Change in prevalence and molecular characteristics of isoniazid-resistant tuberculosis over a 10-year period in China

Treatment outcomes and key factors contributing to unfavourable outcomes among isoniazid-resistant pulmonary tuberculosis patients in Shanghai, China

OBJECTIVE

Given that more than 1 million people annually develop isoniazid-resistant tuberculosis (Hr-TB), the issue of Hr-TB may go unnoticed. However, limited studies have focused on the clinical treatment of Hr-TB in China, particularly regarding treatment outcomes and influencing factors. This study aimed to evaluate the treatment outcomes of Hr-TB patients in Shanghai from 2018 to 2021 and analyse the influencing factors, including demographic characteristics, clinical features, and treatment-related factors.

METHODS

This study retrospectively reviewed the medical records of Hr-TB patients registered in the TB management information system from 2018 to 2021. Differences in demographic characteristics, clinical information, and treatment outcomes were evaluated. Multivariable logistic regression was used to identify risk factors associated with unfavourable outcomes.

RESULTS

A total of 664 patients with Hr-TB were included in the analysis. A total of 84 cases (12.7%) had unfavourable outcomes. Only 318 (47.9%) Hr-TB patients used regimens containing fluoroquinolones. Adverse events occurred in 127 cases (19.1%), of which 12 cases (1.81%) discontinued treatment due to adverse events. There was statistically significant difference in the occurrence of adverse events between the different treatment regimens (P < 0.001). Multivariable logistic regression showed that older age (adjusted odds ratio = 6.13, 95% confidence intervals [CI] = 1.24-30.24, P = 0.026), use of injectable agents (adjusted odds ratio = 3.75, 95% CI = 1.29-10.94, P = 0.016), and treatment duration (95% CI = 21.85-1487.61, P < 0.001) were risk factors for unfavourable treatment outcomes.

CONCLUSIONS

Unfavourable outcomes were more frequent among older patients and those receiving injectable agents among Hr-TB patients in Shanghai, a low-endemic region for TB. This emphasizes the need for timely diagnosis and optimized treatment strategies for isoniazid-resistant tuberculosis.

Phenotypic and genotypic analysis of drug resistance in M. tuberculosis isolates in Gansu, China

Tuberculosis has posed a serious threat to human health. It is imperative to investigate the geographic prevalence of tuberculosis and medication resistance, as this information is essential for informing strategies for its prevention and treatment. Drug resistance was identified using a proportion method. Drug-resistant genes and pathways were predicted using whole genome sequencing. The drug resistance range of bedaquiline was identified using the microporous plate two-fold dilution method, and drug resistance genes were studied using sequencing. The study revealed that 19.99% of the tuberculosis cases had multidrug resistance. The genes of M. tuberculosis are predominantly involved in the synthesis of ABC transporters, two-component systems, and bacterial secretion systems, as well as in energy production and conversion, and lipid transport and metabolism. The genes encode for 82.45% of carbohydrate-related enzymes such as glycoside hydrolases, glycosyl transferases, and carbohydrate esterases. The minimum inhibitory concentration (MIC) of bedaquiline against clinical strains was approximately 0.06 μg/mL, with identified mutations in drug-resistant genes Rv0678, atpE, and pepQ, specifically V152A, P62A, and T222N, respectively. The multidrug resistance tuberculosis development was attributed to the strong medication resistance exhibited. It was concluded that tuberculosis had presented a high level of drug resistance. Phenotypic resistance was related to genes, existing potential genetic resistance in M. tuberculosis. Bedaquiline was found to possess effective antibacterial properties against M. tuberculosis.

Incidence, Outcomes, and Risk Factors for Isoniazid-Resistant Tuberculosis from 2012 to 2022 in Eastern China

BACKGROUND

Isoniazid-resistant, rifampicin-susceptible tuberculosis (Hr-TB) is the most frequent drug-resistant tuberculosis (DR-TB) in the world, and unfavorable outcomes of Hr-TB are more common compared to drug-susceptible TB. Considering there is no optimal regimen accepted worldwide, we undertook a retrospective cohort study in eastern China to estimate incidence trends and risk factors associated with unfavorable outcomes of Hr-TB.

METHODS

Between January 2012 and December 2022, all Hr-TB patients' information was extracted from the Tuberculosis Information Management System (TIMS), which is a national electronic information platform, to record TB patients' clinical information in this study. The incidence of Hr-TB was determined by the mid-year population according to census data published by the government. We categorized treatment regimens depending on fluoroquinolone (FQ) use, and potential risk factors were analyzed using multivariable logistic regression.

RESULTS

A total of 3116 Hr-TB patients fulfilled the inclusion criteria and were enrolled in this study. The average annual rate of Hr-TB in the 11 years under investigation was 0.34 per 100,000 and increased to 0.53 per 100,000 until 2019. In total, six different treatment regimens were utilized in the study sites, and less than 1% of regimens adopted FQ. There was no difference in the unfavorable outcomes between the FQ-included and FQ-excluded groups (p = 0.22). The average treatment duration was 7.06 months, and the longest treatment was 26 months. Approximately 20% (637/3116) of Hr-TB patients had unfavorable outcomes, and 60.13% (383/637) of them proceeded to multidrug-resistant tuberculosis (MDR-TB). Treatment duration and a positive smear at the end of the 5th month were significantly associated with unfavorable outcomes (p < 0.001).

CONCLUSION

The unfavorable treatment outcomes of Hr-TB are still high in eastern China, and the efficacy of FQ-containing regimens needs to be validated for Hr-TB treatment.

Global prevalence of drug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND

Tuberculosis is a bacterial infectious disease, which affects different parts of a human body, mainly lungs and can lead to the patient's death. The aim of this study is to investigate the global prevalence of drug-resistant tuberculosis using a systematic review and meta-analysis.

METHODS

In this study, the PubMed, Scopus, Web of Science, Embase, ScienceDirect and Google Scholar repositories were systematically searched to find studies reporting the global prevalence of drug-resistant tuberculosis. The search did not entail a lower time limit, and articles published up until August 2022 were considered. Random effects model was used to perform the analysis. The heterogeneity of the studies was examined with the I² test. Data analysis was conducted within the Comprehensive Meta-Analysis software.

RESULTS

In the review of 148 studies with a sample size of 318,430 people, the I² index showed high heterogeneity (I² = 99.6), and accordingly random effects method was used to analyze the results. Publication bias was also examined using the Begg and Mazumdar correlation test which indicated the existence of publication bias in the studies (P = 0.008). According to our meta-analysis, the global pooled prevalence of multi-drug resistant TB is 11.6% (95% CI: 9.1-14.5%).

CONCLUSIONS

The global prevalence of drug-resistant tuberculosis was found to be very high, thus health authorities should consider ways to control and manage the disease to prevent a wider spread of tuberculosis and potentially subsequent deaths.

Analysis of Factors Influencing Multidrug-Resistant Tuberculosis and Validation of Whole-Genome Sequencing in Children with Drug-Resistant Tuberculosis

Objective

Pediatric tuberculosis (TB) is one of the top ten causes of death in children. Our study was to analyze influencing factors of multidrug-resistant tuberculosis (MDR-TB) and validation of whole-genome sequencing (WGS) used in children with drug-resistant TB (DR-TB).

Methods

All Mycobacterium tuberculosis (Mtb) strains were isolated from patients aged below 18 years old of Children’s Hospital of Chongqing Medical University, China. A total of 208 Mtb isolates were tested for eight anti-TB drugs with phenotypic drug susceptibility test (DST) and for genetic prediction of the susceptible profile with WGS. The patients corresponding to each strain were grouped according to drug resistance and genotype. Influencing factors of MDR-TB and DR-TB were analyzed.

Results

According to the phenotypic DST and WGS, 82.2% of Mtb strains were susceptible to all eight drugs, and 6.3% were MDR-TB. Using the phenotypic DSTs as the gold standard, the kappa value of WGS to predict isoniazid, rifampin, ethambutol, rifapentine, prothionamide, levofloxacin, moxifloxacin and amikacin was 0.84, 0.89, 0.59, 0.86, 0.89, 0.82, 0.88 and 1.00, respectively. There was significant difference in the distribution of severe TB, diagnosis, treatment and outcome between MDR and drug-susceptible group (P<0.05). The distribution of severe TB and treatment between DR and drug-susceptible group was statistically different (P<0.05). The results of binary logistic regression showed that Calmette–Guérin bacillus (BCG) vaccine is the protective factor for MDR-TB (OR=0.19), and MDR-TB is the risk factor for PTB and EPTB (OR=17.98).

Conclusion

The BCG vaccine is a protective factor for MDR-TB, and MDR-TB might not be confined to pulmonary infection, spreading to extrapulmonary organs in children. MDR-TB had more severe cases and a lower recovery rate than drug-susceptible TB. WGS could provide an accurate prediction of drug susceptibility test results for anti-TB drugs, which are needed for the diagnosis and precise treatment of TB in children.

Evaluation of the Roche cobas MTB and MTB-RIF/INH Assays in Samples from Germany and Sierra Leone

The Roche cobas MTB and MTB-RIF/INH assays allow for detection of Mycobacterium tuberculosis complex (MTBC) nucleic acid and rifampicin (RIF) and isoniazid (INH) resistance-associated mutations in an automated, high-throughput workflow. In this study, we evaluated the performance of these assays, employing samples from settings of low and high tuberculosis (TB) burdens. A total of 325 frozen, leftover respiratory samples collected from treatment-naive patients with presumptive TB in Germany (n = 280) and presumptive RIF-resistant TB in Sierra Leone (n = 45) were used in this study. cobas MTB results for detection of MTBC DNA from N-acetyl-l-cysteine-sodium hydroxide (NALC-NaOH)-treated samples were compared to culture results. Predictions of RIF and INH resistance by the cobas MTB-RIF/INH assay were compared to a composite reference standard (phenotypic drug susceptibility testing and line probe assay). Whole-genome sequencing was used to resolve discordances. The overall sensitivity of cobas MTB for detection of MTBC DNA in culture-positive samples (n = 102) was 89.2% (95% confidence interval [CI], 81.7 to 93.9%). The specificity of cobas MTB was 98.6% (95% CI, 96.1 to 99.5%). Sensitivity and specificity for detection of RIF and INH resistance were 88.4% (95% CI, 75.5 to 94.9%) and 97.6% (95% CI, 87.4 to 99.6%) and 76.6% (95% CI, 62.8 to 86.4%) and 100.0% (95% CI, 90.8 to 100.0%), respectively. Discordant results for RIF and INH resistance were mainly due to uncommon mutations in samples from Sierra Leone that were not covered by the cobas MTB-RIF/INH assay. In conclusion, cobas MTB and MTB-RIF/INH assays provide accurate detection of MTBC DNA and resistance-associated mutations in respiratory samples. The influence of regional variations in the prevalence of resistance-conferring mutations requires further investigation.

A retrospective cohort study of isoniazid-resistant tuberculosis treatment outcomes and isoniazid resistance-associated mutations in eastern China from 2013 to 2018

OBJECTIVES

The current situation of isoniazid-resistant, rifampicin-susceptible tuberculosis (Hr-TB) and associated genetic factors is not clear in China.

METHODS

A retrospective cohort study was conducted from 2013 to 2018 in Jiangsu Province, China. Phenotypic Hr-TB were identified by drug susceptibility testing on Lowenstein-Jensen medium and using a Mycobacterium Growth Indicator Tube 960 (MGIT 960) system, and mutations in the katG 315 codon and inhA promoter nucleotides -8, -15 and -16 were determined by GenoType MTBDRplus and sequencing. All of the Hr-TB patients enrolled were followed up until June 2019.

RESULTS

A total of 1416 smear-positive sputum samples were collected, of which 57 were excluded due to the presence of nontuberculous mycobacteria. Finally, 63/1359 (4.6%) were determined as Hr-TB. After follow-up, 11 Hr-TB patients (17.5%) showed an unfavourable outcome, of whom 5 (7.9%) relapsed, 4 (6.3%) had treatment failure and 2 (3.2%) died. A total of 52 isolates (82.5%) were detected with either katG 315 or inhA promoter nucleotide -8, -15 or -16 mutations, whereas no canonical mutations were found in 8 isolates (12.7%); 3 isolates failed in mutation detection. TB history was found to be associated with unfavourable outcomes for Hr-TB (odds ratio = 6.13, 95% confidence interval 1.05-35.82; P = 0.04). However, mutations in katG 315 and the inhA promoter region were not found to be associated with Hr-TB unfavourable outcomes (P = 0.15).

CONCLUSION

Unfavourable outcomes for Hr-TB are serious in eastern China, especially for previously treated patients. Meanwhile, current genetic determination of Hr-TB is inadequate.