Clinical standards for the assessment, management and rehabilitation of post-TB lung disease

BACKGROUND: Increasing evidence suggests that post-TB lung disease (PTLD) causes significant morbidity and mortality. The aim of these clinical standards is to provide guidance on the assessment and management of PTLD and the implementation of pulmonary rehabilitation (PR).METHODS: A panel of global experts in the field of TB care and PR was identified; 62 participated in a Delphi process. A 5-point Likert scale was used to score the initial ideas for standards and after several rounds of revision the document was approved (with 100% agreement).RESULTS: Five clinical standards were defined: Standard 1, to assess patients at the end of TB treatment for PTLD (with adaptation for children and specific settings/situations); Standard 2, to identify patients with PTLD for PR; Standard 3, tailoring the PR programme to patient needs and the local setting; Standard 4, to evaluate the effectiveness of PR; and Standard 5, to conduct education and counselling. Standard 6 addresses public health aspects of PTLD and outcomes due to PR.CONCLUSION: This is the first consensus-based set of Clinical Standards for PTLD. Our aim is to improve patient care and quality of life by guiding clinicians, programme managers and public health officers in planning and implementing adequate measures to assess and manage PTLD.

Tuberculosis is associated with non-tuberculosis-related deaths among HIV/AIDS patients in Rio de Janeiro

SETTING

Human immunodeficiency virus (HIV) infected patients followed in a large cohort in Rio de Janeiro, Brazil.

OBJECTIVE

To evaluate the association of tuberculosis (TB) and other covariables with non-TB-related (NTR) causes of death (CODs).

DESIGN

Patients aged >18 years were followed from 1997 to 2009, until death or 31 December 2009, whichever was earlier. CODs were ascertained using a standardised algorithm. TB diagnosis and prophylaxis followed Brazilian guidelines. Poisson models were used to calculate adjusted rate ratios (aRRs).

RESULTS

Of 2887 patients included in the study, 761 had TB (26.4%). NTR death rates were twice as high among patients with TB (4/100 vs. 2.09/100 patient-years). TB was associated with NTR deaths (aRR 1.4, 95%CI 1.05-1.86, P = 0.01). Highly active antiretroviral treatment (HAART) was protective against NTR (aRR 0.46, 95%CI 0.34-0.61, P < 0.001). Among patients who had never had active TB, prophylaxis was also protective against NTR (aRR 0.45, P = 0.04). The CD4 cell count increase was very modest for both TB and NTR CODs compared to those who did not die (0 vs. 249 cells, P < 0.001).

CONCLUSIONS

TB was significantly associated with increased NTR CODs, indicating rapid progression of disease and increased long-term risk of mortality, probably related to persistent immunodeficiency or incomplete immune recovery. Our results confirm the benefits of HAART and TB prophylaxis.

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.

Multicentre evaluation of an automated BACTEC 960 system for susceptibility testing of Mycobacterium tuberculosis

SETTING

Three mycobacteria reference laboratories in the south-eastern part of Brazil.

OBJECTIVE

To evaluate the automated Mycobacteria Growth Indicator Tube (MGIT) for drug susceptibility testing of Mycobacterium tuberculosis.

DESIGN

Performance of the automated BACTEC MGIT 960 (M960) system for testing M. tuberculosis susceptibility to streptomycin (SM), isoniazid (INH), rifampicin (RMP) and ethambutol (EMB) was evaluated with 95 clinical isolates and compared to the results of the radiometric BACTEC 460TB (B460) system, the proportion method (PM), and the resistance ratio method (RRM). Judicial susceptibility profiles of 88 isolates were defined based on two or more concordant results among B460, PM and RRM, and used as a reference for comparison with M960 results.

RESULTS

Agreement rates between M960 and conventional methods were 95.2% with B460, 96.6% with the PM and 93.4% with the RRM. The lowest agreement rates were obtained for SM with the RRM and for EMB with B460. When comparing M960 with judicial susceptibility profiles, the agreement rate was 97.9%. The agreement rates obtained for INH and RMP were 99.2% and for SM and EMB they were 96.2% and 96.9%, respectively. The mean time to reporting the M960 results was 6.9 days.

CONCLUSION

M960 offers great improvements when compared to the proportion and resistance ratio methods and would benefit patient treatment.

Differentiation of Mycobacterium tuberculosis from other mycobacteria with rho-nitrobenzoic acid using MGIT960

SETTING

Mycobacteria growth in media with the addition of inhibitory substances has been used in species identification. Growth of the Mycobacterium tuberculosis complex (MTC) is inhibited by rho-nitrobenzoic acid (PNB), whereas non-tuberculous mycobacteria (NTM) are resistant.

OBJECTIVE

To develop a rapid PNB test using the automated BACTEC MGIT960 system and to evaluate its usefulness in the screening of mycobacterial isolates.

DESIGN

PNB tests were performed in 93 MTC strains and 61 NTM strains from the Instituto Adolfo Lutz Culture Collection. PNB was added to Löwenstein-Jensen (LJ) medium and to BACTEC MGIT960 medium.

RESULTS

The MTC strains were all PNB-susceptible, confirming the original identification. Among 10 NTM species, all were found to be resistant to PNB, except for one strain of M. kansasii and another of M. marinum. The median time to obtain presumptive identification of MTC by inhibition test in the BACTEC MGIT960 system was 6.3 days and for NTM it was 2.5 days. The presumptive identification of MTC in LJ was mostly obtained after day 20.

CONCLUSION

The key finding of this analysis was the possibility of combining the traditionally accepted method proposed by Tsukamura and Tsukamura in 1964 with the modern, safe and rapid BACTEC MGIT960 methodology.

Alternative anti-tuberculosis regimen including ofloxacin for the treatment of patients with hepatic injury

SETTING

Tuberculosis (TB) clinic of a university-based public hospital in Rio de Janeiro city, Brazil.

OBJECTIVE

To describe treatment outcomes for TB patients with liver injury who received a 12-month regimen of ethambutol (E, EMB) and ofloxacin (O, OFL), including streptomycin (S, SM) for the first 3 months (3SEO/9EO) under routine clinical care conditions.

DESIGN

A retrospective study of a cohort of TB patients prescribed 3SEO/9EO was conducted over a 66-month period. Data were obtained by review of existing medical records. Primary outcomes assessed were cure, treatment failure, treatment default, TB relapse and death.

RESULTS

Outcomes were assessed for 40 patients with hepatic injury who met study criteria. Twenty-three (58%) were male and 13 (33%) were human immunodeficiency virus seropositive. Thirty-four (85%) patients were cured. Three patients (7.5%) defaulted from treatment, and three other patients died (7.5%). There were no treatment failures or relapses during 2 years of follow-up. Clinically recognized drug toxicity occurred in five patients (12.5%), and in each case was attributed to SM.

CONCLUSION

In this series of TB patients with serious liver injury, 3SEO/9EO was well-tolerated, and it was effective in 85% of patients when used under routine clinical care conditions.

Cell proliferation and interferon-gamma response to recombinant MBP-3, NarL, MT-10.3, and 16 kDa Mycobacterium tuberculosis antigens in Brazilian tuberculosis patients

Human pulmonary tuberculosis (TB) is a worldwide public health problem. In resistant individuals, control of the infection mainly requires development of a Th1 cell immune response with production of cytokines, of which interferon-gamma (IFN-gamma)plays an important role. Several antigens from Mycobacterium tuberculosis complex has been described for use in vaccine development or for diagnostic purposes, however little evaluation has been done in endemic area for TB. The proliferative and IFN-gamma human T cell immune responses, to four recombinant proteins (MBP-3, NarL, MT-10.3, 16 kDa) and PPD, of 38 Brazilian TB patients (6 untreated and 32 treated) and 67 controls (38 positive and 29 negative tuberculin skin test - TST) were compared. The highest reactivity mean rate was obtained with PPD followed by 16 kDa in TB patients. While most of the patients (87%) and controls (> 64%) respond to the PPD, 16 kDa was more specifically recognized (> 21%) although less sensitive (54%). When TB patients were divided according to treatment status, opposite to PPD, higher average level of IFN-gamma was induced by 16 kDa in untreated (505 pg/ml) compared to treated TB patients and TST+ (269.8 pg/ml x 221.6 pg/ml, respectively), although the difference was not significant. These data show that in contrast with the other recombinant proteins, the stimulatory potency of 16 kDa to induce proliferative and INF-gamma response was more effective and is more recognized by active TB untreated patients, eliciting in control individuals a more selective immune response than PPD.

Prevalence of pulmonary tuberculosis among respiratory symptomatic subjects in an out-patient primary health unit

SETTING

Out-patient primary health unit (OPHU) in Rio de Janeiro City, Brazil.

OBJECTIVE

To evaluate the impact on the detection of tuberculosis (TB) cases of reducing the time of respiratory symptoms from 'cough > or = 3 weeks' to 'cough > or = 1 week' as a criteria for TB case finding among individuals visiting an OPHU for any other reason.

DESIGN

Cross-sectional study.

RESULTS

During the period of the study, 10.7% (765/ 7174) of subjects reported cough > or = 1 week. Among 542 subjects enrolled in the study with cough > or = 1 week, 15 (2.7%) cases were diagnosed with pulmonary tuberculosis (PTB, 2767/100000). The probability of detecting TB in the OPHU setting among subjects seeking care for respiratory symptoms was significantly higher than among those presenting to the OPHU for other reasons (OR 31.5, 95% CI 4.1-241.9; P < 0.0001). The probability of identifying TB among patients seeking care due to respiratory symptoms was not influenced by the duration of cough (P = 0.7).

CONCLUSION

These findings suggest that the screening criteria for TB case finding of cough for less than the usual 3 weeks among patients who attend a health facility due to respiratory symptoms in settings with a high prevalence of TB may significantly improve the proportion of TB cases diagnosed.

Improvements in treatment success rates with directly observed therapy in Rio de Janeiro City

SETTING

Rio de Janeiro City, Brazil.

OBJECTIVE

To evaluate the effect of directly observed therapy (DOT) on treatment success, by comparing the treatment success rates between patients treated under DOT with those who received self-administered therapy (SAT).

DESIGN

A longitudinal study in a cohort of tuberculosis (TB) patients. Of 9929 new pulmonary TB cases, 1190 (12%) were treated under DOT and 8739 (88%) under SAT. All patients received a three-drug regimen consisting of rifampicin (RMP), isoniazid (INH) and pyrazinamide for 2 months followed by 4 months of RMP and INH.

RESULTS

Patients under DOT were more likely to convert to sputum-negative at the end of the second month than those treated under SAT (86.3% vs. 61.9%, P < 0.001). DOT alone was significantly associated with successful treatment (OR 1.6, 95%CI 1.37-1.86, P < 0.001), even when controlled by sex, age and positive smear or culture at enrollment (OR 1.56, 95%CI 1.33-1.82, P < 0.001).

CONCLUSION

This pilot DOTS implementation phase showed that DOT is highly effective and feasible in a large urban centre of a developing country.

Detection of Mycobacterium tuberculosis by a polymerase chain reaction colorimetric dot-blot assay

SETTING

A public health laboratory in a tuberculosis-endemic region in Brazil.

OBJECTIVE

To evaluate the accuracy of a combined polymerase chain reaction (PCR) colorimetric dot-blot protocol for Mycobacterium tuberculosis detection in clinical samples in a public health laboratory.

DESIGN

Eighty clinical samples (13 cerebrospinal fluid, 31 induced sputum, 17 expectorated sputum, eight bronchoalveolar lavage and 11 pleural fluid) were assayed with the developed protocol. The accuracy of polymerase chain reaction (PCR) dot-blot methodology was compared to PCR agarose gel electrophoresis (PCR-AG) using as a gold standard the bacteriological result (culture and biochemical identification) combined with clinical follow-up. One internal region of the IS6110 repetitive element of the M. tuberculosis complex was selected for amplification and the amplified product transferred to nylon membranes to be detected by biotinylated DNA probe.

RESULTS

Overall sensitivity and specificity obtained were respectively 90% and 97% for PCR-AG and 95% and 97% for the PCR dot-blot. Among the 56 respiratory specimens, the sensitivity and specificity results for PCR-AG were respectively 88% and 95%, and for PCR dot-blot they were 94% and 95%. Among the 24 non-respiratory specimens the sensitivity and specificity results were respectively 83% and 100% for PCR-AG, and 100% and 100% for the PCR dot-blot protocol.

CONCLUSION

The results demonstrated that the PCR dot-blot assay may be helpful in the diagnosis of tuberculosis, and feasible even in resource-poor countries.