Risk factors associated with drug-resistant tuberculosis in Ethiopia: A systematic review and meta-analysis

Drug-Resistant Profiles and Genetic Diversity of Mycobacterium Tuberculosis Revealed by Whole-Genome Sequencing in Hinggan League of Inner Mongolia, China

Background

Tuberculosis remains a major public health concern in China, with varying prevalence and drug resistance profiles across regions. This study explores the genetic diversity and drug-resistant profiles of MTB strains in Hinggan League, a high TB burden in Inner Mongolia, China.

Methods

This population-based retrospective study, encompassing all culture-positive TB cases from Jun. 2021 to Jun. 2023 in Hinggan League. Drug resistant profiles and genetic diversity of MTB strains were assessed using phenotypic drug susceptibility testing and whole-genome sequencing. Risk factors associated with drug resistance were analyzed using univariate and multivariate logistic regression models.

Results

A total of 211 MTB strains were recovered successfully and included into final analysis. Lineage 2.2.1 (88.6%, 187/211) was the dominant sub-lineage, followed by lineage 4.5 (7.1%, 15/211) and lineage 4.4 (4.3%, 9/211). MTB strains exhibited the highest resistance rates to isoniazid (16.1%, 34/211), followed by rifampicin (10.0, 21/211). In addition, the MTB strains also showed relatively high rates of resistance against new and repurposed anti-TB drugs, with resistant rates of 2.4% (5/211) to delamanid and 1.9% (4/211) to bedaquiline. Overall, 25.6% (54/211) of MTB strains were DR-TB, and 14 MTB strains met the definition of MDR-TB, including 7 strains of simple-MDR-TB, 5 of pre-XDR-TB, and 2 of XDR-TB. Genetic analysis revealed that the dominant mutations of isoniazid-, rifampin-, ethambutol-, levofloxacin-/moxifloxacin-, and ethionamide- resistance were katG_Ser315Thr(46.4%), rpoB_Ser450Leu (47.4%), embB_Met306Val (25.0%), gyrA_Asp94Ala (40.0%), and fabG1_c15t (42.9%), respectively. Previously treated patients (AOR = 2.015, 95% CI: 1.052-4.210) and male patients (AOR = 3.858, 95% CI: 1.416-10.511) were identified as independent risk factors associated with DR-TB.

Conclusion

Our study offers crucial insights into the genetic diversity and drug-resistant profiles of TB strains circulating in Hinggan League. These findings are valuable for DR-TB surveillance and for guiding treatment regimens and public health interventions in the region.

Risk factors associated with multidrug-resistant tuberculosis in areas with a moderate tuberculosis burden

BACKGROUND

The emergence of multidrug-resistant tuberculosis (MDR-TB) or rifampicin-resistant (RR) TB poses a significant challenge for TB control initiatives on a global scale. This study's aim was to estimate the incidence of MDR-/RR-TB and identify the risk factors associated with their incidence in four provinces in northern Iran.

METHODS

Drug susceptibility testing was conducted using the proportion method on Lowenstein-Jensen media. The demographic and clinical data were collected from the Iranian TB registry.

RESULTS

Among 1083 individuals diagnosed with TB, 27 (2.5%) were identified as having MDR-/RR-TB, while 73 cases (6.7%) were any drug resistant (ADR). The statistical analysis revealed a significant association between marital status and MDR-/RR-TB (p=0.003). In addition, significant associations were observed between ADR-TB and gender (p=0.035) and previous treatment for TB (p=0.02).

CONCLUSIONS

Our findings provide important information on the drug resistance pattern of Mycobacterium tuberculosis strains, as well as risk factors in northern Iran. Given the identified risk factors, creative approaches to promote treatment adherence in TB patients, particularly divorced/widowed women and individuals with a previous history of TB treatment, are required.

Predictors, mortality, and health outcomes of intensive phase non-adherence to a regimen in patients with drug-susceptible tuberculosis: a nationwide linkage database

OBJECTIVES

The clinical importance of adhering to the regimen in tuberculosis patients has been widely investigated, but most studies were conducted in controlled settings and in limited populations. We aimed to measure the level of real-world adherence during intensive phase and investigate the predictors and the risk of mortality and health outcomes of intensive phase non-adherence in tuberculosis patients.

STUDY DESIGN

We conducted a nationwide cohort study by linking the Korean National Tuberculosis Surveillance System and the National Health Information Database.

METHODS

We included all incident drug-susceptible tuberculosis patients who initiated the regimens recommended by the World Health Organization from 2013 to 2018. Adherence was measured using the proportion of days covered (poor [<50%], moderate [50%-79%], and high [≥80%]). We used logistic regression model to assess predictors and the Cox proportional hazard model to evaluate the risk of mortality and health outcomes with intensive phase non-adherence.

RESULTS

Of 46,818 patients, there were 8% and 11% with poor and moderate adherent groups, respectively. Age ≥45 years, insulin use, and history of renal failure were predictors of non-adherence. Compared with high adherent group, poor and moderate adherent groups were associated with a substantial risk of mortality (poor: hazard ratio, 2.14 [95% confidence interval, 1.95-2.34]; moderate: 1.76 [1.62-1.92]). Similar trends were observed for health outcomes. Stratified analyses showed a higher risk of mortality in patients with medical aid, low income, and history of renal failure, systematic corticosteroids, and immunomodulators.

CONCLUSIONS

Non-adherence during intensive phase increased mortality risk by twofold, underscoring targeted intervention for high-risk population, including advanced diabetes, and immunocompromised patients.

A descriptive study on isoniazid resistance-associated mutations, clustering and treatment outcomes of drug-resistant tuberculosis in a high burden country

PURPOSE

To describe katG and inhA mutations, clinical characteristics, treatment outcomes and clustering of drug-resistant tuberculosis (TB) in the State of São Paulo, southeast Brazil.

METHODS

Mycobacterium tuberculosis isolates from patients diagnosed with drug-resistant TB were screened for mutations in katG and inhA genes by line probe assay and Sanger sequencing, and typed by IS6110-restriction fragment-length polymorphism for clustering assessment. Clinical, epidemiological and demographic data were obtained from surveillance information systems for TB.

RESULTS

Among the 298 isolates studied, 127 (42.6%) were isoniazid-monoresistant, 36 (12.1%) polydrug-resistant, 93 (31.2%) MDR, 16 (5.4%) pre-extensively drug-resistant (pre-XDR), 9 (3%) extensively drug-resistant (XDR) and 17 (5.7%) susceptible after isoniazid retesting. The frequency of katG 315 mutations alone was higher in MDR isolates, while inhA promoter mutations alone were more common in isoniazid-monoresistant isolates. Twenty-six isolates phenotypically resistant to isoniazid had no mutations either in katG or inhA genes. The isolates with inhA mutations were found more frequently in clusters (75%) when compared to the isolates with katG 315 mutations (59.8%, p = 0.04). In our population, being 35-64 years old, presenting MDR-, pre-XDR- or XDR-TB and being a retreatment case were associated with unfavourable TB treatment outcomes.

CONCLUSION

We found that katG and inhA mutations were not equally distributed between isoniazid-monoresistant and MDR isolates. In our population, clustering was higher for isolates with inhA mutations. Finally, unfavourable TB outcomes were associated with specific factors.

Validity of automated audiometry for hearing examination in patients with multidrug-resistant tuberculosis

Background: The objective of this study was to test the validity of automated audiometry as a method of hearing examination in patients with multidrug-resistant tuberculosis. Method s: This was a cross-sectional comparative study with a retrospective approach, using patient medical records. Patients with multidrug-resistant tuberculosis (MDR-TB) were recruited based-on medical records that met the inclusion and exclusion criteria at the Pulmonology outpatient unit, then referred to the Otorhinolaryngology outpatient unit of the Dr. Soetomo Academic Medical Center. The subjects' hearing function was measured with two different devices (automated audiometer and conventional audiometer) before being given anti-tuberculosis drug therapy (aminoglycoside injection) as ototoxicity monitoring from July to December 2019 period. Sensitivity and specificity analysis was used to assess the validity of the test. Results: A total of 36 patients (72 ears) were included. The comparison test results using the Mann-Whitney test showed that there were significant differences between automated audiometry and conventional audiometry in both ears. Analysis values were: sensitivity 80-97%, specificity 37-96%, positive predictive value 74-98%, and negative predictive value 59-96%. Conclusion s: Automated audiometry is valid for use as a method of hearing examination and monitoring in patients with multidrug-resistant tuberculosis.

Validity of automated audiometry for hearing examination in patients with multidrug-resistant tuberculosis

Background: The objective of this study was to test the validity of automated audiometry as a method of hearing examination in patients with multidrug-resistant tuberculosis. Method s: This was a cross-sectional comparative study with a retrospective approach, using patient medical records. Patients with multidrug-resistant tuberculosis (MDR-TB) were recruited based-on medical records that met the inclusion and exclusion criteria at the Pulmonology outpatient unit, then referred to the Otorhinolaryngology outpatient unit of the Dr. Soetomo Academic Medical Center. The subjects' hearing function was measured with two different devices (automated audiometer and conventional audiometer) before being given anti-tuberculosis drug therapy (aminoglycoside injection) as ototoxicity monitoring from July to December 2019 period. Sensitivity and specificity analysis was used to assess the validity of the test. Results: A total of 36 patients (72 ears) were included. The comparison test results using the Mann-Whitney test showed that there were significant differences between automated audiometry and conventional audiometry in both ears. Analysis values were: sensitivity 80-97%, specificity 37-96%, positive predictive value 74-98%, and negative predictive value 59-96%. Conclusion s: Automated audiometry is valid for use as a method of hearing examination and monitoring in patients with multidrug-resistant tuberculosis.