Management of patients with multidrug-resistant/extensively drug-resistant tuberculosis in Europe: a TBNET consensus statement

Predictors of poor treatment outcomes in multidrug-resistant tuberculosis patients: a retrospective cohort study

OBJECTIVES

We aimed to determine the characteristics, treatment outcomes and risk factors for poor treatment outcomes among multidrug-resistant (MDR) tuberculosis (TB) patients in Khyber Pakhtunkhwa province, Pakistan.

METHODS

A retrospective cohort study including all patients with MDR-TB who sought care at the MDR-TB unit in Peshawar was conducted between January 2012 and April 2014. Patients were followed until an outcome of TB treatment was recorded as successful (cured or completed) or unsuccessful. Binary logistic regression was used to identify predictors of poor outcome, i.e. unsuccessful treatment outcomes.

RESULTS

Overall, 535 patients were included. The proportion of female subjects was relatively higher (n = 300, 56.1%) than male subjects. The mean (standard deviation) age of patients was 30.37 (14.09) years. Of 535 patients for whom treatment outcomes were available, 402 (75.1%) were cured, 4 (0.7%) completed therapy, 34 (6.4%) had disease that failed to respond to therapy, 93 (17.4%) died and two (0.4%) defaulted; in total, 129 (24.1%) had an unsuccessful outcome. We found three significant predictors of unsuccessful treatment during multivariate logistic regression: being married (odds ratio (OR) = 2.17, 95% confidence interval (CI) 1.01, 4.66), resistance to second-line drugs (OR = 2.61, 95% CI 1.61, 4.21) and presence of extensively drug-resistant TB (OR = 7.82, 95% CI 2.90, 21.07).

CONCLUSIONS

Approximately 75% of the treatment success rate set by the Global Plan to Stop TB was achieved. Resistance to second-line drugs and presence of extensively drug-resistant TB are the main risk factors for poor treatment outcomes.

Infection control, genetic assessment of drug resistance and drug susceptibility testing in the current management of multidrug/extensively-resistant tuberculosis (M/XDR-TB) in Europe: A tuberculosis network European Trialsgroup (TBNET) study

AIM

Europe has the highest documented caseload and greatest increase in multidrug and extensively drug-resistant tuberculosis (M/XDR-TB) of all World Health Organization (WHO) regions. This survey examines how recommendations for M/XDR-TB management are being implemented.

METHODS

TBNET is a pan-European clinical research collaboration for tuberculosis. An email survey of TBNET members collected data in relation to infection control, access to molecular tests and basic microbiology with drug sensitivity testing.

RESULTS

68/105 responses gave valid information and were from countries within the WHO European Region. Inpatient beds matched demand, but single rooms with negative pressure were only available in low incidence countries; ultraviolet decontamination was used in 5 sites, all with >10 patients with M/XDR-TB per year. Molecular tests for mutations associated with rifampicin resistance were widely available (88%), even in lower income and especially in high incidence countries. Molecular tests for other first line and second line drugs were less accessible (76 and 52% respectively). A third of physicians considered that drug susceptibility results were delayed by > 2 months.

CONCLUSION

Infection control for inpatients with M/XDR-TB remains a problem in high incidence countries. Rifampicin resistance is readily detected, but tests to plan regimens tailored to the drug susceptibilities of the strain of Mycobacterium tuberculosis are significantly delayed, allowing for further drug resistance to develop.

The Tuberculosis Network European Trials Group (TBNET): new directions in the management of tuberculosis

The Tuberculosis Network European Trials Group (TBNET) is the largest clinical research organisation in Europe. Educational activities include the TBNET Academy and the European Advanced Course in Clinical Tuberculosis. Four of their publications are reviewed to show how the clinical management of tuberculosis is changing.

Learn about @TBnet_EU, the largest clinical research organisation in Europehttp://ow.ly/NHTh30e53KE

Multidrug-resistant Tuberculosis Burden among the New Tuberculosis Patients in Zhejiang Province: An Observational Study, 2009-2013

BACKGROUND

Screening on multidrug-resistant tuberculosis (MDR-TB) has been limited to the serious TB subpopulations excluding the new TB patients. This study aimed to examine MDR-TB burden among the new TB patients.

METHODS

We conducted a study in Zhejiang Province during 2009-2013 to screen for MDR-TB patients among the low MDR-TB risk patients and five subpopulations of high MDR-TB risk patients. The number, prevalence, and trend of MDR-TB were compared while the logistic regression model was used to examine risk factors related to MDR-TB.

RESULTS

A total of 200 and 791 MDR-TB cases were, respectively, identified from the 9830 new TB cases and 2372 high-risk suspects who took MDR-TB screening from 2009 to 2013. The MDR-TB rates went down in both of the new TB patients and five MDR-TB high-risk groups over the study time, but the percentage of MDR-TB patients identified from the new TB patients in all diagnosed MDR-TB cases kept stable from 28.3% in 2011 to 27.0% in 2012 to 26.0% in 2013.

CONCLUSIONS

The study indicated that MDR-TB burden among new TB patients was high, thus screening for MDR-TB among the new TB patients should be recommended in China as well as in the similar situation worldwide.

Sterilizing Effect of Ertapenem-Clavulanate in a Hollow-Fiber Model of Tuberculosis and Implications on Clinical Dosing

Carbapenems are now being explored for treatment of multidrug-resistant tuberculosis (MDR-TB), especially in conjunction with clavulanate. Clinical use is constrained by the need for multiple parenteral doses per day and the lack of knowledge of the optimal dose for sterilizing effect. Our objective was to identify the ertapenem exposure associated with optimal sterilizing effect and then design a once-a-day dose for clinical use. We utilized the hollow-fiber system model of tuberculosis in a 28-day exposure-response study of 8 different ertapenem doses in combination with clavulanate. The systems were sampled at predetermined time points to verify the concentration-time profile and identify the total bacterial burden. Inhibitory sigmoid maximum-effect (E_max) modeling was used to identify the relationship between total bacterial burden and the drug exposure and to identify optimal exposures. Contrary to the literature, ertapenem-clavulanate combination demonstrated good microbial kill and sterilizing effect. In a dose fractionation hollow-fiber study, efficacy was linked to percentage of the 24-h dosing interval of ertapenem concentration persisting above MIC (%T_MIC). We performed 10,000 MDR-TB patient computer-aided clinical trial simulations, based on Monte Carlo methods, to identify the doses and schedule that would achieve or exceed a %T_MIC of ≥40%. We identified an intravenous dosage of 2 g once per day as achieving the target in 96% of patients. An ertapenem susceptibility breakpoint MIC of 2 mg/liter was identified for that dose. An ertapenem dosage of 2 g once daily is the most suitable to be tested in a phase II study of sterilizing effect in MDR-TB patients.

Outcomes of multidrug-resistant tuberculosis in Zambia: a cohort analysis

PURPOSE

The purpose of this study was to establish a baseline for measuring the impact of the programmatic management of drug-resistant TB program by following up on outcomes of all patients diagnosed with multidrug-resistant tuberculosis in Zambia between 2012 and 2014.

METHODS

A cohort study of all the MDR-TB patients diagnosed at the national TB reference laboratory from across Zambia. MDR-TB was diagnosed by culture and DST, whereas outcome data were collected in 2015 by patient record checks and home visits.

RESULTS

The total number of patients diagnosed was 258. Of those, 110 (42.6%) patients were traceable for this study. There were 67 survivor participants (60.9%); 43 (39.1%) were deceased. Out of the 110 patients who were traced, only 71 (64.5%) were started on second-line treatment. Twenty-nine (40.8%) patients were declared cured and 16.9% were still on treatment; 8.4% had failed treatment. The survival rate was 20.2 per 100 person-years of follow-up. Taking ARVs was associated with a decreased risk of dying (hazard ratio 0.12, p = 0.002). Sex, age, marital status and treatment category were not important predictors of survival in MDR-TB patients.

CONCLUSIONS

More than half of the patients diagnosed with MDR-TB were lost to follow-up before second-line treatment was initiated.

Pharmacokinetics of Levofloxacin in Multidrug- and Extensively Drug-Resistant Tuberculosis Patients

Pharmacodynamics are especially important in the treatment of multidrug- and extensively drug-resistant tuberculosis (M/XDR-TB). The free area under the concentration time curve in relation to MIC (fAUC/MIC) is the most relevant pharmacokinetic (PK)-pharmacodynamic (PD) parameter for predicting the efficacy of levofloxacin (LFX). The objective of our study was to assess LFX PK variability in M/XDR-TB patients and its potential consequence for fAUC/MIC ratios. Patients with pulmonary M/XDR-TB received LFX as part of the treatment regimen at a dose of 15 mg/kg administered once daily. Blood samples obtained at steady state before and 1, 2, 3, 4, 7, and 12 h after drug administration were measured by validated liquid chromatography-tandem mass spectrometry. The MIC values of LFX were determined by the agar dilution method on Middlebrook 7H10 and the MGIT960 system. Twenty patients with a mean age of 31 years (interquartile range [IQR] = 27 to 35 years) were enrolled in this study. The median AUC_0-24 was 98.8 mg/h/liter (IQR = 84.8 to 159.6 mg/h/liter). The MIC median value for LFX was 0.5 mg/liter with a range of 0.25 to 2.0 mg/liter, and the median fAUC_0-24/MIC ratio was 109.5 (IQR = 48.5 to 399.4). In 4 of the 20 patients, the value was below the target value of ≥100. When MICs of 0.25, 0.5, 1.0, and 2.0 mg/liter were applicable, 19, 18, 3, and no patients, respectively, had an fAUC/MIC ratio that exceeded 100. We observed a large variability in AUC. An fAUC_0-24/MIC of ≥100 was only observed when the MIC values for LFX were 0.25 to 0.5 mg/liter. Dosages exceeding 15 mg/kg should be considered for target attainment if exposures are assumed to be safe. (This study has been registered at ClinicalTrials.gov under registration no. NCT02169141.).

Investigation of pre-XDR Beijing Mycobacterium tuberculosis transmission to a healthcare worker in France, 2016

A case of occupational contamination of a healthcare worker by a pre-extensively drug-resistant (pre-XDR) Beijing strain of Mycobacterium tuberculosis at the University Hospital of Montpellier, France is reported. The index case was identified using genetic fingerprinting of isolates. This report underscores the risk of healthcare-associated contamination by pre-XDR tuberculosis (TB) in low-incidence countries and the importance of molecular tools for TB care. It also calls for increased vigilance in the management of multi-drug-resistant/XDR TB patients.

Genotypic distribution of multidrug-resistant and extensively drug-resistant tuberculosis in northern Thailand

Background

Multidrug/extensively drug-resistant tuberculosis (M/XDR-TB) is a major public health problem, and early detection is important for preventing its spread. This study aimed to demonstrate the distribution of genetic site mutation associated with drug resistance in M/XDR-TB in the northern Thai population.

Methods

Thirty-four clinical MTB isolates from M/XDR-TB patients in the upper northern region of Thailand, who had been identified for drug susceptibility using the indirect agar proportion method from 2005 to 2012, were examined for genetic site mutations of katG, inhA, and ahpC for isoniazid (INH) drug resistance and rpoB for rifampicin (RIF) drug resistance. The variables included the baseline characteristics of the resistant gene, genetic site mutations, and drug susceptibility test results.

Results

All 34 isolates resisted both INH and RIF. Thirty-two isolates (94.1%) showed a mutation of at least 1 codon for katG, inhA, and ahpC genes. Twenty-eight isolates (82.4%) had a mutation of at least 1 codon of rpoB gene. The katG, inhA, ahpC, and rpoB mutations were detected in 20 (58.7%), 27 (79.4%), 13 (38.2%), and 28 (82.3%) of 34 isolates. The 3 most common mutation codons were katG 315 (11/34, 35.3%), inhA 14 (11/34, 32.4%), and inhA 114 (11/34, 32.4%). For this population, the best genetic mutation test panels for INH resistance included 8 codons (katG 310, katG 340, katG 343, inhA 14, inhA 84, inhA 86, inhA 114, and ahpC 75), and for RIF resistance included 6 codons (rpoB 445, rpoB 450, rpoB 464, rpoB 490, rpoB 507, and rpoB 508) with a sensitivity of 94.1% and 82.4%, respectively.

Conclusion

The genetic mutation sites for drug resistance in M/XDR-TB are quite variable. The distribution of these mutations in a certain population must be studied before developing the specific mutation test panels for each area. The results of this study can be applied for further molecular M/XDR-TB diagnosis in the upper northern region of Thailand.

Strategies for halting the rise of multidrug resistant TB epidemics: assessing the effect of early case detection and isolation

Background

The increasing rates of multidrug resistant TB (MDR-TB) have posed the question of whether control programs under enhanced directly observed treatment, short-course (DOTS-Plus) are sufficient or implemented optimally. Despite enhanced efforts on early case detection and improved treatment regimens, direct transmission of MDR-TB remains a major hurdle for global TB control.

Methods

We developed an agent-based simulation model of TB dynamics to evaluate the effect of transmission reduction measures on the incidence of MDR-TB. We implemented a 15-day isolation period following the start of treatment in active TB cases. The model was parameterized with the latest estimates derived from the published literature.

Results

We found that if high rates (over 90%) of TB case identification are achieved within 4 weeks of developing active TB, then a 15-day patient isolation strategy with 50% effectiveness in interrupting disease transmission leads to 10% reduction in the incidence of MDR-TB over 10 years. If transmission is fully prevented, the rise of MDR-TB can be halted within 10 years, but the temporal reduction of MDR-TB incidence remains below 20% in this period.

Conclusions

The impact of transmission reduction measures on the TB incidence depends critically on the rates and timelines of case identification. The high costs and adverse effects associated with MDR-TB treatment warrant increased efforts and investments on measures that can interrupt direct transmission through early case detection.

New drugs for the treatment of Mycobacterium tuberculosis infection

Tuberculosis presents a grave challenge to health, globally instigating 1.5 million mortalities each year. Following the breakthrough of first-line anti-TB medication, the number of mortalities reduced greatly; nonetheless, the swift appearance of tuberculosis which was drug-resistant, as well as the capability of the bacterium to survive and stay dormant are a considerable problem for public health. In order to address this issue, several novel possible candidates for tuberculosis therapy have been subjected to clinical trials of late. The novel antimycobacterial agents are acquired from different categories of medications, operate through a range of action systems, and are at various phases of advancement. We therefore talk about the present methods of treating tuberculosis and novel anti-TB agents with their action method, in order to advance awareness of these new compounds and medications.

Predictors of unfavourable treatment outcome in patients with multidrug-resistant tuberculosis in India

Setting: India has one of the highest global rates of multidrug-resistant tuberculosis (MDR-TB), which is associated with poor treatment outcomes. A better understanding of the risk factors for unfavourable outcomes is needed. Objectives: To describe 1) the demographic and clinical characteristics of MDR-TB patients registered in three states of India during 2009-2011, 2) treatment outcomes, and 3) factors associated with unfavourable outcomes. Design: A retrospective cohort study involving a record review of registered MDR-TB patients. Results: Of 788 patients, 68% were male, 70% were aged 15-44 years, 90% had failed previous anti-tuberculosis treatment or were retreatment smear-positive, 60% had a body mass index < 18.5 kg/m² and 72% had additional resistance to streptomycin and/or ethambutol. The median time from sputum collection to the start of MDR-TB treatment was 128 days (IQR 103-173). Unfavourable outcomes occurred in 40% of the patients, mostly from death or loss to follow-up. Factors significantly associated with unfavourable outcomes included male sex, age ⩾ 45 years, being underweight and infection with the human immunodeficiency virus. Adverse drug reactions were reported in 24% of patients, with gastrointestinal disturbance, psychiatric morbidity and ototoxicity the most common. Conclusion: Long delays from sputum collection to treatment initiation using conventional methods, along with poor treatment outcomes, suggest the need to scale up rapid diagnostic tests and shorter regimens for MDR-TB.

The epidemiology, pathogenesis, transmission, diagnosis, and management of multidrug-resistant, extensively drug-resistant, and incurable tuberculosis

Global tuberculosis incidence has declined marginally over the past decade, and tuberculosis remains out of control in several parts of the world including Africa and Asia. Although tuberculosis control has been effective in some regions of the world, these gains are threatened by the increasing burden of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. XDR tuberculosis has evolved in several tuberculosis-endemic countries to drug-incurable or programmatically incurable tuberculosis (totally drug-resistant tuberculosis). This poses several challenges similar to those encountered in the pre-chemotherapy era, including the inability to cure tuberculosis, high mortality, and the need for alternative methods to prevent disease transmission. This phenomenon mirrors the worldwide increase in antimicrobial resistance and the emergence of other MDR pathogens, such as malaria, HIV, and Gram-negative bacteria. MDR and XDR tuberculosis are associated with high morbidity and substantial mortality, are a threat to health-care workers, prohibitively expensive to treat, and are therefore a serious public health problem. In this Commission, we examine several aspects of drug-resistant tuberculosis. The traditional view that acquired resistance to antituberculous drugs is driven by poor compliance and programmatic failure is now being questioned, and several lines of evidence suggest that alternative mechanisms-including pharmacokinetic variability, induction of efflux pumps that transport the drug out of cells, and suboptimal drug penetration into tuberculosis lesions-are likely crucial to the pathogenesis of drug-resistant tuberculosis. These factors have implications for the design of new interventions, drug delivery and dosing mechanisms, and public health policy. We discuss epidemiology and transmission dynamics, including new insights into the fundamental biology of transmission, and we review the utility of newer diagnostic tools, including molecular tests and next-generation whole-genome sequencing, and their potential for clinical effectiveness. Relevant research priorities are highlighted, including optimal medical and surgical management, the role of newer and repurposed drugs (including bedaquiline, delamanid, and linezolid), pharmacokinetic and pharmacodynamic considerations, preventive strategies (such as prophylaxis in MDR and XDR contacts), palliative and patient-orientated care aspects, and medicolegal and ethical issues.

Cost-effectiveness of adding novel or group 5 interventions to a background regimen for the treatment of multidrug-resistant tuberculosis in Germany

Background

Treatment of multidrug-resistant tuberculosis (MDR-TB) is complex, lengthy, and involves a minimum of four drugs termed a background regimen (BR), that have not previously been prescribed or that have proven susceptible to patient sputum culture isolates. In recent years, promising new treatment options have emerged as add-on therapies to a BR. The aim of this study was to evaluate the long-term costs and effectiveness of adding the novel or group 5 interventions bedaquiline, delamanid, and linezolid to a background regimen (BR) of drugs for the treatment of adult patients with pulmonary multidrug-resistant tuberculosis (MDR-TB), within their marketing authorisations, from a German healthcare cost-effectiveness perspective.

Methods

A cohort-based Markov model was developed to simulate the incremental cost-effectiveness ratio of bedaquiline plus BR, delamanid plus BR, or linezolid plus BR versus BR alone in the treatment of MDR-TB, over a 10-year time horizon. Effectiveness of treatment was evaluated in Quality-Adjusted Life-Years (QALYs) and Life-Years Gained (LYG), using inputs from clinical trials for bedaquiline and delamanid and from a German observational study for linezolid. Cost data were obtained from German Drug Directory costs (€/2015), published literature, and expert opinion. A 3% yearly discount rate was applied. Probabilistic and deterministic sensitivity analyses were conducted.

Results

The total discounted costs per-patient were €85,575 for bedaquiline plus BR, €81,079 for delamanid plus BR, and €80,460 for linezolid plus BR, compared with a cost of €60,962 for BR alone. The total discounted QALYs per-patient were 5.95 for bedaquiline plus BR, 5.36 for delamanid plus BR, and 3.91 for linezolid plus BR, compared with 3.68 for BR alone. All interventions were therefore associated with higher QALYs and higher costs than BR alone, with incremental costs per QALY gained of €22,238 for bedaquiline, €38,703 for delamanid, and €87,484 for linezolid, versus BR alone. In a fully incremental analysis, bedaquiline plus BR was the most cost-effective treatment option at thresholds greater than €22,000 per QALY gained. In probabilistic analyses, the probability that bedaquiline plus BR was the most cost-effective treatment strategy at a willingness-to-pay threshold of €30,000 was 54.5%, compared with 22.9% for BR alone, 18.2% for delamanid plus BR, and 4.4% for linezolid.

Conclusions

In Germany, the addition of bedaquiline, delamanid, or linezolid to a BR would result in QALY gains over BR alone. Based on this analysis, bedaquiline is likely to be the most cost-effective intervention for the treatment of MDR-TB, when added to a BR regimen at thresholds greater than €22,000 per QALY.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2118-2) contains supplementary material, which is available to authorized users.

Reduced Chance of Hearing Loss Associated with Therapeutic Drug Monitoring of Aminoglycosides in the Treatment of Multidrug-Resistant Tuberculosis

Hearing loss and nephrotoxicity are associated with prolonged treatment duration and higher dosage of amikacin and kanamycin. In our tuberculosis center, we used therapeutic drug monitoring (TDM) targeting preset pharmacokinetic/pharmacodynamic (PK/PD) surrogate endpoints in an attempt to maintain efficacy while preventing (oto)toxicity. To evaluate this strategy, we retrospectively evaluated medical charts of tuberculosis (TB) patients treated with amikacin or kanamycin in the period from 2000 to 2012. Patients with culture-confirmed multiresistant or extensively drug-resistant tuberculosis (MDR/XDR-TB) receiving amikacin or kanamycin as part of their TB treatment for at least 3 days were eligible for inclusion in this retrospective study. Clinical data, including maximum concentration (C_max), C_min, and audiometry data, were extracted from the patients' medical charts. A total of 80 patients met the inclusion criteria. The mean weighted C_max/MIC ratios obtained from 57 patients were 31.2 for amikacin and 12.3 for kanamycin. The extent of hearing loss was limited and correlated with the cumulative drug dose per kg of body weight during daily administration. At follow-up, 35 (67.3%) of all patients had successful outcome; there were no relapses. At a median dose of 6.5 mg/kg, a correlation was found between the dose per kg of body weight during daily dosing and the extent of hearing loss in dB at 8,000 Hz. These findings suggest that the efficacy at this lower dosage is maintained with limited toxicity. A randomized controlled trial should provide final proof of the safety and efficacy of TDM-guided use of aminoglycosides in MDR-TB treatment.

One-year mortality of HIV-positive patients treated for rifampicin- and isoniazid-susceptible tuberculosis in Eastern Europe, Western Europe, and Latin America

OBJECTIVES

The high mortality among HIV/tuberculosis (TB) coinfected patients in Eastern Europe is partly explained by the high prevalence of drug-resistant TB. It remains unclear whether outcomes of HIV/TB patients with rifampicin/isoniazid-susceptible TB in Eastern Europe differ from those in Western Europe or Latin America.

METHODS

One-year mortality of HIV-positive patients with rifampicin/isoniazid-susceptible TB in Eastern Europe, Western Europe, and Latin America was analysed and compared in a prospective observational cohort study. Factors associated with death were analysed using Cox regression modelsRESULTS:: Three hundred and forty-one patients were included (Eastern Europe 127, Western Europe 165, Latin America 49). Proportions of patients with disseminated TB (50, 58, 59%) and initiating rifampicin + isoniazid + pyrazinamide-based treatment (93, 94, 94%) were similar in Eastern Europe, Western Europe, and Latin America respectively, whereas receipt of antiretroviral therapy at baseline and after 12 months was lower in Eastern Europe (17, 39, 39%, and 69, 94, 89%). The 1-year probability of death was 16% (95% confidence interval 11-24%) in Eastern Europe, vs. 4% (2-9%) in Western Europe and 9% (3-21%) in Latin America; P < 0.0001. After adjustment for IDU, CD4 cell count and receipt of antiretroviral therapy, those residing in Eastern Europe were at nearly 3-fold increased risk of death compared with those in Western Europe/Latin America (aHR 2.79 (1.15-6.76); P = 0.023).

CONCLUSIONS

Despite comparable use of recommended anti-TB treatment, mortality of patients with rifampicin/isoniazid-susceptible TB remained higher in Eastern Europe when compared with Western Europe/Latin America. The high mortality in Eastern Europe was only partially explained by IDU, use of ART and CD4 cell count. These results call for improvement of care for TB/HIV patients in Eastern Europe.

Recurrence after Successful Treatment of Multidrug-Resistant Tuberculosis in Taiwan

Recurrence after successful treatment for multidrug-resistant tuberculosis (MDR-TB) is challenging because of limited retreatment options. This study aimed to determine rates and predictors of MDR-TB recurrence after successful treatment in Taiwan. Recurrence rates were analyzed by time from treatment completion in 295 M DR-TB patients in a national cohort. Factors associated with MDR-TB recurrence were examined using a multivariate Cox regression analysis. Ten (3%) patients experienced MDR-TB recurrence during a median follow-up of 4.8 years. The overall recurrence rate was 0.6 cases per 1000 person-months. Cavitation on chest radiography was an independent predictor of recurrence (adjusted hazard ratio [aHR] = 6.3; 95% CI, 1.2-34). When the analysis was restricted to 215 patients (73%) tested for second-line drug susceptibility, cavitation (aHR = 10.2; 95% CI, 1.2-89) and resistance patterns of extensively drug-resistant TB (XDR-TB) or pre-XDR-TB (aHR = 7.3; 95% CI, 1.2-44) were associated with increased risk of MDR-TB recurrence. In Taiwan, MDR-TB patients with cavitary lesions and resistance patterns of XDR-TB or pre-XDR-TB are at the highest risk of recurrence. These have important implications for MDR-TB programs aiming to optimize post-treatment follow-up and early detection of recurrent MDR-TB.

Tackling TB in low-incidence countries: improving diagnosis and management in vulnerable populations

In low tuberculosis incidence regions, tuberculosis is mainly concentrated among hard-to-reach populations like migrants, homeless people, drug or alcohol abusers, prisoners and people living with HIV. To be able to eliminate tuberculosis from these low incidence regions tuberculosis screening and treatment programs should focus on these hard-to-reach populations. Here we discuss the barriers and facilitators of health care-seeking, interventions improving tuberculosis screening uptake and interventions improving treatment adherence in these hard-to-reach populations.

Choice between Levofloxacin and Moxifloxacin and Multidrug-Resistant Tuberculosis Treatment Outcomes

RATIONALE

We previously showed that the choice of levofloxacin or moxifloxacin for the treatment of patients with fluoroquinolone-sensitive multidrug-resistant tuberculosis (MDR-TB) did not affect sputum culture conversion at 3 months of treatment.

OBJECTIVES

To compare final treatment outcomes between patients with MDR-TB randomized to levofloxacin or moxifloxacin.

METHODS

A total of 151 participants with MDR-TB who were included for the final analysis in our previous trial were followed through the end of treatment. Treatment outcomes were compared between 77 patients in the levofloxacin group and 74 in the moxifloxacin group, based on the 2008 World Health Organization definitions as well as 2013 revised definitions of treatment outcomes. In addition, the time to culture conversion was compared between the two groups.

MEASUREMENTS AND MAIN RESULTS

Treatment outcomes were not different between the two groups, based on 2008 World Health Organization definitions as well as 2013 definitions. With 2008 definitions, cure was achieved in 54 patients (70.1%) in the levofloxacin group and 54 (73.0%) in the moxifloxacin group (P = 0.72). Treatment success rates, including cure and treatment completed, were not different between the two groups (87.0 vs. 81.1%, P = 0.38). With 2013 definitions, cure rates (83.1 vs. 78.4%, P = 0.54) and treatment success rates (84.4 vs. 79.7%, P = 0.53) were also similar between the levofloxacin and moxifloxacin groups. Time to culture conversion was also not different between the two groups (27.0 vs. 45.0 d, P = 0.11 on liquid media; 17.0 vs. 42.0 d, P = 0.14 on solid media). Patients in the levofloxacin group had more adverse events than those in the moxifloxacin group (79.2 vs. 63.5%, P = 0.03), especially musculoskeletal ones (37.7 vs. 14.9%, P = 0.001).

CONCLUSIONS

The choice of levofloxacin or moxifloxacin made no difference to the final treatment outcome among patients with fluoroquinolone-sensitive MDR-TB. Clinical trial registered with www.clinicalrials.gov (NCT01055145).

Drug resistant TB: UK multicentre study (DRUMS): Treatment, management and outcomes in London and West Midlands 2008-2014

OBJECTIVES

Detailed information regarding treatment practices and outcomes of MDR-TB treatment in the UK is required as a baseline for care improvements.

METHODS

100 consecutive cases between 2008 and 2014 were reviewed retrospectively at 4 MDR-TB treatment centres in England to obtain information on drug treatment choices, hospital admission duration and outcomes for MDR-TB.

RESULTS

Initial hospital admission was long, median 62.5 (IQR 20-106, n = 92) days, and 13% (12/92) of patients lost their home during this period. Prolonged admission was associated with pulmonary cases, cavities on chest radiograph, a public health policy of waiting for sputum culture conversion (CC) and loss of the patient's home. Sputum CC occurred at a median of 33.5 (IQR 16-55, n = 46) days. Treatment success was high (74%, 74/100) and mortality low (1%, 1/100). A significant proportion of the cohort had "neutral" results due to deportation and transfer overseas (12%, (12/100)). 14% (14/100) had negative outcomes for which poor adherence was the main reason (62%, 9/14).

CONCLUSIONS

Successful outcome is common in recognised centres and limited by adherence rather than microbiological failure. Duration of hospital admission is influenced by lack of suitable housing and some variation in public health practice. Wider access to long-term assisted living facilities could improve completion rates.

Management of multidrug-resistant TB: novel treatments and their expansion to low resource settings

Despite overall progress in global TB control, the rising burden of multidrug-resistant TB (MDR-TB) threatens to undermine efforts to end the worldwide epidemic. Of the 27 countries classified as high burden for MDR-TB, 17 are in ‘low’ or ‘low–middle’ income countries. Shorter, all oral and less toxic multidrug combinations are required to improve treatment outcomes in these settings. Suitability for safe co-administration with HIV drugs is also desirable. A range of strategies and several new drugs (including bedaquiline, delamanid and linezolid) are currently undergoing advanced clinical evaluations to define their roles in achieving these aims. However, several clinical questions and logistical challenges need to be overcome before these new MDR-TB treatments fulfil their potential.

Clinical implications of the global multidrug-resistant tuberculosis epidemic

Multidrug-resistant tuberculosis (MDR TB) is a significant threat to global health estimated to account for nearly half a million new cases and over 200,000 deaths in 2013. The number of MDR TB cases in the UK has risen over the last 15 years, with ever more complex clinical cases and associated challenging public health and societal implications. In this review, we provide an overview of the epidemiology of MDR TB globally and in the UK, outline the clinical management of MDR TB and summarise recent advances in diagnostics and prospects for new treatment.

Predictors of Prolonged TB Treatment in a Dutch Outpatient Setting

INTRODUCTION

Standard treatment duration for drug-susceptible tuberculosis (TB) treatment is 6 months. Treatment duration is often extended-and for various different reasons. The aim of this study was to determine the prevalence and to assess risk factors associated with extended TB treatment.

METHODS

A cross-sectional study was conducted. Data including demographic, clinical, radiological and microbiological information from the Netherlands TB Register (NTR) of 90 patients with smear and culture positive pulmonary TB of the region Haaglanden, The Netherlands, was eligible for analysis.

RESULTS

Treatment was extended to ≥ 200 days by 46 (51%) patients. Extended TB treatment was associated with a higher frequency of symptoms, presumed to be due to adverse drug reactions (ADR; OR 2.39 95% CI: 1.01-5.69), drug-induced liver injury (DILI) (OR: 13.51; 95% CI: 1.66-109.82) and longer than 2 month smear and culture conversion rate (OR: 11.00; 95% CI: 1.24-97.96 and OR: 8.56; 95% CI: 1.53-47.96). In the multivariable logistic analysis, development of DILI emerged as the single statistically strong risk factor necessitating extension of TB treatment.

CONCLUSION

This finding will need further confirmation in a prospective study, exploring the possible mutual role of pharmacokinetic and pharmacogenetic determinants of DILI among TB patients.

Extensively Drug-Resistant Tuberculosis: Report and Literature Review on Two Cases Requiring Prolonged Treatment

BACKGROUND Extensively drug-resistant tuberculosis (XDR-TB) is a global problem due to the high morbidity and mortality it causes. Peru is one of the countries with the highest numbers of cases of XDR-TB, which increase every year. CASE REPORT We present the case of two siblings who developed XDR-TB, underwent surgery twice, and were in individualized treatment for more than 6 years. Finally they achieved remission of symptoms, despite not having standardized treatment schemes during their diagnosis period. CONCLUSIONS Extensively drug-resistant tuberculosis can be cured with a treatment that involves both medical care and patient actions to achieve remission of the disease.

Hepatic and Intra-abdominal Tuberculosis: 2016 Update

Mycobacterium tuberculosis (TB) infection affects nearly 10 million people a year and causes 1.5 million deaths. TB is common in the immunosuppressed population with 12 % of all new diagnoses occurring in human immune deficiency virus (HIV)-positive patients. Extra-pulmonary TB occurs in 12 % of patients with active TB infection of which 3.5 % is hepatobiliary and 6-38 % is intra-abdominal. Hepatobiliary and intra-abdominal TB can present with a myriad of non-specific symptoms, and therefore, diagnosis requires a high level of suspicion. Accurate and rapid diagnosis requires a multidisciplinary team (MDT) approach using radiology, interventional radiology, surgery and pathology services. Treatment of TB is predominantly medical, yet surgery plays an important role in managing the complications of hepatobiliary and intra-abdominal TB.

Clinical management of adults and children with multidrug-resistant and extensively drug-resistant tuberculosis

BACKGROUND

Globally there is a burgeoning epidemic of drug monoresistant tuberculosis (TB), multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Almost 20% of all TB strains worldwide are resistant to at least one major TB drug, including isoniazid. In several parts of the world there is an increasing incidence of MDR-TB, and alarmingly, almost a third of MDR-TB cases globally are resistant to either a fluoroquinolone or aminoglycoside. This trend cannot be ignored because drug-resistant TB is associated with greater morbidity compared to drug-susceptible TB, accounts for almost 25% of global TB mortality, is extremely costly to treat, consumes substantial portions of budgets allocated to national TB programmes in TB-endemic countries and is a major threat to healthcare workers, who are already in short supply in resource-poor settings. Even more worrying is the growing epidemic of resistance beyond XDR-TB, including resistance to newer drugs such as bedaquiline and delamanid, as well as the increasing prevalence of programmatically incurable TB in countries like South Africa, Russia, India and China. These developments threaten to reverse the gains already made against TB.

SOURCES

Articles related to MDR-TB and XDR-TB found on PubMed in all languages up to September 2016, published reviews, and files of the authors.

AIM AND CONTENT

To review the clinical management of adults and children with MDR- and XDR-TB with a particular emphasis on the utility of newer and repurposed drugs such as linezolid, bedaquiline and delamanid, as well as management of MDR- and XDR-TB in special situations such as in HIV-infected persons and in children.

IMPLICATIONS

This review informs on the prevention, diagnosis, and clinical management of MDR-TB and XDR-TB.

The perfect storm: incarceration and the high-risk environment perpetuating transmission of HIV, hepatitis C virus, and tuberculosis in Eastern Europe and Central Asia

Despite global reductions in HIV incidence and mortality, the 15 UNAIDS-designated countries of Eastern Europe and Central Asia (EECA) that gained independence from the Soviet Union in 1991 constitute the only region where both continue to rise. HIV transmission in EECA is fuelled primarily by injection of opioids, with harsh criminalisation of drug use that has resulted in extraordinarily high levels of incarceration. Consequently, people who inject drugs, including those with HIV, hepatitis C virus, and tuberculosis, are concentrated within prisons. Evidence-based primary and secondary prevention of HIV using opioid agonist therapies such as methadone and buprenorphine is available in prisons in only a handful of EECA countries (methadone or buprenorphine in five countries and needle and syringe programmes in three countries), with none of them meeting recommended coverage levels. Similarly, antiretroviral therapy coverage, especially among people who inject drugs, is markedly under-scaled. Russia completely bans opioid agonist therapies and does not support needle and syringe programmes-with neither available in prisons-despite the country's high incarceration rate and having the largest burden of people with HIV who inject drugs in the region. Mathematical modelling for Ukraine suggests that high levels of incarceration in EECA countries facilitate HIV transmission among people who inject drugs, with 28-55% of all new HIV infections over the next 15 years predicted to be attributable to heightened HIV transmission risk among currently or previously incarcerated people who inject drugs. Scaling up of opioid agonist therapies within prisons and maintaining treatment after release would yield the greatest HIV transmission reduction in people who inject drugs. Additional analyses also suggest that at least 6% of all incident tuberculosis cases, and 75% of incident tuberculosis cases in people who inject drugs are due to incarceration. Interventions that reduce incarceration itself and effectively intervene with prisoners to screen, diagnose, and treat addiction and HIV, hepatitis C virus, and tuberculosis are urgently needed to stem the multiple overlapping epidemics concentrated in prisons.

[Treatment of tuberculosis. Current standards]

The treatment of drug-sensitive tuberculosis consists of 2 months of isoniazid, rifampin, pyrazinamide and ethambutol, followed by 4 months of isoniazid and rifampin. These drugs are well tolerated and cure rate are above 95 %. In contrast the treatment of drug-resistent tuberculosis is difficult, mostly due to side effects of the drugs used under these circumstances. Therefore, any treatment of drug-resistant tuberculosis has to be done by experts.

Personalized Medicine for Chronic Respiratory Infectious Diseases: Tuberculosis, Nontuberculous Mycobacterial Pulmonary Diseases, and Chronic Pulmonary Aspergillosis

Chronic respiratory infectious diseases are causing high rates of morbidity and mortality worldwide. Tuberculosis, a major cause of chronic pulmonary infection, is currently responsible for approximately 1.5 million deaths per year. Although important advances in the fight against tuberculosis have been made, the progress towards eradication of this disease is being challenged by the dramatic increase in multidrug-resistant bacilli. Nontuberculous mycobacteria causing pulmonary disease and chronic pulmonary aspergillosis are emerging infectious diseases. In contrast to other infectious diseases, chronic respiratory infections share the trait of having highly variable treatment outcomes despite longstanding antimicrobial therapy. Recent scientific progress indicates that medicine is presently at a transition stage from programmatic to personalized management. We explain current state-of-the-art management concepts of chronic pulmonary infectious diseases as well as the underlying methods for therapeutic decisions and their implications for personalized medicine. Furthermore, we describe promising biomarkers and techniques with the potential to serve future individual treatment concepts in this field of difficult-to-treat patients. These include candidate markers to improve individual risk assessment for disease development, the design of tailor-made drug therapy regimens, and individualized biomarker-guided therapy duration to achieve relapse-free cure. In addition, the use of therapeutic drug monitoring to reach optimal drug dosing with the smallest rate of adverse events as well as candidate agents for future host-directed therapies are described. Taken together, personalized medicine will provide opportunities to substantially improve the management and treatment outcome of difficult-to-treat patients with chronic respiratory infections.

Tuberculous pleural effusion

Although it is curable, tuberculosis remains one of the most frequent causes of pleural effusions on a global scale, especially in developing countries. Tuberculous pleural effusion (TPE) is one of the most common forms of extrapulmonary tuberculosis. TPE usually presents as an acute illness with fever, cough and pleuritic chest pain. The pleural fluid is an exudate that usually has predominantly lymphocytes. The gold standard for the diagnosis of TPE remains the detection of Mycobacterium tuberculosis in pleural fluid, or pleural biopsy specimens, either by microscopy and/or culture, or the histological demonstration of caseating granulomas in the pleura along with acid fast bacilli, Although adenosine deaminase and interferon-γ in pleural fluid have been documented to be useful tests for the diagnosis of TPE. It can be accepted that in areas with high tuberculosis prevalence, the easiest way to establish the diagnosis of TPE in a patient with a lymphocytic pleural effusion is to generally demonstrate a adenosine deaminase level above 40 U/L. The recommended treatment for TPE is a regimen with isoniazid, rifampin, and pyrazinamide for two months followed by four months of two drugs, isoniazid and rifampin.

New Antituberculosis Drugs: From Clinical Trial to Programmatic Use

Treatment of multidrug-resistant tuberculosis (MDR-TB) cases is challenging because it relies on second-line drugs that are less potent and more toxic than those used in the clinical management of drug-susceptible TB. Moreover, treatment outcomes for MDR-TB are generally poor compared to drug sensitive disease, highlighting the need for of new drugs. For the first time in more than 50 years, two new anti-TB drugs were approved and released. Bedaquiline is a first-in-class diarylquinoline compound that showed durable culture conversion at 24 weeks in phase IIb trials. Delamanid is the first drug of the nitroimidazole class to enter clinical practice. Similarly to bedaquiline results of phase IIb studies showed increased sputum-culture conversion at 2 months and better final treatment outcomes in patients with MDR-TB. Among repurposed drugs linezolid and carbapenems may represent a valuable drug to treat cases of MDR and extensively drug-resistant TB. The recommended regimen for MDR-TB is the combination of at least four drugs to which M. tuberculosis is likely to be susceptible for the duration of 20 months. Drugs are chosen with a stepwise selection process through five groups on the basis of efficacy, safety, and cost. Clinical phase III trials on new regimen are ongoing that could prove transformative against MDR-TB, by being shorter (six months), simpler (an all-oral regimen) and safer than current standard therapy. It is fundamental that the adoption of the new drugs is done responsibly to avoid inappropriate use. Concentration of in-patient MDR-TB treatment in specialized centers could be considered in countries with low numbers of cases in order to provide appropriate clinical case management and to prevent emergence of drug resistance.

Emergence of mixed infection of Beijing/Non-Beijing strains among multi-drug resistant Mycobacterium tuberculosis in Pakistan

Tuberculosis (TB) remains as one of the deadliest diseases after HIV globally with 95 % of deaths confined to low-and-middle income countries. Pakistan is fifth among the 22 high-burden TB countries with the incidence rate of 230/100,000 persons, however, studies related to prevalent Mycobacterium tuberculosis strains and their spread, drug resistance pattern and evolutionary genetics are inadequate. The present study was undertaken to highlight the circulation of M. tuberculosis strains causing drug resistant TB in our community by targeting the molecular marker IS6110 and then characterization of these strains as Beijing and Non-Beijing genotypes. Sputum samples from 102 MDR TB suspects from different cities of Punjab were collected and their record was stored in a database. Sputum samples were evaluated by Ziehl Neelson staining and cultured on Lownstein Jensen medium by Modified Petroff’s method. DST was performed for first-line anti-mycobacterial drugs by indirect proportion method. Mycobacterium tuberculosis isolates were investigated for the presence of IS6110 and further identification as Beijing, Non-Beijing or mixed genotype. Percentage of male and female patients was found to be 58.8 and 41.2 % respectively. DST showed resistance of 93 % of isolates to isoniazid and rifampicin. All of the isolates showed positive results for IS6110 amplification. Based on PCR amplification of Beijing and non-Beijing primer sets 4.9 % of the patients showed infection with pure Beijing isolates, 14.7 % with both Beijing and non-Beijing isolates and 80.3 % with pure non-Beijing isolates. Analysis of IS6110 and Beijing sequences showed the presence of putative transposase conserved domain while non-Beijing sequences were epitomized with RAMP_I_III superfamily domain (CRISPR-associated protein family). TB in Pakistan is predominantly caused by Non-Beijing genotypes, but Beijing strains showed incessant circulation in our community as both single and mixed (co-infecting Non-Beijing and Beijing) strains.

Genomic and functional analyses of Mycobacterium tuberculosis strains implicate ald in D-cycloserine resistance

A more complete understanding of the genetic basis of drug resistance in Mycobacterium tuberculosis is critical for prompt diagnosis and optimal treatment, particularly for toxic second-line drugs such as D-cycloserine. Here we used the whole-genome sequences from 498 strains of M. tuberculosis to identify new resistance-conferring genotypes. By combining association and correlated evolution tests with strategies for amplifying signal from rare variants, we found that loss-of-function mutations in ald (Rv2780), encoding L-alanine dehydrogenase, were associated with unexplained drug resistance. Convergent evolution of this loss of function was observed exclusively among multidrug-resistant strains. Drug susceptibility testing established that ald loss of function conferred resistance to D-cycloserine, and susceptibility to the drug was partially restored by complementation of ald. Clinical strains with mutations in ald and alr exhibited increased resistance to D-cycloserine when cultured in vitro. Incorporation of D-cycloserine resistance in novel molecular diagnostics could allow for targeted use of this toxic drug among patients with susceptible infections.

Extensively Drug-Resistant Tuberculosis: Principles of Resistance, Diagnosis, and Management

Extensively drug-resistant (XDR) tuberculosis (TB) is an unfortunate by-product of mankind's medical and pharmaceutical ingenuity during the past 60 years. Although new drug developments have enabled TB to be more readily curable, inappropriate TB management has led to the emergence of drug-resistant disease. Extensively drug-resistant TB describes Mycobacterium tuberculosis that is collectively resistant to isoniazid, rifampin, a fluoroquinolone, and an injectable agent. It proliferates when established case management and infection control procedures are not followed. Optimized treatment outcomes necessitate time-sensitive diagnoses, along with expanded combinations and prolonged durations of antimicrobial drug therapy. The challenges to public health institutions are immense and most noteworthy in underresourced communities and in patients coinfected with human immunodeficiency virus. A comprehensive and multidisciplinary case management approach is required to optimize outcomes. We review the principles of TB drug resistance and the risk factors, diagnosis, and managerial approaches for extensively drug-resistant TB. Treatment outcomes, cost, and unresolved medical issues are also discussed.