Most people infected by Mycobacterium tuberculosis (Mtb) do not have any signs or disease symptoms, a condition known as latent tuberculosis infection (LTBI). The introduction of biological agents, mainly tumor necrosis factor (TNF) inhibitors, for the treatment of immune-mediated diseases such as Rheumatoid Arthritis (RA) and other rheumatic diseases, increased the risk of reactivation of LTBI, leading to development of active TB. Thus, this review will approach the aspects related to LTBI in patients with rheumatologic diseases, especially those using iTNF drugs. For this purpose it will be considered the definition and prevalence of LTBI, mechanisms associated with diseases and medications in use, criteria for screening, diagnosis and treatment. Considering that reactivation of LTBI accounts for a large proportion of the incidence of active TB, adequate diagnosis and treatment are crucial, especially in high-risk groups such as patients with rheumatologic diseases.

Keywords: Tuberculosis; Latent tuberculosis; Tuberculin skin test; Anti-TNF therapy; Tumor necrosis factor-alpha; Rheumatoid arthritis.

Objective: To characterize the prevalence of latent tuberculosis infection (LTBI) in patients with interstitial lung diseases (ILDs) requiring immunosuppression. Only 5 to 10% of individuals infected with Mycobacterium tuberculosis develop tuberculosis, and certain groups of patients have an increased risk of illness, such as the immunocompromised. Patients with ILDs are frequently treated with immunosuppressants and, therefore, might have a higher risk of developing the disease. Methods: Prospective study conducted at the ILD reference center of the Federal University of Paraná from January 2019 to December 2020. The screening of LTBI was performed with the use of the tuberculin skin test (TST). Results: The sample consisted of 88 patients, of whom 64.8% were women, with a mean age of 61.4 years. The most frequent diagnoses were autoimmune rheumatic disease ILD (38.6%) and hypersensitivity pneumonitis (35.2%). The most common immunosuppressant in use at the time of the TST was prednisone, either in combination with mycophenolate (19.3%) or alone (17.1%). The majority of participants had fibrotic lung disease, characterized by a reticular interstitial pattern on chest computed tomography (79.5%) and moderate to severe functional impairment (mean FVC 69.2%). A prevalence of LTBI of 9.1% (CI 95%, 2.1%-15.1%) was found, with a TST median of 13. Conclusion: Patients with ILD who are treated with immunosuppressants are not commonly screened for LTBI, despite being under a greater risk of progression to active disease. This study suggests the need for a more cautious approach to these patients.

Keywords: Latent tuberculosis infection; Interstitial lung diseases; Immunosuppression; Tuberculin test.

Since the beginning of the use of anti-TNF in the treatment of rheumatoid arthritis and other inflammatory diseases, cases of pulmonary tuberculosis and extrapulmonary tuberculosis have been reported in patients receiving such treatment. In most cases, the disease develops by the time the patient has received the sixth infusion. Every patient should be evaluated for latent tuberculosis infection prior to the use of a TNF inhibitor. However, the diagnosis of latent tuberculosis infection is a challenge. The tuberculin test, which was the only test available to detect latent tuberculosis infection for nearly a century, presents a number of limitations. Tests based on the detection of the in-vitro production of IFN-γ by mononuclear cells activated by specific antigens appear to be more accurate and have been studied in patients with rheumatoid arthritis.

Keywords: Tuberculosis, pulmonary; Arthritis, rheumatoid; Tumor necrosis factor-alpha; Infection.

Objective: To evaluate the incidence rates of mycobacterial infections in silicosis patients with systemic autoimmune rheumatic disease (ARD). Methods: This was a retrospective cohort of silicosis patients between January of 1999 and December of 2023. We compared the incidence of tuberculosis and nontuberculous mycobacterial disease (NTM) in patients with silicosis with and without ARD. We also compared the tuberculosis incidence in the overall cohort with general Brazilian population estimates. Results: The study comprised 369 silicosis patients, of whom 35 (9.5%) had ARD. Having ARD did not affect the cumulative incidence of mycobacterial diseases. The risk of tuberculosis was higher in the cohort when compared with that in the adult Brazilian male population (age-adjusted incidence rate ratio = 20.46; 95% CI 14.89-28.13). Conclusions: In this cohort of patients with silicosis, ARD was not associated with the incidence of mycobacterial diseases.

Keywords: Silicosis; Tuberculosis; Mycobacterium infections, nontuberculous; Arthritis, rheumatoid; Scleroderma, systemic; Lupus erythematosus, systemic.

Objective: To determine the clinical and epidemiological profile of patients who are candidates for TNF-α inhibitor use and are classified as having latent tuberculosis (LTB), as well as to evaluate the outcomes of prophylactic treatment with isoniazid. Methods: A prospective descriptive analysis followed by an analytical, observational, cross-sectional study of the outcomes of prophylactic treatment in a group of 45 candidates for TNF-α inhibitor use. We evaluated the patients through anamnesis, clinical examination, chest X-ray, and tuberculin skin test (TST) using the Mantoux method. Results: The mean age was 45 years, and 56.0% of the patients were female. Chronic rheumatic diseases, chronic dermatological diseases, and Crohn's disease were present in 46.7%, 40.0%, and 13.3% of the patients, respectively. The mean TST induration was 14.6 mm (range: 5-30 mm). The majority (n = 30) of the 45 patients (66.7%) had an induration > 10 mm. In the 16 patients with BCG vaccination scars, the mean induration was 15.7 mm, and 14 of those patients had an induration > 10 mm. Chest X-ray results were considered normal, with minimal alterations, in 64.4% and 35.6% of the patients, respectively. The treatment with isoniazid was abandoned by 1 patient (2.2%) and completed by 41 (91.2%), whereas it was interrupted because of drug-induced hepatitis in 2 (4.4%), and 1 patient (2.2%) was transferred to another hospital. Of those who completed the treatment, 5 experienced mild side effects. Conclusions: Determining the profile of candidates for TNF-α inhibitor use is important for the management of LTB treatment and for the establishment of clinical protocols for the use and monitoring of the use of these medications.

Keywords: Tuberculosis; Latent tuberculosis; Tuberculin test; Isoniazid; Tumor necrosis factor-alpha.

Objective: To determine the prevalence of latent tuberculosis infection (LTBI) and the risk of infection in patients with chronic kidney disease treated at a hemodialysis center. Methods: We included 307 patients with chronic kidney disease undergoing hemodialysis at the Mineiro Institute of Nephrology, located in the city of Belo Horizonte, Brazil. All of the patients were submitted to tuberculin skin tests (TSTs). We investigated the booster effect and TST conversion. If the initial TST (TST1) was negative, a second TST (TST2) was performed 1-3 weeks later in order to investigate the booster effect. If TST2 was also negative, a third TST (TST3) was performed one year after TST2 in order to determine whether there was TST conversion. Results: When we adopted a cut-off induration of 5 mm, the prevalence of LTBI was 22.2% on TST1, increasing by 11.2% on TST2. When we adopted a cut-off induration of 10 mm, the prevalence of LTBI was 28.5% on TST1, increasing by 9.4% on TST2. The prevalence of LTBI increased significantly from TST1 to TST2 (booster effect), as well as from TST2 to TST3 (p < 0.01 for both). In our sample, the mean annual risk of infection was 1.19%. Conclusions: In the population studied, the prevalence of LTBI was high, and the mean annual risk of infection was similar to that reported for the general population of Brazil, which suggests recent infection.

Keywords: Tuberculosis; Renal insufficiency, chronic; Tuberculin test.

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.

Objective: To estimate the prevalence of latent Mycobacterium tuberculosis infection (LTBI) in renal transplant recipients and to assess sociodemographic, behavioral, and clinical associations with positive tuberculin skin test (TST) results. Methods: This was a cross-sectional study of patients aged ≥ 18 years who underwent renal transplantation at the Renal Transplant Center of the Federal University of Minas Gerais Hospital das Clínicas, located in the city of Belo Horizonte, Brazil. We included renal transplant recipients who underwent the TST between January 2011 and July 2013. If the result of the first TST was negative, a second TST was administered. Bivariate and multivariate analyses using logistic regression were used to determine factors associated with positive TST results. Results: The sample included 216 patients. The prevalence of LTBI was 18.5%. In the multivariate analysis, history of contact with a tuberculosis case and preserved graft function (estimated glomerular filtration rate ≥ 60 mL/min/1.73 m2) were associated with positive TST results. TST induration increased by 5.8% from the first to the second test, which was considered significant (p = 0.012). Conclusions: The prevalence of LTBI was low in this sample of renal transplant recipients. The TST should be administered if renal graft function is preserved. A second TST should be administered if the first TST is negative.

Keywords: Tuberculosis; Tuberculin test; Immunocompromised host.

Objective: To determine the prevalence of and the factors associated with latent Mycobacterium tuberculosis infection (LTBI) in prisoners in the state of Minas Gerais, Brazil. Methods: This was a cross-sectional cohort study conducted in two prisons in Minas Gerais. Tuberculin skin tests were performed in the individuals who agreed to participate in the study. Results: A total of 1,120 individuals were selected for inclusion in this study. The prevalence of LTBI was 25.2%. In the multivariate analysis, LTBI was associated with self-reported contact with active tuberculosis patients within prisons (adjusted OR = 1.51; 95% CI: 1.05-2.18) and use of inhaled drugs (adjusted OR = 1.48; 95% CI: 1.03-2.13). Respiratory symptoms were identified in 131 (11.7%) of the participants. Serological testing for HIV was performed in 940 (83.9%) of the participants, and the result was positive in 5 (0.5%). Two cases of active tuberculosis were identified during the study period. Conclusions: Within the prisons under study, the prevalence of LTBI was high. In addition, LTBI was associated with self-reported contact with active tuberculosis patients and with the use of inhaled drugs. Our findings demonstrate that it is necessary to improve the conditions in prisons, as well as to introduce strategies, such as chest X-ray screening, in order to detect tuberculosis cases and, consequently, reduce M. tuberculosis infection within the prison system.

Keywords: Prisons; Tuberculin test; Latent tuberculosis, HIV.

Objective: Mycobacteriosis is frequently diagnosed among HIV-infected patients. In Mozambique, where few patients are under antiretroviral therapy and the prevalence of tuberculosis is high, there is need for better characterization of mycobacteria at the species level, as well as for the identification of patterns of resistance to antituberculous drugs. Methods: We studied a sample of 503 HIV-infected individuals suspected of having pulmonary tuberculosis. Of those 503, 320 tested positive for mycobacteria through sputum smear microscopy or culture of bronchoalveolar lavage fluid. Results: Acid-fast bacilli were observed in the sputum of 73% of the individuals presenting positive cultures. Of 277 isolates tested, only 3 were nontuberculous mycobacteria: 2 were identified as Mycobacterium avium and one was identified as M. simiae. Strains initially characterized as M. tuberculosis complex through polymerase chain reaction restriction analysis (PRA) of the hsp65 gene were later confirmed as such through PRA of the gyrB gene. Among the M. tuberculosis isolates, resistance patterns were as follows: to isoniazid, 14%; to rifampin, 6%; and multidrug resistance, 5%. Previously treated cases showed significantly higher rates of resistance to first-line antituberculous drugs. The most common radiological pattern was interstitial infiltrate (in 67%), followed by mediastinal lymph node enlargement (in 30%), bronchiectasis (in 28%), miliary nodules (in 18%) and cavitation (in 12%). Patients infected with nontuberculous mycobacteria presented clinical profiles indistinguishable from those of other patients. The median CD4 lymphocyte count in this group was 134 cells/mm3. Conclusions: There is a strong association between tuberculosis and AIDS in Mozambique, as expected in a country with a high prevalence of tuberculosis. Although drug resistance rates are high, the isoniazid-rifampin regimen continues to be the appropriate choice for initial therapy.

Keywords: Tuberculosis; Mycobacteria, atypical; HIV; Acquired immunodeficiency syndrome; Drug Resistance, Multiple; Mozambique.

Objective: Many biologic agents cause some degree of immunosuppression, which can increase the risk of reactivation of tuberculosis infection (TBI). This risk is variable between individual biologics. We aimed to assess current (and recommended) clinical practice of TBI screening and treatment among patients initiating treatment with biologic agents. Methods: An online questionnaire was distributed via email to members of the Global Tuberculosis Network and associated professional organisations to seek insights into the screening for and treatment of TBI in patients treated with biologics. Results: A total of 163 respondents in 27 countries answered at least one question. For all biologics described in the questionnaire, respondents advised increasing screening relative to current practice. Observed and supported TBI screening rates in patients treated with TNF-a inhibitors were high, especially for older TNF-a inhibitors. Most participants supported TBI screening in patients treated with B- or T-cell inhibitors but not in those treated with interleukin inhibitors. Guideline awareness was higher for TNF-a inhibitors than for other biologic classes (79% vs. 34%). Conclusions: Although respondents stated that TBI screening rates are lower than what they consider ideal, there was a tendency to recommend TBI screening in patients treated with biologics not known to be associated with an increased risk of TBI. As a result, there is a potential risk of over-screening and over-treatment of TBI, potentially causing harm, in patients treated with biologics other than TNF-a inhibitors. There is a need to research the risk of TBI associated with biologics and for guidelines to address the spectrum of TBI risk across all types of biologics.

Keywords: Latent tuberculosis; Biological products; Immunosuppression therapy; Recurrence; Mass screening.

Objectives: To verify the prevalence of tuberculosis (TB)/HIV co-infection and the ability of the clinical history to detect the HIV infection in TB inpatients. Setting: Eduardo de Menezes Hospital, reference for both TB and AIDS. Patients and methods: All patients admitted with TB in a pneumology ward were evaluated prospectively from 1/1/1997 to 1/31/1998. The clinical history was directed to the presence of risk factors for AIDS or TB, previous treatments or abandoned treatments for TB, and TB clinical forms. Patients with AIDS defining illnesses, except for TB, and with previous anti-HIV tests were excluded. All patients had an ELISA anti-HIV serology, and when positive, a Western-Blot test was performed to confirm the previous result. X-square test and Fisher test were used for statistical analysis. Results: Sixty-five patients were divided into group I (positive serology for HIV, n = 6) and group II (negative serology for HIV, n = 59). There were no statistical differences between the groups comparing the risk factors for AIDS and TB, previous treatments or abandoned treatments for TB, or TB clinical forms. Conclusions: The high prevalence of TB/HIV co-infection (9.2%) reinforces that: 1) the clinical history was not able to detect a significant number of patients with TB/HIV co-infection and that: 2) anti-HIV serology should be performed in all patients with active TB forms.

Keywords: tuberculosis, acquired immundeficiency syndrome, prevalence

Background: The risk for nosocomial transmission of tuberculosis exists in health care institutions. Objective: To evaluate indicators of transmission risk among patients with pulmonary tuberculosis treated at a university hospital. Method: A retrospective study covering the January 1997 to September of 1999 period and evaluating patients admitted to the Hospital de Clínicas of the Universidade Estadual de Campinas with pulmonary tuberculosis. Three intervals were determined: from admission to collection of sputum for acid-fast bacilli microscopy; from admission to implementation of airborne infection control measures; from sputum collection to the initiation of treatment. Results: The final sample included 63 cases. Concomitant human immunodeficiency virus-positivity was found in 31.7%. Forty patients (63.5%) were admitted through the emergency room. In 42 (66.7%) patients, TB was suspected at admission. The interval between admission and sputum collection exceeded 12 hours in 27.5% of cases admitted through the emergency room and in 30.4% of those admitted directly to wards (p = 0.803). Delayed respiratory isolation occurred in 31 cases (49.2%). The delay in isolation was correlated to no diagnosis of tuberculosis at admission (p < 0.000) and lower bacillary load in the sputum (p = 0.032). Co-infection with human immunodeficiency virus (p = 0.530), hospitalization ward (p = 0.284) and underlying diseases (p = 0.541) were not correlated with delayed isolation. The interval between sputum collection and initiation of treatment was greater than 24 hours in 15.9% of the cases. Conclusion: Delayed isolation was observed in many cases. Policies of continuing education are called for, especially in high-risk areas.

Keywords: Tuberculosis. Infection Control. Brazil. Delay. Diagnosis.

Objective: Preventive treatment of active tuberculosis is one of the main strategies for reducing the incidence of tuberculosis. We sought to evaluate the rates of latent tuberculosis infection (LTBI) treatment completion with three months of once-weekly isoniazid plus rifapentine (3HP) and compare them with those for six to nine months of daily isoniazid (6H/9H). Methods: This was a retrospective cross-sectional study. Consecutive patients undergoing LTBI treatment with 3HP or 6H/9H were included in the study. Treatment completion rates and adverse effects were analyzed. Results: A total of 226 patients were included in the study: 113 in the 3HP group and 113 in the 6H/9H group. The frequency of adverse effects was not significantly different between the 3HP and 6H/9H groups. The 3HP group had a higher treatment completion rate (93.8%) than did the 6H/9H group (84.1%), the difference being significant. Conclusions: The rates of LTBI treatment completion appear to be higher with 3HP than with 6H/9H. Health care professionals should be vigilant in managing adverse effects to further maximize LTBI treatment completion.

Keywords: Tuberculosis, pulmonary; Latent tuberculosis/prevention & control; Mycobacterium tuberculosis.

Objective: To develop a set of descriptive terms applied to the sensation of dyspnea (dyspnea descriptors) for use in Brazil and to investigate the usefulness of these descriptors in four distinct clinical conditions that can be accompanied by dyspnea. Methods: We collected 111 dyspnea descriptors from 67 patients and 10 health professionals. These descriptors were analyzed and reduced to 15 based on their frequency of use, similarity of meaning, and potential pathophysiological value. Those 15 descriptors were applied in 50 asthma patients, 50 COPD patients, 30 patients with heart failure, and 50 patients with class II or III obesity. The three best descriptors, as selected by the patients, were studied by cluster analysis. Potential associations between the identified clusters and the four clinical conditions were also investigated. Results: The use of this set of descriptors led to a solution with seven clusters, designated sufoco (suffocating), aperto (tight), rápido (rapid), fadiga (fatigue), abafado (stuffy), trabalho/inspiração (work/inhalation), and falta de ar (shortness of breath). Overlapping of descriptors was quite common among the patients, regardless of their clinical condition. Asthma was significantly associated with the sufoco and trabalho/inspiração clusters, whereas COPD and heart failure were associated with the sufoco, trabalho/inspiração, and falta de ar clusters. Obesity was associated only with the falta de ar cluster. Conclusions: In Brazil, patients who are accustomed to perceiving dyspnea employ various descriptors in order to describe the symptom, and these descriptors can be grouped into similar clusters. In our study sample, such clusters showed no usefulness in differentiating among the four clinical conditions evaluated.

Keywords: Dyspnea; Pulmonary disease, chronic obstructive; Asthma; Heart failure.

Objective: To identify risk factors for the development of hospital-acquired pneumonia (HAP) caused by multidrug-resistant (MDR) bacteria in non-ventilated patients. Methods: This was a retrospective observational cohort study conducted over a three-year period at a tertiary-care teaching hospital. We included only non-ventilated patients diagnosed with HAP and presenting with positive bacterial cultures. Categorical variables were compared with chi-square test. Logistic regression analysis was used to determine risk factors for HAP caused by MDR bacteria. Results: Of the 140 patients diagnosed with HAP, 59 (42.1%) were infected with MDR strains. Among the patients infected with methicillin-resistant Staphylococcus aureus and those infected with methicillin-susceptible S. aureus, mortality was 45.9% and 50.0%, respectively (p = 0.763). Among the patients infected with MDR and those infected with non-MDR gram-negative bacilli, mortality was 45.8% and 38.3%, respectively (p = 0.527). Univariate analysis identified the following risk factors for infection with MDR bacteria: COPD; congestive heart failure; chronic renal failure; dialysis; urinary catheterization; extrapulmonary infection; and use of antimicrobial therapy within the last 10 days before the diagnosis of HAP. Multivariate analysis showed that the use of antibiotics within the last 10 days before the diagnosis of HAP was the only independent predictor of infection with MDR bacteria (OR = 3.45; 95% CI: 1.56-7.61; p = 0.002). Conclusions: In this single-center study, the use of broad-spectrum antibiotics within the last 10 days before the diagnosis of HAP was the only independent predictor of infection with MDR bacteria in non-ventilated patients with HAP.

Keywords: Pneumonia, bacterial; Drug resistance, bacterial; Cross infection.