Objective: To evaluate deaths attributed to multiple causes in which tuberculosis was one of the causes listed. Methods: All deaths among residents of the state of Rio de Janeiro, Brazil, occurring between 1999 and 2001 and for which the death certificate mentioned tuberculosis, were investigated. The World Health Organization guidelines were used in characterizing the underlying and associated (non-underlying) causes of death. Results: In deaths from tuberculosis, conditions related to its natural history were the principal associated causes, together with alcoholism and diabetes. In approximately three-fifths of all deaths for which tuberculosis was listed as an associated cause, the underlying cause of death was acquired immunodeficiency syndrome. High proportion of ill-defined causes of death, low values found for the number of causes informed per death certificate and for TB as an associated cause point towards a certain degree of underestimation of the actual number of TB-related deaths in Rio de Janeiro State. Conclusion: The study shows that the rates of tuberculosis-related mortality in the state of Rio de Janeiro, calculated based on the number of times tuberculosis was listed as a cause of death (underlying or associated), are the highest in the country. Epidemiological studies of mortality are recommended as a means of guiding the activities of the tuberculosis control program.

Keywords: Tuberculosis/mortality; Acquired immunodeficiency syndrome; Multipe cause of death; Brazil

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.

This retrospective molecular study involving restriction fragment length polymorphism, using insertion sequence 6110 as a marker, was conducted in order to provide an initial insight into the genetic diversity of Mycobacterium tuberculosis strains isolated in the slums of the Complexo de Manguinhos, located in the city of Rio de Janeiro, Brazil. Of the 67 strains evaluated, 23 (34.3%) were found to belong to clusters (total clusters, 10). Household and social chains of transmission were associated with clustering, in 20% and 60%, respectively. Living in the Conjunto Habitacional Programado 2 slum was associated with clustering. Although not significant, it is relevant that 26% of the clustered strains presented primary resistance. These findings, although possibly underestimating the prevalence due to the failure to analyze all strains, could help improve the local tuberculosis control program.

Keywords: Tuberculosis; Epidemiology, molecular; Mycobacterium tuberculosis/transmission; Polymorphism, Restriction Fragment Length.

Objective: To describe the difficulties and peculiarities encountered by health professionals during the treatment and investigation of contacts of tuberculosis (TB) patients in disadvantaged communities. Methods: A qualitative study carried out at health care facilities in Health Programming Area 1.0, located in the city of Rio de Janeiro, Brazil, which has a TB incidence rate of 240/100,000 inhabitants. From among the professionals responsible for visiting and treating TB cases and their contacts, two home visit agents and one clinical nurse were selected to be interviewed for the study. Data were transcribed and structured in the form of quotations, emphasizing the predominant ideas. Results: The central ideas focus on the issue of violence, one significant facet of which is the set of rules imposed by narcotraffickers, and on the barriers to the movement of patients/health professionals for TB treatment, as well as on public safety (police). Conclusion: This study provides public health officials, as well as institutions that graduate health professionals, data for reflection and analysis of the difficulties that urban violence creates for the control of TB in a disadvantaged community.

Keywords: Tuberculosis; Prevention and control; Violence; Directly observed therapy; Community health nursing.

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.

Objective: To describe the clinical and therapeutic aspects of pulmonary tuberculosis and compare the adverse effects of the treatment and its outcome in elderly and nonelderly patients. Methods: This was a case-control study of 117 elderly individuals (over the age of 60 years) and 464 nonelderly individuals (aged 15-49 years). All subjects presented pulmonary tuberculosis that had been diagnosed and treated at the Thoracic Diseases Institute of the Federal University of Rio de Janeiro between 1980 and 1996. Results: In the elderly group, pulmonary tuberculosis was found to be correlated with diabetes (OR = 3.98; 95% CI = 2.07-7.65; p = 0.001), lung disease (OR = 7.24; 95% CI = 3.64‑14.46; p = 0.001) and heart disease (OR = 5.86; 95% CI = 2.88-11.95; p = 0.001). Smoking (OR = 2.07; 95% CI = 1.26‑3.42; p = 0.002) and alcohol abuse (OR = 1.63; 95% CI = 1.01-2.68; p = 0.041) were also more common in the elderly group. In the elderly group, the treatment more frequently resulted in adverse reactions (OR = 1.62; 95% CI = 1.04-2.54; p = 0.024), especially gastrointestinal reactions (OR = 1.64; 95% CI = 1.01-2.77; p = 0.047), and treatment efficacy was lower: cure rate, 51%; mortality rate, 24%. Treatment adherence was low (approximately 77%) in both groups. Conclusions: In the elderly group, adverse reactions were more common, treatment outcomes were less favorable, there was a greater frequency of clinical complications and deaths related to drug toxicity, and the prevalence of concomitant diseases was higher.

Keywords: Tuberculosis, pulmonary; Aged; Drug therapy; Treatment outcome.

Objective: To determine the epidemiological profile of inpatients at a TB referral hospital. Methods: This was a descriptive, retrospective study of the medical charts of patients with TB hospitalized at the Hospital Estadual Santa Maria (HESM), in the city of Rio de Janeiro, Brazil, between January of 2002 and December of 2003. Data were collected using a standardized form. Results: Of the 451 patients included in the study, 313 (69.4%) had been referred to the HESM from health care clinics, and 302 (67.0%) were male. Most of the patients were in the 30-59  year age bracket, 443 (98.2%) lived in the greater metropolitan region of Rio de Janeiro, and 298 (66.1%) lived in the city of Rio de Janeiro itself. The most common reason for hospitalization was poor health status (in 237, 52.5%). The most common comorbidity was AIDS (in 137, 30.4%). The most common signs and symptoms at admission were weight loss, fever and productive cough. Sputum smear microscopy was positive in 122 (71.0%) of the patients presenting with productive cough at admission. Of the 212 patients being retreated, 156 (73.6%) reported noncompliance with previous treatment. Regarding the outcome, 273 (65.8%) of the patients were referred to municipal health care centers, 83 (18.4%) died, 44 (9.8%) were cured, and 27 (6%) were discharged against medical advice. Conclusions: Providing hospitals specializing in TB is relevant for TB control, especially in metropolitan regions. In addition to taking biosafety measures, these hospitals must be prepared to treat patients with TB-related comorbidities and social problems. This study has resulted in improvements at the HESM.

Keywords: Tuberculosis; Epidemiology; Hospitalization.

In 2005 and 2006, 8,121 clinical specimens submitted to the Mycobacteriology Laboratory of the Clementino Fraga Filho University Hospital/Thoracic Diseases Institute, in the city of Rio de Janeiro, Brazil, were inoculated on Löwenstein-Jensen medium containing glycerol and pyruvate. There were 79 mycobacteria isolates that presented growth only on pyruvate-containing medium, and those isolates were selected for the presumptive identification of Mycobacterium bovis. The selected isolates were screened with biochemical tests, PCR amplification (with the specific primers Rv0577 and Rv1510), and pyrazinamide susceptibility tests. All of the strains isolated showed specific phenotypical and genotypical patterns characteristic of M. tuberculosis, and no M. bovis strains were detected.

Keywords: Tuberculosis; Mycobacterium bovis; Polymerase chain reaction.

Objective: To analyze the frequency of tuberculosis and of the other principal opportunistic infections defining acquired immunodeficiency syndrome at the time such cases were reported in the city of Rio de Janeiro, Brazil. Methods: Analysis of the data compiled in the Rio de Janeiro Municipal Program for the Surveillance of Sexually Transmitted Diseases and Acquired Immunodeficiency Syndrome database from 1993 to 2002. Results: The expanded definition of a case of acquired immunodeficiency syndrome, implemented in 1998, resulted in a substantial increase in the number of reported cases of acquired immunodeficiency syndrome, especially of those defined by immunologic criteria. Among the cases of acquired immunodeficiency syndrome defined only by disease, esophageal candidiasis, in its various forms, remained the most common opportunistic infection present at the time the cases of acquired immunodeficiency syndrome were reported. Although Pneumocystis carinii pneumonia was the second leading opportunistic infection in most of the years evaluated, it was surpassed by tuberculosis in 2001. Conclusion: Despite the decreased numbers of cases of acquired immunodeficiency syndrome defined by disease, tuberculosis remains a significant acquired immunodeficiency syndrome-defining event, currently more common than P. carinii pneumonia and toxoplasmosis. This is probably due to the high rate of tuberculosis prevalence in the city.

Keywords: Tuberculosis; Acquired immunodeficiency syndrome; AIDS-related opportunistic infections

Objective: In order to study the scenario of respiratory infections in pediatrics after the emergence of SARS-CoV-2 in Brazil, this study aimed to compare characteristics of children admitted for SARS or upper airway infection caused by either RSV or SARS-CoV-2. Methods: This was a cross-sectional study involving children up to 48 months of age admitted to a tertiary pediatric hospital with a diagnosis of SARS or upper airway infection between April of 2020 and April of 2021. Respiratory secretion samples were collected 2-5 days after hospitalization, and antigen/PCR tests for viral etiologies were performed. In this analysis, patients with laboratorial diagnosis of SARS-CoV-2 and/or RSV were selected, and their clinical and epidemiological characteristics were compared using logistic regression. Results: Our sample initially comprised 369 participants. SARS-CoV-2 and RSV infections were confirmed in 55 (15%) and 59 children (16%), respectively. Mean age was 12 months (0-48 months), and 47 were female. The following characteristics were significantly more frequent in patients with RSV when compared with those with COVID-19: younger age (OR = 0.94; 95% CI: 0.90-0.98); lower frequency of fever (OR = 0.18; 95% CI: 0.05-0.66); and more frequent upper airway symptoms: cough (OR = 7.36; 95% CI: 1.04-52.25); and tachypnea (OR = 6.06; 95% CI: 1.31-28.0). Conclusions: Children with RSV-related SARS were younger, had lower frequency of fever at admission, but had a higher frequency of signs of upper airway infection and lower systemic inflammation when compared with children hospitalized for COVID-19 during the first year of the pandemic.

Keywords: SARS-CoV-2; Respiratory syncytial virus infections; Pediatrics; Brazil.

Objective: To analyze the clinical characteristics and evolution of a group of patients with positive sputum cultures for multidrug-resistant (MDR) Mycobacterium tuberculosis and treated at a referral center in the city of Rio de Janeiro, Brazil. Methods: Based on the positive results in sputum cultures for MDR M. tuberculosis, 50 patients were selected, and their clinical data were obtained from the Brazilian Ministry of Health MDR-TB Database. The frequencies of noncompliance, relapses, failures and previous treatments for TB up to diagnosis of MDR-TB were compiled. The radiological patterns were classified as unilateral or bilateral, and with or without cavitation. Two years after the end of the standard treatment for MDR-TB, the outcome (cure, failure, noncompliance or death) for each patient was evaluated and reassessed every two years. The post-treatment follow-up period was eight years. Results: The mean number of previous treatments was 2.3 ± 0.9. The mean interval between the initial diagnosis and the development of MDR-TB was 2.0 ± 1.7 years. Two years after the initial treatment for MDR-TB, 2 patients had abandoned treatment, 8 had died, 18 had been cured, and 22 had presented treatment failure. The bivariate analysis showed that bilateral pulmonary involvement and cavitary pattern markedly reduced the chances for cure, with a relative risk of 1-0.6 (40%) and 1-0.7 (30%), respectively. At the end of the follow-up period, 2 patients had abandoned treatment, 9 had presented treatment failure, 17 had been cured, and 22 had died. Conclusions: Bilateral pulmonary involvement and cavity pattern greatly reduced the chances for cure of the patients with MDR-TB. Most patients who presented treatment failure died within the 8-year follow-up period.

Keywords: Tuberculosis, multidrug-resistant; Treatment outcome; Disease-free survival; Treatment refusal; Treatment failure.

To describe some aspects of tuberculosis in a low-income community (the Complexo de Manguinhos, in Rio de Janeiro, Brazil), a retrospective study was carried out. Of the 290 cases reported in the 2000-2002 period, 75.8% were new cases. The annual incidence rates were 157/100,000 (2000), 205/100,000 (2001), and 145/100,000 (2002). Although there was a tendency toward a decrease in the number of cases over the period studied, the difference was not significant, suggesting that tuberculosis continues to be endemic in the area. Therefore, despite the existence of local public health care services, more efficient strategies should be implemented in order to increase the effectiveness of tuberculosis control programs in the area.

Keywords: Tuberculosis/epidemiology; Poverty areas; Mycobacterium tuberculosis.

Objective: To identify nontuberculous mycobacteria (NTM) isolated from sterile sites in patients hospitalized between 2001 and 2006 at the Clementino Fraga Filho University Hospital, located in the city of Rio de Janeiro, Brazil. Methods: During the study period, 34 NTM isolates from sterile sites of 14 patients, most of whom were HIV-positive, were submitted to phenotypic identification and hsp65 PCR-restriction enzyme analysis (PRA). Results: Most isolates were identified as Mycobacterium avium, followed by M. monacense, M. kansasii, and M. abscessus. Conclusions: The combination of PRA, a relatively simple and inexpensive method, with the evaluation of a few phenotypic characteristics can allow NTM to be accurately identified in the routine of clinical laboratories.

Keywords: Mycobacteria, atypical; Molecular biology; Polymerase chain reaction.

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.

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 estimate the total time elapsed between symptom onset and diagnosis of pulmonary tuberculosis (patient delay plus health care system delay), analyzing the factors associated with delayed diagnosis in the state of Rio de Janeiro, Brazil. Methods: We conducted a questionnaire-based survey involving 218 pulmonary tuberculosis patients treated for two months at 20 health care clinics and 3 hospitals in eight cities within the state of Rio de Janeiro. We collected socioeconomic and demographic data, as well as data regarding the health care system and the medical history of the patients. Results: The median time elapsed from the onset of symptoms to diagnosis was 68 days (interquartile range [IQR]: 35-119 days). The median patient delay (time from symptom onset to initial medical visit) was 30 days (IQR: 15-60 days), and the median health care system delay (time from initial medical visit to diagnosis) was 21 days (IQR: 8-47 days). A cut-off point of 21 days was adopted. The factors independently associated with patient delay were female gender, cough, and unemployment [adjusted OR (95% CI) = 2.7 (1.3-5.6); 11.6 (2.3-58.8); and 2.0 (1.0-3.8), respectively], whereas only female gender was independently associated with health care system delay (OR= 3.2; 95% CI: 1.7-6.0). Conclusions: Delayed diagnosis of pulmonary tuberculosis remains a problem in Rio de Janeiro, increasing the risk of transmission and mortality, that risk being greater for women and the socioeconomically disadvantaged. Patients might not recognize the significance of chronic cough as a health problem. Tuberculosis education programs targeting women might improve this situation.

Keywords: Lung neoplasms; Neoplasm metastasis; Antineoplastic combined chemotherapy protocols; Radiotherapy, computer-assisted.

Introduction: The teaching hospital, HUCFF, Southeastern Brazil, annually receives three hundred tuberculosis cases. Medical students have their practice at that hospital. Objective: To determine the prevalence of Mycobacterium tuberculosis (Mtb) infection among the students of the UFRJ School of Medicine. Design: Cross-sectional study of medical students at different levels of their training programs. Information about social and demographic characteristics, BCG vaccination history, and potential exposures to tuberculosis were obtained with a standardized questionnaire. Tuberculin skin testing was used to determine the prevalence of tuberculosis infection. Results: The prevalence of tuberculin skin testing positivity among medical students increased as they advanced to higher training levels (4.6%, 7.8%, 16.2%, respectively; P = 0.002). The risks were greatest during the years of clinical training, when medical students had more contact with patients. Conclusions: Medical students in the HUCFF/UFRJ may be at an increased risk of M. tuberculosis infection. A program of routine tuberculin skin testing, combined with interventions to confirm TST conversion and to reduce the risk of nosocomial transmission in the workplace is needed.

Keywords: Nosocomial infection. Medical students. Risk factors. Cross-sectional studies.

Background: In 1998, tuberculosis incidence and mortality rates in the state of Rio de Janeiro (RJ) were the highest in Brazil. However, the RJ tuberculosis database (SINAN-TBRJ) has proven unreliable. Objective: To evaluate the current tuberculosis control program by analyzing tuberculosis-attributed deaths. Methods: Descriptive studies of the SINAN-TB-RJ and tuberculosis mortality (SIM-TB-RJ) databases were carried out. Both databases were linked using the Reclink program. A study based on medical records was performed in the five hospitals where the greatest numbers of tuberculosis deaths occurred. Results: In the SINAN-TB-RJ database, 16,567 cases were registered in adults (> 14 years of age). Pulmonary disease was present in 13,989 (84.5%), of whom 8223 (56.8%) presented sputum smears that were positive for acid fast bacilli. Anti-HIV testing, recommended for all patients with tuberculosis, was performed in only 4141 (25%) of tuberculosis cases. The SIM-TB-RJ database showed 1146 deaths that were attributed to tuberculosis. Only 478 (41.7%) of those had been reported to the health care system (SINAN-TB-RJ). Among the 302 medical records analyzed, 154 (50.9%)recorded hospitalizations of up to 10 days and 143 (47.3%) had respiratory symptoms for more than 60 days before diagnosis. Among 125 cases of retreatment, the RHZE regimen recommended by the Brazilian Ministry of Health was prescribed for only 43 (34.4%). Conclusion: This study demonstrates weakness in the RJ tuberculosis control program, characterized by delayed diagnosis, limited use of the recommended tests, poor reporting, and non-compliance with the Ministry of Health guidelines.

Keywords: Tuberculosis. Epidemiology. Program Evaluation

Background: Tuberculosis become important challenge to health care settings. Brazil has high prevalence of the disease and Rio de Janeiro has high incidence rates with 30% of cases notified at hospitals. Objective: To evaluate prevalence of initial and acquired drug resistance at a general hospital, reference for aids treatment in Rio de Janeiro and to identify associated factors. Methods: Mycobacterium tuberculosis strains from 165 patients were analyzed, between August 1996 and February 1998. Results: Twenty per cent (33/165) were resistant to at least one drug; 13% (12/165) to isoniazid; 3.64% (6/ 165) to rifampin and 3.64% (6/165) to both. Among HIV seropositive subjects (52/165); 28.85% (15/52) were resistant to at least one drug. Acquired resistance occurred in 15.79% of 19 patients that mentioned previous antiTB treatment. Association statistically significant was found with non cavitation on X-ray in bivariate analyses ( P=0.05). Eighty four patients refereed no previous treatment (NPT). Resistance to 1 or more drugs was found in 28.57% (24/84) of NPT patients. Association statistically significant with initial resistance was found with health care workers (P=0.004), unemployment (P=0.03), and diarrhea (P=0.01) in bivariate analyses. On multivariate analyses, health care workers ( P=0.002) remained significantly associated with initial resistance. Conclusions: High resistance rates was found. It corroborates that hospitals needs attention for TB control especially which concerns to health care works infection.

Keywords: Mycobacterium tuberculosis. Drug resistance. Disease transmission, patient to professional. Hospitals.

Background: The Hospital Ferreira Machado, utilized, in part, as a clinical training center for graduate students from the Faculdade de Medicina de Campos, admitted 65 tuberculosis (TB) patients in 2001. Objective: To estimate the prevalence of positive tuberculin skin tests (TST) among medical students during distinct periods of their training and to identify and analyze correlated factors. To compare positivity rates, taking into account the booster effect, and estimate incidence of positive TST by class year. Methods: A cross-sectional study was conducted among 500 students registered in the first semester of 2002. Using a structured and validated questionnaire, data regarding demographics, BCG vaccination and potential exposure to TB patients were obtained. A professional licensed by the Health Department administered the TSTs, and the twostep Mantoux method (PPD Rt23) was used. Results: Of the 500 eligible subjects, 316 (63.2%) were excluded. Analysis showed increasing two-step TST positivity rates corresponding to extent of clinical experience (4%, 6.4% and 13.1%) and a tendency toward correlation with professional level. The highest percentage of positive TSTs was found during the period of clinical training, which corresponded to the time of greatest exposure to patients (1000 hours). Conclusions: a) the TST positivity rate was high (7.9%) among students; b) TST was correlated with in-hospital training stage; c) evaluation of the booster effect lead us to highly recommended boosters in order to reduce the number of false-negative TST results.

Keywords: Tuberculin. Tuberculin test. Tuberculosis. Students/Medical. Cross-sectional studies.