasii. Conclusions: In immunocompetent patients, NTM can infect the lungs. It is important to identify the specific NTM in order to establish the correct diagnosis and choose the most appropriate therapeutic regimen. The PRA-hsp65 method is useful in identifying NTM species and can be implemented in molecular biology laboratories that do not specialize in the identification of mycobacteria. Keywords:

Keywords: Tuberculosis; Mycobacteria, atypical; Polymerase chain reaction; Brazil.

We evaluated the diagnostic yield of fiberoptic bronchoscopy for the diagnosis of smear-negative pulmonary tuberculosis in patients treated at a referral hospital in Lima, Peru. Of the 611 patients who underwent the procedure, 140 (23%) were diagnosed with tuberculosis based on the analysis of BAL samples. Being young and being male were significantly associated with positive cultures. In addition, 287 patients underwent post-bronchoscopic sputum smear testing for AFB, the results of which increased the diagnostic yield by 22% over that obtained through the analysis of BAL samples alone. We conclude that the analysis of BAL samples and post-bronchoscopic sputum samples provides a high diagnostic yield in smear-negative patients suspected of having pulmonary tuberculosis.

Keywords: Tuberculosis, pulmonary/diagnosis; Bronchoscopy; Sputum.

We compared the nitrate reductase assay with the proportion method, which is considered the gold standard, in 57 Mycobacterium tuberculosis strains isolated from patients treated at the Federal University of Minas Gerais Hospital das Clínicas, located in the city of Belo Horizonte, Brazil. For rifampin and isoniazid, the sensitivity, specificity, and accuracy of the nitrate reductase assay were all 100%, whereas they were 100%, 88.9%, and 66.7%, respectively, for streptomycin and 98.0%, 100%, and 98.2%, respectively, for ethambutol. The mean time to results was ten days. In the study sample, the nitrate reductase assay proved highly accurate and showed excellent concordance with the gold standard.

Keywords: Mycobacterium tuberculosis; Microbial sensitivity tests; Tuberculosis, multidrug-resistant; Nitrate reductase.

Objective: To estimate the rates of recurrence, cure, and treatment abandonment in patients with pulmonary tuberculosis treated with a four-drug fixed-dose combination (FDC) regimen, as well as to evaluate possible associated factors. Methods: This was a retrospective observational study involving 208 patients with a confirmed diagnosis of pulmonary tuberculosis enrolled in the Hospital Tuberculosis Control Program at the Institute for Thoracic Diseases, located in the city of Rio de Janeiro, Brazil. Between January of 2007 and October of 2010, the patients were treated with the rifampin-isoniazid-pyrazinamide (RHZ) regimen, whereas, between November of 2010 and June of 2013, the patients were treated with the rifampin-isoniazid-pyrazinamide-ethambutol FDC (RHZE/FDC) regimen. Data regarding tuberculosis recurrence and mortality in the patients studied were retrieved from the Brazilian Case Registry Database and the Brazilian Mortality Database, respectively. The follow-up period comprised two years after treatment completion. Results: The rates of cure, treatment abandonment, and death were 90.4%, 4.8%, and 4.8%, respectively. There were 7 cases of recurrence during the follow-up period. No significant differences in the recurrence rate were found between the RHZ and RHZE/FDC regimen groups (p = 0.13). We identified no factors associated with the occurrence of recurrence; nor were there any statistically significant differences between the treatment groups regarding adverse effects or rates of cure, treatment abandonment, or death. Conclusions: The adoption of the RHZE/FDC regimen produced no statistically significant differences in the rates of recurrence, cure, or treatment abandonment; nor did it have any effect on the occurrence of adverse effects, in comparison with the use of the RHZ regimen.

Keywords: Tuberculosis, pulmonary, Drug combinations; Recurrence.

The objective of this study was to review the literature on bronchoalveolar lavage fluid cell profiles in healthy children and adolescents, as well as on the use of BAL as a diagnostic and follow-up tool for lung disease patients in this age bracket. To that end, we used the Medline database, compiling studies published between 1989 and 2009 employing the following MeSH descriptors (with Boolean operators) as search terms: bronchoalveolar lavage AND cytology OR cell AND child. In healthy children, the cell profile includes alveolar macrophages (> 80%), lymphocytes (approximately 10%), neutrophils (approximately 2%) and eosinophils (< 1%). The profile varies depending on the disease under study. The number of neutrophils is greater in wheezing children, especially in non-atopic children, as well as in those with pulmonary infectious and inflammatory profiles, including cystic fibrosis and interstitial lung disease. Eosinophil counts are elevated in children/adolescents with asthma and can reach high levels in those with allergic bronchopulmonary aspergillosis or eosinophilic syndromes. In a heterogenous group of diseases, the number of lymphocytes can increase. Evaluation of the BAL fluid cell profile, when used in conjunction with clinical and imaging findings, has proven to be an essential tool in the investigation of various lung diseases. Less invasive than transbronchial and open lung biopsies, BAL has great clinical value. Further studies adopting standard international protocols should be carried out. Such studies should involve various age groups and settings in order to obtain reference values for BAL fluid cell profiles, which are necessary for a more accurate interpretation of findings in children and adolescents with lung diseases.

Keywords: Bronchoalveolar lavage; Bronchoalveolar lavage fluid/cytology; Child; Adolescent.

Background: Tracheostomy is a procedure commonly required in the intensive care unit. In the last two decades, the use of the percutaneous method has increased in parallel with improvements in the technique. Objective: To describe our experience in employing the percutaneous method over the last 3.5 years. Methods: We created, retrospectively, a database of prospective tracheostomy data related to 78 patients evaluated between January 2000 and July 2003. We used the percutaneous tracheostomy techniques of either progressive dilatation (in 36 patients) or forceps dilatation (in 42 patients). Data are expressed as number of occurrences or median with interquartile ranges. Results: The mean age of the patients was 66 (range, 43-75), and the median APACHE II score was 16 (range, 12-21). The median time spent on mechanical ventilation prior to tracheostomy was 14 days (range, 10-17 days). Of the 78 patients studied, 18 (23%) died while in the intensive care unit. The most common cause of admission was acute central nervous system disturbance (in 45%). Most of the tracheostomies performed were indicated due to difficulty in weaning from mechanical ventilation (in 50%) or to Glasgow Coma scores consistently lower than 8 (in 49%). Bronchoscopy was used in all but 6 of the procedures. There were complications in 33% of the procedures. The most common complication was light bleeding, without need for transfusion. No patient died due to complications arising from the procedure. Conclusion: Percutaneous tracheostomy is reasonable and safe when performed in an intensive care unit.

Keywords: Tracheostomy/methods. Respiration, Artificial/methods. Respiratory insufficiency/therapy. Respiratory insufficiency/complications.

Objective: To describe the incidence of active tuberculosis and the occurrence of adverse events after isoniazid treatment in patients with latent tuberculosis infection (LTBI) who also had chronic inflammatory diseases and were treated with immunobiologic agents in an endemic area in Brazil. Methods: The diagnosis of LTBI was based on anamnesis, clinical examination, chest X-ray, and a tuberculin skin test (TST). Patients received prophylactic treatment (isoniazid for six months) in accordance with the Brazilian guidelines. Results: A total of 101 patients were evaluated between July of 2011 and July of 2015. Of those, 55 (54.46%) were women (mean age, 53.16 ± 1.76 years) and 46 (45.54%) were men (mean age, 45.39 ± 2.13 years). A total of 79 patients (78.22%) were being treated with immunobiologic agents and 22 (21.78%) were being treated with immunomodulatory or immunosuppressive agents. In the screening for LTBI, 53 patients (52.48%) had a TST induration ≥ 10 mm. Chest X-ray findings consistent with LTBI were observed in 36 patients (35.64%). Isoniazid preventive therapy was effective in 96 (95.05%) of the 101 patients evaluated. It is of note that 84 (83.17%) of the patients experienced no adverse effects from the use of isoniazid and that 83 (98.81%) of those patients completed the prophylactic treatment (p = 0.002). Active tuberculosis was diagnosed in 5 (6.33%) of the 79 patients treated with immunobiologic agents and in 1 (4.55%) of the 22 patients treated with other immunomodulators/immunosuppressants. Conclusions: A six-month course of isoniazid proved to be safe and effective in the treatment of LTBI, which is essential to reducing the risk of developing active tuberculosis.

Keywords: Latent tuberculosis; Tuberculin test; Tumor necrosis factors/antagonists & inhibitors; Isoniazid.

In view of the fact that the World Health Organization has recommended the use of the mycobacteria growth indicator tube (MGIT) 960 system for the diagnosis of tuberculosis and that there is as yet no evidence regarding the clinical impact of its use in health care systems, we conducted a pragmatic clinical trial to evaluate the clinical performance and cost-effectiveness of the use of MGIT 960 at two health care facilities in the city of Rio de Janeiro, Brazil, where the incidence of tuberculosis is high. Here, we summarize the methodology and preliminary results of the trial. (ISRCTN.org Identifier: ISRCTN79888843 [http://isrctn.org/])

Keywords: Controlled clinical trial; Tuberculosis; Diagnostic tests, routine.

Objective: To evaluate clinical aspects and the diagnosis of pulmonary tuberculosis (PT) in the aged. Methods: We compared 117 patients over 60 years of age (elderly group) and 464 patients aged 15 to 49 years old (nonelderly group) treated at the Thoracic Diseases Institute of the Federal University of Rio de Janeiro, from 1980 to 1996. Results: Previous history of PT was predominant in the elderly group (OR = 2.09; 95% CI = 1.26-3.45; p = 0.002), whereas household contact with PT was predominant in the nonelderly group (OR = 0.26; 95% CI = 0.10-0.66; p = 0.002). Mean time for diagnosis was 90 days in the elderly group and 60 days in the nonelderly group. In the elderly group, dyspnea (OR = 1.64; 95% CI = 1.06-2.53; p = 0.018) and weight loss (OR = 1.66; 95% CI = 1.01-2.82; p = 0.047) were predominant. In the nonelderly group, hemoptysis (OR = 0.51; 95% CI = 0.32-0.81; p = 0.002), chest pain (OR = 0.62; 95% CI = 0.40-0.97; p = 0.027) and fever (OR = 0.55; 95% CI = 0.35-0.86; p = 0.006) were more common. The most common radiological abnormalities were infiltrates and cavitations. Bilateral involvement was more common in the elderly patients (OR = 1.76; 95% CI = 1.12-2.78; p = 0.009). There were no differences between the two groups regarding positivity for Mycobacterium tuberculosis identified through tuberculin skin testing, sputum smear microscopy and culture. Conclusions: There are few clinical and laboratory differences between the age groups. The delayed diagnosis in the elderly group can be explained by the low clinical suspicion in these patients.

Keywords: Tuberculosis, pulmonary; Aged; Signs and symptoms, respiratory; Diagnosis.