Clinical outcome of multidrug-resistant tuberculosis patients receiving standardized second-line treatment regimen in China

Drug recommendation for optimization on treatment outcome for MDR/RR-TB based on a multi-center, large scale, retrospective cohort study in China

OBJECTIVE

With the change in drug-resistant pattern, MDR/RR-TB was faced with underlying changes in regimens. A multi-center, large-scale, retrospective study performed aims to provide a recommendation of drug selection on optimization of outcome for the patients.

METHOD

The study was conducted in six TB-specialized hospitals in China. Patients were included from 2018-2021 and followed up throughout the treatment. Using a multivarariable and propensity score-matched logistic regression analysis, we evaluated associations between outcomes and drug use, as well as clinical characteritics.

RESULTS

Of 3112 patients, 74.29% had treatment sucess, 14.52% lost to follow-up, 9.67% failure, and 1.51% died. Treatment success was positively associated with Bedaquiline(Bdq), Linezolid(Lzd), and Cycloserin(Cs). Capreomycin(Cm) increased the risk of unfavorable outcomes. other drugs such as Amikacin(Amk) and clofazimine had no significant effect on outcomes. If isolates were susceptible to fluoroquinolones(FQs), FQs could decrease the risk of unfavorable outcomes.

CONCLUSIONS

The recommendation order for the treatment of MDR/RR-TB is Bdq, Lzd, and Cs. FQs were decreased in use intensity. Injection drugs, whether Amk or Cm, are not recommended.

Management of rifampicin-resistant tuberculosis in conflict-affected areas: The case of Iraq

Since December 2019, the World Health Organization (WHO) has encouraged National Tuberculosis Programs to deprioritize the use of injectable-containing regimens and roll-out all-oral bedaquiline-containing regimens for rifampicin-resistant tuberculosis (RR-TB) treatment. Consequently, Iraq gradually replaced the injectable-containing regimen with an all-oral regimen, including bedaquiline. To assess treatment enrolment and outcomes of both regimens during a transitioning phase in Iraq, where health system services are recovering from decades of war, we conducted a nationwide retrospective cohort study using routinely collected programmatic data for patients enrolled between 2019-2021. We describe treatment enrolment and use logistic regression to identify predictors of unfavorable treatment outcomes (failure, death, or lost to follow-up), including regimen type. Nationwide, a total of 301 RR-TB patients started treatment, of whom 167 concluded treatment. The proportion of patients enrolled on the all-oral regimen increased from 53.2% (50/94) in 2020, to 75.5% (80/106) in 2021. Successful treatment was achieved in 82.1% (32/39) and 63.3% (81/128), for all-oral and injectable-containing regimens respectively. Moreover, the proportion of lost to follow-up was lower among those treated with the all-oral versus the long injectable-containing regimen; respectively 2.6% (1/39) versus 17.9% (23/128: p = 0.02). Unfavorable treatment outcome was associated with male gender (aOR 2.12, 95%CI:1.02-4.43) and age <15 years (vs 30-49 years, aOR 5.80, 95%CI:1.30-25.86). Regimen type (aOR 2.37, 95%CI: 0.91-6.13) was not significantly associated with having an unfavorable treatment outcome. In Iraq, the use of bedaquiline-containing all-oral regimen resulted in a high treatment success and reduced lost to follow-up.

The emerging threat of fluroquinolone-, bedaquiline-, and linezolid-resistant Mycobacterium tuberculosis in China: Observations on surveillance data

BACKGROUND

Drug-resistant tuberculosis (TB), especially multidrug-resistant tuberculosis (MDR-TB), constitutes a major obstacle to fulfill end TB strategy globally. Although fluoroquinolones (FQs), linezolid (LZD) and bedaquiline (BDQ) were classified as Group A drugs for MDR-TB treatment, our knowledge of the prevalence of TB which were resistant to Group A drugs in China is quite limited.

METHODS

In this study, we conducted a prospective multicenter surveillance study in China to determine the proportion of TB patients that were resistant to Group A drugs. A total of 1877 TB patients were enrolled from 2022 at four TB specialized hospitals. The drug susceptibility of isolated strains was conducted using the MGIT 960 system and the molecular mechanisms conferring drug resistance were investigated by Sanger sequencing.

RESULTS

12.9% of isolates were resistant to levofloxacin (LFX), 13.2% were resistant to moxifloxacin (MOX), 0.2% were resistant to bedaquiline (BDQ), and 0.8% were resistant to linezolid (LZD). Totally, 14.0% and 0.4% were classified as multidrug resistant- (MDR-) and extensively drug resistant- (XDR-) TB. The drug resistance was more common in retreated TB cases compared to new cases. In addition, 70.0% of fluoroquinolone (FQ)-resistant isolates harbored mutations in the gyrA and gyrB gene. By contrast, the common drug-resistant mutations were only found in 50% BDQ-resistant and 20% LZD-resistant isolates.

CONCLUSIONS

Our data demonstrate that approximate half of MDR -TB patients are resistant to fluoroquinolones, with extremely low prevalence of initial BDQ and LZD resistance. Findings from this study provide important implications for the current management of MDR-TB patients.

Treatment outcomes of multidrug-resistant tuberculosis patients receiving ambulatory treatment in Shenzhen, China: a retrospective cohort study

Background

WHO recommended multidrug-resistant tuberculosis (MDR-TB) should be treated mainly under ambulatory model, but outcome of ambulatory treatment of MDR-TB in China was little known.

Methods

The clinical data of 261 MDR-TB patients treated as outpatients in Shenzhen, China during 2010-2015 were collected and analyzed retrospectively.

Results

Of 261 MDR-TB patients receiving ambulatory treatment, 71.1% (186/261) achieved treatment success (cured or completed treatment), 0.4% (1/261) died during treatment, 11.5% (30/261) had treatment failure or relapse, 8.0% (21/261) were lost to follow-up, and 8.8% (23/261) were transferred out. The culture conversion rate at 6 months was 85.0%. Although 91.6% (239/261) of patients experienced at least one adverse event (AE), only 2% of AEs caused permanent discontinuation of one or more drugs. Multivariate analysis showed that previous TB treatment, regimens containing capreomycin and resistance to FQs were associated with poor outcomes, while experiencing three or more AEs was associated with good outcomes.

Conclusion

Good treatment success rates and early culture conversions were achieved with entirely ambulatory treatment of MDR-TB patients in Shenzhen, supporting WHO recommendations. Advantageous aspects of the local TB control program, including accessible and affordable second-line drugs, patient support, active monitoring and proper management of AEs and well-implemented DOT likely contributed to treatment success rates.

Improved outcomes following addition of bedaquiline and clofazimine to a treatment regimen for multidrug-resistant tuberculosis

OBJECTIVE

To investigate if the addition of bedaquiline and clofazimine to a treatment regimen for multidrug-resistant tuberculosis (MDR-TB) could improve patient outcomes.

METHODS

A prospective, randomized, controlled study was conducted in patients with MDR-TB. Treatment was for 18 months. Patients in the experimental group received bedaquiline and clofazimine in addition to their regular treatment regimen whereas patients in the control group did not.

RESULTS

68 patients with MDR-TB were randomised to treatment, 34 to each group. At the end of treatment, cure rates were statistically significantly greater for the experimental group compared with the control group (82% vs. 56%). There was no difference between groups in the number of severe adverse events (3[9%]) in both groups and none were skin-related.

CONCLUSIONS

The addition of bedaquiline and clofazimine to the treatment regimen significantly improves outcomes for patients with MDR-TB. Clinicians should be aware of the clinical benefits of this addition but be mindful of contraindications and adverse effects.

Determination of critical concentration for drug susceptibility testing of Mycobacterium tuberculosis against para-aminosalicylic acid with clinical isolates with thyA, folC and dfrA mutations

Background & Objectives

Accurate determination of antimicrobial resistance profiles is of great importance to formulate optimal regimens against multidrug-resistant tuberculosis (MDR-TB). Although para-aminosalicylic acid (PAS) has been widely used clinically, the reliable testing methods for PAS susceptibility were not established. Herein, we aimed to establish critical test concentration for PAS on the Mycobacterial Growth Indicator Tube (MGIT) 960 in our laboratory settings.

Methods

A total of 102 clinical isolates were included in this study, including 82 wild-type and 20 resistotype isolates. Minimum inhibitory concentration (MIC) was determined by MGIT 960. Whole-genome sequencing was used to identify the mutation patterns potentially conferring PAS resistance. Sequence alignment and structure modelling were carried out to analyze potential drug-resistant mechanism of folC mutant.

Results

Overall, the Minimum inhibitory concentration (MIC) distribution demonstrated excellent separation between wild-type and resistotype isolates. The wild-type population were all at least 1 dilution below 4 μg/ml, and the resistotype population were no lower than 4 μg/ml, indicating that 4 μg/ml was appropriate critical concentration to separate these two populations. Of 20 mutant isolates, 12 (60.0%) harbored thyA mutations, 2 (10%) had a mutation on upstream of dfrA, and the remaining isolates had folC mutations. Overall, thyA and folC mutations were scattered throughout the whole gene without any one mutation predominating. All mutations within thyA resulted in high-level resistance to PAS (MIC > 32 μg/ml); whereas the MICs of isolates with folC mutations exhibited great diversity, ranged from 4 to > 32 μg/ml, and sequence and structure analysis partially provided the possible reasons for this diversity.

Conclusions

We propose 4 μg/ml as tentative critical concentration for MGIT 960. The major mechanism of PAS resistance is mutations within thyA and folC in MTB isolations. The whole-gene deletion of thyA locus confers high-level resistance to PAS. The diversity of many distinct mutations scattered throughout the full-length folC gene challenges the PCR-based mutation analysis for PAS susceptibility.

High Incidence of Psychiatric Disorders Associated with Cycloserine Treatment of Multidrug-Resistant Tuberculosis Patients: A Cohort Study in Beijing, China

Objective

Cycloserine (CS) is a group B anti-tuberculosis (TB) drug endorsed by the World Health Organization (WHO) for the treatment of drug-resistant (DR)-TB. Despite CS widespread acceptance and known efficacy, the high potential of drug-associated psychiatric disorders is a major concern to multidrug-resistant (MDR)-TB patients. In this study, we investigated CS-associated psychiatric disorders in a cohort of MDR-TB patients in Beijing, China. Our aim was to determine psychiatric disorder prevalence rates and associated risk factors in this population.

Methods

This MDR-TB cohort study was conducted at Beijing Chest Hospital between February 2018 and February 2021. All patients received individualized treatment regimens that included CS at some point during the full treatment course. Patient psychological status was assessed using the Symptom Checklist (SCL-90) questionnaire during the post-treatment follow-up period.

Results

Two hundred and thirty-seven MDR-TB patients were included in the final analysis. Overall, psychiatric disorders were recorded in 22 (9.28%) of the 237 patients in our cohort, with severity grades of 1 or 2 observed for the majority (8.44%) of psychiatric adverse events. As compared to results obtained for control group patients who were ≥40 years of age, patients who were <40 years of age (77.3%, 17/22) were more likely to experience psychiatric disorders [adjusted odds ratio (aOR) = 3.060; 95% CI (1.060–8.828)]. Additionally, patients with body mass index (BMI)s of <18.5 kg/m² [aOR = 3.824; 95% CI (1.502–9.739)] had significantly higher odds of being afflicted with psychiatric disorders as compared with patients with BMIs that were ≥18.5 kg/m².

Conclusion

Our results demonstrated that approximately one-tenth of Chinese MDR-TB patients experienced psychiatric disorders during CS treatment, with the majority of adverse events of moderate severity. In addition, low BMI and age <40 years were identified as independent risk factors for psychiatric disorders in MDR-TB patients receiving CS therapy.

Distinguishing Relapse From Reinfection With Whole-Genome Sequencing in Recurrent Pulmonary Tuberculosis: A Retrospective Cohort Study in Beijing, China

Background: Tuberculosis recurrence is still a major problem for the control of tuberculosis, and the cause of the recurrence is still unclear.

Methods: We retrospectively recruited 68 pairs of samples of Mycobacterium tuberculosis (MTB) from recurrent TB cases in Beijing Chest Hospital between January 2008 and December 2019. The whole-genome sequencing was conducted to analyze single-nucleotide polymorphism (SNP) and to identify whether recurrent disease was due to relapse or reinfection. The BACTEC MGIT was performed to compare differences in drug susceptibility profiles between two episodes.

Results: 62 (91.2%) out of 68 confirmed recurrence were due to relapse, whereas the remaining six (8.8%) were due to reinfection. And there was a strong association between earlier relapse and underlying chronic diseases. In addition, the MTB isolates from non-diabetic patients had a higher mutation rate than those from diabetic patients. A community transmission was also identified in our cohort. Levofloxacin resistance was the most frequently observed drug resistance for 12.9% relapse cases.

Conclusion: The relapse of a previous episode in Beijing. The underlying chronic diseases are associated with an earlier TB relapse. MTB isolates were more prone to develop levofloxacin resistance than moxifloxacin resistance after FQ exposure. The patients at high-risk for relapses deserve more careful investigation.

Prediction of Multidrug-Resistant Tuberculosis Using Machine Learning Algorithms in SWAT, Pakistan

In this paper, we have focused on machine learning (ML) feature selection (FS) algorithms for identifying and diagnosing multidrug-resistant (MDR) tuberculosis (TB). MDR-TB is a universal public health problem, and its early detection has been one of the burning issues. The present study has been conducted in the Malakand Division of Khyber Pakhtunkhwa, Pakistan, to further add to the knowledge on the disease and to deal with the issues of identification and early detection of MDR-TB by ML algorithms. These models also identify the most important factors causing MDR-TB infection whose study gives additional insights into the matter. ML algorithms such as random forest, k-nearest neighbors, support vector machine, logistic regression, leaset absolute shrinkage and selection operator (LASSO), artificial neural networks (ANNs), and decision trees are applied to analyse the case-control dataset. This study reveals that close contacts of MDR-TB patients, smoking, depression, previous TB history, improper treatment, and interruption in first-line TB treatment have a great impact on the status of MDR. Accordingly, weight loss, chest pain, hemoptysis, and fatigue are important symptoms. Based on accuracy, sensitivity, and specificity, SVM and RF are the suggested models to be used for patients' classifications.

Prevalence of extensively drug-resistant tuberculosis in a Chinese multidrug-resistant TB cohort after redefinition

OBJECTIVES

Recently, the definition of extensively drug-resistant TB (XDR-TB) has been revised. In this study, we conducted a descriptive and retrospective study to determine the prevalence of XDR-TB in a Chinese multidrug-resistant TB (MDR-TB) cohort.

METHODS

Broth microdilution method was performed to determine in vitro susceptibilities of Mycobacterium tuberculosis (MTB) isolates to (FQs), bedaquiline (BDQ) and linezolid (LZD). The putative drug target genes conferring drug resistance were screened by DNA sequencing.

RESULTS

A total of 425 MDR-TB isolates were included from 13 pilots in China. LZD and BDQ resistance were noted in 30 (7.1%) and 10 (2.4%) isolates. On the basis of latest definitions, 114 (26.8%) were MDR-TB, 282 (66.4%) were pre-XDR-TB, and 29 (6.8%) were XDR-TB. Among 311 FQ-resistant isolates, 265 harbored genetic mutations within QRDRs. The most common mutations were observed at codon 94 of gyrA, accounting for 47.2% of FQ-resistant MTB isolates. Only mutations within the Rv0678 gene were found to confer BDQ resistance in our cohort, conferring 40.0% of BDQ resistance. For LZD resistance, 53.3% of LZD-resistant isolates carried genetic mutations in rplC or 23S rRNA. The most frequent mutation was Cys154Arg in the rplC gene. In addition, we recorded two MDR-TB patients with resistance to both BDQ and LZD, of which one patient experienced continuous positive culture of MTB despite inclusion of efficacious moxifloxacin.

CONCLUSION

Our results demonstrate that the low prevalence of XDR-TB holds great promise for MDR-TB treatment with WHO-endorsed regimens containing BDQ-LZD combination, whereas the high prevalence of FQ-resistance in MDR-TB patients warrants national attention.

Incidence and risk factors of postoperative complications in patients with tuberculosis-destroyed lung

Background

The purpose of this study was to determine risk factors of postoperative complications in tuberculosis-destroyed lung (TDL) patients.

Methods

We retrospectively analyzed the data from all consecutive TDL patients undergoing surgical treatment at the Beijing Chest Hospital from January 2001 to September 2019.

Results

Of 113 TDL cases experiencing surgery, 33 (29.2%) experienced postoperative complications. The patients with low BMI were more likely to have postoperative complications compared to those with normal BMI, whereas a significant lower rate of postoperative complications was noted in patients with BMI ≥ 25 kg/m². In addition, significant increased risk was observed in patients with smoking history. We found that the patients with underlying infection, including aspergillus and nontuberculous mycobacteria (NTM), had significantly higher odds of having postoperative complications compared with those without underlying infection. The anaemia was another important independent factor associated with postoperative complication. Patients with blood transfusion above 1000 mL had a strongly increased frequency of postoperative complications than patients with blood transfusion below 1000 mL.

Conclusion

In conclusion, our data demonstrate that approximate one third of TDL patients experience postoperative complications in our cohort. Patients with low BMI, anaemia, tobacco smoking, and coinfected aspergillus or NTM are at markedly higher risk to experience postoperative complications after pneumonectomy.

Lymphocyte-Related Immunological Indicators for Stratifying Mycobacterium tuberculosis Infection

Background

Easily accessible tools that reliably stratify Mycobacterium tuberculosis (MTB) infection are needed to facilitate the improvement of clinical management. The current study attempts to reveal lymphocyte-related immune characteristics of active tuberculosis (ATB) patients and establish immunodiagnostic model for discriminating ATB from latent tuberculosis infection (LTBI) and healthy controls (HC).

Methods

A total of 171 subjects consisted of 54 ATB, 57 LTBI, and 60 HC were consecutively recruited at Tongji hospital from January 2019 to January 2021. All participants were tested for lymphocyte subsets, phenotype, and function. Other examination including T-SPOT and microbiological detection for MTB were performed simultaneously.

Results

Compared with LTBI and HC, ATB patients exhibited significantly lower number and function of lymphocytes including CD4⁺ T cells, CD8⁺ T cells and NK cells, and significantly higher T cell activation represented by HLA-DR and proportion of immunosuppressive cells represented by Treg. An immunodiagnostic model based on the combination of NK cell number, HLA-DR⁺CD3⁺ T cells, Treg, CD4⁺ T cell function, and NK cell function was built using logistic regression. Based on receiver operating characteristic curve analysis, the area under the curve (AUC) of the diagnostic model was 0.920 (95% CI, 0.867-0.973) in distinguishing ATB from LTBI, while the cut-off value of 0.676 produced a sensitivity of 81.48% (95% CI, 69.16%-89.62%) and specificity of 91.23% (95% CI, 81.06%-96.20%). Meanwhile, AUC analysis between ATB and HC according to the diagnostic model was 0.911 (95% CI, 0.855-0.967), with a sensitivity of 81.48% (95% CI, 69.16%-89.62%) and a specificity of 90.00% (95% CI, 79.85%-95.34%).

Conclusions

Our study demonstrated that the immunodiagnostic model established by the combination of lymphocyte-related indicators could facilitate the status differentiation of MTB infection.

Risk factors associated with postoperative respiratory failure in tuberculous empyema patients

Our objective was to identify independent risk factors for predicting which patients in the Chinese population would likely develop respiratory failure.A descriptive analysis was conducted of demographic and clinical data of patients with tuberculous empyema (TE) admitted to the Beijing Chest Hospital, Capital Medical University between January 2001 and January 2020. Risk factors associated with postsurgical respiratory failure in TE patients were identified based on results of analyses based on univariable and multivariable logistic regression models.A total of 139 TE patients who underwent surgical treatment in the Beijing Chest Hospital, Capital Medical University from January 2001 to January 2020 were enrolled in this study. Cases included 109 male and 30 female patients, with an overall mean age (range 17-73) of 39.3 years. Of 139 TE patients, 26 (18.7%) experienced respiratory failure after surgery. Among significant risk factors for postsurgical respiratory failure, intraoperative blood loss volume greater than 1000 mL had the highest odds ratio value of 6.452. In addition, a pathologic preoperative pulmonary function test result showing a high partial pressure of carbon dioxide level was an independent risk factor for respiratory failure. Moreover, the presence of tuberculosis lesions in the contralateral lung was another significant risk factor for respiratory failure, as determined using multivariate analysis.Respiratory failure is a predominant complication experienced by TE patients undergoing surgery. High intraoperative blood loss, high preoperative high partial pressure of carbon dioxide level, and tuberculosis lesion(s) in the contralateral lung of TE patients were associated with increased risk of postoperative respiratory failure.

Low Rate of Acquired Linezolid Resistance in Multidrug-Resistant Tuberculosis Treated With Bedaquiline-Linezolid Combination

In this retrospective study in China, we aimed to: (1) determine the prevalence of linezolid (LZD) resistance among multidrug-resistant tuberculosis (MDR-TB)-infected patients; (2) monitor for dynamic LZD susceptibility changes during anti-TB treatment; and (3) explore molecular mechanisms conferring LZD resistance. A total of 277 MDR-TB patients receiving bedaquiline (BDQ)-containing regimens in 13 TB specialized hospitals across China were enrolled in the study. LZD and BDQ susceptibility rates were determined using the minimum inhibitory concentration (MIC) method, then DNA sequences of patient isolates were analyzed using Sanger sequencing to detect mutations conferring LZD resistance. Of 277 patients in our cohort, 115 (115/277, 41.5%) with prior LZD exposure yielded 19 (19/277, 6.9%) isolates exhibiting LZD resistance. The LZD resistance rate of LZD-exposed group isolates significantly exceeded the corresponding rate for non-exposed group isolates (P = 0.047). Genetic mutations were observed in 10 (52.6%, 10/19) LZD-resistant isolates, of which a Cys154Arg (36.8%, 7/19) substitution within ribosomal protein L3 was most prevalent. Analysis of sequential positive cultures obtained from 81 LZD-treated patients indicated that cultured organisms obtained from most patients (85.2%, 69/81) retained original LZD MIC values; however, organisms cultured later from two patients exhibited significantly increased MIC values that were attributed to the rplC substitution T460C. Overall, LZD resistance was detected in 6.9% of patients of an MDR-TB cohort in China. Low rate of acquired LZD resistance was noted in MDR-TB treated with BDQ-LZD combination.

Treatment Outcome of a Shorter Regimen Containing Clofazimine for Multidrug-resistant Tuberculosis: A Randomized Control Trial in China

BACKGROUND

The emergence of multidrug-resistant tuberculosis (MDR-TB) poses a serious obstacle to global TB control programs.

METHODS

We carried out a prospective, randomized, multicenter study in China that was focused on the potential of a shorter regimen containing clofazimine (CFZ) for the treatment of MDR-TB. There were 135 MDR-TB cases that met eligibility requirements and were randomly stratified into either the control group or experimental group. Patients in the control group received an 18-month treatment regimen, whereas patients in the experimental group received a 12-month treatment regimen containing CFZ.

RESULTS

At the completion of the treatment period, the difference in sputum-culture conversion rates between the experimental group and the control group was not significant. Notably, by the end of 3 months of treatment, 68.7% patients receiving the experimental regimen had sputum-culture conversion, as compared with 55.9% of those receiving the control regimen; this was a significant difference, suggesting an early sputum conversion (P = .04). There were 67 adverse events reported in 56 patients in this study, including 32 in the control group and 35 in the experimental group. No significant difference in the overall incidences of adverse events was observed between the 2 groups.

CONCLUSIONS

The MDR-TB patients treated with the shorter regimen containing CFZ had a comparable successful outcome rate when compared to those with the standard regimen. The patients assigned to the experimental group achieved more rapid sputum-culture conversion, reflecting superior antimicrobial activity against MDR-TB.

CLINICAL TRIALS REGISTRATION

Chinese Clinical Trial Registry ChiCTR 1800020391.

Comparative in vitro susceptibility of a novel fluoroquinolone antibiotic candidate WFQ-228, levofloxacin, and moxifloxacin against Mycobacterium tuberculosis

OBJECTIVE

WFQ-228 is a novel developed fluoroquinolone (FQ) displaying potent antimicrobial activity against various clinical isolates of pathogens, including FQ-resistant isolates. The aim was to comparatively analyze in vitro susceptibilities of WFQ-228, levofloxacin (LFX), and moxifloxacin (MFX) against Mycobacterium tuberculosis (MTB) isolates, especially with gyrA mutations.

METHODS

We selected a panel of 75 MTB isolates, consisting of 25 FQ-susceptible and 50 FQ-resistant isolates determined by conventional drug susceptibility testing. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of FQs to MTB isolates were assessed.

RESULTS

MFX exhibited the most potent activity against FQ-susceptible MTB, demonstrating a MIC₅₀ of 0.031 mg/L, which was lower than that of LFX and WFQ-228. Against FQ-resistant MTB isolates, the MIC₅₀ of WFQ-228 was higher than that of MFX but lower than that of LFX. For WFQ-228, there was a significant overlap existing in the MIC distributions between the probable susceptible (PS) and probable resistant (PR) groups. Six out of 50 PR isolates were classified as susceptible based on a proposed critical concentration (CC) of 0.5 mg/L, yielding a poor sensitivity of 88.0%. These discordant isolates had GyrA substitution in Ala90Val, Ser91Pro, and Asp94Tyr. Additionally, MFX exhibited bactericidal activity against MTB isolates without gyrA mutations, which was significantly higher than that of isolates with gyrA mutations.

CONCLUSION

WFQ-228 is more efficacious than LFX in isolates with specific mutations conferring low-level FQ resistance. The bactericidal effect is noted more frequently in FQ-susceptible isolates than FQ-resistant isolates for MFX.

Policy changes and the screening, diagnosis and treatment of drug-resistant tuberculosis patients from 2015 to 2018 in Zhejiang Province, China: a retrospective cohort study

OBJECTIVES

To examine changes in the screening, diagnosis, treatment and management of drug-resistant tuberculosis (DRTB) patients, and investigate the impacts of DRTB-related policies on patients of different demographic and socioeconomic characteristics.

DESIGN

A retrospective cohort study using registry data, plus a survey on DRTB-related policies.

SETTING

All prefecture-level Centres for Disease Control in Zhejiang Province, China.

MAIN OUTCOME MEASURES

Alongside the care cascade, we examined: (1) reported number of presumptive DRTB patients; (2) percentage of presumptive patients with drug susceptibility testing (DST) records; (3) percentage of DRTB/rifampicin-resistant (RR) patients registered; (4) percentage of RR/multidrug-resistant TB (MDRTB) patients that received anti-DRTB treatment; and (5) percentage of RR/MDRTB patients cured/completed treatment among those treated. Multivariate logistic regressions were conducted to explore the impacts of DRTB policies after adjusting for other factors.

RESULTS

The number of reported presumptive DRTB patients and the percentage with DST records largely increased during 2015-2018, and the percentage of registered patients who received anti-DRTB treatment also increased from 59.0% to 86.5%. Patients under the policies of equipping GeneXpert plus expanded criteria for DST had a higher likelihood of being registered compared with no GeneXpert (adjusted OR (aOR)=2.57, 95% CI: 1.20 to 5.51), while for treatment initiation the association was only significant when further expanding the registration criteria (aOR=2.38, 95% CI: 1.19 to 4.79). Patients with registered residence inside Zhejiang were more likely to be registered (aOR=1.96, 95% CI: 1.52 to 2.52), treated (aOR=3.83, 95% CI: 2.78 to 5.28) and complete treatment (aOR=1.92, 95% CI: 1.03 to 3.59) compared with those outside.

CONCLUSION

The policy changes on DST and registration have effectively improved DRTB case finding and care. Nevertheless, challenges remain in servicing vulnerable groups such as migrants and improving equity in the access to TB care. Future policies should provide comprehensive support for migrants to complete treatment at their current place of residence.

Bipolar Distribution of Minimum Inhibitory Concentration of Q203 Across Mycobacterial Species

In this study, we conducted an experimental study to evaluate in vitro susceptibility of Q203 against Mycobacterium tuberculosis, as well as the major pathogenic nontuberculous mycobacterial species. A total of 344 nonduplicate mycobacterium isolates were randomly selected for in vitro susceptibility testing. Overall, Q203 exhibited excellent activity against multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) isolates, whereas it showed high minimum inhibitory concentration (MIC) values for all nontuberculous mycobacteria (NTM) isolates tested. The MIC₅₀ and MIC₉₀ values were both 0.008 mg/L for MDR- and XDR-TB isolates, respectively. In contrast, the MIC₅₀ and MIC₉₀ values of four NTM species were all >16 mg/L. QcrB of M. tuberculosis, a component of the CytBC1 complex of the respiratory chain targeted by Q230, shared 89.7% amino acid sequence identity with Mycobacterium avium QcrB, 87.9% with that of Mycobacterium intracellulare, and 84.0% with that of Mycobacterium fortuitum, whereas with low sequence identity observed in QcrB sequence of Mycobacterium abscessus. Notably, the QcrBs of M. avium and M. intracellulare contained a 10-amino acid insertion in the linker between the eighth and ninth helical region. In conclusion, our data demonstrate the bipolar distribution of Q203 MICs across mycobacterial species. Compared with the high MICs in four clinically relevant mycobacterial species, MDR- and XDR-TB isolates have extremely low MICs, indicating that Q203 is a particularly promising candidate for TB treatment. In addition, the 10-amino acid insertion within QcrBs of M. avium and M. intracellulare may be a plausible explanation for the natural resistance to Q203 among these two species.

The epidemiologic impact and cost-effectiveness of new tuberculosis vaccines on multidrug-resistant tuberculosis in India and China

BACKGROUND

Despite recent advances through the development pipeline, how novel tuberculosis (TB) vaccines might affect rifampicin-resistant and multidrug-resistant tuberculosis (RR/MDR-TB) is unknown. We investigated the epidemiologic impact, cost-effectiveness, and budget impact of hypothetical novel prophylactic prevention of disease TB vaccines on RR/MDR-TB in China and India.

METHODS

We constructed a deterministic, compartmental, age-, drug-resistance- and treatment history-stratified dynamic transmission model of tuberculosis. We introduced novel vaccines from 2027, with post- (PSI) or both pre- and post-infection (P&PI) efficacy, conferring 10 years of protection, with 50% efficacy. We measured vaccine cost-effectiveness over 2027-2050 as USD/DALY averted-against 1-times GDP/capita, and two healthcare opportunity cost-based (HCOC), thresholds. We carried out scenario analyses.

RESULTS

By 2050, the P&PI vaccine reduced RR/MDR-TB incidence rate by 71% (UI: 69-72) and 72% (UI: 70-74), and the PSI vaccine by 31% (UI: 30-32) and 44% (UI: 42-47) in China and India, respectively. In India, we found both USD 10 P&PI and PSI vaccines cost-effective at the 1-times GDP and upper HCOC thresholds and P&PI vaccines cost-effective at the lower HCOC threshold. In China, both vaccines were cost-effective at the 1-times GDP threshold. P&PI vaccine remained cost-effective at the lower HCOC threshold with 49% probability and PSI vaccines at the upper HCOC threshold with 21% probability. The P&PI vaccine was predicted to avert 0.9 million (UI: 0.8-1.1) and 1.1 million (UI: 0.9-1.4) second-line therapy regimens in China and India between 2027 and 2050, respectively.

CONCLUSIONS

Novel TB vaccination is likely to substantially reduce the future burden of RR/MDR-TB, while averting the need for second-line therapy. Vaccination may be cost-effective depending on vaccine characteristics and setting.

Time to sputum culture conversion and its predictors among patients with multidrug-resistant tuberculosis in Hangzhou, China: A retrospective cohort study

The objective is to investigate the time to initial sputum culture conversion (SCC) and its predictors among multidrug-resistant tuberculosis (MDR-TB) patients in Hangzhou, China.A retrospective cohort study was conducted among patients who initiated MDR-TB treatment from 2011 to 2015 in Hangzhou, China. Successful achievement of initial SCC was defined as 2 consecutive negative cultures taken at least 30 days apart after initiation of treatment of MDR-TB. Successful treatment outcomes included being cured and completing treatment, while poor treatment outcomes included treatment failure, loss to follow-up, and death. Time to initial SCC was analyzed using the Kaplan-Meier method, and Cox proportional hazards regression was used to identify predictors of SCC.Among 384 patients enrolled with MDR-TB, 359 (93.5%) successfully achieved initial SCC after a median of 85 days (interquartile range, 40-112 days). A higher rate of SCC was observed in participants with successful treatment outcomes than those with poor treatment outcomes (P<.01). Multivariate analysis showed that age 25 to 64 years (compared with age<25; adjusted odds ratio [AOR], 0.7; 95% confidence interval [CI], 0.5-0.9; P < .01), age ≥65 years (compared with age < 25; AOR, 0.5; 95% CI, 0.3-0.8; P < .01), and household registration in Hangzhou (compared with non-Hangzhou registration; AOR, 1.3; 95% CI, 1.0-1.5; P < .05) were found to be associated with SCC.Although high SCC and treatment success rates were observed among MDR-TB patients in Hangzhou, the prolonged duration to initial SCC underscores the importance of emphasizing measures for infection control. A new policy of shifting outpatient treatment to inpatient treatment in China may reduce the risk of transmission from patients in the time window prior to SCC.

Challenges Faced by Multidrug-Resistant Tuberculosis Patients in Three Financially Affluent Chinese Cities

Purpose

The aim of this study was to analyze socioeconomic burdens and other difficulties that multidrug-resistant tuberculosis (MDR-TB) patients in cities are facing, to identify major obstacles and which groups of patients are most affected.

Methods

Face-to-face and phone-call interviews were conducted in early 2018 to follow-up with patients newly diagnosed with MDR-TB in 2017 in three tuberculosis hospitals in three financially affluent Chinese cities. Demographic data and information on their medical care, insurance coverage, and medical expenses were collected and analyzed.

Results

A total of 144 newly diagnosed MDR-TB cases were reviewed during the study period, excluding 38 who were lost to follow-up and 29 patients who refused to participate, 77 patients were enrolled in this study. A total of 61 (79%) of these patients were hospitalized after MDR-TB diagnosis with an average hospital stay of 14 days, of them 57 (74%) were sputum positive on diagnosis. The proportion of patients who failed community care were 48% married, 56% in white collar employment and 43% in temp jobs/unemployed. In terms of insurance coverage, the proportion of patients who failed community care were 23% with no insurance and/or New Rural Co-operative Medical Care Scheme (NRCMS) and 45% with Urban Employee Basic Medical Insurance (UEBMI)/Urban Residents Basic Medical Insurance (URBMI) and commercial insurance. Difficulties patients encountered were, financial pressure (33%), psychological stress (26%), adverse drug reactions (23%), repulsive reaction to injections (17%). Fourty-eight percent of the patients spent over ¥2000 (USD300) per month on TB treatment.

Conclusion

Despite insurance coverage, financial hardship remains the number one difficulty MDR-TB patients encountered in relatively financially affluent cities. Among them, the married working class were found to be the most financially sensitive group and have the highest tendency to fail community care. It is of utmost urgency to enhance the current medical policy to improve treatment adherence.

Acquisition of clofazimine resistance following bedaquiline treatment for multidrug-resistant tuberculosis

OBJECTIVES

We described the prevalence of clofazimine (CFZ) resistance in a multidrug-resistant tuberculosis (MDR-TB) cohort in China. We also aimed to identify dynamic changes in CFZ susceptibility and its molecular mechanism after exposure to bedaquiline (BDQ) and/or CFZ.

METHODS

The experimental settings were conducted based on our MDR-TB cohort receiving BDQ-containing regimens. Sequential isolates were obtained from patients. CFZ and BDQ susceptibility of isolates were determined using the minimum inhibitory concentration (MIC) method. The fragments of Rv0678 and pepQ were sequenced.

RESULTS

A total of 277 patients infected with MDR-TB were included in our study. CFZ resistance was noted in 23 (23/277, 8.3%) isolates. The rate of acquired CFZ resistance (12/189, 6.3%) was significantly greater than that of primary resistance (11/88, 12.5%, P = 0.028). Out of 23 CFZ-resistant isolates, five (5/23) were BDQ-resistant, and the other 18 (18/23) were susceptible to BDQ. Of note, nine 9/23) out of 23 CFZ-resistant isolates had mutations within either target genes. Kaplan-Meier analysis demonstrated that the baseline CFZ resistance had no influence on time to culture conversion in our cohort (P = 0.828). Acquired CFZ resistance emerged in eight (8/94, 8.5%) patients during treatment for MDR-TB, including three patients receiving regimens without CFZ.

CONCLUSIONS

Our results demonstrate the high rate of CFZ resistance among MDR-TB patients in China. Patients treated with BDQ-containing regimens achieve comparative culture conversion rate regardless of baseline CFZ susceptibility. The presence of acquired CFZ-resistance following BDQ treatment without known mutation indicates that other mechanisms conferring cross resistance to these two compounds may exist.

Emergence of nontuberculous mycobacteria infections during bedaquiline-containing regimens in multidrug-resistant tuberculosis patients

OBJECTIVES

The World Health Organization recommends the use of bedaquiline (BDQ) to formulate efficacious combination regimens against multidrug-resistant tuberculosis (MDR-TB). This study reports, for the first time, a case series of MDR-TB patients treated with BDQ who experienced sputum culture reconversion due to emergence of nontuberculous mycobacteria (NTM) infections.

METHODS

A multicentre case series was established, including patients who started treatment for laboratory-confirmed MDR-TB between January 1, 2018 and March 31, 2020. The study included patients with positive cultures that had no expression of tuberculosis-specific MPT64 protein. Multilocus sequence analysis was used to perform rapid species identification. Susceptibility to BDQ was detected using Thermo Fisher frozen microtiter plates by the laboratory staff at Beijing Chest Hospital.

RESULTS

Among the 286 patients receiving BDQ regimens included in this study, the emergence of NTM isolations was reported in nine cases (3.1%). After exposure to BDQ, seven out of these nine patients achieved culture conversion by 4 weeks. The median time for reported NTM infection was 12 weeks (range: 4-24 weeks). Of these, seven were rapidly growing mycobacteria, and two were slow growing. The most frequent NTM species was M. abscessus (five isolates), followed by M. fortuitum (two isolates), M. avium (one isolate), and M. intracellulare (one isolate). In addition, three patients showed resistance to BDQ at baseline.

CONCLUSION

In conclusion, our results demonstrated the emergence of novel NTM populations in MDR-TB patients during BDQ therapy. The notably rapid development of NTM infections underlines the need for systematic species identification during the follow-up period.

Treatment outcomes of multidrug-resistant tuberculosis in Hangzhou, China, 2011 to 2015

Treatment of multidrug-resistant tuberculosis (MDR-TB) is challenging. More research is needed to understand treatment outcomes and associated factors.A retrospective cohort study was conducted to assess trends and predictors of treatment success among 398 MDR-TB and extensively drug resistant TB patients who started treatment in 2011 to 2015 in Hangzhou, China. Sociodemographic and clinical characteristic data were obtained from the national reporting database. Chi-square test for trend was used to evaluate changes in treatment success rates over the study years, and Cox regression analysis was used to identify predictors for poor treatment outcomes.The treatment success rate was 76% (301/398) for all participants, 77% (298/387) for MDR-TB cases and 27% (3/11) for extensively drug-resistant tuberculosis -TB cases. Treatment success increased significantly from 66% among patients who started treatment in 2011 to 85% in 2015 (P < .01). Of the 97 (24.4%) patients with unsuccessful treatment outcomes, 10 (2.5%) died, 64 (16.1%) failed treatment, and 23 (5.8%) were lost to follow-up. Patients who started treatment in 2013 to 2015 were less likely to have unsuccessful outcomes than those who started in 2011-2012 (adjusted odds ratio [AOR] 0.4, 95% confidence interval [CI] 0.3-0.6), patients ≥25 years were more likely to have unsuccessful outcomes than younger patients (AOR 1.6, 95% CI 1.3-2.1), and cases with kanamycin resistance was associated with three times the odds of having unsuccessful outcomes than kanamycin-susceptible cases (AOR 3.0, 95% CI 1.5-5.8).With proper case management of MDR-TB, patients can achieve a high treatment success rate. Hangzhou's program offers clinical evidence that can be used to inform MDR-TB programs elsewhere in China and abroad.

Survival of patients with multidrug-resistant tuberculosis in Central China: a retrospective cohort study

The aim of this study was to evaluate long-term survival and risk factors associated with multidrug-resistant tuberculosis (MDR-TB) patient survival in Central China. Between December 2006 and June 2011, incident and retreatment adult MDR-TB patients were enrolled in the present study. Cox proportional hazard regression analysis was used to evaluate the risk factors affecting survival. The total follow-up period was 270 person-years (PY) for 356 MDR-TB cases in Wuhan. Of the 356 cases, 103 patients died, yielding an average case fatality rate of 381.2 per 1000 TB patients per year. Using adjusted Cox regression analysis, older age (adjusted hazard ratio (aHR) >3.0 starting from 30 years) and low education level (primary and middle school; aHR 1.67 (95% CI 1.01–2.77)) were independently associated with lower survival. Diabetes mellitus profoundly affected the survival of MDR-TB patients (aHR 1.95 (95% CI 1.30–2.93)). Our data demonstrate that coexistent diabetes significantly and negatively impacted MDR-TB patient survival. In addition, MDR-TB patients aged 60 years or older exhibited a greater risk of mortality during follow-up. Our findings emphasise that MDR-TB patients with comorbidities that increase their risk of death require additional medical interventions to reduce mortality.

In Vitro Susceptibility Testing of GSK656 against Mycobacterium Species

In this study, we aimed to assess the in vitro susceptibility to GSK656 among multiple mycobacterial species and to investigate the correlation between leucyl-tRNA synthetase (LeuRS) sequence variations and in vitro susceptibility to GSK656 among mycobacterial species. A total of 187 mycobacterial isolates, comprising 105 Mycobacterium tuberculosis isolates and 82 nontuberculous mycobacteria (NTM) isolates, were randomly selected for the determination of in vitro susceptibility. For M. tuberculosis, 102 of 105 isolates had MICs of ≤0.5 mg/liter, demonstrating a MIC₅₀ of 0.063 mg/liter and a MIC₉₀ of 0.25 mg/liter. An epidemiological cutoff value of 0.5 mg/liter was proposed for identification of GSK656-resistant M. tuberculosis strains. For NTM, the MIC₅₀ and MIC₉₀ values were >8.0 mg/liter for both Mycobacterium intracellulare and Mycobacterium avium In contrast, all Mycobacterium abscessus isolates had MICs of ≤0.25 mg/liter, yielding a MIC₉₀ of 0.063 mg/liter. LeuRS from M. abscessus showed greater sequence similarity to M. tuberculosis LeuRS than to LeuRSs from M. avium and M. intracellulare Sequence alignment revealed 28 residues differing between LeuRSs from M. avium and M. intracellulare and LeuRSs from M. tuberculosis and M. abscessus; among them, 15 residues were in the drug binding domain. Structure modeling revealed that several different residues were close to the tRNA-LeuRS interface or the entrance of the drug-tRNA binding pocket. In conclusion, our data demonstrate significant species diversity in in vitro susceptibility to GSK656 among various mycobacterial species. GSK656 has potent efficacy against M. tuberculosis and M. abscessus, whereas inherent resistance was noted for M. intracellulare and M. avium.

Increased prevalence of levofloxacin-resistant Mycobacterium tuberculosis in China is associated with specific mutations within the gyrA gene

OBJECTIVES

To compare the prevalence of levofloxacin (LFX) resistance and the population structure of Mycobacterium tuberculosis (MTB) with different mutations conferring LFX resistance between 2005 and 2015.

METHODS

A total 542 MTB isolates were randomly selected from pulmonary tuberculosis (TB) patients in 2005 and 2015 and analyzed regarding minimum inhibitory concentrations (MICs) and quinolone resistance-determining regions (QRDR).

RESULTS

One hundred and eleven of the 542 MTB isolates analyzed (20.5%) were resistant to LFX. There were 42 and 69 LFX-resistant isolates from 2005 and 2015, respectively, and MIC high-level LFX resistance was significantly higher in 2015 (40.6%, 28/69) than in 2005 (16.7%, 7/42) (p = 0.02). There were 87 (78.4%) mutations of these 111 LFX-resistant isolates. In addition, a significant difference in proportion was observed in the isolates with mutations in codon 90 of the gyrA gene between 2005 and 2015 (11.9% in 2005 versus 29.0% in 2015, p = 0.04).

CONCLUSIONS

There was an alarming increase in prevalence of LFX-resistant TB in China between 2005 and 2015. This dynamic change is mostly attributed to the increase in high-level LFX resistance. Moreover, a significant difference was noted in the proportion of LFX-resistant isolates harboring specific mutations within the gyrA gene between 2005 and 2015.

External quality control of phenotypic drug susceptibility testing for Mycobacterium tuberculosis in China

The aim of our study was to evaluate the performance of conventional drug susceptibility testing (DST) among the tuberculosis (TB)-specialized hospitals in China. A total of 40 hospitals participated in the external quality assurance program for assessment of DST results from each hospital. The sensitivity, specificity, and accuracy of DST were analyzed. The mean accuracy was 96.5% for isoniazid (INH), 95.8% for rifampin (RIF), 97.0% for ethambutol (EMB), 96.8% for ofloxacin (OFX), 97.1% for kanamycin (KAN), 96.1% for amikacin (AMK), and 93.6% for capreomycin (CAP), respectively. Of the 40 participating laboratories, 4 (10.0%) and 6 (15%) failed to achieve 90% accuracy for INH and RIF, respectively. In addition, six hospitals (15%) were confirmed as certified to provide reliable DST results for both first-line and second-line drugs. The certified proportion for DST dropped from 73.9% in the non-western region to 59.2% in the western region. The significant difference was observed in the certified proportion for first-line drugs between the western and non-western region (P = 0.013). Our results demonstrate that the quality of phenotypical DST is frequently unsatisfactory, with approximately one-third of participated laboratories failing to produce certified phenotypical DST results. In addition, the uncertified laboratories majorly come from the western region in China.

Factors predictive of the success of tuberculosis treatment: A systematic review with meta-analysis

OBJECTIVE

To produce pooled estimates of the global results of tuberculosis (TB) treatment and analyze the predictive factors of successful TB treatment.

METHODS

Studies published between 2014 and 2019 that reported the results of the treatment of pulmonary TB and the factors that influenced these results. The quality of the studies was evaluated according to the Newcastle-Ottawa quality assessment scale. A random effects model was used to calculate the pooled odds ratio (OR) and 95% confidence interval (CI). This review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) in February 2019 under number CRD42019121512.

RESULTS

A total of 151 studies met the criteria for inclusion in this review. The success rate for the treatment of drug-sensitive TB in adults was 80.1% (95% CI: 78.4-81.7). America had the lowest treatment success rate, 75.9% (95% CI: 73.8-77.9), and Oceania had the highest, 83.9% (95% CI: 75.2-91.0). In children, the success rate was 84.8% (95% CI: 77.7-90.7); in patients coinfected with HIV, it was 71.0% (95% CI: 63.7-77.8), in patients with multidrug-resistant TB, it was 58.4% (95% CI: 51.4-64.6), in patients with and extensively drug-resistant TB it was 27.1% (12.7-44.5). Patients with negative sputum smears two months after treatment were almost three times more likely to be successfully treated (OR 2.7; 1.5-4.8), whereas patients younger than 65 years (OR 2.0; 1.7-2.4), nondrinkers (OR 2.0; 1.6-2.4) and HIV-negative patients (OR 1.9; 1.6-2.5 3) were two times more likely to be successfully treated.

CONCLUSION

The success of TB treatment at the global level was good, but was still below the defined threshold of 85%. Factors such as age, sex, alcohol consumption, smoking, lack of sputum conversion at two months of treatment and HIV affected the success of TB treatment.

Rapid Diagnosis Of Multidrug-Resistant Tuberculosis Impacts Expenditures Prior To Appropriate Treatment: A Performance And Diagnostic Cost Analysis

Background

In this study, we aimed to describe the impact of the Genotype® MTBDRplus line probe assay (LPA) for multidrug-resistant tuberculosis (MDR-TB) on total costs in a high-burden setting in China. The second objective was to evaluate the performance of HAIN on smear-positive sputum and clinical isolates.

Methods

All definitive TB inpatients at the Shandong Provincial Chest Hospital between May 2012 and May 2017 were included in the study. Two sputum specimens were collected from each patient to conduct smear microscopy, conventional drug susceptibility testing (DST), and the HAIN test. Laboratory and cost data were collected from the electronic medical record system.

Results

A total of 1670 definitive TB patients were included in this study. Of these patients, 1307 (78.3%) had smear-positive/culture-positive tuberculosis, and the remaining 363 (21.7%) had smear-negative/culture-positive tuberculosis. The sensitivity and specificity of the HAIN test for RIF resistance was 94.8% (95% confidence interval [CI]: 91.9-97.6%) and 98.8% (95% CI: 98.3-99.4%), respectively. For INH resistance, the sensitivity and specificity was 89.5% (95% CI: 85.7-93.2%) and 95.6% (95% CI: 94.5-96.7%), respectively. The mean time for detection of MDR-TB in smear-negative cases was determined to be 32 days by the HAIN test, which was significantly shorter than that by conventional DST (56 days). Similarly, the mean time for detection of MDR-TB by the HAIN test was significantly shorter than that by conventional DST in smear-positive cases (3 versus 53 days). In addition, by utilizing the HAIN test, the total health care cost decreased by 71.0% for smear-positive cases and 25.9% for smear-negative cases.

Conclusion

In conclusion, our data demonstrate that the HAIN test is an accurate rapid test for detecting both RIF and INH resistance in TB patients. The use of the HAIN test can decrease health care costs and reduce the detection time for MDR-TB patients in China, despite the increased costs for laboratory testing.

Treatment Outcomes and Adverse Events from a Standardized Multidrug-Resistant Tuberculosis Regimen in a Rural Setting in Angola

Treatment for multidrug-resistant tuberculosis (MDR TB) is associated with adverse events (AE). Patients treated with an MDR TB regimen in Hospital Nossa Senhora da Paz, Cubal, Angola, were prospectively enrolled from May 2013 to July 2015. Baseline characteristics, AE, and clinical and microbiological outcomes were recorded. A total of 216 patients were treated with an MDR TB regimen and 179 (82.9%) patients developed at least one AE. The most common AE were elevation of liver enzymes (46.8% of patients), elevated creatinine (44.4% of patients), and ototoxicity (40.7% of patients). Previous TB treatment was associated with the occurrence of AE (OR 4.89, 95% CI: 2.09-11.46, P < 0.001) and months on treatment was associated to severe AE (OR 1.11 95% CI: 1.04-1.18, P = 0.001). Successful treatment was achieved in 117 (54.2%) patients. Incidence of AE was associated with an unsuccessful outcome (OR 1.23, 95% CI: 1.09-1.40, P = 0.001). Patients treated with MDR TB treatment frequently experience AE, and these are related with previous TB treatment and duration of treatment. Given the high percentage of patients experiencing AE and the low treatment success rates, more effective and less toxic drugs to treat MDR TB are urgently needed.

High incidence of drug-resistant Mycobacterium tuberculosis in Hainan Island, China

OBJECTIVES

To assess the proportion of drug-resistant tuberculosis (TB) cases and to identify independent risk factors associated with drug-resistant TB in Hainan.

METHODS

Descriptive analysis of demographic and clinical data of culture-positive TB patients to assess the trends in drug-resistant TB at the Provincial Clinical Center on Tuberculosis of Hainan between 2014 and 2017.

RESULTS

994 patients were recruited into the study. Overall, the proportion of patients resistant to at least one TB drug tested was 36.1% (359/994). The most frequent resistance was to isoniazid (INH, 29.8%), followed by rifampin (RIF, 29.3%), streptomycin (19.3%), ofloxacin (OFX, 17.4%), ethambutol (9.5%) and kanamycin (KAN, 3.2%). Of 291 RIF-resistant isolates, 228 (78.4%) were also resistant to INH, while the remaining 63 (21.6%) were susceptible to INH. Among those with multidrug-resistant tuberculosis (MDR-TB), 41.2% had additional resistance to OFX and 3.9% to KAN. 8.8% of MDR-TB patients were affected by extensively drug-resistant (XDR-TB). Females were more likely to infected with MDR-TB than males, and young people (<20 years old) were more likely to have MDR-TB; patients exhibited decreasing MDR-TB risk with increasing age.

CONCLUSIONS

Our data provide the first primary understanding of the drug-resistant TB epidemic in Hainan. The high incidence of drug resistance, especially RIF and FQ resistance, highlight the importance of interventions for preventing epidemics of drug-resistant TB. Younger age is an independent predictor of MDR-TB, reflecting the potential transmission in this population.

Efficacy and safety of cycloserine-containing regimens in the treatment of multidrug-resistant tuberculosis: a nationwide retrospective cohort study in China

Background

Our aim was to assess whether the use of cycloserine (CS) would bring additional benefit for multidrug-resistant tuberculosis (MDR-TB) patients, and to estimate the incidence and associated risk factors of adverse drug reactions (ADRs) from CS.

Patients and methods

In this study, we retrospectively reviewed the clinical outcomes and ADRs of MDR-TB patients treated with CS containing regimens between January 2012 and June 2015 in China.

Results

A total of 623 MDR-TB cases enrolled in this study received regimens containing CS. Of these cases, in 411 of the patients 374 (66.0%) were “cured” and 37 (5.9%) “complete treatment” by the end of the study. The elderly, patients with prolonged previous exposure to and history of anti-TB drugs, and pre-existing co-morbidity were more likely to be associated with adverse outcomes of MDR-TB patients (P<0.05). Hyperuricemia (22.8%, 142/623) was the most frequently observed ADR among these cases, while the most noted ADRs associated with the administration of CS was psychiatric symptoms, accounting for 4.3% (27/623) of study population. Nineteen (70.4%) out of 27 cases with psychiatric symptoms occurred before the 6-month timepoint, and were notably, the highest proportion of serious adverse, 29.6% (8/27) of which were noted after discontinuation of CS.

Conclusion

Our study demonstrates that a CS-containing regimen achieved a highly successful outcome in the treatment of MDR-TB and promising tolerance in Chinese population. The potential emergence of serious psychiatric symptoms highlights that patients need to be closely monitored for these conditions during treatment that includes CS.