Factors associated with non-completion of latent tuberculosis infection treatment in Rio de Janeiro, Brazil: A non-matched case control study.

INTRODUCTION: There are scarce data on the routine latent tuberculosis infection treatment (LTBIT) and factors associated with a non-completion in high tuberculosis burden countries. Therefore, in this study we aimed to evaluate the factors associated with non-completion of LTBIT. MATERIALS AND METHODS: This was a non-matched case control study conducted at a University Hospital in Rio de Janeiro, Brazil. A total of 114 cases and 404 controls were enrolled between January/1999 and December/2009. Cases were close contacts who did not complete the LTBIT and controls were the contacts that completed it. Multivariate analysis was used to investigate risk factors associated with non-completion of LTBIT among contacts in two different periods of recruitment. RESULTS: Factors associated with non-completion LTBIT included: drug use (OR 23.33, 95% CI 1.83-296.1), TB treatment default by the index case (OR 16.97, 95% CI 3.63-79.24) and drug intolerance. TB disease rates after two years of follow up varied from 0.4% to 1.9%. The number necessary to treat to prevent one TB case among contacts was 116. CONCLUSIONS: Non-completion treatment by the index case and illicit drug use were associated with not completing latent tuberculosis infection treatment and no tuberculosis disease was identified among those who completed latent tuberculosis infection treatment.

Contribution of Xpert MTB/RIF to clinical diagnosis in adolescents with tuberculosis in Rio de Janeiro, Brazil.

SETTING: Rio de Janeiro, RJ, Brazil, a high tuberculosis (TB) burden city.OBJECTIVE: To compare the sociodemographics, clinical characteristics, care process indicators (CPIs) and treatment outcomes among adolescents with pulmonary TB (PTB) and those with PTB + extrapulmonary TB (EPTB), who underwent testing with Xpert® and sputum culture.DESIGN: This was a retrospective study of data from three national databases from 2014 to 2016 of adolescents (aged 10-18 years) residing and notified in Rio de Janeiro City. Three groups were identified according to their Xpert and culture results: Group 1, Xpert- and culture-positive; Group 2, Xpert-positive and culture-negative; and Group 3, Xpert- and culture-negative. Study CPIs were as follows: the time between 'sample collection and Xpert result release', 'sample collection and treatment initiation' and 'notification and treatment outcome'.RESULTS: Of 258 adolescents included in the study, 223 (86.4%) were in Group 1, 20 (7.8%) in Group 2 and 15 (5.8%) in Group 3. Groups 1 and 2 had a similar profile. Compared to Group 1, Group 3 had a higher proportion of HIV-positive cases (21.4% vs. 3.0%, P = 0.016), adolescents with a hospital diagnosis (53.3% vs. 7.6%, P < 0.001), and PTB + EPTB cases (20% vs. 0.4%; P < 0.001). There were no statistically significant differences in CPIs or treatment outcomes.CONCLUSION: The clinical diagnosis was decisive in more critical or complex patients, despite Xpert-negative results.

Molecular characterisation of multidrug-resistant Mycobacterium tuberculosis isolates from a high-burden tuberculosis state in Brazil.

Tuberculosis (TB) is the leading cause of death among infectious diseases worldwide. Among the estimated cases of drug-resistant TB, approximately 60% occur in the BRICS countries (Brazil, Russia, India, China and South Africa). Among Brazilian states, primary and acquired multidrug-resistant TB (MDR-TB) rates were the highest in Rio Grande do Sul (RS). This study aimed to perform molecular characterisation of MDR-TB in the State of RS, a high-burden Brazilian state. We performed molecular characterisation of MDR-TB cases in RS, defined by drug susceptibility testing, using 131 Mycobacterium tuberculosis (M.tb) DNA samples from the Central Laboratory. We carried out MIRU-VNTR 24loci, spoligotyping, sequencing of the katG, inhA and rpoB genes and RDRio sublineage identification. The most frequent families found were LAM (65.6%) and Haarlem (22.1%). RDRio deletion was observed in 42 (32%) of the M.tb isolates. Among MDR-TB cases, eight (6.1%) did not present mutations in the studied genes. In 116 (88.5%) M.tb isolates, we found mutations associated with rifampicin (RIF) resistance in rpoB gene, and in 112 isolates (85.5%), we observed mutations related to isoniazid resistance in katG and inhA genes. An insertion of 12 nucleotides (CCAGAACAACCC) at the 516 codon in the rpoB gene, possibly responsible for a decreased interaction of RIF and RNA polymerase, was found in 19/131 of the isolates, belonging mostly to LAM and Haarlem families. These results enable a better understanding of the dynamics of transmission and evolution of MDR-TB in the region.

Prevalence of pyrazinamide resistance and Wayne assay performance analysis in a tuberculosis cohort in Lima, Peru.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) regimens often contain pyrazinamide (PZA) even if susceptibility to the drug has not been confirmed. This gap is due to the limited availability and reliability of PZA susceptibility testing. OBJECTIVES: To estimate the prevalence of PZA resistance using the Wayne assay among TB patients in Lima, Peru, to describe characteristics associated with PZA resistance and to compare the performance of Wayne with that of BACTEC™ MGIT™ 960. METHODS: PZA susceptibility using the Wayne assay was tested in patients diagnosed with culture-positive pulmonary TB from September 2009 to August 2012. Factors associated with PZA resistance were evaluated. We compared the performance of the Wayne assay to that of MGIT 960 in a convenience sample. RESULTS: The prevalence of PZA resistance was 6.6% (95%CI 5.8-7.5) among 3277 patients, and 47.7% (95%CI 42.7-52.6) among a subset of 405 MDR-TB patients. In multivariable analysis, MDR-TB (OR 86.0, 95%CI 54.0-136.9) and Latin American-Mediterranean lineage (OR 3.40, 95%CI 2.33-4.96) were associated with PZA resistance. The Wayne assay was in agreement with MGIT 960 in 83.9% of samples (κ 0.66, 95%CI 0.56-0.76). CONCLUSION: PZA resistance was detected using the Wayne assay in nearly half of MDR-TB patients in Lima. This test can inform the selection and composition of regimens, especially those dependent on additional resistance.

Outcomes from patients with presumed drug resistant tuberculosis in five reference centers in Brazil.

BACKGROUND: The implementation of rapid drug susceptibility testing (DST) is a current global priority for TB control. However, data are scarce on patient-relevant outcomes for presumptive diagnosis of drug-resistant tuberculosis (pDR-TB) evaluated under field conditions in high burden countries. METHODS: Observational study of pDR-TB patients referred by primary and secondary health units. TB reference centers addressing DR-TB in five cities in Brazil. Patients age 18 years and older were eligible if pDR-TB, culture positive results for Mycobacterium tuberculosis and, if no prior DST results from another laboratory were used by a physician to start anti-TB treatment. The outcome measures were median time from triage to initiating appropriate anti-TB treatment, empirical treatment and, the treatment outcomes. RESULTS: Between February,16th, 2011 and February, 15th, 2012, among 175 pDR TB cases, 110 (63.0%) confirmed TB cases with DST results were enrolled. Among study participants, 72 (65.5%) were male and 62 (56.4%) aged 26 to 45 years. At triage, empirical treatment was given to 106 (96.0%) subjects. Among those, 85 were treated with first line drugs and 21 with second line. Median time for DST results was 69.5 [interquartile - IQR: 35.7-111.0] days and, for initiating appropriate anti-TB treatment, the median time was 1.0 (IQR: 0-41.2) days. Among 95 patients that were followed-up during the first 6 month period, 24 (25.3%; IC: 17.5%-34.9%) changed or initiated the treatment after DST results: 16/29 MDRTB, 5/21 DR-TB and 3/45 DS-TB cases. Comparing the treatment outcome to DS-TB cases, MDRTB had higher proportions changing or initiating treatment after DST results (p = 0.01) and favorable outcomes (p = 0.07). CONCLUSIONS: This study shows a high rate of empirical treatment and long delay for DST results. Strategies to speed up the detection and early treatment of drug resistant TB should be prioritized.

Safety and effectiveness of HAART in tuberculosis-HIV co-infected patients in Brazil.

BACKGROUND: Antiretroviral therapy (ART) significantly reduces tuberculosis (TB) incidence among persons with human immunodeficiency virus (HIV), but the safety and effectiveness of concomitant treatment for both diseases remain unclear. OBJECTIVE: To evaluate the impact of ART and anti-tuberculosis treatment on survival and risk of adverse events (AE) among co-infected individuals. METHODS: In a retrospective cohort study, clinical data were collected from 618 TB-HIV patients treated with rifampin, isoniazid and pyrazinamide ± ethambutol between 1 January 1995 and 31 December 2003. Patients were categorized into two groups: highly active ART (HAART) or no ART. Different HAART regimens were evaluated. Bivariate analysis, multivariate logistic regression and survival analysis using Cox proportional hazards regression were used. RESULTS: One-year mortality was lower for patients receiving HAART (adjusted hazard ratio [aHR] 0.17, 95%CI 0.09-0.31) compared to no ART. HAART increased the risk of AE (aHR 2.08, 95%CI 1.29-3.36). The odds of AE when receiving a ritonavir + saquinavir HAART regimen was eight-fold higher compared to no ART (OR 8.31, 95%CI 3.04-22.69), while efavirenz-based HAART was not associated with a significantly increased risk of AE (OR 1.42, 95%CI 0.76-2.65). CONCLUSION: HIV patients with TB have significantly better survival if they receive HAART during anti-tuberculosis treatment. Efavirenz-based HAART is associated with fewer AEs than protease inhibitor-based HAART.

Tuberculosis caused by RDRio Mycobacterium tuberculosis is not associated with differential clinical features.

BACKGROUND: We recently described the Mycobacterium tuberculosis RD(Rio) genotype, a clonally derived sublineage within the Latin American-Mediterranean (LAM) family. Genetic diversity of M. tuberculosis likely affects the clinical aspects of tuberculosis (TB). Prospective studies that address this issue are scarce and remain controversial. OBJECTIVE: To determine the association of differential clinical features of pulmonary TB with the RD(Rio) M. tuberculosis etiology. METHODS: Culture-proven pulmonary TB patients (n = 272) were clinically evaluated, including history, physical examination, chest X-ray and anti-human immunodeficiency virus serology. Isolates were classified as RD(Rio) or non-RD(Rio) M. tuberculosis by multiplex polymerase chain reaction and further spoligotyped. Clinical and M. tuberculosis genotype data were analyzed. RESULTS: RD(Rio) M. tuberculosis caused disease in 26.5% (72/270) of all TB cases. The LAM genotype, of which RD(Rio) strains are members, was responsible for 46.0% of the TB cases. Demographic data, major signs and symptoms, radiographic presentation, microbiological features and clinical outcomes were not significantly different among patients with TB caused by RD(Rio) and non-RD(Rio) strains. CONCLUSIONS: Disease caused by M. tuberculosis RD(Rio) strains was not clinically distinctive or more severe than disease caused by non-RD(Rio) strains in this series of TB patients. Larger prospective studies specifically designed to disclose differential clinical characteristics of TB caused by specific M. tuberculosis lineages are needed.

Interleukin-10 and interferon-gamma patterns during tuberculosis treatment: possible association with recurrence.

Interleukin (IL) 10 and interferon-gamma (IFN-) levels in induced sputum supernatants of 21 tuberculosis (TB) patients at diagnosis and during chemotherapy were correlated to recurrence rates. IL-10 decreased until day 60 of treatment (T60), and between T60 and T180 it increased again in 7 cases (Pattern 1) and further decreased in 14 cases (Pattern 2). Follow-up of 69 months was performed in 20/21 cases; 6 had recurrence of TB, of which 5/7 (71%) had Pattern 1 and 1/13 (7.7%) Pattern 2 (OR 30.0, 95%CI 2.19411.3, P 0.0072). This was not observed for IFN-. High IL-10 levels at the end of treatment may function as a risk factor for TB recurrence.

Challenges and perspectives for improved management of HIV/Mycobacterium tuberculosis co-infection.

HIV and Mycobacterium tuberculosis (MTB) are two widespread and highly successful microbes whose synergy in pathogenesis has created a significant threat for human health globally. In acknowledgement of this fact, the European Union (EU) has funded a multinational support action, the European Network for global cooperation in the field of AIDS and TB (EUCO-Net), that brings together experts from Europe and those regions that bear the highest burden of HIV/MTB co-infection. Here, we summarise the main outcome of the EUCO-Net project derived from an expert group meeting that took place in Stellenbosch (South Africa) (AIDS/TB Workshop on Research Challenges and Opportunities for Future Collaboration) and the subsequent discussions, and propose priority areas for research and concerted actions that will have impact on future EU calls.

Drug-resistant tuberculosis in six hospitals in Rio de Janeiro, Brazil.

SETTING: Tuberculosis (TB) drug resistance survey in six hospitals in Rio de Janeiro, Brazil. OBJECTIVE: To estimate resistance to at least one drug (DR) and multidrug resistance (MDR) and identify associated factors. DESIGN: One-year cross-sectional survey. Hospitals were included as a convenience sample. RESULTS: Of 595 patients investigated, 156 (26.2%) had previously undergone anti-tuberculosis treatment, 433 (72.8%) were not previously treated and information on the remaining 6 was not available. Overall, DR and MDR rates were high, at respectively 102 (17.1%, 95%CI 14.3-20.5) and 44 (7.4%, 95%CI 5.5-9.9) cases. Among individuals not previously treated, 17 had MDR (3.9%, 95%CI 2.4-6.3) and diagnosis in a TB reference hospital was independently associated with MDR (prevalence ratio [PR] 3.3, 95%CI 1.2-8.7) after multivariate analysis. Among previously treated individuals, 27 had MDR (17.3%, 95%CI 11.7-24.2). MDR-TB was independently associated with diagnosis in a TB reference hospital (PR 3.6, 95%CI 1.5-8.7), male sex (PR 2.3, 95%CI 1.2-4.4) and dyspnoea (PR 0.3, 95%CI 0.1-0.7). CONCLUSION: We found high levels of DR- and MDR-TB. Our study design did not permit us to determine the contribution of community versus nosocomial transmission. Further studies are needed to establish this. Nevertheless, hospitals should be recognised as a potential source of transmission of resistant TB strains and urgent measures to avoid nosocomial TB transmission should be taken.

Access to tuberculosis diagnosis in Itaboraí City, Rio de Janeiro, Brazil: the patient's point of view.

SETTING: Itaboraí Municipality in Rio de Janeiro, Brazil. OBJECTIVE: To evaluate access to tuberculosis (TB) diagnosis for users of the Family Health Program (FHP) and Reference Ambulatory Units (RAUs). DESIGN: A cross-sectional study was conducted in Itaboraí City, Rio de Janeiro, Brazil. Between July and October 2007, a sample of 100 TB patients registered consecutively with the TB Control Program was interviewed using the primary care assessment tool. The two highest scores, describing 'almost always' and 'always', or 'good' and 'very good', were used as a cut-off point to define high quality access to diagnosis. RESULTS: FHP patients were older and had less education than RAU interviewees. Sex and overcrowding did not differ in the two groups. Patient groups did not differ with regard to the number of times care was sought at a unit, transport problems, cost of attending units and availability of consultation within 24 h. Adequate access to diagnosis was identified by 62% of the FHP patients and 53% of the RAU patients (P = 0.01). CONCLUSION: In Itaboraí, Rio de Janeiro, TB patients believe that the FHP units provide greater access to TB diagnosis than RAUs. These findings will be used by the Department of Health to improve access to diagnosis in Itaboraí.

Development of multiplex assay for rapid characterization of Mycobacterium tuberculosis.

We have developed a multiplex assay, based on multiplex ligation-dependent probe amplification (MLPA), that allows simultaneous detection of multiple drug resistance mutations and genotype-specific mutations at any location in the Mycobacterium tuberculosis genome. The assay was validated on a reference panel of well-characterized strains, and the results show that M. tuberculosis can be accurately characterized by our assay. Eighteen discriminatory markers identifying drug resistance (rpoB, katG, inhA, embB), members of the M. tuberculosis complex (16S rRNA, IS6110, TbD1), the principal genotypic group (katG, gyrA), and Haarlem and Beijing strains (ogt, mutT2, mutT4) were targeted. A sequence specificity of 100% was reached for 16 of the 18 selected genetic targets. In addition, a panel of 47 clinical M. tuberculosis isolates was tested by MLPA in order to determine the correlation between phenotypic drug resistance and MLPA and between spoligotyping and MLPA. Again, all mutations present in these isolates that were targeted by the 16 functional probes were identified. Resistance-associated mutations were detected by MLPA in 71% of the identified rifampin-resistant strains and in 80% of the phenotypically isoniazid-resistant strains. Furthermore, there was a perfect correlation between MLPA results and spoligotypes. When MLPA is used on confirmed M. tuberculosis clinical specimens, it can be a useful and informative instrument to aid in the detection of drug resistance, especially in laboratories where drug susceptibility testing is not common practice and where the rates of multidrug-resistant and extensively drug resistant tuberculosis are high. The flexibility and specificity of MLPA, along with the ability to simultaneously genotype and detect drug resistance mutations, make MLPA a promising tool for pathogen characterization.

Low expression of antigen-presenting and costimulatory molecules by lung cells from tuberculosis patients

Costimulatory and antigen-presenting molecules are essential to the initiation of T cell immunity to mycobacteria. The present study analyzed by immunocytochemistry, using monoclonal antibodies and alkaline phosphatase-anti-alkaline phosphatase method, the frequency of costimulatory (CD86, CD40, CD40L, CD28, and CD152) and antigen-presenting (MHC class II and CD1) molecules expression on human lung cells recovered by sputum induction from tuberculosis (TB) patients (N = 22) and non-TB controls (N = 17). TB cases showed a statistically significant lower percentage of HLA-DR+ cells than control subjects (21.9 ± 4.2 vs 50.0 ± 7.2 percent, P < 0.001), even though similar proportions of TB cases (18/22) and control subjects (16/17, P = 0.36) had HLA-DR-positive-stained cells. In addition, fewer TB cases (10/22) compared to control subjects (16/17) possessed CD86-expressing cells (P = 0.04; OR: 0.05; 95 percentCI = 0.00-0.51), and TB cases expressed a lower percentage of CD86+ cells (P = 0.04). Moreover, TB patients with clinically limited disease (£1 lobe) on chest X-ray exhibited a lower percentage of CD86-bearing cells compared to patients with more extensive lung disease (>1 lobe) (P = 0.02). The lower expression by lung cells from TB patients of HLA-DR and CD86, molecules involved in antigen presentation and activation of T cells, may minimize T cell recognition of Mycobacterium tuberculosis, fostering an immune dysfunctional state and active TB.

Pleural fluid ADA, IgA-ELISA and PCR sensitivities for the diagnosis of pleural tuberculosis.

The diagnosis of pleural tuberculosis (pTB) is difficult, and more sensitive and specific techniques are needed. In the period August 1998 to November 2002, we evaluated 132 patients with a pleural effusion submitted to a thoracentesis and pleural biopsy in a tertiary care hospital in Rio de Janeiro, Brazil. Three tests were performed and compared in the pleural fluid: ADA activity measurement, IgA-ELISA for two combined specific Mycobacterium tuberculosis antigens, and polymerase chain reaction (PCR) for detection of M. tuberculosis DNA. Ninety-five patients (72%) were given a final diagnosis of pTB. Overall histopathologic sensitivity was 77%. The sensitivities of pleural fluid culture and AFB smear were 42% and 1%, respectively. Twenty-one (22%) additional patients had a clinical diagnosis of pTB. Median follow-up time of all TB patients after the completion of antituberculous treatment was 13 months. Sensitivities of ADA, IgA-ELISA and PCR were 91%, 78% and 82%, while specificities were 93%, 96% and 85%, respectively. Only ADA sensitivity was significantly higher than the histopathologic examination (McNemar chi2 test; p = 0.002) and also significantly higher than ELISA (p = 0.049), but not higher than PCR (p = 0.143). We conclude that the routine use of ADA activity measurement in pleural fluid can obviate the need for a pleural biopsy in the initial diagnostic approach to pleural effusions, while IgA-ELISA and PCR techniques, potentially more specific tests, need further refinement to improve their accuracy.

Low expression of antigen-presenting and costimulatory molecules by lung cells from tuberculosis patients.

Costimulatory and antigen-presenting molecules are essential to the initiation of T cell immunity to mycobacteria. The present study analyzed by immunocytochemistry, using monoclonal antibodies and alkaline phosphatase-anti-alkaline phosphatase method, the frequency of costimulatory (CD86, CD40, CD40L, CD28, and CD152) and antigen-presenting (MHC class II and CD1) molecules expression on human lung cells recovered by sputum induction from tuberculosis (TB) patients (N = 22) and non-TB controls (N = 17). TB cases showed a statistically significant lower percentage of HLA-DR+ cells than control subjects (21.9 +/- 4.2 vs 50.0 +/- 7.2%, P < 0.001), even though similar proportions of TB cases (18/22) and control subjects (16/17, P = 0.36) had HLA-DR-positive-stained cells. In addition, fewer TB cases (10/22) compared to control subjects (16/17) possessed CD86-expressing cells (P = 0.04; OR: 0.05; 95%CI = 0.00-0.51), and TB cases expressed a lower percentage of CD86+ cells (P = 0.04). Moreover, TB patients with clinically limited disease ( pound1 lobe) on chest X-ray exhibited a lower percentage of CD86-bearing cells compared to patients with more extensive lung disease (>1 lobe) (P = 0.02). The lower expression by lung cells from TB patients of HLA-DR and CD86, molecules involved in antigen presentation and activation of T cells, may minimize T cell recognition of Mycobacterium tuberculosis, fostering an immune dysfunctional state and active TB.

Latent tuberculosis infection among undergraduate medical students in Rio de Janeiro State, Brazil.

SETTING: Five medical schools in three cities with different tuberculosis (TB) incidence rates in Rio de Janeiro State, Brazil. OBJECTIVE: To estimate prevalence of and associated factors for latent tuberculosis infection (LTBI) among medical students. DESIGN: A cross-sectional survey was conducted among undergraduate students in pre-clinical, early and late clinical years from schools in cities with low (28/100,000), intermediate (63/100,000) and high (114/100,000) TB incidence rates. Information on socio-demographic profile, previous BCG vaccination, potential TB exposure, co-morbidity and use of respiratory protective masks was obtained. A tuberculin skin test (TST) was performed using the Mantoux technique by an experienced professional. A positive TST, defined as induration > or = 10 mm, was considered LTBI. RESULTS: LTBI prevalence was 6.9% (95%CI 5.4-8.6). In multivariate analysis, male sex (adjusted odds ratio [aOR] 1.8; 95% CI 1.1-3.0), late clinical years (aOR 1.9; 95% CI 1.01-3.5), intermediate TB incidence (aOR 4.3; 95% CI 1.3-14.6) and high TB incidence in the city of medical school (aOR 5.1; 95% CI 1.6-16.8) were significantly associated with LTBI. CONCLUSIONS: The higher prevalence of LTBI in late clinical years suggests that medical students are at increased risk for nosocomial Mycobacterium tuberculosis infection. The implementation of a TB control program may be necessary in medical schools, particularly in cities with higher TB incidence.

A multicenter evaluation of tuberculin skin test positivity and conversion among health care workers in Brazilian hospitals.

SETTING: Four general Brazilian hospitals. OBJECTIVE: To assess the occupational risk of Mycobacterium tuberculosis (TB) in participating hospitals. DESIGN: In phase one of this longitudinal study, a cross-sectional survey documented baseline tuberculin skin test (TST) positivity rates. In phase two, TST conversion rates were evaluated in participants with an initial negative two-step TST. TST conversion data were analyzed to determine risk factors for TB infection using an increase of > or = 10 mm compared to baseline TST. RESULTS: The initial TST positivity rate was 63.1%; the follow-up TST conversion rate was 10.7 per 1000 person-months (p-m). Hospital of employment, recent bacille Calmette-Guerin (BCG) vaccination, nosocomial TB exposure, and employment as a nurse were independent risk factors for TST conversion. Hospitals without TB infection control measures had higher conversion rates than those with control measures (16.0 vs. 7.8/ 1000 p-m, P < 0.001). CONCLUSIONS: This study indicates an important occupational risk of infection in health care settings with a high TB incidence. Longitudinal TST studies are a valuable tool to assess the occupational risk of TB, even in BCG-vaccinated populations, and should be used to direct limited resources for infection control.