Transmission of fluoroquinolones resistance among multidrug-resistant tuberculosis in Shanghai, China: a retrospective population-based genomic epidemiology study

Fluoroquinolones (FQ) are essential for the treatment of multidrug-resistant tuberculosis (MDR-TB). The FQ resistance (FQ-R) rate in MDR-TB in China and its risk factors remain poorly understood. We conducted a retrospective, population-based genomic epidemiology study of MDR-TB patients in Shanghai, China, from 2009 to 2018. A genomic cluster was defined as strains with genetic distances ≤ 12 single nucleotide polymorphisms. The transmitted FQ-R was defined as the same FQ resistance-conferring mutations shared by ≥ 2 strains in a genomic cluster. We used multivariable logistic regression analysis to identify the risk factors for drug resistance. Among the total 850 MDR-TB patients included in the study, 72.8% (619/850) were male, the median age was 39 (interquartile range 28, 55) years, 52.7% (448/850) were migrants, and 34.5% (293/850) were previously treated patients. Most of the MDR-TB strains belong to the Beijing lineage (91.7%, 779/850). Overall, the genotypic resistance rate of FQ was 34.7% (295/850), and 47.1% (139/295) FQ-R patients were in genomic clusters, of which 98 (33.2%, 98/295) were presumed as transmitted FQ-R. Patients with treatment-naïve (aOR = 1.84; 95% CI: 1.09, 3.16), diagnosed in a district-level hospital (aOR = 2.69; 95% CI: 1.56, 4.75), and streptomycin resistance (aOR = 3.69; 95% CI: 1.65, 9.42) were significantly associated with the transmission of FQ-R. In summary, the prevalence of FQ-R among MDR-TB patients was high in Shanghai, and at least one-third were transmitted. Enforced interventions including surveillance of FQ drug susceptibility testing and screening among MDR-TB before initiation of treatment were urgently needed.

Particulate matter deposition and its impact on tuberculosis severity: A cross-sectional study in Taipei

The objective of this study was to examine the association between the lung lobe-deposited dose of inhaled fine particulate matter (PM2.5) and chest X-ray abnormalities in different lung lobes of pulmonary tuberculosis (TB), multidrug-resistant tuberculosis (MDR-TB), and non-tuberculosis mycobacteria infections (NTM). A cross-sectional study was conducted between 2014 and 2022, comprising 1073 patients who were recruited from chest department clinic in a tertial refer hospital in Taipei City, Taiwan. Ambient 1-, 7-, and 30-day PM2.5 exposure and the deposition of PM2.5 in different lung lobes were estimated in each subject. The β coefficient for PM2.5 and deposited PM2.5 in lungs with the outcome variables (pulmonary TB, MDR-TB, and NTM infection) was derived through regression analysis and adjusted for age, gender, BMI, smoking status, and family income. We observed that a 1 μg/m3 increase in ambient PM2.5 was associated with an increase of MDR-TB infections of 0.004 times (95%CI: 0.001-0.007). A 1 μg/m3 increase in 1-day and 7-day PM2.5 deposition in left upper lobe and left lower lobe was associated with an increase in chest X-ray abnormalities of 9.19 % and 1.18 % (95%CI: 0.87-17.51 and 95%CI: 0.08-2.28), and 4.52 % and 5.20 % (95%CI: 0.66-8.38 and 95%CI: 0.51-9.89) in left lung of TB patients, respectively. A 1 μg/m3 increase in 30-day PM2.5 deposition in alveolar region was associated with an increase in percent abnormality of 2.50 % (95%CI: 0.65-4.35) in left upper lobe and 3.33 % (95%CI: 0.65-6.01) in right middle lobe, while in total lung was 0.63 % (95%CI: 0.01-1.27) in right upper lobe and 0.37 % (95%CI, 0.06-0.81) in right lung of MDR-TB patients. Inhaled PM2.5 deposition in lungs was associated with an exacerbation of the radiographic severity of pulmonary TB, particularly in pulmonary MDR-TB patients in upper and middle lobes. Particulate air pollution may potentially exacerbate the radiographic severity and treatment resistance in individuals with pulmonary TB.

Unlocking InhA: Novel approaches to inhibit Mycobacterium tuberculosis

Multidrug-resistant tuberculosis continues to pose a health security risk and remains a public health emergency. Antimicrobial resistance result from treatment regimens that are both insufficient and incomplete leading to the emergence of multidrug-resistant tuberculosis, extensively drug-resistant tuberculosis and totally drug-resistant tuberculosis. The impact of tuberculosis on the people suffering from HIV (Human immunodeficiency virus infection) have resulted in the increased research efforts in designing and discovery of novel antitubercular drugs that may result in decreasing treatment duration, minimising the need for multiple drug intake, minimising cytotoxicity and enhancing the mechanism of action of drug. While many drugs are available to treat tuberculosis, a precise and timely cure is still absent. Consequently, further investigation is needed to identify more recent molecular equivalents that have the potential to swiftly remove this disease. Isoniazid (INH), a treatment for tuberculosis (TB), targets the enzyme InhA (mycobacterium enoyl acyl carrier protein reductase), the Mycobacterium tuberculosis enoyl-acyl carrier protein (ACP) reductase, most common INH resistance is circumvented by InhA inhibitors that do not require KatG (catalase-peroxidase) activation, as a result, researchers are trying to work in the area of development of InhA inhibitors which could help in eradicating the era of tuberculosis from the world.

A pregnant woman with pre-XDR PTB giving birth to a healthy newborn: A case report

We reported a late-pregnancy woman with pre-XDR PTB who had not received regular anti-tuberculosis treatment prior to delivery. Despite this, she successfully delivered a premature baby who exhibited normal growth and development, and subsequently completed her anti-tuberculosis treatment. This report suggests that delayed treatment for pre-XDR TB during late pregnancy does not necessarily increase the risk of treatment failure for the mother or the risk of neonatal tuberculosis.

Development of a multiplex droplet digital PCR method for detection and monitoring of Mycobacterium tuberculosis and drug-resistant tuberculosis

BACKGROUND

The prevalence of multidrug-resistant tuberculosis (MDR-TB) among Korean tuberculosis patients is about 4.1%, which is higher than the OECD average of 2.6%. Inadequate drug use and poor patient compliance increase MDR-TB prevalence through selective pressure. Therefore, prompt detection of drug resistance in tuberculosis patients at the time of diagnosis and quantitative monitoring of these resistant strains during treatment are crucial.

METHODS

A multiplex droplet digital PCR (ddPCR) assay was developed and assessed using DNA material of nine Mycobacterium tuberculosis strains with known mutation status that were purchased from the Korean National Tuberculosis Association. We collected a total of 18 MDR-TB residual samples referred for PCR analysis. Total DNA was extracted from the samples and subjected to the quadruplex ddPCR assay. Their results were compared to those of known resistance phenotypes.

RESULTS

The analytical sensitivity and specificity of the multiplex ddPCR assay for detecting INH, RIF, EMB, FQ, and SM resistance-causing mutations ranged from 71.43 to 100% and 94.12-100%, respectively. Follow-up sample results showed that the quadruplex ddPCR assay was sensitive enough to detect IS6110 and other mutations even after onset of treatment.

CONCLUSIONS

We developed a sensitive and accurate multiplex ddPCR assay that can detect the presence of tuberculosis quantitatively and resistance-conveying mutations concurrently. This tool could aid clinicians in the diagnosis and treatment monitoring of tuberculosis.

Contact investigation in multidrug-resistant tuberculosis: ethical challenges

Contact investigation is an evidence-based intervention of multidrug-resistant tuberculosis (MDR-TB) to protect public health by interrupting the chain of transmission. In pursuit of contact investigation, patients' MDR-TB status has to be disclosed to third parties (to the minimum necessary) for tracing the contacts. Nevertheless, disclosure to third parties often unintentionally leads the MDR-TB patients suffered from social discrimination and stigma. For this reason, patients are less inclined to reveal their MDR-TB status and becomes a significant issue in contact investigation. This issue certainly turns into a negative impact on the public interest. Tension between keeping MDR-TB status confidential and safeguarding public health arises in relation to this issue. Regarding MDR-TB management, patient compliance with treatment and contact investigation are equally important. Patients might fail to comply with anti-TB therapy and be reluctant to seek healthcare due to disclosure concerns. In order to have treatment adherence, MDRTB patients should not live through social discrimination and stigma arising from disclosure and TB team has a duty to support them as a mean of reciprocity. However, implementation of contact investigation as a public health policy can still be challenging even with promising reciprocal support to the patients because MDR-TB patients are living in different contexts and situations. There can be no straight forward settlement but an appropriate justification for each distinct context is needed to strike a balance between individual confidentiality and public interest.

Second-line antituberculosis drug exposure thresholds predictive of adverse events in multidrug-resistant tuberculosis treatment

OBJECTIVES

This study aimed to investigate the association between drug exposure and adverse events (AEs) during the standardized multidrug-resistant tuberculosis (MDR-TB) treatment, as well as to identify predictive drug exposure thresholds.

METHODS

We conducted a prospective, observational multicenter study among participants receiving standardized MDR-TB treatment between 2016 and 2019 in China. AEs were monitored throughout the treatment and their relationships to drug exposure (e.g., the area under the drug concentration-time curve from 0 to 24 h, AUC0-24 h) were analyzed. The thresholds of pharmacokinetic predictors of observed AEs were identified by boosted classification and regression tree (CART) and further evaluated by external validation.

RESULTS

Of 197 study participants, 124 (62.9%) had at least one AE, and 15 (7.6%) experienced serious AEs. The association between drug exposure and AEs was observed including bedaquiline, its metabolite M2, moxifloxacin and QTcF prolongation (QTcF >450 ms), linezolid and mitochondrial toxicity, cycloserine and psychiatric AEs. The CART-derived thresholds of AUC0-24 h predictive of the respective AEs were 3.2 mg·h/l (bedaquiline M2); 49.3 mg·h/l (moxifloxacin); 119.3 mg·h/l (linezolid); 718.7 mg·h/l (cycloserine).

CONCLUSIONS

This study demonstrated the drug exposure thresholds predictive of AEs for key drugs against MDR-TB treatment. Using the derived thresholds will provide the knowledge base for further randomized clinical trials of dose adjustment to minimize the risk of AEs.

Pre-extensively drug-resistant and extensively drug-resistant tuberculosis in Latin America and the Caribbean: A systematic review and meta-analysis

BACKGROUND

The growing threat from pre-extensively drug-resistant tuberculosis (pre-XDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) poses a major public health concern in Latin America and the Caribbean (LAC). Therefore, this study aimed to summarize the available evidence on the prevalence of pre-XDR-TB and XDR-TB among patients with multidrug-resistant tuberculosis in LAC.

METHODS

A systematic review was conducted in the following databases on June 3, 2023: PubMed, Scopus, Ovid Medline, Web of Science, Scielo and LILACS. We estimated pooled proportions using a random effects model (Dersimonian and Laird). The 95% confidence intervals (95% CI) were calculated using the binomial exact method (Clopper-Pearson Method). Subgroup (by time period and country) and sensitivity analyses were performed.

RESULTS

Twenty-nine studies were eligible for qualitative synthesis and 27 for meta-analysis (n = 15,565). The pooled prevalence of XDR-TB in the study participants was 5% (95% CI: 3%-6%), while that of pre-XDR-TB was 10% (95% CI 7%-14%). Cuba (6%, 95% CI 0%-17%) and Peru (6%, 95% CI 5%-7%) had the highest pooled prevalence of XDR-TB. Regarding pre-XDR-TB, Brazil (16%, 95% CI 11%-22%) and Peru (13%, 95% CI: 9%-16%) showed the highest prevalence.

CONCLUSIONS

The pooled prevalence of pre-XDR-TB and XDR-TB in LAC was 10% and 5%, respectively. Governments should strengthen drug-resistance surveillance and TB programs.

Transmission dynamics and phylogeography of Mycobacterium tuberculosis in China based on whole-genome phylogenetic analysis

OBJECTIVES

This study aimed to describe the lineage-specific transmissibility and epidemiological migration of Mycobacterium tuberculosis in China.

METHODS

We curated a large set of whole-genome sequences from 3204 M. tuberculosis isolates, including thousands of newly sequenced genomes, and applied a series of metrics to compare the transmissibility of M. tuberculosis strains between lineages and sublineages. The countrywide transmission patterns of major lineages were explored.

RESULTS

We found that lineage 2 (L2) was the most prevalent lineage in China (85.7%), with the major sublineage 2.2.1 (80.9%), followed by lineage 4 (L4) (13.8%), which comprises major sublineages 4.2 (1.5%), 4.4 (6.2%) and 4.5 (5.8%). We showed evidence for frequent cross-regional spread and large cluster formation of L2.2.1 strains, whereas L4 strains were relatively geographically restricted in China. Next, we applied a series of genomic indices to evaluate M. tuberculosis strain transmissibility and uncovered higher transmissibility of L2.2.1 compared with the L2.2.2 and L4 sublineages. Phylogeographic analysis showed that southern, eastern, and northern China were highly connected regions for countrywide L2.2.1 strain spread.

CONCLUSIONS

The present study provides insights into the different transmission and migration patterns of the major M. tuberculosis lineages in China and highlights that transmissible L2.2.1 is a threat to tuberculosis control.

Treatment outcomes and risk factors for an unsuccessful outcome among patients with highly drug-resistant tuberculosis in Ukraine

OBJECTIVES

To describe demographics, clinical features, and treatment outcomes of patients with highly drug-resistant tuberculosis (TB) in Ukraine, and to evaluate risk factors for an unsuccessful outcome.

METHODS

Data from patients with multi-, pre-extensively, or extensively drug-resistant TB were collected prospectively from TB dispensaries in 15 out of 24 Ukrainian oblasts (regions) from 2020 to 2021. Treatment outcomes were evaluated using WHO definitions. Risk factors for an unsuccessful outcome were identified using a multivariable logistic regression model.

RESULTS

Among 1748 patients, the overall proportion of successful outcomes was 58% (95% confidence interval [95% CI] 56-60) (n = 1015/1748), ranging from 65% (95% CI: 62-69) (n = 531/814) for multidrug-resistant TB to 54% (95% CI: 49-58) (n = 301/563) for pre-extensively drug-resistant TB and 49% (95% CI: 44-55) (n = 183/371) for extensively drug-resistant TB. Results were similar across oblasts, with few exceptions. The strongest risk factors for an unsuccessful outcome were extensively drug-resistant TB (adjusted OR [aOR] 3.23; 95% CI: 1.88-5.53), total serum protein below 62 g/L in adults and below 57 g/L for children and adolescents (aOR 2.79; 95% CI: 1.93-4.04), psychiatric illness (aOR 2.79; 95% CI: 1.46-5.33), age at TB diagnosis >65 years (aOR 2.50; 95% CI: 1.42-4.42), and alcohol misuse (aOR 2.48; 95% CI: 1.89-3.26).

DISCUSSION

The overall proportion of successful outcomes among Ukrainians treated for highly drug-resistant TB was 58%, notably better compared with previous years, but still low for extensively drug-resistant TB. Risk factors for unsuccessful outcomes highlight that addressing socioeconomic factors in TB management is crucial. Efforts in maintaining TB dispensaries during and following the ongoing war are highly warranted.

Molecular Detection of Multidrug Resistance and Characterizations of Mutations in Mycobacterium Tuberculosis Using Polycarbonate Track-Etched Membrane Based DNA Bio-Chip

With the widespread use of rifampicin (RMP) and isoniazid (INH), multidrug resistance (MDR) in Mycobacterium tuberculosis (M.tb) poses a threat to the success of tuberculosis (TB) control programs. We have developed a new polycarbonate track-etched membranes (PC-TEM) based DNA bio-chip designed for rapid detection of mutations conferring MDR in M.tb culture isolates. Bio-chips were designed to contain 14 specific probes for wild type and mutated allele of selected codons within 80 bp rifampicin resistance determining region of rpoB gene, katG gene and mabA-inhA regulatory region. RMP-resistance-associated gene mutation points rpoB 516, 526, 531 and 533, and the INH-resistance-associated gene mutation points katG315 and inhA-15 were targeted. Bio-chip signal was detected using enhanced chemiluminescence. A total of 50 culture isolates that were sensitive or resistant to RMP and/or INH were analyzed by bio-chip. The results of culture-based drug susceptibility testing (DST) were used as the gold standard and gene sequencing was performed to resolve the discordance. Amongst 50 culture isolates, we have detected 18 MDR, 9 RMP mono-resistant, 6 INH mono-resistant, and 17 fully susceptible isolates. The developed DNA bio-chip has a sensitivity of 90% for RMP and MDR and 100% for INH resistance. The bio-chip has a specificity of 100% for RMP and MDR and 88.8% for INH detection. The identification of mutations using the DNA bio-chip was 100% concordant with the sequencing data for the probes covered by the bio-chip. The detection of rpoB, katG and inhA gene mutation points by a DNA bio-chip may be used as a rapid, accurate, and economical, clinical detection method for MDR detection in M.tb. This is very valuable for the control of TB epidemics.

Travel distance to rifampicin-resistant tuberculosis treatment and its impact on loss to follow-up: the importance of continued RR-TB treatment decentralization in South Africa

BACKGROUND

Understanding why patients experience loss to follow-up (LTFU) is essential for TB control. This analysis examines the impact of travel distance to RR-TB treatment on LTFU, which has yet to be analyzed within South Africa.

METHODS

We retrospectively analyzed 1436 patients treated for RR-TB at ten South African public hospitals. We linked patients to their residential ward using data reported to NHLS and maps available from the Municipal Demarcation Board. Travel distance was calculated from each patient's ward centroid to their RR-TB treatment site using the georoute command in Stata. The relationship between LTFU and travel distance was modeled using multivariable logistic regression.

RESULTS

Among 1436 participants, 75.6% successfully completed treatment and 24.4% were LTFU. The median travel distance was 40.96 km (IQR: 17.12, 63.49). A travel distance > 60 km increased odds of LTFU by 91% (p = 0.001) when adjusting for HIV status, age, sex, education level, employment status, residential locale, treatment regimen, and treatment site.

CONCLUSION

People living in KwaZulu-Natal and Eastern Cape travel long distances to receive RR-TB care, placing them at increased risk for LTFU. Policies that bring RR-TB treatment closer to patients, such as further decentralization to PHCs, are necessary to improve RR-TB outcomes.

Risk factors for diagnosis and treatment delay among patients with multidrug-resistant tuberculosis in Hunan Province, China

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) is a global health threat associated with high morbidity and mortality rates. Diagnosis and treatment delays are associated with poor treatment outcomes in patients with MDR-TB. However, the risk factors associated with these delays are not robustly investigated, particularly in high TB burden countries such as China. Therefore, this study aimed to measure the length of diagnosis and treatment delays and identify their risk factors among patients with MDR-TB in Hunan province.

METHODS

A retrospective cohort study was conducted using MDR-TB data from Hunan province between 2013 and 2018. The main outcomes of the study were diagnosis and treatment delay, defined as more than 14 days from the date of symptom to diagnosis confirmation (i.e., diagnosis delay) and from diagnosis to treatment commencement (i.e., treatment delay). A multivariable logistic regression model was fitted, and an adjusted odds ratio (AOR) with a 95% confidence interval (CI) was used to identify factors associated with diagnosis and treatment delay.

RESULTS

In total, 1,248 MDR-TB patients were included in this study. The median length of diagnosis delays was 27 days, and treatment delays were one day. The proportion of MDR-TB patients who experienced diagnosis and treatment delay was 62.82% (95% CI: 60.09-65.46) and 30.77% (95% CI: 28.27-33.39), respectively. The odds of experiencing MDR-TB diagnosis delay among patients coming through referral and tracing was reduced by 41% (AOR = 0.59, 95% CI: 0.45-0.76) relative to patients identified through consultations due to symptoms. The odds of experiencing diagnosis delay among ≥ 65 years were 65% (AOR = 0.35, 0.14-0.91) lower than under-15 children. The odds of developing treatment delay among foreign nationalities and people from other provinces were double (AOR = 2.00, 95% CI: 1.31-3.06) compared to the local populations. Similarly, the odds of experiencing treatment delay among severely ill patients were nearly 2.5 times higher (AOR = 2.49, 95% CI: 1.41-4.42) compared to patients who were not severely ill. On the other hand, previously treated TB cases had nearly 40% (AOR = 0.59, 95% CI: 0.42-0.85) lower odds of developing treatment delay compared with new MDR-TB cases. Similarly, other ethnic minority groups had nearly 40% (AOR = 0.57, 95% CI: 0.34-0.96) lower odds of experiencing treatment delay than the Han majority.

CONCLUSIONS

Many MDR-TB patients experience long diagnosis and treatment delays in Hunan province. Strengthening active case detection can significantly reduce diagnosis delays among MDR-TB patients. Moreover, giving attention to patients who are new to MDR-TB treatment, are severely ill, or are from areas outside Hunan province will potentially reduce the burden of treatment delay among MDR-TB patients.

Effectiveness and safety of tuberculosis preventive treatment for contacts of patients with multidrug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND

Contacts of patients with multidrug-resistant tuberculosis (MDR-TB) are at risk of developing TB disease. Tuberculosis preventive treatment (TPT) is an intervention that can potentially reduce this risk.

OBJECTIVES

To evaluate the effectiveness and safety of TPT for contacts of patients with MDR-TB.

DATA SOURCES

EMBASE, PubMed, Web of Science, and the Cochrane Library were searched for eligible studies on 24 July 2023, without start date restrictions.

STUDY ELIGIBILITY CRITERIA

We included studies that compared TPT with no treatment in contacts of patients with MDR-TB and reported outcomes of progression to TB disease.

PARTICIPANTS

Contacts of patients with MDR-TB.

INTERVENTIONS

TPT.

ASSESSMENT OF RISK OF BIAS

A modified version of the Newcastle-Ottawa Scale was used.

METHODS OF DATA SYNTHESIS

Random-effects meta-analysis was utilized to calculate the relative risk for disease progression to TB in contacts of patients with MDR-TB who received TPT compared to those who did not. Additionally, completion, adverse effect, and discontinued rates were assessed.

RESULTS

Involving 1105 individuals from 11 studies, the pooled relative risk for disease progression in contacts receiving TPT versus those without treatment was 0.34 (95% CI: 0.16-0.72). Subgroup analysis indicated a lower pooled relative risk for regimens based on the drug-resistance profile of the index patients with TB compared to uniform treatment regimens (0.22 [95% CI: 0.06-0.84] vs. 0.49 [95% CI: 0.17-1.35]), although not statistically significant. The pooled completed rate was 83.8%, adverse effect rate was 22.9%, and discontinued rate was 6.5%. After excluding the levofloxacin and pyrazinamide regimen study, the completed rate increased to 88.0%, and adverse effects and discontinued rates decreased to 8.0% and 4.0%, respectively.

DISCUSSION

TPT reduces TB disease progression risk in contacts of patients with MDR-TB. Tailored TPT regimens based on drug-resistance profiles may offer additional benefits. Furthermore, efforts to improve completed rates and manage adverse effects are essential for optimizing effectiveness and safety.

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.

[Drug-resistant pulmonary tuberculosis at Maradi Regional Hospital Center, Niger (2014-2018)]

Aim of study

To describe the clinical, therapeutic and evolutionary profile of patients followed for rifampicin-resistant pulmonary tuberculosis (RR-TB) at the Regional Hospital Centre (RHC) of Maradi (Niger) from 2014 to 2018.

Methods

We conducted a retrospective and descriptive study based on the records of patients followed for Multidrug-resistant tuberculosis (MDR-TB) between January 1, 2014 and June 30, 2018 at the resistant tuberculosis management unit in Maradi (Niger). This unit is located within the RHC of Maradi and has a capacity of 20 beds in 4 wards. It receives patients with tuberculosis resistant to first-line anti-tuberculosis drugs. In this study, patients diagnosed with RR-TB by genotypic (GeneXpert MTB/RIF) or phenotypic (culture) testing were included. We excluded from this study: patients previously treated for more than 1 month with second-line anti-TB drugs; patients with resistance to second-line injectables (SLI) and/or fluoroquinolones (FQ); patients with an electrocardiogram QTc greater than 500 ms (the corrected QT (QTc) estimates the QT interval at a rate of 60 beats per second); cases of atypical mycobacteriosis detected by phenotypic testing.Patients were previously on 2RHZE/4RH prior to the discovery of resistance. The treatment protocol for resistant TB was as follows: 4KmMfxPtoCfzHZE/5MfxCfzZE (The second-line injectable was replaced by Lzd in case of initial or treatment-emergent deafness). HIV co-infected patients received, in addition to anti-tuberculosis drugs, antiretrovirals and cotrimoxazole in preventive doses.

Results

A total of 80 patients were included in the present study (70 males and 10 females, mean age 34.4 years with extremes ranging from 18 to 71 years). Patients aged 18-35 years accounted for more than half. Patients with primary treatment failure were the most frequent type (36%) followed by patients with retreatment failure (24%) and patients with retreatment relapse (17%). It should be noted that 77 patients (96%) were previously treated for TB and only 3 patients (4%) were new cases. The majority of patients (70%) had a Body mass index of less than 18 kg/m2. 7.5% of patients were HIV positive, one was diabetic, 52% of the patients had grade 2 radiological lesions. Grade 1 deafness was noted at the beginning of treatment in 3%. A third of patients (36%) were primary treatment failures. The treatment protocol was as follows: 4KmMfxPtoCfzHZE/5MfxCfzZE. Only 1 patient had a positive culture at the end of the 4th month of treatment. Most of the patients had experienced adverse events, mainly digestive, with vomiting being the most common. The therapeutic success rate was 88%. We noted 10% of deaths, 1% of therapeutic failure and 1% of lost to follow-up.Six months after treatment, 48 patients (60%) were smear negative and 43 (54%) were culture negative. In 32 patients (40%), the smear was not performed and culture was not performed in 37.

Conclusion

The short treatment regime gives satisfactory results in the absence of resistance to fluoroquinolones, with rare adverse effects. In Niger, further efforts should be made to minimize the delay in diagnosis which is responsible for most deaths during treatment. A centre could usefully be designated to organize "TB consiliums" allowing any practitioner to submit difficult cases of MDR-TB.

Determinants of catastrophic costs among households affected by multi-drug resistant tuberculosis in Ho Chi Minh City, Viet Nam: a prospective cohort study

BACKGROUND

Globally, most people with multidrug-resistant tuberculosis (MDR-TB) and their households experience catastrophic costs of illness, diagnosis, and care. However, the factors associated with experiencing catastrophic costs are poorly understood. This study aimed to identify risk factors associated with catastrophic costs incurrence among MDR-TB-affected households in Ho Chi Minh City (HCMC), Viet Nam.

METHODS

Between October 2020 and April 2022, data were collected using a locally-adapted, longitudinal WHO TB Patient Cost Survey in ten districts of HCMC. Ninety-four people with MDR-TB being treated with a nine-month TB regimen were surveyed at three time points: after two weeks of treatment initiation, completion of the intensive phase and the end of the treatment (approximately five and 10 months post-treatment initiation respectively). The catastrophic costs threshold was defined as total TB-related costs exceeding 20% of annual pre-TB household income. Logistic regression was used to identify variables associated with experiencing catastrophic costs. A sensitivity analysis examined the prevalence of catastrophic costs using alternative thresholds and cost estimation approaches.

RESULTS

Most participants (81/93 [87%]) experienced catastrophic costs despite the majority 86/93 (93%) receiving economic support through existing social protection schemes. Among participant households experiencing and not experiencing catastrophic costs, median household income was similar before MDR-TB treatment. However, by the end of MDR-TB treatment, median household income was lower (258 [IQR: 0-516] USD vs. 656 [IQR: 462-989] USD; p = 0.003), and median income loss was higher (2838 [IQR: 1548-5418] USD vs. 301 [IQR: 0-824] USD; p < 0.001) amongst the participant households who experienced catastrophic costs. Being the household's primary income earner before MDR-TB treatment (aOR = 11.2 [95% CI: 1.6-80.5]), having a lower educational level (aOR = 22.3 [95% CI: 1.5-344.1]) and becoming unemployed at the beginning of MDR-TB treatment (aOR = 35.6 [95% CI: 2.7-470.3]) were associated with experiencing catastrophic costs.

CONCLUSION

Despite good social protection coverage, most people with MDR-TB in HCMC experienced catastrophic costs. Incurrence of catastrophic costs was independently associated with being the household's primary income earner or being unemployed. Revision and expansion of strategies to mitigate TB-related catastrophic costs, in particular avoiding unemployment and income loss, are urgently required.

Treatment of drug-resistant tuberculosis in children and young adolescents in Brazil

Introduction

Drug-resistant tuberculosis (DR-TB) is a global threat and a challenge for public health authorities worldwide. In children, the diagnosis is even more challenging and DR-TB is poorly described in the literature, as are its treatment outcomes. In this study, we aimed to describe the treatment of drug-resistant TB in children and young adolescents in Brazil.

Methods

A descriptive epidemiological study of treatment for DR-TB in children under 15 years of age in Brazil between 2013 and 2020. The primary data source was the Information System for Special Tuberculosis Treatments (SITE-TB). Categorical variables were analyzed using relative frequencies (%) and continuous variables by measures of central tendency to characterize the profile of the cases, namely: sociodemographic, clinical characteristics, procedures, tests performed and treatment success. In order to verify the distribution of cases, a spatial analysis was carried out based on the municipality where the cases resided.

Results

Between 2013 and 2020, 19,757 tuberculosis (TB) cases occurred in children aged <15 years in Brazil, and 46 cases of treatment for DR-TB were reported during the same period (annual average of 6 cases). Of these, 73.9% were aged 10-14, 65.2% were male, 4.3% were HIV+ and 43.3% were underweight (BMI<18.5) at the start of treatment. 17.4% had previous contact with TB, 69.6% had primary resistance, 47.8% multidrug resistance. The median duration of treatment was 15 months. DOT and standardized treatment regimen were performed in 52.2% of cases. Bacilloscopy was performed for 97.8% (57.8% positive); culture for 89.1% (75.6% positive), rapid molecular test for 73.9% with proven resistance to rifampicin in 55.8%. Susceptibility testing revealed resistance mainly to isoniazid (87.8%) and rifampicin (60.6%). 73.9% of cases were successfully treated and one death was reported. Cases were treated in 26 Brazilian municipalities, with the majority in Rio de Janeiro (15) and São Paulo (4).

Conclusion

DR-TB treatment was recorded in <1% of general TB cases in children and young adolescents, suggesting underreporting of drug-resistant cases in the country. Despite the low number of registered cases, the data reflect the situation of DR-TB in this population and describe important aspects of the problem, as the child needs comprehensive, individualized care, with support from different professionals. We recommend a strengthening of the country's referral services for the care of children with DR-TB so that surveillance and health care services can work together to identify and follow up cases.

Survival status and risk factors for mortality among multidrug-resistant tuberculosis patients in Addis Ababa, Ethiopia: A retrospective follow-up study

Background

Tuberculosis continues to be a major health concern around the world. It kills an estimated 1.6 million people each year. The World Health Organization (WHO) removed Ethiopia from its list of thirty countries having a high prevalence of MDR/RR-TB in 2021. As a result, the aim of this study was to assess the current context of survival status and risk factors of multidrug-resistant tuberculosis patients in Addis Ababa, Ethiopia, in 2022.

Methods

An institutional-based retrospective cohort study with 245 patients was undertaken using multidrug-resistant tuberculosis patients who were recruited from January 1st, 2018 to December 30th, 2021, in St. Peter's specialized hospital. To find independent predictors of survival status, Cox regression analysis was used. An adjusted hazard ratio with a 95% confidence interval and a p-value of < 0.05 was used to establish association and statistical significance.

Results

The result of the study revealed that the incidence of mortality in this study was 13.1% (95% CI: 10.3-16.5). Moreover, being male (AOR = 3.7: 95% CI = 1.2, 11.4), old age (AOR = 14: 95% CI = 3.0, 60.4), site of TB (AOR = 0.2: 95% CI = 0.03, 0.6), and presence of comorbidity (AOR = 9.2: 95% CI = 2.4, 35.3), were independent predictors of time to death.

Conclusion

Generally, the death rate among research participants was high. Moreover, male gender, old age, site of tuberculosis, and presence of other comorbidity were predictors of mortality among MDR-TB patients.

Anxiety and depression level of patients with multidrug-resistant tuberculosis (MDR-TB) in two hospitals in Banten province, Indonesia

Purpose

Anxiety and depression can be found in patients diagnosed with multidrug-resistant Tuberculosis (MDR-TB). The purpose of this research is to measure the level of anxiety and depression in new patients with MDR-TB.

Methods

One hundred two new patients newly diagnosed with MDR TB in two hospitals in Banten province, Indonesia, are measured for depression and anxiety symptoms. The measurements used the Indonesian language version of the Zung Anxiety Self-Assessment Scale Questionnaire and the Indonesian version of Zung Self-Rating Depression Scale Questionnaire for Pulmonary Tuberculosis Patients that have been validated. The results include the demographic data presented descriptively as tables and charts.

Results

The mean age of the patients is 39,57+12,48 years. The monthly income of the patients is 54,9% low and 45,1% medium with no high income. Male is 61,8%, and 38,2% are female. The mean score of the anxiety index is 57,32+10,23. The mean score of the depression index is 55,02+12,36. The percentage of patients with no anxiety is 13,7%, minimal to moderate anxiety 46,1%, marked to severe anxiety 33,3%, and most extreme anxiety 6,9%.

Conclusions

A significant proportion of patients newly diagnosed with MDR-TB experience anxiety and depression.

Meropenem-vaborbactam restoration of first-line drug efficacy and comparison of meropenem-vaborbactam-moxifloxacin versus BPaL MDR-TB regimen

BACKGROUND

Meropenem in combination with β-lactamase inhibitors (BLIs) and other drugs was tested to identify alternative treatment regimens for multidrug-resistant tuberculosis (MDR-TB).

METHODS

The following were performed: (1) MIC experiments; (2) static time-kill studies (STKs) with different BLIs; and (3) a hollow fibre model system of TB (HFS-TB) studies with meropenem-vaborbactam combined with human equivalent daily doses of 20 mg/kg or 35 mg/kg rifampin, or moxifloxacin 400 mg, or linezolid 600 mg vs. bedaquiline-pretonamid-linezolid (BPaL) for MDR-TB. The studies were performed using Mycobacterium tuberculosis (M. tuberculosis) H37Rv and an MDR-TB clinical strain (named M. tuberculosis 16D) that underwent whole genome sequencing. Exponential decline models were used to calculate the kill rate constant (K) of different HFS-TB regimens.

RESULTS

Whole genome sequencing revealed mutations associated with resistance to rifampin, isoniazid, and cephalosporins. The meropenem-vaborbactam MIC of M. tuberculosis was H37Rv 2 mg/L and > 128 mg/L for M. tuberculosis 16D. Relebactam and vaborbactam improved both the potency and efficacy of meropenem in STKs. Meropenem-vaborbactam alone failed to kill M. tuberculosis 16D but killed below day 0 burden when combined with isoniazid and rifampin, with the moxifloxacin combination being the most effective and outranking bedaquiline and pretomanid. In the HFS-TB, meropenem-vaborbactam-moxifloxacin and BPaL had the highest K (log10 cfu/mL/day) of 0.31 (95% CI 0.17-0.58) and 0.34 (95% CI 0.21-0.56), while meropenem-vaborbactam-rifampin (35 mg/kg) had a K of 0.18 (95% CI 0.12-0.25). The K for meropenem-vaborbactam-moxifloxacin-linezolid demonstrated antagonism.

CONCLUSION

Adding meropenem-vaborbactam could potentially restore the efficacy of isoniazid and rifampin against MDR-TB. The meropenem-vaborbactam-moxifloxacin backbone regimen has implications for creating a new effective MDR-TB regimen.

Diabetes mellitus affects the treatment outcomes of drug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND

Both tuberculosis (TB) and diabetes mellitus (DM) are major public health problems threatening global health. TB patients with DM have a higher bacterial burden and affect the absorption and metabolism for anti-TB drugs. Drug-resistant TB (DR-TB) with DM make control TB more difficult.

METHODS

This study was completed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline. We searched PubMed, Excerpta Medica Database (EMBASE), Web of Science, ScienceDirect and Cochrance Library for literature published in English until July 2022. Papers were limited to those reporting the association between DM and treatment outcomes among DR-TB and multidrug-resistant TB (MDR-TB) patients. The strength of association was presented as odds ratios (ORs) and their 95% confidence intervals (CIs) using the fixed-effects or random-effects models. This study was registered with PROSPERO, number CRD: 42,022,350,214.

RESULTS

A total of twenty-five studies involving 16,905 DR-TB participants were included in the meta-analysis, of which 10,124 (59.89%) participants were MDR-TB patients, and 1,952 (11.54%) had DM history. In DR-TB patients, the pooled OR was 1.56 (95% CI: 1.24-1.96) for unsuccessful outcomes, 0.64 (95% CI: 0.44-0.94) for cured treatment outcomes, 0.63 (95% CI: 0.46-0.86) for completed treatment outcomes, and 1.28 (95% CI: 1.03-1.58) for treatment failure. Among MDR-TB patients, the pooled OR was 1.57 (95% CI: 1.20-2.04) for unsuccessful treatment outcomes, 0.55 (95% CI: 0.35-0.87) for cured treatment outcomes, 0.66 (95% CI: 0.46-0.93) for treatment completed treatment outcomes and 1.37 (95% CI: 1.08-1.75) for treatment failure.

CONCLUSION

DM is a risk factor for adverse outcomes of DR-TB or MDR-TB patients. Controlling hyperglycemia may contribute to the favorite prognosis of TB. Our findings support the importance for diagnosing DM in DR-TB /MDR-TB, and it is needed to control glucose and therapeutic monitoring during the treatment of DR-TB /MDR-TB patients.

Advanced drug delivery and therapeutic strategies for tuberculosis treatment

Tuberculosis (TB) remains a significant global health challenge, necessitating innovative approaches for effective treatment. Conventional TB therapy encounters several limitations, including extended treatment duration, drug resistance, patient noncompliance, poor bioavailability, and suboptimal targeting. Advanced drug delivery strategies have emerged as a promising approach to address these challenges. They have the potential to enhance therapeutic outcomes and improve TB patient compliance by providing benefits such as multiple drug encapsulation, sustained release, targeted delivery, reduced dosing frequency, and minimal side effects. This review examines the current landscape of drug delivery strategies for effective TB management, specifically highlighting lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, emulsion-based systems, carbon nanotubes, graphene, and hydrogels as promising approaches. Furthermore, emerging therapeutic strategies like targeted therapy, long-acting therapeutics, extrapulmonary therapy, phototherapy, and immunotherapy are emphasized. The review also discusses the future trajectory and challenges of developing drug delivery systems for TB. In conclusion, nanomedicine has made substantial progress in addressing the challenges posed by conventional TB drugs. Moreover, by harnessing the unique targeting abilities, extended duration of action, and specificity of advanced therapeutics, innovative solutions are offered that have the potential to revolutionize TB therapy, thereby enhancing treatment outcomes and patient compliance.

Selecting an appropriate all-oral short-course regimen for patients with multidrug-resistant or pre-extensive drug-resistant tuberculosis in China: A multicenter prospective cohort study

OBJECTIVES

Long, ineffective, and toxic regimens hinder the treatment of patients with multidrug-resistant tuberculosis (MDR-TB) and pre-extensive drug-resistant tuberculosis (pre-XDR-TB).

METHODS

We conducted a multicenter cohort study to prospectively evaluate the safety and efficacy of three 9-month, all-oral, 5-drug regimens. Regimen A (bedaquiline [Bdq]+linezolid [Lzd]+moxifloxacin [Mfx]+cycloserine [Cs]+pyrazinamide [Pza]) and Regimen B (Lzd+Mfx+Cs+clofazimine [Cfz]+Pza) were used to treat MDR-TB patients (Groups A and B, respectively, assigned according to the patient's treatment preference), while Regimen C (Bdq+Lzd+Cs+Cfz+Pza) was used to treat pre-XDR-TB patients (Group C). The primary endpoint was the occurrence of an unfavorable outcome within 12 months of treatment completion, regardless of regimen.

RESULTS

A total of 104 patients (34 in Group A, 46 in Group B, and 24 in Group C), with a median age of 35.5 (29.0-54.0) years, were included in the analysis population. At 12 months after treatment completion, five patients were deemed non-assessable. Of the remaining 99 participants, seven (7.1%) had an unfavorable outcome (including two deaths from any cause, four with treatment failure, and one loss to follow-up) and 92 (92.9%) had a favorable outcome. Culture conversion was achieved in 82.5% (80/97) of participants at month 2 and in 97.9% (94/97) of participants at month 6. Adverse events (AEs) resulting in drug adjustment occurred in 69.2% (72/104) of participants, mainly due to Lzd and Pza use. A QT interval prolongation of ≥ 500 ms occurred in 5.8% (6/104) of participants.

CONCLUSION

The primary outcome of the three tailored, 9-month, all-oral, 5-drug regimens was satisfactory in the vast majority of MDR-TB and pre-XDR-TB patients, with manageable and reversible AEs.

Risk factor analysis of postoperative complications after adjunctive pulmonary resection in patients with multidrug-resistant tuberculosis: A multi-institutional study

BACKGROUND AND OBJECTIVE

Multidrug-resistant tuberculosis (MDR-TB) requires extended treatment with regimens with multiple side effects, resulting in high treatment failure rates. Adjunctive lung resection combined with anti-tubercular agents improves outcomes. However, few studies have evaluated the potential harm from surgery and determined the optimal conditions for surgery. We aimed to analyze perioperative conditions to assess risk factors for postoperative complications in a multi-institutional setting.

METHODS

This retrospective study included 44 patients with MDR-TB who underwent adjunctive lung resection at three management groups of the Taiwan MDR-TB consortium between January 2007 and December 2020. Demographic data, clinical characteristics, radiological findings, sputum culture status before surgery, primary or acquired drug resistance, surgical procedure, complications, and treatment outcomes were collected and analyzed. Multivariate logistic regression was used to identify risk factors for postoperative complications.

RESULTS

Twenty-seven patients (61.4%) underwent lung resection using video-assisted thoracic surgery (VATS). The overall surgical complication rate was 20.5%, and the surgical mortality rate was 9.1%. Postsurgical hemothorax was the most common complication (11.4%). According to the univariate analysis, hilum involvement in images, positive preoperative sputum culture, and thoracotomy approach were unfavorable factors. VATS approach [adjusted OR, 0.088 (95% CI, 0.008-0.999)] was the only favorable factor identified by multivariate analysis.

CONCLUSION

The minimally invasive approach is a growing trend, and lobectomies and sublobar resections were the main procedures for MDR-TB. The VATS approach significantly reduced the surgical complication rate. Postsurgical hemothorax was noteworthy, and meticulous hemostasis of the chest wall and residual lung surface is critical for successful resections.

Risk factors for multidrug-resistant tuberculosis in the Central African Republic: A case-control study

BACKGROUND

The emergence and spread of multidrug-resistant tuberculosis (MDR-TB) presents a challenge to the "End TB by 2035" strategy. This study aimed to identify the risk factors associated with MDR-TB in patients admitted to the pneumo-physiology clinic of the National University Hospital of Bangui in Central African Republic.

METHODS

This was a "retrospective" chart review study. Cases were represented by patients more than 18 years of age treated for MDR-TB and controls were patients with "at least rifampicin-susceptible" TB treated "with first-line anti-TB regimen" and who at the end of treatment were declared cured. The status of "cured" was exclusively applicable to non-MDR TB. Risk factors associated with MDR-TB were identified by multivariate analysis.

RESULTS

We included 70 cases and 140 controls. The median age was 35 years, IQR (22;46 years). The main factors associated with the occurrence of MDR-TB in multivariate analysis were male gender (0 R = 3.02 [1.89-3.99], p = 0.001), residence in a peri-urban/urban area (0 R = 3.06 [2.21-4.01], p = 0.002), history of previous TB treatment (0 R= 3.99 [2.77-4.25], p < 0.001) and the presence of multidrug-resistant TB in the family (0 R=1.86 [1.27-2.45], p = 0.021).

CONCLUSION

The emergence of MDR-TB can be reduced by implementing appropriate strategies, such as preventive therapy in contacts of MDR-TB patients and detecting and appropriately treating MDR-TB patients to prevent further spread of infection.

Fluoroquinolone-resistant latent tuberculosis infection: A literature review and case series of 5 patients treated with linezolid monotherapy

Latent tuberculosis infection (LTBI) constitutes an important public health problem because of risk of progression to TB disease. Effective treatment of multi-drug resistant (MDR) LTBI would prevent progression to MDR TB disease, which would improve patient and public health outcomes. The majority of MDR LTBI treatment studies have focused on the use of fluoroquinolone-based antibiotic regimens. Options for and experience in the treatment of fluoroquinolone-resistant MDR LTBI are limited in the published literature and not comprehensively addressed in current guidelines. In this review, we share our experience with the treatment of fluoroquinolone-resistant MDR LTBI with linezolid. We discuss treatment options for MDR TB that provide context for predicting effective MDR LTBI treatment, with a focus on the microbiologic and pharmacokinetic properties of linezolid that support its use. We then summarize the evidence for treatment of MDR LTBI. Finally, we present our experiences treating fluoroquinolone-resistant MDR LTBI with linezolid with an emphasis on dosing considerations to optimize efficacy and minimize potential toxicities.

What clinic closure reveals about care for drug-resistant TB: a qualitative study

BACKGROUND

There have been calls for "person-centered" approaches to drug-resistant tuberculosis (DR-TB) care. In 2020, Charles James Hospital in South Africa, which incorporated person-centered care, was closed. Patients were referred mid-course to a centralized, tertiary hospital, providing an opportunity to examine person-centered DR-TB and HIV care from the perspective of patients who lost access to it.

METHODS

The impact of transfer was explored through qualitative interviews performed using standard methods. Analysis involved grounded theory; interviews were assessed for theme and content.

RESULTS

After switching to the centralized site, patients reported being unsatisfied with losing access to a single clinic and pharmacy where DR-TB, HIV and chronic disease care were integrated. Patients also reported a loss of care continuity; at the decentralized site there was a single, familiar clinician whereas the centralized site had multiple, changing clinicians and less satisfactory communication. Additionally, patients reported more disease-related stigma and less respectful treatment, noting the loss of a "special place" for DR-TB treatment.

CONCLUSION

By focusing on a DR-TB clinic closure, we uncovered aspects of person-centered care that were critical to people living with DR-TB and HIV. These perspectives can inform how care for DR-TB is operationalized to optimize treatment retention and effectiveness.

Cost of treatment support for multidrug-resistant tuberculosis using patient-centred approaches in Ethiopia: a model-based method

BACKGROUND

Patient and health system costs for treating multidrug-resistant tuberculosis (MDR-TB) remain high even after treatment duration was shortened. Many patients do not finish treatment, contributing to increased transmission and antimicrobial resistance. A restructure of health services, that is more patient-centred has the potential to reduce costs and increase trust and patient satisfaction. The aim of the study is to investigate how costs would change in the delivery of MDR-TB care in Ethiopia under patient-centred and hybrid approaches compared to the current standard-of-care.

METHODS

We used published data, collected from 2017 to 2020 as part of the Standard Treatment Regimen of Anti-Tuberculosis Drugs for Patients with MDR-TB (STREAM) trial, to populate a discrete event simulation (DES) model. The model was developed to represent the key characteristics of patients' clinical pathways following each of the three treatment delivery strategies. To the pathways of 1000 patients generated by the DES model we applied relevant patient cost data derived from the STREAM trial. Costs are calculated for treating patients using a 9-month MDR-TB treatment and are presented in 2021 United States dollars (USD).

RESULTS

The patient-centred and hybrid strategies are less costly than the standard-of-care, from both a health system (by USD 219 for patient-centred and USD 276 for the hybrid strategy) and patient perspective when patients do not have a guardian (by USD 389 for patient-centred and USD 152 for the hybrid strategy). Changes in indirect costs, staff costs, transport costs, inpatient stay costs or changes in directly-observed-treatment frequency or hospitalisation duration for standard-of-care did not change our results.

CONCLUSION

Our findings show that patient-centred and hybrid strategies for delivering MDR-TB treatment cost less than standard-of-care and provide critical evidence that there is scope for such strategies to be implemented in routine care. These results should be used inform country-level decisions on how MDR-TB is delivered and also the design of future implementation trials.

Crystal violet decolorization assay: a simplified colorimetric test for the rapid detection of multidrug-resistant Mycobacterium tuberculosis isolates

The increased prevalence of multi-drug resistant M. tuberculosis is quite possibly the direst and most difficult task for the early diagnosis and treatment. A rapid, reliable, and inexpensive diagnostic method is the need of the hour. The current study on crystal violet decolorization assay explores the possibility to develop a rapid and simple detection method to detect multi-drug-resistant tuberculosis isolates by comparing the results with the traditional liquid culture drug susceptibility testing method based on their sensitivity, specificity, positive predictive value, and negative predictive value. 70 isolates were used for the study and were detected as multi-drug resistant, mono drug-resistant, and sensitive by using crystal violet decolourization assay and further compared with the results of DST and using H37Rv as the standard control strain. The sensitivity, specificity, positive predictive value, and negative predictive value of crystal violet decolorization assay (Rifampicin: 100%, 94.60%, 100% and 82.40%; isoniazid: 100%, 94.10%, 100%, 86.40%) are calculated and the percentage were compared with the conventional liquid culture drug susceptibility testing for M. tuberculosis using rifampicin and isoniazid. Crystal violet decolourization assay is rapid, reproducible, and doesn't require any highly experienced personal or sophisticated laboratory instruments for interpretation. This assay is found to be nearly as reliable as conventional liquid culture drug susceptibility testing and may thus be of great help in phenotypic confirmation of multi-drug resistant tuberculosis by providing results more rapidly.

Cost-Effectiveness Analysis of Combined Chemotherapy Regimen Containing Bedaquiline in the Treatment of Multidrug-Resistant Tuberculosis in China

Objective

This study aims to estimate the cost-effectiveness of the combined chemotherapy regimen containing Bedaquiline (BR) and the conventional treatment regimen (CR, not containing Bedaquiline) for the treatment of adults with multidrug-resistant tuberculosis (MDR-TB) in China.

Methods

A combination of a decision tree and a Markov model was developed to estimate the cost and effects of MDR patients in BR and CR within ten years. The model parameter data were synthesized from the literature, the national TB surveillance information system, and consultation with experts. The incremental cost-effectiveness ratio (ICER) of BR vs. CR was determined.

Results

BR ( vs. CR) had a higher sputum culture conversion rate and cure rate and prevented many premature deaths (decreased by 12.8%), thereby obtaining more quality-adjusted life years (QALYs) (increased by 2.31 years). The per capita cost in BR was as high as 138,000 yuan, roughly double that of CR. The ICER for BR was 33,700 yuan/QALY, which was lower than China's 1× per capita Gross Domestic Product (GDP) in 2020 (72,400 yuan).

Conclusion

BR is shown to be cost effective. When the unit price of Bedaquiline reaches or falls below 57.21 yuan per unit, BR is expected to be the dominant strategy in China over CR.

[Tuberculosis-Update 2022]

According to the annual global reports from the Word Health Organization (WHO), children under 15 years of age represent 11% of all cases of tuberculosis (TB) globally. Nearly 50% of these cases are children below 5 years old. This continuing medical education (CME) article provides an overview of the current recommendations and innovations based on the revised WHO guidelines on TB management in children and adolescents published in 2022.

New Horizons in the Diagnosis of Tuberculosis of the Spine: The Role of Whole Genome Sequencing

Study Design

Prospective study.

Purpose

To evaluate the utility of whole genome sequencing (WGS) in drug resistance testing, lineage of the organisms, and organism- related factors responsible for bacilli settling in the spine.

Overview of Literature

The workstream for the diagnosis of tuberculosis (TB) involves isolation and culture of the organism and drug resistance testing using phenotypic methods. Xpert MTB/RIF Ultra is a genetic-based method that detects for Mycobacterium tuberculosis DNA in the rpoB gene. Meanwhile, WGS is a newer genetic-based method that assesses the whole genome of the bacterium. Very few studies have reported the use of WGS for extrapulmonary TB. Herein, we used WGS to diagnose spinal TB.

Methods

Tissues from 61 patients undergoing surgery for spinal TB underwent histologic examination, Xpert MTB/RIF Ultra, and culture and sensitivity testing. DNA from the cultured bacteria was sent for WGS. The test bacterial genome was compared to a reference strain of pulmonary TB.

Results

Acid-fast bacilli were observed in 9/58 specimens. Meanwhile, histology confirmed TB in all the patients. Bacilli were cultured in 28 patients (48.3%), and the average time to culture was 18.7 days. Xpert MTB/RIF Ultra was positive in 47 patients (85%). WGS was performed in 23 specimens. Overall, 45% of the strains belonged to lineage 2 (East Asian). There was one case of multidrug- resistant TB and two cases of non-tuberculous mycobacteria on WGS. We could not confirm any genomic difference between pulmonary and spinal TB strains.

Conclusions

Xpert MTB/RIF Ultra of tissues or pus is the investigation of choice when diagnosing spinal TB. Meanwhile, WGS can diagnose multidrug-resistant TB and non-tuberculous mycobacteria more accurately. No mutations were identified in spinal and pulmonary TB bacteria.

Treatment cascade for patients with multidrug- or rifampicin-resistant tuberculosis and associated factors with patient attrition in southeastern China: a retrospective cohort study

OBJECTIVES

To address gaps in health services for multidrug- or rifampicin-resistant tuberculosis (MDR/RR-TB), a treatment cascade model was used to evaluate patient retention and attrition at each successive step required to achieve a successful treatment outcome.

METHODS

From 2015-2018, a four-step treatment cascade model was established in patients with confirmed MDR/RR-TB in southeast China. Step 1: diagnosis of MDR/RR-TB, step 2: Initiation of treatment, step 3: still under treatment at 6 month and step 4: cure or completion of MDR/RR-TB treatment, with each successive step including a gap that shows attrition of patients between steps. The retention and attrition of each step were graphed. Multi-variate logistic regression was carried out to further identify potential factors associated with the attrition.

RESULTS

In the treatment cascade consisting of 1752 MDR/RR-TB patients, the overall patient attrition rate was 55.8% (978/1752), with 28.0% (491/1752), 19.9% (251/1261), and 23.4% (236/1010) of patients attrition in the first, second, and third gap. Factors associated with MDR/RR-TB patients not initiating treatment included age ≥60 years (OR:2.875), and time for diagnosis ≥30 days (OR: 2.653). Patients who were diagnosed with MDR/RR-TB through rapid molecular test (OR: 0.517) and non-migrant residents of Zhejiang Province (OR: 0.273) both exhibited a lower likelihood of attrition during the treatment initiation phase. Meanwhile, old age (OR: 2.190) and non-resident migrants to the province were factors associated with not completing ≥ 6 months of treatment. Old age (OR: 3.883), retreatment (OR: 1.440), and time to diagnosis ≥30 days (OR: 1.626) were factors contributing to poor treatment outcomes.

CONCLUSION

Several programmatic gaps were identified in the MDR/RR-TB treatment cascade. Future policies should provide more comprehensive support for vulnerable populations to improve the care quality at each step.

Epidemiology of extensively drug-resistant tuberculosis among multidrug resistant tuberculosis patients: A systematic review and meta-analysis

OBJECTIVE

To estimate the pooled proportion of extensively drug-resistant tuberculosis (XDR-TB) and pre-extensively drug-resistant tuberculosis (pre-XDR-TB) in multidrug-resistant TB (MDR-TB) patients.

METHODS

We systematically searched articles from electronic databases: MEDLINE (PubMed), ScienceDirect, and Google Scholar. We also searched grey from different literature sources main outcome of the review was either XDR-TB or pre-XDR-TB in MDR-TB patients. We used the random-effects model considering substantial heterogeneity among studies. Heterogeneity was assessed by subgroup analyses. STATA version 14 was used for analysis.

RESULTS

A total of 64 studies reported on 12,711 MDR-TB patients from 22 countries were retrieved. The pooled proportion of pre-XDR-TB was 26% (95%CI: 22%-31%), while XDR-TB in MDR-TB cases was 9% (95%CI: 7%-11%) in patients treated for MDR-TB. The pooled proportion of resistance to fluoroquinolones was 27% (95%CI: 22%-33%) and second-line injectable-drugs was 11% (95%CI: 9%-13%). Whereas the pooled resistance proportion to bedaquiline, clofazimine, delamanid, and linezolid was 5% (95%CI: 1%-8%), 4% (95%CI: 0%-10%), 5% (95%CI; 2%- 8%), and 4% (95%CI: 2%-10%), respectively.

CONCLUSIONS

The burden of pre-XDR-TB and XDR-TB in MDR-TB were considerable. The high burdens of pre-XDR-TB and XDR-TB in patients treated for MDR-TB is suggesting the need of strengthen TB program and drug resistance surveillance.

Socioeconomic disparities and multidrug-resistant tuberculosis in South Korea: Focus on immigrants and income levels

Risk factors of MDR-TB remain unclear in South Korea, despite being an important public health issue. Findings from this study, which included ≥50,000 patients with TB from South Korea, suggests that immigrants and patients with lower income levels were strong predictors of MDR-TB in a high-income, high TB incidence country.

Protocol for a feasibility randomized controlled trial to evaluate the efficacy, safety and tolerability of N-acetylcysteine in reducing adverse drug reactions among adults treated for multidrug-resistant tuberculosis in Tanzania

BACKGROUND

Adverse drug reactions (ADRs) frequently occur in patients using second-line anti-tuberculosis medicine for treatment of multidrug resistant tuberculosis (MDR-TB). ADRs contribute to treatment interruptions which can compromise treatment response and risk acquired drug resistance to critical newer drugs such as bedaquiline, while severe ADRs carry considerable morbidity and mortality. N-acetylcysteine (NAC) has shown promise in reducing ADRs for medications related to TB in case series or randomized controlled trials in other medical conditions, yet evidence is lacking in MDR-TB patients. TB endemic settings have limited capacity to conduct clinical trials. We designed a proof-of-concept clinical trial primarily to explore the preliminary evidence on the protective effect of NAC among people treated for MDR-TB with second-line anti-TB medications.

METHODS

This is a proof-of-concept randomized open label clinical trial with 3 treatment arms including a control arm, an interventional arm of NAC 900 mg daily, and an interventional arm of NAC 900 mg twice-daily administered during the intensive phase of MDR-TB treatment. Patients initiating MDR-TB treatment will be enrolled at Kibong'oto National Center of Excellence for MDR-TB in the Kilimanjaro region of Tanzania. The minimum anticipated sample size is 66; with 22 participants in each arm. ADR monitoring will be performed at baseline and daily follow-up over 24 weeks including blood and urine specimen collection for hepatic and renal function and electrolyte abnormalities, and electrocardiogram. Sputum will be collected at baseline and monthly thereafter and cultured for mycobacteria as well as assayed for other molecular targets of Mycobacterium tuberculosis. Adverse drug events will be analysed over time using mixed effect models. Mean differences between arms in change of the ADRs from baseline (with 95% confidence intervals) will be derived from the fitted model.

DISCUSSION

Given that NAC promotes synthesis of glutathione, an intracellular antioxidant that combats the impact of oxidative stress, it may protect against medication induced oxidative damage in organs such as liver, pancreas, kidney, and cells of the immune system. This randomized controlled trial will determine if NAC leads to fewer ADRs, and if this protection is dose dependent. Fewer ADRs among patients treated with MDR-TB may significantly improve treatment outcomes for multidrug regimens that necessitate prolonged treatment durations. Conduct of this trial will set the needed infrastructure for clinical trials.

TRIAL REGISTRATION

PACTR202007736854169 Registered 03 July 2020.

Development of DNA Bio-chip for Detection of Mutations of rpoB, embB and inhA Genes in Drug-Resistant Mycobacterium Tuberculosis

Drug-resistant (DR) tuberculosis (TB) is a global threat to health security and TB control programs. Since conventional drug susceptibility testing (DST) takes several weeks, we have developed a molecular method for the rapid identification of DR strains of Mycobacterium Tuberculosis (M.tb) utilizing DNA bio-chips. DNA bio-chips were prepared by immobilizing oligonucleotides (probes) on highly microporous polycarbonate track-etched membranes (PC-TEM) as novel support. Bio-chip was designed to contain 15 specific probes to detect mutations in three genes (rpoB, embB, and inhA). A sensitive and specific chemiluminescence based bio-chip assay was developed based on multiplex PCR followed by hybridization on bio-chip. Fifty culture isolates were used to evaluate the ability of in-house developed bio-chip to detect the mutations. Bio-chip analysis shows that 37.7% of samples show wild type sequences, 53.3% of samples were monoresistance showing resistance to either rifampicin (RMP), isoniazid (INH), or ethambutol (EMB). 4.4% of samples were polydrug resistant showing mutations in both the rpoB gene and embB gene while 4.4% of samples were multidrug-resistant (MDR), harboring mutations in the rpoB and inhA genes. The results were compared with DST and sequencing. Compared to sequencing, bio-chip assay shows a sensitivity of 96.5% and specificity of 100% for RMP resistance. For EMB and INH, the results were in complete agreement with sequencing. This study demonstrates the first-time use of PC-TEMs for developing DNA bio-chip for the detection of mutations associated with drug resistance in M.tb. Developed DNA bio-chip accurately detected different mutations present in culture isolates and thus provides detailed and reliable data for clinical diagnosis.

Discrepancy in the transmissibility of multidrug-resistant Mycobacterium tuberculosis in urban and rural areas in China

The fitness of multidrug-resistant tuberculosis (MDR-TB) is thought to be an important determinant of a strain's ability to be transmitted and cause outbreaks. Studies in the laboratory have demonstrated that MDR-TB strains have reduced fitness but the relative transmissibility of MDR-TB versus drug-susceptible (DS) TB strains in human populations remains unresolved. We used data on genomic clustering from our previous molecular epidemiological study in Songjiang (2011-2020) and Wusheng (2009-2020), China, to compare the relative transmissibility of MDR-TB versus DS-TB. Genomic clusters were defined with a threshold distance of 12-single-nucleotide-polymorphisms and the risk for MDR-TB clustering was analyzed by logistic regression. In total, 2212 culture-positive pulmonary TB patients were enrolled in Songjiang and 1289 in Wusheng. The clustering rates of MDR-TB and DS-TB strains were 19.4% (20/103) and 26.3% (509/1936), respectively in Songjiang, and 43.9% (29/66) and 26.0% (293/1128) in Wusheng. The risk of MDR-TB clustering was 2.34 (95% CI 1.38-3.94) times higher than DS-TB clustering in Wusheng and 0.64 (95% CI 0.38-1.06) times lower in Songjiang. Neither lineage 2, compensatory mutations nor rpoB S450L were significantly associated with MDR-TB transmission, and katG S315T increased MDR-TB transmission only in Wusheng (OR 5.28, 95% CI 1.42-19.21). MDR-TB was not more transmissible than DS-TB in either Songjiang or Wusheng. It appears that the different transmissibility of MDR-TB in Songjiang and Wusheng is likely due to differences in the quality of the local TB control programs. These results suggest that the most effective way to control MDR-TB is by improving local TB control programs.

Prevalence of long-term physical sequelae among patients treated with multi-drug and extensively drug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND

Physical sequelae related to multi-drug resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) are emerging and under-recognised global challenges. This systematic review and meta-analysis aimed to quantify the prevalence and the types of long-term physical sequelae associated with patients treated for MDR- and XDR-TB.

METHODS

We systematically searched CINAHL (EBSCO), MEDLINE (via Ovid), Embase, Scopus, and Web of Science from inception through to July 1, 2022, and the last search was updated to January 23, 2023. We included studies reporting physical sequelae associated with all forms of drug-resistant TB, including rifampicin-resistant TB (RR-TB), MDR-TB, Pre-XDR-TB, and XDR-TB. The primary outcome of interest was long-term physical sequelae. Meta-analysis was conducted using a random-effect model to estimate the pooled proportion of physical sequelae. The sources of heterogeneity were explored through meta-regression using study characteristics as covariates. The research protocol was registered in PROSPERO (CRD42021250909).

FINDINGS

From 3047 unique publications identified, 66 studies consisting of 37,380 patients conducted in 30 different countries were included in the meta-analysis. The overall pooled estimate was 44.4% (95% Confidence Interval (CI): 36.7-52.1) for respiratory sequelae, 26.7% (95% CI: 23.85-29.7) for hearing sequelae, 10.1% (95% CI: 7.0-13.2) for musculoskeletal sequelae, 8.4% (95% CI: 6.5-10.3) for neurological sequelae, 8.1% (95% CI: 6.3-10.0) for renal sequelae, 7.3% (95% CI: 5.1-9.4) for hepatic sequelae, and 4.5% (95% CI: 2.7-6.3) for visual sequelae. There was substantial heterogeneity in the estimates. The stratified analysis showed that the pooled prevalence of hearing sequelae was 26.6% (95% CI: 12.3-40.9), neurological sequelae was 31.5% (95% CI: 5.5-57.5), and musculoskeletal sequelae were 21.5% (95% CI: 9.9-33.1) for patients with XDR-TB, which were higher than the pooled prevalence of sequelae among patients with MDR-TB. Respiratory sequelae were the highest in low-income countries (59.3%) and after completion of MDR-TB treatment (57.7%).

INTERPRETATION

This systematic review found that long-term physical sequelae such as respiratory, hearing, musculoskeletal, neurological, renal, hepatic, and visual sequelae were common among survivors of MDR- and XDR-TB. There was a significant difference in the prevalence of sequelae between patients with MDR- and XDR-TB. Post-MDR- and XDR-TB treatment surveillance for adverse outcomes needs to be incorporated into the current programmatic management of MDR-TB to enable early detection and prevention of post-treatment sequelae.

FUNDING

Australian National Health and Medical Research Council, through an Emerging Leadership Investigator grant, and the Curtin University Higher Degree Research scholarship.

GenoType MTBDRsl for detection of second-line drugs and ethambutol resistance in multidrug-resistant Mycobacterium tuberculosis isolates at a high-throughput laboratory

We assessed the performance of MTBDRsl for detection of resistance to fluoroquinolones, aminoglycosides/cyclic peptides, and ethambutol compared to BACTEC MGIT 960 by subjecting simultaneously to both tests 385 phenotypically multidrug-resistant-Mycobacterium tuberculosis isolates from Sao Paulo, Brazil. Discordances were resolved by Sanger sequencing. MTBDRsl correctly detected 99.7% of the multidrug-resistant isolates, 87.8% of the pre-XDR, and 73.9% of the XDR. The assay showed sensitivity of 86.4%, 100%, 85.2% and 76.4% for fluoroquinolones, amikacin/kanamycin, capreomycin and ethambutol, respectively. Specificity was 100% for fluoroquinolones and aminoglycosides/cyclic peptides, and 93.6% for ethambutol. Most fluoroquinolone-discordances were due to mutations in genome regions not targeted by the MTBDRsl v. 1.0: gyrA_H70R and gyrB_R446C, D461N, D449V, and N488D. Capreomycin-resistant isolates with wild-type rrs results on MTBDRsl presented tlyA mutations. MTBDRsl presented good performance for detecting resistance to second-line drugs and ethambutol in clinical isolates. In our setting, multidrug-resistant. isolates presented mutations not targeted by the molecular assay.

Limited effect of reducing pulmonary tuberculosis incidence amid mandatory facial masking for COVID-19

Although the incidence and mortality rates associated with tuberculosis (TB) have been decreasing in many countries, TB remains a major public health concern. Obligatory facial masking and reduced health-care capacity because of COVID-19 may substantially influence TB transmission and care. The Global Tuberculosis Report 2021 published by the World Health Organization indicated a TB rebound at the end of 2020, which coincided with the COVID-19 pandemic. We explored this rebound phenomenon in Taiwan by investigating whether TB incidence and mortality are affected by COVID-19 because of their common route of transmission. In addition, we investigated whether the incidence of TB varies across regions with different incidences of COVID-19. Data (2010-2021) regarding annual new cases of TB and multidrug-resistant TB were collected from the Taiwan Centers for Disease Control. TB incidence and mortality were assessed in Taiwan's seven administrative regions. Over the last decade, TB incidence decreased continually, even during 2020 and 2021, the years coinciding with the COVID-19 pandemic. Notably, TB incidence remained high in regions with low COVID-19 incidence. However, the overall decreasing trends of TB incidence and mortality remained unchanged during the pandemic. Facial masking and social distancing may prevent COVID-19 transmission but exhibit limited efficacy in reducing TB transmission. Thus, during health-related policymaking, policymakers must consider TB rebound, even in the post-COVID-19 era.

Adjunctive Zoledronate+IL-2 administrations enhance anti-tuberculosis Vγ2Vδ2 T-effector populations, and improve treatment outcome of multidrug-resistant tuberculosis

Multidrug-resistant tuberculosis (MDR-TB) is a refractory disease with high mortality rate due to no or few choices of antibiotics. Adjunctive immunotherapy may help improve treatment outcome of MDR-TB. Our decade-long studies demonstrated that phosphoantigen-specific Vγ2Vδ2 T cells play protective roles in immunity against TB. Here, we hypothesized that enhancing protective Vγ2Vδ2 T-effector cells could improve treatment outcome of MDR-TB. To address this, we employed clinically approved drugs Zoledronate (ZOL) and IL-2 to induce anti-TB Vγ2Vδ2 T-effector cells as adjunctive immunotherapy against MDR-TB infection of macaques. We found that adjunctive ZOL/IL-2 administrations during TB drugs treatment of MDR-TB-infected macaques significantly expanded Vγ2Vδ2 T cells and enhanced/sustained Vγ2Vδ2 T-effector subpopulation producing anti-TB cytokines until week 21. ZOL/IL-2 administrations, while expanding Vγ2Vδ2 T cells, significantly increased/sustained numbers of circulating CD4⁺ Th1 and CD8⁺ Th1-like effector populations, with some γδ T- or αβ T-effector populations trafficking to airway at week 3 until week 19 or 21 after MDR-TB infection. Adjunctive ZOL/IL-2 administrations after MDR-TB infection led to lower bacterial burdens in lungs than TB drugs alone, IL-2 alone or saline controls, and resulted in milder MDR-TB pathology/lesions. Thus, adjunctive Zoledronate + IL-2 administrations can enhance anti-TB Vγ2Vδ2 T- and αβ T-effector populations, and improve treatment outcome of MDR-TB.

TB-PRACTECAL: study protocol for a randomised, controlled, open-label, phase II-III trial to evaluate the safety and efficacy of regimens containing bedaquiline and pretomanid for the treatment of adult patients with pulmonary multidrug-resistant tuberculosis

BACKGROUND

Globally rifampicin-resistant tuberculosis disease affects around 460,000 people each year. Currently recommended regimens are 9-24 months duration, have poor efficacy and carry significant toxicity. A shorter, less toxic and more efficacious regimen would improve outcomes for people with rifampicin-resistant tuberculosis.

METHODS

TB-PRACTECAL is an open-label, randomised, controlled, phase II/III non-inferiority trial evaluating the safety and efficacy of 24-week regimens containing bedaquiline and pretomanid to treat rifampicin-resistant tuberculosis. Conducted in Uzbekistan, South Africa and Belarus, patients aged 15 and above with rifampicin-resistant pulmonary tuberculosis and requiring a new course of therapy were eligible for inclusion irrespective of HIV status. In the first stage, equivalent to a phase IIB trial, patients were randomly assigned one of four regimens, stratified by site. Investigational regimens include oral bedaquiline, pretomanid and linezolid. Additionally, two of the regimens also included moxifloxacin (arm 1) and clofazimine (arm 2) respectively. Treatment was administered under direct observation for 24 weeks in investigational arms and 36 to 96 weeks in the standard of care arm. The second stage of the study was equivalent to a phase III trial, investigating the safety and efficacy of the most promising regimen/s. The primary outcome was the percentage of unfavourable outcomes at 72 weeks post-randomisation. This was a composite of early treatment discontinuation, treatment failure, recurrence, lost-to-follow-up and death. The study is being conducted in accordance with ICH-GCP and full ethical approval was obtained from Médecins sans Frontières ethical review board, London School of Hygiene and Tropical Medicine ethical review board as well as ERBs and regulatory authorities at each site.

DISCUSSION

TB-PRACTECAL is an ambitious trial using adaptive design to accelerate regimen assessment and bring novel treatments that are effective and safe to patients quicker. The trial took a patient-centred approach, adapting to best practice guidelines throughout recruitment. The implementation faced significant challenges from the COVID-19 pandemic. The trial was terminated early for efficacy on the advice of the DSMB and will report on data collected up to the end of recruitment and, additionally, the planned final analysis at 72 weeks after the end of recruitment.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02589782. Registered on 28 October 2015.

A case of primary multidrug-resistant pulmonary tuberculosis with high minimum inhibitory concentration value for bedaquiline

Bedaquiline is a new ATP synthesis inhibitor developed as an anti-tuberculosis agent. It has resistance-associated variants (RAV), regardless of preceding bedaquiline exposure. Herein, we describe the case of a patient with multidrug-resistant tuberculosis (MDR-TB) who had no history of bedaquiline therapy but presented a relatively high minimum inhibitory concentration (MIC) of bedaquiline (1 μg/mL). Whole genome sequencing revealed a mutation in the resistance-associated gene Rv0678. The patient was first treated with a five-drug regimen (bedaquiline, delamanid, levofloxacin, cycloserine, and amikacin), which induced negative sputum culture conversion. Despite the successful treatment outcome, several questions remain regarding the efficacy of bedaquiline in this patient. Bedaquiline is an indispensable drug for MDR-TB treatment, but its clinical efficiency in the presence of Rv0678 mutations remains unclear. Therefore, evaluating the MIC of bedaquiline even in patients without a history of bedaquiline use is important for therapeutic regimen selection and may emphasize the importance of therapeutic drug monitoring in cases of bedaquiline RAV.

Intra-urban variation in tuberculosis and community socioeconomic deprivation in Lisbon metropolitan area: a Bayesian approach

Background

Multidrug resistant tuberculosis (MDR-TB) is a recognized threat to global efforts to TB control and remains a priority of the National Tuberculosis Programs. Additionally, social determinants and socioeconomic deprivation have since long been associated with worse health and perceived as important risk factors for TB. This study aimed to analyze the spatial distribution of non-MDR-TB and MDR-TB across parishes of the Lisbon metropolitan area of Portugal and to estimate the association between non-MDR-TB and MDR-TB and socioeconomic deprivation.

Methods

In this study, we used hierarchical Bayesian spatial models to analyze the spatial distribution of notification of non-MDR-TB and MDR-TB cases for the period from 2000 to 2016 across 127 parishes of the seven municipalities of the Lisbon metropolitan area (Almada, Amadora, Lisboa, Loures, Odivelas, Oeiras, Sintra), using the Portuguese TB Surveillance System (SVIG-TB). In order to characterise the populations, we used the European Deprivation Index for Portugal (EDI-PT) as an indicator of poverty and estimated the association between non-MDR-TB and MDR-TB and socioeconomic deprivation.

Results

The notification rates per 10,000 population of non-MDR TB ranged from 18.95 to 217.49 notifications and that of MDR TB ranged from 0.83 to 3.70. We identified 54 high-risk areas for non-MDR-TB and 13 high-risk areas for MDR-TB. Parishes in the third [relative risk (RR) = 1.281, 95% credible interval (CrI): 1.021–1.606], fourth (RR = 1.786, 95% CrI: 1.420–2.241) and fifth (RR = 1.935, 95% CrI: 1.536–2.438) quintile of socioeconomic deprivation presented higher non-MDR-TB notifications rates. Parishes in the fourth (RR = 2.246, 95% CrI: 1.374–3.684) and fifth (RR = 1.828, 95% CrI: 1.049–3.155) quintile of socioeconomic deprivation also presented higher MDR-TB notifications rates.

Conclusions

We demonstrated significant heterogeneity in the spatial distribution of both non-MDR-TB and MDR-TB at the parish level and we found that socioeconomically disadvantaged parishes are disproportionally affected by both non-MDR-TB and MDR-TB. Our findings suggest that the emergence of MDR-TB and transmission are specific from each location and often different from the non-MDR-TB settings. We identified priority areas for intervention for a more efficient plan of control and prevention of non-MDR-TB and MDR-TB.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-00949-1.

Screening and identification of differentially expressed long non-coding RNAs in multidrug-resistant tuberculosis

BACKGROUND

Efforts to eradicate tuberculosis are largely threatened by drug-resistant tuberculosis, particularly, multidrug-resistant tuberculosis (MDR-TB). Screening and identification potential biomarkers for MDR-TB is crucial to diagnose early and reduce the incidence of MDR-TB.

METHODS

To screen the differentially expressed long non-coding RNAs in MDR-TB, the lncRNA and mRNA expression profiles in serum derived from healthy controls (HCs), individuals with MDR-TB and drug-sensitive tuberculosis (DS-TB) were analyzed by microarray assay and 10 lncRNAs were randomly selected for further validation by reverse transcription-quantitative real-time PCR(RT-qPCR). The biological functions of differentially expressed mRNAs as well as relationships between genes and signaling pathways were investigated using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG), respectively.

RESULTS

A total of 353 differentially expressed lncRNAs (312 upregulated) and 202 mRNAs (99 upregulated) were found in the MDR-TB group compared to HCs. And compared with the DS-TB group, 442 differentially expressed lncRNAs (115 upregulated) and 190 mRNAs (87 upregulated) were found in the MDR-TB group. The expression levels of lncRNA n335659 were found to differ significantly between each group by RT-qPCR. Compared with DS-TB group, the GO analysis showed that the differential mRNAs were mainly enriched in the processes associated with the detection of the chemical stimulus, the regulation of mRNA metabolic process and neutrophil activation in the MDR-TB group; the KEGG analysis indicated that the differential mRNAs between DS-TB and MDR-TB were mainly enriched in proteasome and Notch signaling pathway, which might reveal a fraction of the mechanism of MDR-TB. The discovery of the serum lncRNA n335659 might serve as a potential biomarker for MDR-TB and Notch signaling pathway provided a new clue for the investigation of the pathological mechanism of MDR-TB.

Combining LAMP and Au-Nanoprobe to detect INH-RIF resistance accurately in tuberculosis: an evidence-based review

Approximately 1.41 million people die annually due to tuberculosis. One of the main problems in Tuberculosis eradication is the development of resistance to various antibiotics. However, current efforts to detect resistances face challenges such as limited equipment, budget, and time. This evidence-based review investigated loop-mediated isothermal amplification, an alternative molecular diagnostic tool with promising performance and applicability in developing countries, and its use combined with Au-Nanoprobe to detect antibiotic resistance in tuberculosis. The literature search was conducted through four databases (Proquest, EBSCOhost, Scopus, and Pubmed) for useful articles on loop-mediated isothermal amplification and Au-Nanoprobe in detecting tuberculosis and tuberculosis resistance. After filtering the result with inclusion and exclusion criteria, the search produced three papers that best answer the clinical question. Loop-mediated isothermal amplification amplifies a target sequence, and Au-Nanoprobe responds to the DNA specific to the target mutant, producing an observable color change. Loop-mediated isothermal amplification and Au-Nanoprobe showed 100% sensitivity and specificity in detecting rifampicin and isoniazid resistance. Another study investigated its viability to detect tuberculosis and found 98.2% sensitivity and 88.2% specificity. Combining loop-mediated isothermal amplification and Au-Nanoprobe had a shorter time to get results and should also be relatively cheaper because it does not need a high temperature to work and requires less equipment. In conclusion, loop-mediated isothermal amplification and Au-Nanoprobe can be used as an efficient and accurate method to detect isoniazid and rifampicin-resistant tuberculosis strains. The new technology is promising for developing countries due to their high disease burden but facing several healthcare barriers.

Transmission of multidrug-resistant tuberculosis in Shimen community in Shanghai, China: a molecular epidemiology study

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) has become a major public health problem in China, with mounting evidence suggesting that recent transmission accounts for the majority of MDR-TB. Here we aimed to reveal the transmission pattern of an MDR-TB outbreak in the Jing'an District of Shanghai between 2010 and 2015.

METHODS

We used whole-genome sequencing (WGS) to conduct genomic clustering analysis along with field epidemiological investigation to determine the transmission pattern and drug resistance profile of a cluster with ten MDR-TB patients in combining field epidemiological investigation.

RESULTS

The ten MDR-TB patients with genotypically clustered Beijing lineage strains lived in a densely populated, old alley with direct or indirect contact history. The analysis of genomic data showed that the genetic distances of the ten strains (excluding drug-resistant mutations) were 0-20 single nucleotide polymorphisms (SNPs), with an average distance of 9 SNPs, suggesting that the ten MDR-TB patients were infected and developed the onset of illness by the recent transmission of M. tuberculosis. The genetic analysis confirmed definite epidemiological links between the clustered cases.

CONCLUSIONS

The integration of the genotyping tool in routine tuberculosis surveillance can play a substantial role in the detection of MDR-TB transmission events. The leverage of genomic analysis in combination with the epidemiological investigation could further elucidate transmission patterns. Whole-genome sequencing could be integrated into intensive case-finding strategies to identify missed cases of MDR-TB and strengthen efforts to interrupt transmission.

Causes of multidrug-resistant tuberculosis from the perspectives of health providers: challenges and strategies for adherence to treatment during the COVID-19 pandemic in Brazil

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) is a serious phenomenon on a global scale that can worsen with the COVID-19 pandemic. The study aimed to understand the perceptions of health professionals about MDR-TB, their strategies to ensure adherence to treatment and their challenges in the context of the COVID-19 pandemic in a priority municipality for disease control.

METHODS

We conducted a qualitative study and recruited 14 health providers (four doctors, three nurses, three nursing technicians, three nursing assistants and a social worker) working in a city in the state of São Paulo, Brazil. Remote semi-structured interviews were conducted with the participants. For data analysis, the thematic content analysis technique was applied according to the study's theoretical framework.

RESULTS

The study revealed the causes of MDR-TB are associated with poverty, vulnerability, and social risk. A pre-judgement from the providers was observed, namely, all patients do not adhere due their resistance and association with drug abuse or alcoholism. The study also observed difficulty among health providers in helping patients reconstruct and reframe their life projects under a care perspective, which would strengthen adherence. Other issues that weakened adherence were the cuts in social protection and the benefits really necessary to the patients and a challenge for the providers manage that. The participants revealed that their actions were impacted by the pandemic and insecurity and fear manifested by patients after acquiring COVID-19. For alleviating this, medical appointments by telephone, delivery of medicine in the homes of patients and visits by health professionals once per week were provided.

CONCLUSION

The study advances knowledge by highlighting the challenges faced by the health system with the adherence of patients with MDR-TB in a context aggravated by the pandemic. An improvement in DOT is really necessary to help the patients reframe their lives without prejudices, face their fears and insecurity, recover their self-esteem and motivate in concluding their treatment.