Revised Category II regimen as an alternative strategy for retreatment of Category I regimen failure and irregular treatment cases

Effect of a modified regimen on drug-sensitive retreated pulmonary tuberculosis: A multicenter study in China

Background and objective

Retreatment pulmonary tuberculosis (PTB) still accounts for a large proportion of tuberculosis, and the treatment outcome is unfavorable. The recurrence of retreatment PTB based on long-term follow-up has not been well demonstrated. This study aimed to evaluate effect of a modified regimen on drug-sensitive retreated pulmonary tuberculosis.

Methods

This multicenter cohort study was conducted in 29 hospitals from 23 regions of China from July 1, 2009, to December 31, 2020. Patients were divided into two treatment regimen groups including experimental group [modified regimen (4H-Rt2-E-Z-S(Lfx)/4H-Rt2-E)]and control group [standard regimen (2H-R-E-Z-S/6H-R-E or 3H-R-E-Z/6H-R-E)]. The patients enrolled were followed up of 56 months after successful treatment. We compared the treatment success rate, treatment failure rate, adverse reaction rate, and recurrence rate between two regimens. Multivariate Cox regression model was used to identify the potential risk factors for recurrence after successful treatment with proportional hazards assumptions tested for all variables.

Results

A total of 381 patients with retreatment PTB were enrolled, including 244 (64.0%) in the experimental group and 137 (36.0%) in the control group. Overall, the treatment success rate was significant higher in the experimental group than control group (84.0 vs. 74.5%, P = 0.024); no difference was observed in adverse reactions between the two groups (25.8 vs. 21.2%, P > 0.05). A total of 307 patients completed the 56 months of follow-up, including 205 with the modified regimen and 102 with the standard regimen. Among these, 10 cases (3.3%) relapsed, including 3 in the experimental group and 7 in the control group (1.5% vs 6.9%, P = 0.035). Reduced risks of recurrence were observed in patients treated with the modified regimen compared with the standard regimen, and the adjusted hazard ratio was 0.19 (0.04-0.77).

Conclusion

The modified retreatment regimen had more favorable treatment effects, including higher treatment success rate and lower recurrence rate in patients with retreated drug-sensitive PTB.

Assessing the impacts of short-course multidrug-resistant tuberculosis treatment in the Southeast Asia Region using a mathematical modeling approach

This study aimed to predict the impacts of shorter duration treatment regimens for multidrug-resistant tuberculosis (MDR-TB) on both MDR-TB percentage among new cases and overall MDR-TB cases in the WHO Southeast Asia Region. A deterministic compartmental model was constructed to describe both the transmission of TB and the MDR-TB situation in the Southeast Asia region. The population-level impacts of short-course treatment regimens were compared with the impacts of conventional regimens. Multi-way analysis was used to evaluate the impact by varying programmatic factors (eligibility for short-course MDR-TB treatment, treatment initiation, and drug susceptibility test (DST) coverage). The model predicted that overall TB incidence will be reduced from 246 (95% credible intervals (CrI), 221–275) per 100,000 population in 2020 to 239 (95% CrI, 215–267) per 100,000 population in 2035, with a modest reduction of 2.8% (95% CrI, 2.7%–2.9%). Despite the slight reduction in overall TB infections, the model predicted that the MDR-TB percentage among newly notified TB infections will remain steady, with 2.4% (95% CrI, 2.1–2.9) in 2020 and 2.5% (95% CrI, 2.3–3.1) in 2035, using conventional MDR-TB treatment. With the introduction of short-course regimens to treat MDR-TB, the development of resistance can be slowed by 38.6% (95% confidence intervals (CI), 35.9–41.3) reduction in MDR-TB case number, and 37.6% (95% CI, 34.9–40.3) reduction in MDR-TB percentage among new TB infections over the 30-year period compared with the baseline using the standard treatment regimen. The multi-way analysis showed eligibility for short-course treatment and treatment initiation greatly influenced the impacts of short-course treatment regimens on reductions in MDR-TB cases and percentage resistance among new infections. Policies which promote the expansion of short-course regimens and early MDR-TB treatment initiation should be considered along with other interventions to tackle antimicrobial resistance in the region.

Drug-associated adverse events in the treatment of multidrug-resistant tuberculosis: an individual patient data meta-analysis

BACKGROUND

Treatment of multidrug-resistant tuberculosis requires long-term therapy with a combination of multiple second-line drugs. These drugs are associated with numerous adverse events that can cause severe morbidity, such as deafness, and in some instances can lead to death. Our aim was to estimate the absolute and relative frequency of adverse events associated with different tuberculosis drugs to provide useful information for clinicians and tuberculosis programmes in selecting optimal treatment regimens.

METHODS

We did a meta-analysis using individual-level patient data that were obtained from studies that reported adverse events that resulted in permanent discontinuation of anti-tuberculosis medications. We used a database created for our previous meta-analysis of multidrug-resistant tuberculosis treatment and outcomes, for which we did a systematic review of literature published between Jan 1, 2009, and Aug 31, 2015 (updated April 15, 2016), and requested individual patient-level information from authors. We also considered for this analysis studies contributing patient-level data in response to a public call made by WHO in 2018. Meta-analysis for proportions and arm-based network meta-analysis were done to estimate the incidence of adverse events for each tuberculosis drug.

FINDINGS

58 studies were identified, including 50 studies from the updated individual patient data meta-analysis for multidrug-resistant tuberculosis treatment. 35 of these studies, with 9178 patients, were included in our analysis. Using meta-analysis of proportions, drugs with low risks of adverse event occurrence leading to permanent discontinuation included levofloxacin (1·3% [95% CI 0·3-5·0]), moxifloxacin (2·9% [1·6-5·0]), bedaquiline (1·7% [0·7-4·2]), and clofazimine (1·6% [0·5-5·3]). Relatively high incidence of adverse events leading to permanent discontinuation was seen with three second-line injectable drugs (amikacin: 10·2% [6·3-16·0]; kanamycin: 7·5% [4·6-11·9]; capreomycin: 8·2% [6·3-10·7]), aminosalicylic acid (11·6% [7·1-18·3]), and linezolid (14·1% [9·9-19·6]). Risk of bias in selection of studies was judged to be low because there were no important differences between included and excluded studies. Variability between studies was significant for most outcomes analysed.

INTERPRETATION

Fluoroquinolones, clofazimine, and bedaquiline had the lowest incidence of adverse events leading to permanent drug discontinuation, whereas second-line injectable drugs, aminosalicylic acid, and linezolid had the highest incidence. These results suggest that close monitoring of adverse events is important for patients being treated for multidrug-resistant tuberculosis. Our results also underscore the urgent need for safer and better-tolerated drugs to reduce morbidity from treatment itself for patients with multidrug-resistant tuberculosis.

FUNDING

Canadian Institutes of Health Research, Centers for Disease Control and Prevention (USA), American Thoracic Society, European Respiratory Society, and Infectious Diseases Society of America.

Predictors of Multidrug-Resistant Tuberculosis (MDR-TB) in Sudan

Multidrug-resistant tuberculosis (MDR-TB) is a global public health threat and burden on the health system. This is especially the case in high tuberculosis (TB) prevalence countries, such as Sudan. Consequently, this study aimed to ascertain the predictors of MDR-TB in Sudan to provide future guidance. An unmatched case-control study to assess the predictors of MDR-TB infections among the Sudanese population was conducted from August 2017 to January 2018 at Abu-Anga referral hospital. Patients’ data was gathered from patients’ cards and via interviews. A structured pre-validated questionnaire was used to gather pertinent information, which included sociodemographic characteristics and other relevant clinical data. Univariate and multivariate logistic regression analysis was employed to determine the predictors of MDR-TB infection. 76 of the 183 patients interviewed (41.5%) had MDR-TB cases. The independent predictors for MDR-TB were living in rural areas [adjusted odds ratio (aOR) = 3.1 (95% confidence interval (CI): 1.2–8.2)], treatment failure [aOR = 56.9 (10.2–319.2)], and smoking [(aOR = 4 (1.2–13.2)], whereas other sociodemographic factors did not predict MDR-TB. In conclusion, the study showed that a history of smoking, living in rural areas, and a previous treatment failure were the predictors of MDR-TB in Sudan. The latter factors are most likely due to issues that are related to access and adherence to treatment and lifestyle. The existence of any of these factors among newly diagnosed TB patients should alert clinicians for the screening of MDR-TB. The implementation of directly observed treatment (DOT) and health education are crucial in stopping the spread of MDR-TB in Sudan.

Treatment correlates of successful outcomes in pulmonary multidrug-resistant tuberculosis: an individual patient data meta-analysis

BACKGROUND

Treatment outcomes for multidrug-resistant tuberculosis remain poor. We aimed to estimate the association of treatment success and death with the use of individual drugs, and the optimal number and duration of treatment with those drugs in patients with multidrug-resistant tuberculosis.

METHODS

In this individual patient data meta-analysis, we searched MEDLINE, Embase, and the Cochrane Library to identify potentially eligible observational and experimental studies published between Jan 1, 2009, and April 30, 2016. We also searched reference lists from all systematic reviews of treatment of multidrug-resistant tuberculosis published since 2009. To be eligible, studies had to report original results, with end of treatment outcomes (treatment completion [success], failure, or relapse) in cohorts of at least 25 adults (aged >18 years). We used anonymised individual patient data from eligible studies, provided by study investigators, regarding clinical characteristics, treatment, and outcomes. Using propensity score-matched generalised mixed effects logistic, or linear regression, we calculated adjusted odds ratios and adjusted risk differences for success or death during treatment, for specific drugs currently used to treat multidrug-resistant tuberculosis, as well as the number of drugs used and treatment duration.

FINDINGS

Of 12 030 patients from 25 countries in 50 studies, 7346 (61%) had treatment success, 1017 (8%) had failure or relapse, and 1729 (14%) died. Compared with failure or relapse, treatment success was positively associated with the use of linezolid (adjusted risk difference 0·15, 95% CI 0·11 to 0·18), levofloxacin (0·15, 0·13 to 0·18), carbapenems (0·14, 0·06 to 0·21), moxifloxacin (0·11, 0·08 to 0·14), bedaquiline (0·10, 0·05 to 0·14), and clofazimine (0·06, 0·01 to 0·10). There was a significant association between reduced mortality and use of linezolid (-0·20, -0·23 to -0·16), levofloxacin (-0·06, -0·09 to -0·04), moxifloxacin (-0·07, -0·10 to -0·04), or bedaquiline (-0·14, -0·19 to -0·10). Compared with regimens without any injectable drug, amikacin provided modest benefits, but kanamycin and capreomycin were associated with worse outcomes. The remaining drugs were associated with slight or no improvements in outcomes. Treatment outcomes were significantly worse for most drugs if they were used despite in-vitro resistance. The optimal number of effective drugs seemed to be five in the initial phase, and four in the continuation phase. In these adjusted analyses, heterogeneity, based on a simulated I² method, was high for approximately half the estimates for specific drugs, although relatively low for number of drugs and durations analyses.

INTERPRETATION

Although inferences are limited by the observational nature of these data, treatment outcomes were significantly better with use of linezolid, later generation fluoroquinolones, bedaquiline, clofazimine, and carbapenems for treatment of multidrug-resistant tuberculosis. These findings emphasise the need for trials to ascertain the optimal combination and duration of these drugs for treatment of this condition.

FUNDING

American Thoracic Society, Canadian Institutes of Health Research, US Centers for Disease Control and Prevention, European Respiratory Society, Infectious Diseases Society of America.

A cross-sectional study of tuberculosis drug resistance among previously treated patients in a tertiary hospital in Accra, Ghana: public health implications of standardized regimens

Background

Mycobacterium tuberculosis drug resistance is a major challenge to the use of standardized regimens for tuberculosis (TB) therapy, especially among previously treated patients. We aimed to investigate the frequency and pattern of drug resistance among previously treated patients with smear-positive pulmonary tuberculosis at the Korle-Bu Teaching Hospital Chest Clinic, Accra.

Methods

This was a cross-sectional survey of mycobacterial isolates from previously treated patients referred to the Chest Clinic Laboratory between October 2010 and October 2013. The Bactec MGIT 960 system for mycobactrerial culture and drug sensitivity testing (DST) was used for sputum culture of AFB smear-positive patients with relapse, treatment failure, failure of smear conversion, or default. Descriptive statistics were used to summarize patient characteristics, and frequency and patterns of drug resistance.

Results

A total of 112 isolates were studied out of 155 from previously treated patients. Twenty contaminated (12.9%) and 23 non-viable isolates (14.8%) were excluded. Of the 112 studied isolates, 53 (47.3%) were pan-sensitive to all first-line drugs tested Any resistance (mono and poly resistance) to isoniazid was found in 44 isolates (39.3%) and any resistance to streptomycin in 43 (38.4%). Thirty-one (27.7%) were MDR-TB. Eleven (35.5%) out of 31 MDR-TB isolates were pre-XDR. MDR-TB isolates were more likely than non-MDR isolates to have streptomycin and ethambutol resistance.

Conclusions

The main findings of this study were the high prevalence of MDR-TB and streptomycin resistance among previously treated TB patients, as well as a high prevalence of pre-XDR-TB among the MDR-TB patients, which suggest that first-line and second-line DST is essential to aid the design of effective regimens for these groups of patients in Ghana.

Efficacy and Safety of Mycobacterium indicus pranii as an adjunct therapy in Category II pulmonary tuberculosis in a randomized trial

Prolonged treatment of tuberculosis (TB) often leads to poor compliance, default and relapse, converting primary TB patients into category II TB (Cat IITB) cases, many of whom may convert to multi-drug resistant TB (MDR-TB). We have evaluated the immunotherapeutic potential of Mycobacterium indicus pranii (MIP) as an adjunct to Anti-Tubercular Treatment (ATT) in Cat II pulmonary TB (PTB) patients in a prospective, randomized, double blind, placebo controlled, multicentric clinical trial. 890 sputum smear positive Cat II PTB patients were randomized to receive either six intra-dermal injections (2 + 4) of heat-killed MIP at a dose of 5 × 10⁸ bacilli or placebo once in 2 weeks for 2 months. Sputum smear and culture examinations were performed at different time points. MIP was safe with no adverse effects. While sputum smear conversion did not show any statistically significant difference, significantly higher number of patients (67.1%) in the MIP group achieved sputum culture conversion at fourth week compared to the placebo (57%) group (p = 0.0002), suggesting a role of MIP in clearance of the bacilli. Since live bacteria are the major contributors for sustained incidence of TB, the potential of MIP in clearance of the bacilli has far reaching implications in controlling the spread of the disease.

An updated systematic review and meta-analysis for treatment of multidrug-resistant tuberculosis

This systematic review aimed to update the current evidence for multidrug-resistant tuberculosis (MDR-TB) treatment.We searched for studies that reported treatment information and clinical characteristics for at least 25 patients with microbiologically confirmed pulmonary MDR-TB and either end of treatment outcomes, 6-month culture conversion or severe adverse events (SAEs). We assessed the association of these outcomes with patients' characteristics or treatment parameters. We identified 74 studies, including 17 494 participants.The pooled treatment success was 26% in extensively drug-resistant TB (XDR-TB) patients and 60% in MDR-TB patients. Treatment parameters such as number or duration and individual drugs were not associated with improved 6-month sputum culture conversion or end of treatment outcomes. However, MDR-TB patients that received individualised regimens had higher success than patients who received standardised regimens (64% versus 52%; p<0.0.01). When reports from 20 cohorts were pooled, proportions of SAE ranged from 0.5% attributed to ethambutol to 12.2% attributed to para-aminosalicylic acid. The lack of significant associations of treatment outcomes with specific drugs or regimens may reflect the limitations of pooling the data rather than a true lack of differences in efficacy of regimens or individual drugs.This analysis highlights the need for stronger evidence for treatment of MDR-TB from better-designed and reported studies.

Characteristics and treatment outcomes of patients with multi-drug resistant tuberculosis at a tertiary care hospital in Peshawar, Pakistan

OBJECTIVES

To determine characteristics and treatment outcomes of multidrugs resistant tuberculosis (MDR-TB) patients and risk factors for poor outcomes in MDR-TB patients in a tertiary care hospital in Peshawar, Pakistan. 

METHODS

This retrospective study was conducted at the Programmatic Management of Drug Resistant TB Unit, Lady Reading Hospital Peshawar, Pakistan and included all MDR-TB patients registered between January 2012 and December 2012. A special proforma was used for data collection. Analysis was performed using SPSS version 16, after exporting data from the proforma. Differences in proportions were assessed using Pearson's Chi square test whereas for predictors of poor outcomes, multivariate logistic regression analysis with Wald Statistical criteria using backward elimination method was performed. 

RESULTS

The treatment success rate was 74.3%. In univariate analysis, poor outcomes were associated in patients with age ≥44 years (odds ratio [OR]=0.250; 95% confidence interval [CI]: 0.114-0.519, p=0.001), rural residence (OR=0.417; 95% CI: 0.18-0.937, p=0.03), lung cavitation (OR=0.22; 95% CI, 0.007-0.067, p=0.001), resistance to second line drugs (SLD) (OR=3.441; 95% CI: 1.579-7.497, p=0.001), and resistance to ofloxacin (OR=2.944; 95% CI: 1.361-6.365, p=0.005); whereas multivariate logistic regression analysis, poor outcomes were associated in patients with age ≥44 years (OR=0.249, 95% CI: 0.075-0.828, p=0.023), rural residence (OR=0.143, 95% CI: 0.052-0.774, p=0.032), and cavitatory lungs (OR=0.022, 95% CI: 0.007-0.072, p=0.000). 

CONCLUSION

The MDR-TB patient needs special attention for better treatment outcomes. The presence of older age, rural area residence, resistance to ofloxacin, SLD resistance, and cavitary disease are independent prognostic factors for poor outcome in patients with MDR-TB.

Characteristics and treatment outcomes of tuberculosis retreatment cases in three regional hospitals, Uganda

SETTING

Three regional referral hospitals in Uganda with a high burden of tuberculosis (TB) and human immunodeficiency virus (HIV) cases.

OBJECTIVE

To determine the treatment outcomes of TB retreatment cases and factors influencing these outcomes.

DESIGN

A retrospective cohort study of routinely collected National Tuberculosis Programme data between 1 January 2009 and 31 December 2010.

RESULTS

The study included 331 retreatment patients (68% males), with a median age of 36 years, 93 (28%) of whom were relapse smear-positive, 21 (6%) treatment after failure, 159 (48%) return after loss to follow-up, 26 (8%) relapse smear-negative and 32 (10%) relapse cases with no smear performed. Treatment success rates for all categories of retreatment cases ranged between 28% and 54%. Relapse smear-positive (P = 0.002) and treatment after failure (P = 0.038) cases were less likely to have a successful treatment outcome. Only 32% of the retreatment cases received a Category II treatment regimen; there was no difference in treatment success among patients who received Category II or Category I treatment regimens (P = 0.73).

CONCLUSION

Management of TB retreatment cases and treatment success for all categories in three referral hospitals in Uganda was poor. Relapse smear-positive or treatment after failure cases were less likely to have a successful treatment outcome.

Anti-tuberculosis drugs adverse reactions: a review of the Iranian literature

INTRODUCTION

Tuberculosis (TB) treatment, in particular therapy for multidrug-resistant TB (MDR-TB), is associated with toxicities and adverse drug reactions (ADRs).

AREAS COVERED

This paper reviews Iranian literature reporting ADRs which occurred during tuberculosis treatment. English language papers were sourced from PubMed, ScienceDirect, Wiley, Ovid and Proquest, with Google Scholar searched for Persian language articles. Reported ADRs, proportion of patients with ADRs, risk factors and determinants, as well as the characteristics of the studies were reviewed. 21 articles were included; about 60% of them were in English and three included patients with MDR-TB. The ratio of ADR per capita was 1.9 (in 6 studies) and 33.63% of patients developed an ADR (in 7 studies). Hepatitis (2.5 - 45.3%) was reported in nearly all of the studies. The mean time from initiation of medication to development of hepatitis ranged from 4.67 to 25.25 days (in 6 studies). Most cases of mortality were due to hepatotoxicity. Except for comorbidities and female gender, other risk factors such as HIV and length of hospitalization were only reported in one article.

EXPERT OPINION

The pattern of ADRs in Iranian articles was found to be similar to many other studies in the present review. We suggest that future studies resolve the confounding factors in this area that are mentioned in this review.

Drug resistance of Mycobacterium tuberculosis in Malawi: a cross-sectional survey

Objective

To document the prevalence of multidrug resistance among people newly diagnosed with – and those retreated for – tuberculosis in Malawi.

Methods

We conducted a nationally representative survey of people with sputum-smear-positive tuberculosis between 2010 and 2011. For all consenting participants, we collected demographic and clinical data, two sputum samples and tested for human immunodeficiency virus (HIV).The samples underwent resistance testing at the Central Reference Laboratory in Lilongwe, Malawi. All Mycobacterium tuberculosis isolates found to be multidrug-resistant were retested for resistance to first-line drugs – and tested for resistance to second-line drugs – at a Supranational Tuberculosis Reference Laboratory in South Africa.

Findings

Overall, M. tuberculosis was isolated from 1777 (83.8%) of the 2120 smear-positive tuberculosis patients. Multidrug resistance was identified in five (0.4%) of 1196 isolates from new cases and 28 (4.8%) of 581 isolates from people undergoing retreatment. Of the 31 isolates from retreatment cases who had previously failed treatment, nine (29.0%) showed multidrug resistance. Although resistance to second-line drugs was found, no cases of extensive drug-resistant tuberculosis were detected. HIV testing of people from whom M. tuberculosis isolates were obtained showed that 577 (48.2%) of people newly diagnosed and 386 (66.4%) of people undergoing retreatment were positive.

Conclusion

The prevalence of multidrug resistance among people with smear-positive tuberculosis was low for sub-Saharan Africa – probably reflecting the strength of Malawi’s tuberculosis control programme. The relatively high prevalence of such resistance observed among those with previous treatment failure may highlight a need for a change in the national policy for retreating this subgroup of people with tuberculosis.