III Brazilian Thoracic Association Guidelines on tuberculosis

In silico identification of phytochemical inhibitors for multidrug-resistant tuberculosis based on novel pharmacophore generation and molecular dynamics simulation studies

BACKGROUND

Multidrug-resistant tuberculosis (particularly resistant to pyrazinoic acid) is a life-threatening chronic pulmonary disease. Running a marketed regime specifically targets the ribosomal protein subunit-1 (RpsA) and stops trans-translation in the non-mutant bacterium, responsible for the lysis of bacterial cells. However, in the strains of mutant bacteria, this regime has failed in curing TB and killing pathogens, which may only because of the ala438 deletion, which inhibit the binding of pyrazinoic acid to the RpsA active site. Therefore, such cases of tuberculosis need an immediate and effective regime.

OBJECTIVE

This study has tried to determine and design such chemotypes that are able to bind to the mutant RpsA protein.

METHODS

For these purposes, two phytochemical databases, i.e., NPASS and SANCDB, were virtually screened by a pharmacophore model using an online virtual screening server Pharmit.

RESULTS

The model of pharmacophore was developed using the potential inhibitor (zr115) for the mutant of RpsA. Pharmacophore-based virtual screening results into 154 hits from the NPASS database, and 22 hits from the SANCDB database. All the predicted hits were docked in the binding pocket of the mutant RpsA protein. Top-ranked five and two compounds were selected from the NPASS and SANCDB databases respectively. On the basis of binding energies and binding affinities of the compounds, three compounds were selected from the NPASS database and one from the SANCDB database. All compounds were found to be non-toxic and highly active against the mutant pathogen. To further validate the docking results and check the stability of hits, molecular dynamic simulation of three compounds were performed. The MD simulation results showed that all these finally selected compounds have stronger binding interactions, lesser deviation or fluctuations, with greater compactness compared to the reference compound.

CONCLUSION

These findings indicate that these compounds could be effective inhibitors for mutant RpsA.

Diagnostic scoring systems for tuberculous pleural effusion in patients with lymphocyte-predominant exudative pleural profile: A development study

Background

Diagnosing tuberculous pleural effusion (TPE) in patients presenting with Lymphocyte-Predominant Exudative pleural effusion (LPE) is challenging, due to the poor clinical utility of TB culture. Adenosine deaminase (ADA) has been recommended for diagnosis, but its high cost and limited availability hinder its clinical utility. We aim to develop diagnostic prediction tools for Thai patients with LPE in scenarios where pleural fluid ADA is available but yields negative results and in situations where pleural fluid ADA is not available.

Methods

Two diagnostic prediction tools were developed using retrospective data from patients with LPE at Surin Hospital. Model 1 is for ADA-negative results, and Model 2 is for situations where pleural fluid ADA testing is unavailable. The models were derived using multivariable logistic regression and presented as two clinical scoring systems: round-up and count scoring. The score cut-point that achieves a positive predictive value (PPV) comparable to the post-test probability of a pleural fluid ADA at a cut-point of 40 U/L was used as a threshold for initiating anti-TB treatment.

Results

A total of 359 patients were eligible for analysis, with 166 diagnosed with TPE and 193 diagnosed with non-TPE. Age <40 years, fever, pleural fluid protein ≥5 g/dL, male gender, pleural fluid color, and pleural fluid ADA ≥20 U/L were identified as final predictors. Both models demonstrated excellent discriminative ability (AuROC: 0.85 to 0.89). The round-up scoring demonstrated PPV above 90% at cut-off points of 4 and 4.5, while the count scoring achieved cut-off points of 3 and 4 for Model 1 (Lex-2P2A) and Model 2 (Lex-2P-MAC), respectively.

Conclusion

These diagnostic tools offer valuable assistance in differentiating between TPE and non-TPE in LPE patients with negative pleural fluid ADA (Lex-2P2A) and in settings where pleural fluid ADA testing is not available (Lex-2P-MAC). Implementing these diagnostic scores may have the potential to improve TPE diagnosis and facilitate prompt initiation of treatment.

A descriptive study on isoniazid resistance-associated mutations, clustering and treatment outcomes of drug-resistant tuberculosis in a high burden country

PURPOSE

To describe katG and inhA mutations, clinical characteristics, treatment outcomes and clustering of drug-resistant tuberculosis (TB) in the State of São Paulo, southeast Brazil.

METHODS

Mycobacterium tuberculosis isolates from patients diagnosed with drug-resistant TB were screened for mutations in katG and inhA genes by line probe assay and Sanger sequencing, and typed by IS6110-restriction fragment-length polymorphism for clustering assessment. Clinical, epidemiological and demographic data were obtained from surveillance information systems for TB.

RESULTS

Among the 298 isolates studied, 127 (42.6%) were isoniazid-monoresistant, 36 (12.1%) polydrug-resistant, 93 (31.2%) MDR, 16 (5.4%) pre-extensively drug-resistant (pre-XDR), 9 (3%) extensively drug-resistant (XDR) and 17 (5.7%) susceptible after isoniazid retesting. The frequency of katG 315 mutations alone was higher in MDR isolates, while inhA promoter mutations alone were more common in isoniazid-monoresistant isolates. Twenty-six isolates phenotypically resistant to isoniazid had no mutations either in katG or inhA genes. The isolates with inhA mutations were found more frequently in clusters (75%) when compared to the isolates with katG 315 mutations (59.8%, p = 0.04). In our population, being 35-64 years old, presenting MDR-, pre-XDR- or XDR-TB and being a retreatment case were associated with unfavourable TB treatment outcomes.

CONCLUSION

We found that katG and inhA mutations were not equally distributed between isoniazid-monoresistant and MDR isolates. In our population, clustering was higher for isolates with inhA mutations. Finally, unfavourable TB outcomes were associated with specific factors.

In Silico Drug Designing for ala438 Deleted Ribosomal Protein S1 (RpsA) on the Basis of the Active Compound Zrl15

Pyrazinoic acid-resistant tuberculosis is a severe chronic disorder. First-line drugs specifically target the ribosomal protein subunit-1 (RpsA) and stop trans-translation in the wild-type bacterium, causing bacterial cell death. In mutant bacterial strain, the deletion of ala438 does not let the pyrazinoic acid to bind to the active site of RpsA and ensures that the bacterium survives. Hence, such tuberculosis cases require an immediate and successful regime. The current study was designed to identify inhibitors that could bind to the mutant state of the RpsA protein. Initially, a pharmacophore model was generated based on the recently published most potent inhibitor for the mutant state of RpsA, i.e., zrl15. The validated pharmacophore model was further used for virtual screening of two chemical libraries, i.e., ZINC and ChemBridge. After applying the Lipinski rule of five (Ro5), a total of 260 and 749 hits from the ChemBridge and ZINC libraries, respectively, were identified using pharmacophore mapping. These hits were then docked into the active site of the mutant state of the RpsA protein, and later, the top 150 compounds from each library were chosen based on the docking score. A total of 21 compounds were shortlisted from each library based on the best protein-ligand interactions. Finally, a total of 05 compounds were subjected to molecular dynamics study to examine the dynamic behavior of each compound in the active site of the mutant state of the RpsA protein. The results revealed that all compounds had good chemical properties such as absorption, distribution, metabolism, excretion, and toxicity (ADMET), and there was no Pan Assay Interference (PAINS) or deviation from Ro5, indicating that these compounds could be useful antagonists for the mutant state of the RpsA protein.

Leptin and advanced glycation end products receptor (RAGE) in tuberculosis patients

Introduction

The pathogenesis of consumptive syndrome of tuberculosis (TB) is largely unknown. Leptin concentrations may be high because of the host’s inflammatory response, contributing to weight loss in patients with TB. The receptor for advanced glycation end products (RAGE) is also associated with weight loss in patients with TB and is related to enhanced mortality. The objective of this study was to evaluate the association between leptin and AGE/RAGE.

Methods

Case-control study. Leptin, AGE (carboxymethyl lysine, CML) and soluble RAGE (sRAGE) were measured from blood samples by ELISA.

Results

We included in the study 34 patients with TB and 34 controls. We found an inverse correlation between serum leptin levels and sRAGE, only in cases (r = -0.609, p < 0.0001). sRAGE levels were lower in patients with TB who died as compared with patients who survive (21.90 ± 4.24 pg/mL vs 66.14 ± 29.49 pg/mL; p = 0.045). Leptin levels were higher in patients with TB who died as compared with patients who survive (14.11 [7.48–14.11] ng/mL vs 3.08 [0.54–6.34] ng/mL; p = 0.028).

Conclusions

We identified lower sRAGE levels and higher leptin levels in patients with TB who died as compared with patients who survive. In addition, an inverse and significant correlation between serum leptin and sRAGE levels was demonstrated. Future studies, with a larger sample size and in different settings, including not only hospitalized patients, are needed to confirm these findings.

Macrophage migration inhibitory factor - 794 CATT5-8 microsatellite polymorphism and susceptibility of tuberculosis

PURPOSE

The establishment of candidate genetic determinants associated with tuberculosis (TB) is a challenge, considering the divergent frequencies among populations. The objective of this study was to evaluate the association between MIF - 794 CATT _5-8 polymorphism and susceptibility to TB.

METHODS

Case-control study. Patients > 18 years, with pulmonary TB were included. The control group consisted of blood donors and household contacts, not relatives, healthy and > 18 years. MIF - 794 CATT _5-8 were genotyped using sequencing of PCR and capillary electrophoresis.

RESULTS

126 patients and 119 controls were included. The genotype 5/5 was more frequent among cases (15.1%) than in controls (5.9%) (p = 0.019). Cases had more frequently the allele 5 (29.4%) as compared with controls (19.3%) (p = 0.010). Prevalence of 7/X + 8/X genotypes was not different between cases and controls (p = 0.821). There was no difference between patients with alleles 7 and 8 and those with alleles 5 and 6 (p = 0.608).

CONCLUSIONS

The genotype 5/5 and the allele 5 of MIF - 794 CATT _5-8 were more frequent among TB patients than in controls.

Association of Xpert MTB/RIF Cycle Threshold Values with Tuberculosis Treatment Outcomes

PURPOSE

Considering the current recommendation of the World Health Organization to replace sputum smear microscopy with Xpert MTB/RIF as an initial diagnostic test for tuberculosis (TB), and that culture takes time to provide results, the cycle threshold (C_T) of the Xpert test may be the only way to assess bacillary load. The objective of this study is to evaluate the association of bacillary load, measured by the Xpert C_T, with the TB treatment outcomes.

METHODS

In cohort study, Xpert C_T values were evaluated in cured and non-cured (failure and death) patients. Multivariate analysis was performed to evaluate if C_T is independently associated with TB treatment outcomes.

RESULTS

During this study period, 155 patients (84 cured and 71 non-cured) met the inclusion and were included in the analysis. The mean C_T value for Xpert MTB/RIF test was 20.7 ± 5.6 in cured patients and 17.1 ± 5.6 in non-cured patients (p < 0.0001). Previous TB was more frequent in non-cured (28.2%) than in cured patients (7.1%) (p < 0.0001). Non-cured patients were younger than cured ones (37.1 ± 13.3 vs 43.6 ± 16.2; p = 0.006). HIV was more frequent in non-cured (28.2%) than in cured patients (15.5%), although this difference was not statistically significant (p = 0.054). In multivariate analysis, C_T values, age, previous TB, and HIV were independently associated with non-cure.

CONCLUSIONS

Lower Xpert MTB/RIF C_T values were independently associated with worse treatment outcomes. The information from even a single test performed before starting treatment proved to be a relatively good predictor of TB treatment outcome.

Use of biologic agents and risk of tuberculosis in Brazil, a tuberculosis high-burden country

Background

Brazil is a country with a high burden of tuberculosis (TB). The immunomodulatory effect of biological therapies is associated with an increased risk of infection. This study evaluated the frequency of TB infection in patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), juvenile idiopathic arthritis (JIA), and psoriatic arthritis (PsA) after the use of biologic agents in a single center of rheumatology.

Methods

In this observational study, 161 consecutive adult patients with RA, JIA, AS, and PsA using biological therapy were followed up during 55 months to evaluate the occurrence of TB infection throughout treatment. All patients were screened for latent TB infection (LTBI), and TB disease was excluded before introduction of biological therapy. Patients with LTBI received prophylaxis with isoniazid before the start of biological treatment.

Results

Of 161 patients on biologics, 31 (19.25%) had positive tuberculin skin test (TST) and received LTBI treatment. Eleven (6.8%) cases of TB were detected in patients on biologics, six (54.5%) had AS, one had PsA (9.09%), two had RA (18.18%), and two had JIA (18.18%). Regarding the use of different biologics, six (54.5%) patients received adalimumab, three (27.2%) infliximab, one (9.09%) etanercept, and one (9.09%) tocilizumab.

Conclusion

In this study, the frequency of TB infection among 161 patients on biologics, during 55 months of follow-up, was 6.8%. Compared with the national registry of patients receiving biologics (BiobadaBrasil — January 01, 2009 to May 31, 2013), a higher incidence of TB (6.8 versus 0.44%) was found in this sample of patients receiving biological therapy. This study highlights that in a country with high TB burden, the possibility of TB infection in a patient receiving biological therapy should always be considered, even after prophylaxis with isoniazid.

Macrophage migration inhibitory factor -173 G>C single nucleotide polymorphism and its association with active pulmonary tuberculosis

PURPOSE

The establishment of candidate genes associated with susceptibility to TB is a challenge especially due to divergent frequencies among different populations. The objective of this study was to evaluate the association between macrophage migration inhibitory factor (MIF) -173 G>C single nucleotide polymorphism (SNP) and susceptibility to pulmonary TB in a population of southern Brazil.

METHODS

Case-control study. Patients > 18 years old, diagnosed with pulmonary TB were included. The control group consisted of blood donors and household contacts, not relatives, healthy and > 18 years old. MIF -173 G>C SNPs were genotyped using real-time PCR using a TaqMan SNP Genotyping assay.

RESULTS

174 patients and 166 controls were included. There were no statistically significant differences between cases and controls regarding genotype prevalence (p>0.05). Comparing patients with normal genotype (GG) with those with at least one C allele, there was also no statistically significant difference (p = 0.135). Also, there was no statistically significant difference comparing the homozygous for the mutation (CC) with the other patients (GG and CG) (p = 0.864).

CONCLUSIONS

We did not find association between MIF -173 G>C polymorphism and susceptibility to pulmonary TB.

Management of multidrug-resistant tuberculosis: main recommendations of the Brazilian guidelines

Over the years, various recommendations have been made in pursuit of controlling resistance to antituberculosis drugs, especially multidrug resistance, in Brazil. Given the importance of standardizing those recommendations, the aim of this study was to describe the main recommendations of the Brazilian guidelines, primarily those related to the treatment and follow-up of cases of tuberculosis. From August through October of 2018, a document search was conducted via the websites of the Brazilian National Ministry of Health, the Brazilian National Tuberculosis Control Program, the JBP, and the Official Gazette of the Federal Republic of Brazil. Data were collected systematically by using a protocol designed specifically for this study. Documents published between 2004 and 2018 were selected. It was possible to understand and trace the history of the measures for the control of multidrug-resistant tuberculosis in Brazil from 2004, when the first documents related to the disease were published, up to 2018, when the second edition of the Brazilian National Guidelines for the Control of Tuberculosis was published. The contents of the documents were analyzed and grouped by case definition, diagnostic criteria, treatment, use of directly observed treatment; mechanisms of social protection for patients; data tools; and organization of care. This analysis allowed us to understand the efforts towards standardizing some measures in Brazil, not only identifying advances in the alignment with international prerogatives (case definition, incorporation of diagnostic technology, and treatment regimens) but also underscoring the need for greater clarity regarding the mechanisms of social protection and the organization of the care provided via the Brazilian health care system.

Association between the radiological presentation and elapsed time for the diagnosis of pulmonary tuberculosis in the emergency department of a university hospital

OBJECTIVE

To evaluate the radiological presentation of patients with pulmonary tuberculosis diagnosed in the emergency department and to investigate its association with the time to diagnosis.

METHODS

This was a prospective observational study involving patients diagnosed with pulmonary tuberculosis in the emergency department of a tertiary university hospital in southern Brazil. Chest X-rays taken on admission were evaluated by a radiologist. The various patterns of radiological findings and locations of the lesions were described. The main study outcome was the total time elapsed between the initial radiological examination and the diagnosis of tuberculosis.

RESULTS

A total of 78 patients were included in the study. The median time from chest X-ray to diagnosis was 2 days, early and delayed diagnosis being defined as a time to diagnosis < 2 days and ≥ 2 days, respectively. Sputum smear positivity was associated with early diagnosis (p = 0.005), and positive culture was associated with delayed diagnosis (p = 0.005). Early diagnosis was associated with the presence of sputum (p = 0.03), weight loss (p = 0.047), cavitation (p = 0.001), and consolidation (p = 0.003). Pulmonary cavitation was found to be an independent predictor of early diagnosis (OR = 3.50; p = 0.028).

CONCLUSIONS

There is a need for tuberculosis-specific protocols in emergency departments, not only to avoid delays in diagnosis and treatment but also to modify the transmission dynamics of the disease.

Access and adherence to isoniazid preventive therapy and occurrence of active TB in a cohort of people living with HIV: a retrospective cohort study in Sao Paulo, Brazil

Tuberculosis (TB) is still a leading cause of morbidity and mortality among people living with HIV (PLHIV). The diagnosis of latent TB is required for the implementation of prophylactic therapy with isoniazid (PTI). However, low access to diagnosis of latent TB and non-adherence to PTI may hinder potential benefits of this essential intervention. In this study, we addressed the access and adherence to PTI in a cohort of PLHIV with positive tuberculin skin test (TST) in a reference HIV clinic in Sao Paulo, Brazil. We have also analyzed the occurrence of active TB over a median of 131 months after a positive TST among study participants. Our findings revealed that 88.3% of the 238 TST-positive patients had access to PTI, and 196 (93.3%) of those with access adhered to PTI. Active tuberculosis was diagnosed in three of the 196 TST-positive patients who adhered to PTI (1.5%; 95% confidence interval [CI] 0.3-4.4%), whereas seven cases were detected among 42 patients without access or who did not adhere to PTI (16.6%; 95% CI 7.0-31.3%). The apparent beneficial effect of PTI in our cohort is consistent with previous studies including PLHIV, and highlights the importance of reliably delivering each of the steps between screening for latent TB and provision of PTI.

CD4+ cell count stratification to guide tuberculosis preventive therapy for people living with HIV

OBJECTIVES

In 2018, Brazilian guidelines changed to recommend tuberculosis (TB) preventive therapy for all people with HIV and a CD4 cell count 350 cells/μl or less, but only for those with a positive tuberculin skin test (TST) if CD4 cell count is than 350 cells/μl. We determined the potential effectiveness of CD4-based guidelines for TB testing and preventive therapy.

DESIGN

Secondary analysis of the stepped-wedge, cluster-randomized THRio trial for isoniazid preventive therapy (IPT).

METHODS

We analyzed data from 4114 newly registered patients with HIV in 29 clinics followed until TB diagnosis, death, or administrative censoring. We compared incidence rates of TB and TB/death between CD4, TST, IPT, and antiretroviral therapy categories.

RESULTS

Initial CD4 cell count was 350 cells/μl or less in 2138 (52%) and more than 350 cells/μl in 1976 (48%) patients. TST was performed for 2922 (71%), of whom 657 (16%) were TST-positive [278 (13%) CD4 ≤ 350 vs. 379 (19%) CD4 > 350]. A total of 619 (15%) received IPT and 2806 (68%) received antiretroviral therapy. For patients with CD4 cell count 350 cells/μl or less who did not receive IPT, the incidence rate of TB was 1.79/100 person-years (pys) and TB/death was 3.89/100 pys. For patients with CD4 cell count more than 350 who did not receive IPT, the incidence rates of TB and TB/death were 0.57/100 and 1.49/100 pys for TST-negatives, and 1.05/100 and 1.64/100 pys for TST-unknowns.

CONCLUSION

TB incidence was high among all patients who did not receive IPT, including those with CD4 cell count more than 350 cells/μl and negative or unknown TST results. TB preventive therapy should be provided to all people living with HIV in medium burden settings, regardless of CD4 cell count and TST status.

A population-based study of tuberculosis incidence among rheumatic disease patients under anti-TNF treatment

Introduction

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. The advent of immunobiologic therapy with TNF inhibitors agents, has been associated with a significant increase in incident cases of tuberculosis in this population.

Objective

To estimate the incidence of tuberculosis in patients receiving TNF inhibitors therapy for rheumatic diseases. As secondary objectives, we sought to evaluate mortality and the clinical impact of screening for latent tuberculosis infection.

Methods

This retrospective study included patients with rheumatic diseases of Public Health System from the Brazilian state, a high TB incidence area, who received prescriptions of TNF inhibitors agents between 2006 and 2016.

Results

A total of 5853 rheumatic disease patients were included. Patients were predominantly women (68.7%) aged 49.5 (± 14.7) years old. Forty-three cases of TB were found (2.86 cases per 1000 person-years; 18 times higher than in the general population). Adalimumab and certolizumab users presented a higher risk for TB development compared to etanercept users (RR: 3.11, 95%CI 1.16–8.35; 7.47, 95%CI 1.39–40.0, respectively). In a subgroup of patients, screening for latent tuberculosis infection was performed in 86% of patients, and 30.2% had a positive tuberculin skin test. Despite latent TB treatment, TB was diagnosed in 2 out of 74 (2.7%) patients. Overall, TB diagnosis did not increase mortality.

Conclusion

In this population-based study of rheumatic disease patients from a high incident area, TNF inhibitor exposure was associated with an 18-time increased TB incidence. Adalimumab and certolizumab were associated with greater and earlier TB diagnosis compared to etanercept.

Cost-effectiveness of QuantiFERON-TB Gold In-Tube versus tuberculin skin test for diagnosis and treatment of Latent Tuberculosis Infection in primary health care workers in Brazil

Objectives

The goal of this study was to perform a cost-effectiveness analysis from the public health system perspective, comparing five strategies for Latent Tuberculosis Infection (LTBI) diagnosis in primary health care workers in Brazil.

Design

Analytical model for decision making, characterized by cost-effectiveness analysis.

Setting

Primary Care Level, considering primary health care workers in Brazil.

Participants

An analytical model for decision making, characterized by a tree of probabilities of events, was developed considering a hypothetical cohort of 10,000 primary health care workers, using the software TreeAge Pro^™ 2013 to simulate the clinical and economic impacts of new diagnostic technology (QuantiFERON^®-TB Gold in-Tube) versus the traditional tuberculin skin test.

Methods

This model simulated five diagnostic strategies for LTBI in primary health care workers (HCW) in Brazil: tuberculin skin testing using ≥5 mm cut-off, tuberculin skin testing ≥10 mm cut-off, QuantiFERON^®-TB Gold in-Tube, tuberculin skin testing using ≥5 mm cut-off confirmed by QuantiFERON^®-TB Gold In-Tube if TST positive, tuberculin skin testing using ≥10 mm cut-off confirmed by QuantiFERON^®-TB Gold In-Tube if TST positive.

Primary and secondary outcome measures

The outcome measures are the number of individuals correctly classified by the test and the number of Tuberculosis cases avoided.

Results

The most cost-effective strategy was the tuberculin skin test considering ≥10mm cut-off. The isolated use of the QuantiFERON^®-TB Gold In-Tube revealed the strategy of lower efficiency with incremental cost-effectiveness ratio (ICER) of US$ 146.05 for each HCW correctly classified by the test.

Conclusions

The tuberculin skin test using ≥10 mm cut-off was the most cost-effective strategy in the diagnosis of Latent Tuberculosis Infection in primary health care works in Brazil.

Diagnosis and treatment of latent tuberculosis infection in patients undergoing treatment with immunobiologic agents: a four-year experience in an endemic area

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.

[Tuberculosis in indigenous children and adolescents in Brazil: factors associated with death and treatment dropout]

The study aimed to describe clinical and sociodemographic characteristics, estimate incidence, and analyze factors associated with dropout and death during treatment of TB cases reported in indigenous children and adolescents in Brazil from 2006 to 2016. A historical case series was performed on incidence according to age bracket and major geographic region, and multinomial logistic regression was used to explain factors associated with treatment dropout and death. Of the 2,096 reported cases, 88.2% evolved to cure, 7.2% dropped out of treatment, and 4.6% evolved to death. There was a predominance of cases in boys 15-19 years of age and a higher proportion of deaths (55.7%) in children < 4 years. Considering indigenous children and adolescents with TB in Brazil as a whole, mean incidence was 49.1/100,000, ranging from 21.5/100,000 to 97.6/100,000 in the Northeast and Central, respectively. Cases with insufficient and irregular follow-up showed higher odds of dropout (OR = 11.1; 95%CI: 5.2-24.8/OR = 4.4; 95%CI: 1.9-10.3) and death (OR = 20.3; 95%CI: 4.9-84.9/OR = 5.1; 95%CI: 1.2-22.7). Cases in retreatment (OR = 2.4; 95%CI: 2.08-8.55) and with HIV coinfection (OR = 8.2; 95%CI: 2.2-30.9) were also associated with dropout. Extrapulmonary (OR = 1.8; 95%CI: 1.1-3.3) and mixed clinical forms (OR = 5.6; 95%CI: 2.8-11.4), age < 4 years (OR = 3.1; 95%CI: 1.5-6.4), and cases from the North (OR = 2.8; 95%CI: 1.1-7.1) and Central (OR = 2.8; 95%CI: 1.1-7.0) were associated with death. TB control in indigenous children and adolescents cannot be achieved without investments in research and development and without reducing social inequalities.

Persistent inflammation during anti-tuberculosis treatment with diabetes comorbidity

Diabetes mellitus (DM) increases risk for pulmonary tuberculosis (TB) and adverse treatment outcomes. Systemic hyper-inflammation is characteristic in people with TB and concurrent DM (TBDM) at baseline, but the impact of TB treatment on this pattern has not been determined. We measured 17 plasma cytokines and growth factors in longitudinal cohorts of Indian and Brazilian pulmonary TB patients with or without DM. Principal component analysis revealed virtually complete separation of TBDM from TB individuals in both cohorts at baseline, with hyper-inflammation in TBDM that continued through treatment completion at six months. By one year after treatment completion, there was substantial convergence of mediator levels between groups within the India cohort. Non-resolving systemic inflammation in TBDM comorbidity could reflect delayed lesion sterilization or non-resolving sterile inflammation. Either mechanism portends unfavorable long-term outcomes including risk for recurrent TB and for damaging immune pathology.

Educational strategy intervention and remote supervision on the post-discharge management of tuberculosis diagnosed in the hospital: Randomized clinical trial

INTRODUCTION

One of the most serious problems in TB control is non-adherence to treatment leading to the risk of drug resistance and subsequent treatment failure.

OBJECTIVES

To assess the impact of an educational strategy intervention and remote supervision on the post-discharge management of new cases of TB diagnosed in hospital on TB cure rate. Secondarily, to assess the impact of this intervention on default rate.

METHODS

Randomized control trial conducted at a general, tertiary care, university affiliated hospital. New cases of TB diagnosed in hospital were included. The primary outcome was cure rate and secondary outcome was default rate. Analysis was carried out by modified intention to treat.

RESULTS

A total of 169 new tuberculosis patients were enrolled. Among them, 80 were assigned to intervention group and 89 to control group. The cure rate was 71.3% in the intervention group and 58.4% in the control group. In the multivariate binary logistic regression model to evaluate the effect of the intervention, controlled by age, sex, current smoking status and directly observed treatment short, intervention was independently associated with cure rate (OR = 0.47; 95% CI: 0.24-0.94; P = 0.033).There was a significant difference in the default rate between the control and intervention groups (18.0% vs 5.0%, respectively, P = 0.039).

CONCLUSION

An educational strategy intervention and remote supervision on the post-discharge management of new cases of TB with in-hospital diagnosis had a positive effect of small magnitude on cure rate. Secondarily, the treatment default rate has been significantly decreased with the intervention.

Latent tuberculosis infection in patients with rheumatic diseases

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.

Advanced glycation end products (AGE) and receptor for AGE (RAGE) in patients with active tuberculosis, and their relationship between food intake and nutritional status

Introduction

The receptor for advanced glycation end products (RAGE) is expressed in normal lungs and is upregulated during infection. AGEs and RAGE cause oxidative stress and apoptosis in lung cells. The objective of this study is to evaluate levels of AGEs and its soluble receptor (sRAGE), and to investigate their relationship with food intake and nutritional status, in a university-affiliated hospital in Brazil.

Methods

Case-control study, from June 2017 to June 2018. AGE (carboxymethyl lysine, CML) and sRAGE were measured from blood samples by Elisa. Nutritional assessment was performed by body mass index, triceps skin-fold thickness, mid-arm circumference, mid-arm muscle circumference, bioelectrical impedance analysis, and food frequency questionnaire.

Results

We included in the study 35 tuberculosis (TB) patients and 35 controls. The mean sRAGE levels were higher in TB patients than in controls (68.5 ± 28.1 vs 57.5 ± 24.0 pg/mL; p = 0.046). Among cases that were current smokers, lower sRAGE levels were associated with mortality, evaluated at the end of hospitalization (p = 0.006), and with weight loss (p = 0.034). There was no statistically significant difference in CML levels and diet CML content between cases and controls. Malnutrition was more frequent in cases, but there was no correlation between nutritional parameters and CML or sRAGE levels.

Conclusions

TB patients had higher sRAGE levels than controls, although it is not clear that this difference is clinically relevant. Also, sRAGE was associated with weight loss and mortality.

Prevalence of latent Mycobacterium tuberculosis infection in renal transplant recipients

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.

Evaluation of the impact that the changes in tuberculosis treatment implemented in Brazil in 2009 have had on disease control in the country

Objective:

To analyze the impact that the 2009 changes in tuberculosis treatment in Brazil had on the rates of cure, tuberculosis recurrence, mortality, treatment abandonment, and multidrug-resistant tuberculosis (MDR-TB).

Methods:

An ordinary least squares regression model was used in order to perform an interrupted time series analysis of secondary data collected from the Brazilian Tuberculosis Case Registry Database for the period between January of 2003 and December of 2014.

Results:

The 2009 changes in tuberculosis treatment in Brazil were found to have no association with reductions in the total number of cases (β = 2.17; 95% CI: −3.80 to 8.14; p = 0.47) and in the number of new cases (β = −0.97; 95% CI: −5.89 to 3.94; p = 0.70), as well as having no association with treatment abandonment rates (β = 0.40; 95% CI: −1.12 to 1.93; p = 0.60). The changes in tuberculosis treatment also showed a trend toward an association with decreased cure rates (β = −4.14; 95% CI: −8.63 to 0.34; p = 0.07), as well as an association with increased mortality from pulmonary tuberculosis (β = 0.77; 95% CI: 0.16 to 1.38; p = 0.01). Although there was a significant increase in MDR-TB before and after the changes (p < 0.0001), there was no association between the intervention (i.e., the changes in tuberculosis treatment) and the increase in MDR-TB cases.

Conclusions:

The changes in tuberculosis treatment were unable to contain the decrease in cure rates, the increase in treatment abandonment rates, and the increase in MDR-TB rates, being associated with increased mortality from pulmonary tuberculosis during the study period.

Keywords: Tuberculosis, pulmonary/epidemiology; Tuberculosis, pulmonary/drug therapy; Tuberculosis, pulmonary/mortality; Interrupted time series analysis; Drug resistance, multiple; Drug compounding.

Tuberculosis treatment

Tuberculosis treatment remains a challenge due to the need to consider, when approaching it, the context of individual and collective health. In addition, social and economic issues have been shown to be variables that need to be considered when it comes to treatment effectiveness. We conducted a critical review of the national and international literature on the treatment of tuberculosis in recent years with the aims of presenting health care workers with recommendations based on the situation in Brazil and better informing decision-making regarding tuberculosis patients so as to minimize morbidity and interrupt disease transmission.

Rapid molecular test for tuberculosis: impact of its routine use at a referral hospital

Objective:

To evaluate the impact of the use of the molecular test for Mycobacterium tuberculosis and its resistance to rifampin (Xpert MTB/RIF), under routine conditions, at a referral hospital in the Brazilian state of Bahia.

Methods:

This was a descriptive study using the database of the Mycobacteriology Laboratory of the Octávio Mangabeira Specialized Hospital, in the city of Salvador, and georeferencing software. We evaluated 3,877 sputum samples collected from symptomatic respiratory patients, under routine conditions, between June of 2014 and March of 2015. All of the samples were submitted to sputum smear microscopy and the Xpert MTB/RIF test. Patients were stratified by gender, age, and geolocation.

Results:

Among the 3,877 sputum samples evaluated, the Xpert MTB/RIF test detected M. tuberculosis in 678 (17.5%), of which 60 (8.8%) showed resistance to rifampin. The Xpert MTB/RIF test detected M. tuberculosis in 254 patients who tested negative for sputum smear microscopy, thus increasing the diagnostic power by 59.9%.

Conclusions:

The use of the Xpert MTB/RIF test, under routine conditions, significantly increased the detection of cases of tuberculosis among sputum smear-negative patients.

Interferon-γ release assay as a sensitive diagnostic tool of latent tuberculosis infection in patients with HIV: a cross-sectional study

Background

In developing countries, tuberculosis (TB) is a major public health problem and the leading cause of death among patients with HIV (Human Immunodeficiency Virus). Until 2001, the tuberculin skin test (TST) was the only available tool for the diagnosis of latent tuberculosis infection (LTBI), but false-negative TST results are frequently reported. Recently, the interferon-γ (IFN-γ) release assay (IGRA) has gained ground because it can detect the IFN-γ secreted by circulating lymphocytes T cells when stimulated by specific TB antigens. However, the role of IGRA in the diagnosis of LTBI in HIV-infected patients has not been well established.

Methods

This cross-sectional study compared the accuracy of TST (performed by the Mantoux method) and IGRA (QuantiFERON-TB Gold In-Tube, Cellestis, Carnegie, Australia) on the diagnosis of LTBI among patients with HIV. LTBI is defined by LTBI risk and at least one positive test (TST or IGRA), without clinical evidence of active TB. We also assessed the accuracy of TST and IGRA among HIV patients with high and low risk for LTBI.

Results

Among 90 HIV patients, 80 met the study criteria for LTBI, fifty-nine (73.7%) patients were TST positive, 21 (26.2%) were negative, whereas 75 patients (93.7%) were IGRA positive, and five (6.2%) were negative. TST showed poor agreement with the diagnosis of LTBI (Kappa: 0.384), while IGRA demonstrated good agreement (Kappa: 0.769). Among 69 patients with high risk and 21 with low risk for LTBI, TST was positive in 48 (69.5%) and 11 (52.4%), while IGRA was positive in 68 (98.5%) and 7 (33.3%) patients, respectively. There were no association between TST and the level of risk (P = 0,191). Conversely, we observed a strong association between the IGRA and risk for LTBI (p < 0.001).

Conclusions

Compared to TST, IGRA positivity is consistent with the risk of TB infection and seems to be a better diagnostic tool for LTBI in HIV-infected patients.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3508-8) contains supplementary material, which is available to authorized users.

The role of Mycobacterium tuberculosis antigen specific cytokines in determination of acid fast bacilli culture status in pulmonary tuberculosis patients co-infected with human immunodeficiency virus

Introduction

The interaction between Mycobacterium tuberculosis and HIV leads to rapid progression of tuberculosis (TB) and human immunodeficiency virus (HIV)-induced immunosuppression. Diagnosis of TB in these patients is more difficult due to its atypical presentations giving contradicting results. The overall aim of this study was to evaluate the ability of pro-inflammatory cytokine (Th1) and anti-inflammatory cytokine (Th2) to discriminate between culture-positive and -negative smear status in HIV-TB co-infected patients.

Methods

In a prospective cohort, a total of 86 study participants were recruited: 46 culture-negative and 40 culture-positive. Blood and sputum samples were collected from all participants. The blood was then analyzed using FACSCalibur flow cytometer to immunophenotype the cells and ELISA performed for cytokine profiles. Sputum samples were analyzed to determine smear status using direct microscopy and Lowenstein Jensen medium. Statistical analyses were performed using R software. Independent samples t-test was used to compare means between the two groups, while the medians were compared using two-sample Wilcoxon rank sum test. Pearson's Chi-square test was used to compare the proportion of male and female participants across the culture and AFB smear status. In order to determine the predictive power of Th1 and Th2 in discriminating Pulmonary Tuberculosis status (PTB) (culture status was used as a confirmatory test), binary logistic regression models were fitted for Th1 covariates [IFN-γ, TNF-α, IL-2 and IL-12(p70)] and Receiver Operating Characteristic (ROC) curves plotted.

Results

The overall mean age of the participants was 39 years (SD=12), 42% being male. Although, lymphocytes counts were higher in culture-positive relative to culture-negative, the CD8, CD19, and CD16/CD56 were comparable in the two groups. The CD4 counts differed between the two groups (P=0.012). The Th1 showed a better discrimination between culture-positive and -negative PTB individuals; IFN-γ (P=0.001), TNF-α (P=0.001), IL-2 (P=0.001) and IL-12(p70) (P=0.016). The Th2 cytokines (IL-4, IL-6 and IL-10) were comparable between the culture-positive and -negative groups. However, when the combination of Th1 cytokines [IFN-γ, TNF-α, IL-2 and IL-12(p70)] was fitted in binary logistic regression models, the predictive power was high with area under curve (AUC) being 89.7% in discriminating PTB.

Conclusion

This study provides evidence for the ability of a combination of Th1 cytokines in discriminating against culture-positive and culture-negative PTB.

The relation between leptin and inflammatory markers with respiratory and peripheral muscle strength in tuberculosis: A case-control study

BACKGROUND

Muscle weakness is a part of the wasting syndrome associated with TB. Cytokines are candidates as the initial causative agents of the metabolic changes in TB. The objective of this study is to assess the peripheral and respiratory muscle strength in patients with TB and controls and relate these findings with leptin, IL-6 and TNF-α serum levels.

METHODS

Case-control study. Hospitalized patients with pulmonary TB and controls were included. Maximal voluntary handgrip strength (HS), maximal inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were measured. Leptin, IL-6 and TNF-α dosage were performed.

RESULTS

We included 35 cases and 35 controls. Leptin was lower and TNF-α levels were higher in TB patients than in controls (P < .0001 for both). Body mass index (BMI), HS, MIP and MEP were all significantly lower in cases than in controls (P < .0001). Lower leptin and higher TNF-α levels are associated with malnutrition and reduced MIP, MEP and HS. Patients who reported fever and those with positive culture for Mycobacterium tuberculosis had higher serum levels of IL-6.

CONCLUSION

Peripheral and respiratory muscle strength and leptin levels were reduced in patients with active TB. Lower levels of leptin and higher levels of TNF-α were associated with malnutrition and with reduced MIP, MEP and HS.

Comparison between Ogawa-Kudoh and modified Petroff techniques for mycobacteria cultivation in the diagnosis of pulmonary tuberculosis

Objective

To compare the performance of the Ogawa-Kudoh method with the modified Petroff technique in diagnosis of pulmonary tuberculosis.

Methods

A total of 205 sputum samples from 166 patients with clinical suspicion or under pulmonary tuberculosis follow-up, seen at a public tertiary care hospital, from July 2014 to July 2016 were used. All samples were simultaneously processed using the Ogawa-Kudoh and modified Petroff decontamination methods, according to the recommendations of the Ministry of Health. In the statistical analysis, the McNemar test and the Kappa index were used, respectively, to compare proportions and verify agreement between data.

Results

The Ogawa-Kudoh and modified Petroff methods were efficient in mycobacteria detection, with no significant differences in results (p=0.549) and contamination rate of the cultures (p=0.065). The agreement between techniques was considered excellent (Kappa index of 0.877) and Ogawa-Kudoh, as compared to the modified Petroff technique, showed sensitivity of 90.4%, specificity of 96.6%, positive predictive value of 94.3% and negative predictive value of 94.2%.

Conclusion

The Ogawa-Kudoh technique proved to be sufficiently sensitive and specific for diagnosis of pulmonary tuberculosis, and, therefore, suitable for routine laboratory application. Since it is simple, low-cost and has less technical requirements for biosafety and professional training, Ogawa-Kudoh is an alternative for managers and healthcare professionals to promote the expansion of bacteriological diagnostic coverage of pulmonary tuberculosis.

Impact of introduction of Xpert MTB/RIF test on tuberculosis (TB) diagnosis in a city with high TB incidence in Brazil

Background

Xpert MTB/RIF is increasingly used in many countries as the initial diagnostic test for tuberculosis (TB). Few studies have evaluated the effect of Xpert on TB diagnosis under programmatic conditions in Brazil. The aim of the present study was to evaluate the impact of introduction of Xpert MTB/RIF on TB diagnosis in a city with high TB incidence in Brazil.

Methods

We included patients evaluated with conventional diagnostic tests during one year before Xpert introduction (pre-Xpert group) and patients evaluated using Xpert during one year after the test introduction (post-Xpert group).

Results

620 patients met the inclusion criteria (208 in the pre-Xpert group and 412 in the post-Xpert group) and were included in the analysis. The time until TB diagnosis was shorter in post-Xpert group (0.7 day, IQR: 0.5–1.0 day) than in pre-Xpert group (2.0 days, IQR: 2.0–2.0 days) (p<0.0001). Atypical disease characteristics, such as less weight loss, fever, dyspnea, night sweats, and hemoptysis; a negative sputum smear; a negative culture, and a chest X-ray atypical of TB were more common in post-Xpert group than in pre-Xpert group (p<0.0001 for all).

Conclusions

We found that the implementation of the Xpert MTB/RIF assay, under programmatic conditions, improve and facilitate TB diagnosis, especially in cases with atypical disease manifestations. These results are likely to be generalizable to settings with a similar high TB incidence.

Tuberculosis and latent infection in employees of different prison unit types

OBJECTIVE

Estimate the prevalence of active tuberculosis and latent tuberculosis infection among the staff that is in contact and the staff that is not in contact with prisoners, and investigate factors associated with latent tuberculosis infection in this population.

METHODS

Observational cross-sectional study, conducted from 2012 to 2015, in employees of different prison units in the municipality of Franco da Rocha, SP. It consisted of the application of a questionnaire, application and reading of the tuberculin test, sputum smear microscopy, sputum culture, and radiological examination. The association between the qualitative variables was calculated by the Pearson's chi-squared test. The sociodemographic and clinical-epidemiological factors related to the latent tuberculosis infection were evaluated by the logistic regression with the odds ratios (OR) calculation and their respective intervals with 95% of confidence (95%CI).

RESULTS

A total of 1,059 employees were examined, 657 (62.0%) of prisons, 249 (23.5%) of CASA Foundation units and 153 (14.5%) of custodial and psychiatric treatment hospitals. The tuberculin test was applied and read for 945 (89.2%) professionals. Of these, 797 (84.3%) were contacts of detainees and 148 (15.7%) were not. Among prison staff, the factors associated with latent tuberculosis infection were: contact with detainee (OR = 2.12, 95%CI 1.21-3.71); male gender (OR = 1.97, 95%CI 1.19-3.27); between 30 and 39 years old (OR = 2.98, 95%CI 1.34-6.63), 40 to 49 years old (OR = 4.32, 95%CI 1.94-9.60), and 50 to 59 years old (OR = 3.98, 95%CI 1.68-9.43); nonwhite color or race (OR = 1.89, 95%CI 1.29-2.78); and smoker (OR = 1.64, 95%CI 1.05-2.55). There were no positive test on sputum smear microscopy and culture. Of the 241 (22.8%) professionals who underwent radiological examination, 48 (19.9%) presented alterations of which 11 were suspected of tuberculosis.

CONCLUSIONS

Prison employees who have direct contact with detainees are 2.12 times more likely to become infected with Mycobacterium tuberculosis in the work environment and consequently to become ill with tuberculosis and should be targeted for disease prevention and control.

Nutrition Status Among HIV-Positive and HIV-Negative Inpatients with Pulmonary Tuberculosis

BACKGROUND

The association between tuberculosis (TB) and malnutrition is well recognized. Considering the risk of mortality due to malnutrition in patients with TB, it is necessary to conduct a thorough nutrition assessment to identify individuals at nutrition risk. The study objective was to assess the nutrition status of hospitalized patients with TB, co-infected or not by human immunodeficiency virus (HIV).

METHODS

Patients with confirmed diagnosis of TB were included using a cross-sectional design. Nutrition assessment parameters included: body mass index (BMI), triceps skin-fold thickness (TSF), bioelectrical impedance analysis (BIA), mid-upper-arm circumference (MUAC), mid-arm muscle circumference (MAMC), food frequency questionnaire, Malnutrition Screening Tool (MST), Subjective Global Assessment (SGA), and serum levels of hemoglobin.

RESULTS

A total 108 patients completed the study. Forty-four patients (40.7%) were HIV positive. Considering the BMI, 36.1% of the patients met the criteria for nutrition deficiency. Body fat percentage was low in 27.8% of patients. In addition, more than half of the participants met criteria for malnutrition according to MUAC, MAMC, TSF, SGA, or MST. Malnutrition measured by MAMC was more frequent in HIV-positive patients (n=33, 75.0%) than in HIV-negative patients (n=31, 48.4%) (P = 0.010). Regarding the components of diet, selenium and vitamin C intake among HIV-positive patients was significantly lower than in HIV-negative patients.

CONCLUSIONS

We identified a high prevalence of malnutrition in hospitalized patients with pulmonary TB, regardless of the method used to assess nutrition status. In HIV-positive patients, malnutrition measured by MAMC was more frequent than in HIV-negative patients.

Intensity of exposure to pulmonary tuberculosis determines risk of tuberculosis infection and disease

Household contacts of pulmonary tuberculosis (TB) patients are at increased risk of TB infection and disease. However, their risk in relation to the intensity of exposure remains unknown.We studied smear-positive TB cases and their household contacts in Vitória, Brazil. We collected clinical, demographic and radiographic information from TB cases, and obtained tuberculin skin test (TST) and QuantiFERON-TB Gold (QFT) results from household contacts. We measured intensity of exposure using a proximity score and sleep location in relation to the TB index case and defined infection by TST ≥10 mm or QFT ≥0.35 UI·mL-1 We ascertained secondary TB cases by reviewing local and nationwide case registries.We included 160 TB index cases and 894 household contacts. 464 (65%) had TB infection and 23 (2.6%) developed TB disease. Risk of TB infection and disease increased with more intense exposures. In an adjusted analysis, the proximity score was associated with TB disease (OR 1.61, 95% CI 1.25-2.08; p<0.000); however, its diagnostic performance was only moderate.Intensity of exposure increased risk of TB infection and disease among household contacts; however, its diagnostic performance was still suboptimal. A biomarker to target preventive therapy is urgently needed in this at-risk population.

Polymerase chain reaction test in induced sputum of patients with pulmonary tuberculosis

INTRODUCTION

Induced sputum (IS) is an alternative method of obtaining sputum, but IS smears are frequently negative. Culture is more time consuming in its results, and less useful to guide the diagnosis. Polymerase chain reaction (PCR) is the most common methodology for rapid diagnosis of tuberculosis (TB), and few studies evaluated its role in IS samples.

OBJECTIVES

The objective of this study is to determine the diagnostic yield of PCR for TB compared with culture in IS samples.

MATERIALS AND METHODS

Prospective study. Inpatients and outpatients of >18 years with respiratory symptoms suggestive of PTB were invited to participate. The subjects were interviewed using a standardized questionnaire, and collected IS. Three samples were obtained for AFB smear and culture. A fourth sample was obtained for PCR test.

RESULTS

A total of 116 IS samples were evaluated. The sensitivity, specificity, positive predictive value and negative predictive values of PCR were 95.2%, 48.4%, 29.0% and 97.9%, respectively. The area under the receiver operating characteristic curve was .72 for the PCR test (P < .0001).

CONCLUSIONS

Although the PCR specificity could be underestimated, if we consider PCR to be more sensitive than the culture method used, we believed that these PCR-positive tests mean false positives. The results of PCR should always be interpreted carefully in conjunction with clinical information.

Tuberculosis Treatment Outcomes and Factors Associated with Each of Them in a Cohort Followed Up between 2010 and 2014

Tuberculosis treatment has undergone recent changes in Brazil. Objective. To assess whether favorable outcomes on tuberculosis therapy improved in recent years. Methods. Retrospective observational study, based on primary data of tuberculosis patients, followed at INI-FIOCRUZ, from January 2012 to December 2014. Results. The outcomes observed were as follows: cure (80%), default (14%), treatment failure (5%), and death (1%). HIV infection without antiretroviral therapy [OR 0.34 (0.15–0.79)], tuberculosis diagnosis based on sputum smear [OR 0.22 (0.07–0.74)], drug use [OR 0.22 (0.11–0.46)], and/or treatment interruption due to adverse reactions [OR 0.23 (0.08–0.67)] decreased the chance of cure. Predictors of default, that is, use of noninjecting drugs [OR 3.00 (95% CL 1.31–6.88)], treatment interruption due to adverse reactions [OR 6.30 (1.81–21.95)], low schooling [OR 2.59 (2.15–5.82)], higher age [OR 0.44 (0.23–0.82)], and female gender [OR 0.28 (0.11–0.71)], reduced the chance of treatment default. Tuberculosis diagnosis based on sputum smear [OR 7.77 (1.94–31.09)] and/or arterial hypertension [OR 4.07 (1.25–13.18)] was associated with treatment failure. Conclusion. Mortality and default were low considering the prevalence of HIV infection; however cure was not significantly increased.

Prevalence and risk factors for latent tuberculosis infection among primary health care workers in Brazil

Health care workers (HCW) are at increased risk of latent tuberculosis infection (LTBI) from occupational exposure to Mycobacterium tuberculosis. The objective was to determine the prevalence of and risk factors for LTBI among primary HCW in five Brazilian cities. We conducted a cross-sectional study, from 2011 to 2013, among primary HCW, using a structured questionnaire and an evaluated for LTBI using the Quantiferon-TB Gold in-tube test. The magnitude of the associations was assessed using hierarchical logistic regression models. Among 708 HCW, the LTBI prevalence was 27% (n = 196; 95%CI: 24%-31%). We found that the following factors were positively associated with LTBI in primary HCW: age > 50 years (OR = 2.94; 95%CI: 1.44-5.99), absence of a BCG scar (OR = 2.10; 95%CI: 1.28-3.43), self-reported ex-smoker status (OR = 1.80; 95%CI: 1.04-3.11), being a nurse (OR = 2.97; 95%CI: 1.13-7.83), being a nurse technician (OR = 3.10; 95%CI: 1.26-7.60), being a community health agent (OR = 2.60; 95%CI: 1.06-6.40), and irregular use of N95 masks (OR = 2.51; 95%CI: 1.11-5.98). In contrast, HCWs who do not work in health care facilities with a TB control program were less likely to have LTBI (OR = 0.66; 95%CI: 0.45-0.97). This study demonstrated a substantial occupational risk of LTBI among primary HCW in Brazil. The Brazilian TB control program, as well as local programs, need to target these high-risk HCW with education, as well as with better personal protective equipment to prevent acquisition of new TB infection.

Estimated rates of recurrence, cure, and treatment abandonment in patients with pulmonary tuberculosis treated with a -four-drug fixed-dose combination regimen at a tertiary health care facility in the city of Rio de Janeiro, Brazil

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.

Incident Mycobacterium tuberculosis infection in household contacts of infectious tuberculosis patients in Brazil

BACKGROUND

In household contact investigations of tuberculosis (TB), a second tuberculin skin test (TST) obtained several weeks after a first negative result consistently identifies individuals that undergo TST conversion. It remains unclear whether this delay in M. tuberculosis infection is related to differences in the infectious exposure, TST boosting, partial host resistance, or some other factor.

METHODS

We conducted a household contact study Vitória, Brazil. Between 2008 and 2013, we identified culture-positive pulmonary TB patients and evaluated their household contacts with both a TST and interferon gamma release assay (IGRA), and identified TST converters at 8-12 weeks post study enrollment. Contacts were classified as TST-positive (≥10 mm) at baseline, TST converters, or persistently TST-negative. We compared TST converters to TST-positive and to TST-negative contacts separately, using generalized estimating equations.

RESULTS

We enrolled 160 index patients and 838 contacts; 523 (62.4%) were TST+, 62 (7.4%) TST converters, and 253 (30.2%) TST-. TST converters were frequently IGRA- at 8-12 weeks. In adjusted analyses, characteristics distinguishing TST converters from TST+ contacts (no contact with another TB patient and residence ownership) were different than those differentiating them from TST- contacts (stronger cough in index patient and contact BCG scar).

CONCLUSIONS

The individual risk and timing of M. tuberculosis infection within households is variable and dependent on index patient, contact and environmental factors within the household, and the surrounding community. Our findings suggest a threshold effect in the risk of infection in humans.

Performance of clinical prediction rules for diagnosis of pleural tuberculosis in a high-incidence setting

OBJECTIVES

Diagnosis of pleural tuberculosis (PT) is still a challenge, particularly in resource-constrained settings. Alternative diagnostic tools are needed. We aimed at evaluating the utility of Clinical Prediction Rules (CPRs) for diagnosis of pleural tuberculosis in Peru.

METHODS

We identified CPRs for diagnosis of PT through a structured literature search. CPRs using high-complexity tests, as defined by the FDA, were excluded. We applied the identified CPRs to patients with pleural exudates attending two third-level hospitals in Lima, Peru, a setting with high incidence of tuberculosis. Besides pleural fluid analysis, patients underwent closed pleural biopsy for reaching a final diagnosis through combining microbiological and histopathological criteria. We evaluated the performance of the CPRs against this composite reference standard using classic indicators of diagnostic test validity.

RESULTS

We found 15 eligible CPRs, of which 12 could be validated. Most included ADA, age, lymphocyte proportion and protein in pleural fluid as predictive findings. A total of 259 patients were included for their validation, of which 176 (67%) had PT and 50 (19%) malignant pleural effusion. The overall accuracy of the CPRs varied from 41% to 86%. Two had a positive likelihood ratio (LR) above 10, but none a negative LR below 0.1. ADA alone at a cut-off of ≥40 IU attained 87% diagnostic accuracy and had a positive LR of 6.6 and a negative LR of 0.2.

CONCLUSION

Many CPRs for PT are available. In addition to ADA alone, none of them contributes significantly to diagnosis of PT.

Tuberculosis incidence among people living with HIV/AIDS with virological failure of antiretroviral therapy in Salvador, Bahia, Brazil

Antiretroviral therapy for HIV has led to increased survival of HIV-infected patients. However, tuberculosis remains the leading opportunistic infection and cause of death among people living with HIV/AIDS. Tuberculosis has been shown to be a good predictor of virological failure in this group. This study aimed to evaluate the incidence of tuberculosis and its consequences among individuals diagnosed with virological failure of HIV. This was a retrospective cohort study involving people living with HIV/AIDS being followed-up in an AIDS reference center in Salvador, Bahia, Brazil. Individuals older than 18 years with HIV infection on antiretroviral therapy for at least six months, diagnosed with virological failure (HIV-RNA greater than or equal to 1000 copies/mL), from January to December 2013 were included. Tuberculosis was diagnosed according to the criteria of the Brazilian Society of Pneumology. Fourteen out of 165 (8.5%) patients developed tuberculosis within two years of follow-up (incidence density = 4.1 patient-years). Death was directly related to tuberculosis in 6/14 (42.9%). A high incidence and tuberculosis-related mortality was observed among patients with virological failure. Diagnosis of and prophylaxis for tuberculosis in high-incidence countries such as Brazil is critical to decrease morbidity and mortality in people living with HIV/AIDS.

[Factors associated with TB/HIV coinfection: evidence from notification data in the State of Amazonas, Brazil, 2001-2012]

Tuberculosis (TB) in persons living with HIV (PLHIV) is the leading infectious cause of AIDS-related death. The aim of this study was to estimate the prevalence of TB/HIV coinfection, evaluate notification of the two diseases over time by probabilistic database linkage, and identify factors associated with AIDS and TB notifications. Prevalence of TB/HIV coinfection was 7.7%. The group of PLHIV with subsequent TB diagnosis was the most representative, despite available preventive measures. Underreporting of TB among AIDS cases was 35%, and 19.6% of TB cases could have been reported as AIDS. For AIDS cases with mention of TB, living in the state capital showed 75% greater odds of being reported to the Tuberculosis Notification System (SINAN-TB), and having died increased the odds of reporting by 40%. Of TB cases with mention of HIV, brown skin color, age 25 to 39 years, living in the state capital, and having evolved to death were associated with higher odds of reporting to the AIDS Notification System. Periodic linkage of these databases can be a powerful tool for programs to decrease underreporting.

Association of outcomes with comprehension, adherence and behavioral characteristics of tuberculosis patients using fixed-dose combination therapy in Contagem, Minas Gerais, Brazil

The present study aimed to assess the association of outcomes with comprehension, adherence and behavioral characteristics of tuberculosis (TB) patients using fixed-dose combination (FDC) therapy in the city of Contagem, MG, Brazil. This study used standardized questionnaires to collect data. Outcomes included cure in 77.2% (64/ 83), noncompliance with treatment in 20.4% (17/ 83), and absence of organ failure or death cases. The rate of adherence to treatment was high (71.1% - 59/ 83), while the level of comprehension of the treatment was insufficient for the majority of patients (72.3% - 60/ 83). When a greater number of medicines was used, the chance of noncompliance with treatment increased exponentially (p = 0.00 - OR 1.72). Light-skinned black patients, alcoholics and those who live with HIV/ AIDS showed a significant association with noncompliance with treatment (p=0.039 - OR 3.38, p=0.002 - OR 4.68, and p=0.001 - OR 9.68, respectively). Comprehension also presented a significant association with noncompliance with treatment (p=0.01 and OR 5.76 and CI 1.49-22.29). The probability of noncompliance with treatment in the first few months was greater than in the subsequent months. This study demonstrates that if the TB patients had a better understanding of the treatment, the outcome would have been more favorable as regards a proper cure.

Distance Learning Course for Healthcare Professionals: Continuing Education in Tuberculosis

BACKGROUND

Continuing education of healthcare workers (HCWs) is an essential strategy for the control of tuberculosis (TB) transmission, enabling HCWs in early detection and appropriate treatment of TB cases.

METHODS

We developed a distance learning (DL) course on TB for nurses. We conducted a quasi-experimental before and after study to evaluate the DL community at the participant's learning level. In addition, to evaluate the DL community at the level of participant satisfaction, a cross-sectional study was carried out after the course. Nurses involved in active inpatient or outpatient care of patients were recruited to participate in the study.

RESULTS

Sixty-six participants started and completed the course and they were included in the analysis. The overall mean pretest and post-test scores were 10.3 ± 2.2 and 11.4 ± 2.7, respectively. Participants increased their knowledge to a statistically significant degree (p < 0.0001). At baseline, the frequency of correct answers was very low in some questions: number of people infected by Mycobacterium tuberculosis in the world (10.6%); number of TB cases in Brazil (36.4%); contagiousness of latent TB infection (LTBI) (28.8%); and definition of active case finding (45.5%). Course feedback was mostly positive, with majority of users saying they were satisfied or totally satisfied.

CONCLUSIONS

A brief DL course on TB was associated with some improvement in knowledge among nurses. The baseline knowledge was low regarding TB epidemiologic data, concepts on LTBI, and active case finding. This finding emphasizes the need to further improve the competencies and knowledge of nurses.

Tomographic Aspects of Advanced Active Pulmonary Tuberculosis and Evaluation of Sequelae following Treatment

Objectives. To evaluate tomographic changes in pulmonary tuberculosis (TB), degree of agreement among three radiologists regarding tomographic diagnoses, and sequelae following treatment. Methods. Cross-sectional and descriptive study of 74 TB patients confirmed by sputum culture and chest computed tomography before (CT1) and 6 months after (CT2) drug therapy. Results were performed by three radiologists blinded to clinical and laboratory results. Results. Main findings in CT1 included nodules indicating the presence of a tree-in-bud pattern in 93% of cases, ill-defined nodules in 84% of cases, consolidation in 77% of cases, architectural distortion in 71% of cases, cavitary lesions in 62% of cases, and ground glass opacities in 37% of cases. Airway involvement, characterized by increased thickness and dilatation of the bronchial walls, occurred in 93% of cases. Pleural involvement occurred in 54%. There was an agreement on active TB among the three radiologists in 85% of cases. The results in CT2 indicated the presence of architectural distortion in 91% of cases and cylindrical bronchiectasis in 86%. Conclusions. The study established a tomographic pattern for diagnosis of active TB characterized by the presence of airway nodules, consolidation, architectural distortion, and cavitary lesions, and an almost complete degree of agreement (Kappa) was observed among the radiologists (0.85). CT after treatment assists in defining the cure.