Extrapulmonary drug-resistant tuberculosis at a drug-resistant tuberculosis center, Mumbai: Our experience - Hope in the midst of despair!

Utilization of Truenat chips in defining XDR, pre-XDR and MDR in tuberculous meningitis

SETTING AND OBJECTIVE

To develop and evaluate newer molecular tests that identify drug resistance according to contemporary definitions in Tuberculous meningitis (TBM), the most severe form of EPTB.

DESIGN

93 cerebrospinal fluid (CSF) specimens [41 culture-positive and 52 culture-negative], were subjected to Truenat MTB Plus assay along with chips for rifampicin, isoniazid, fluoroquinolones and bedaquiline resistance. The performance was compared against phenotypic drug susceptibility testing (pDST), Line probe assay (LPA) and gene sequencing.

RESULTS

Against pDST, Truenat chips had a sensitivity and specificity of 100%; 94.47%, 100%; 94.47%, 100%; 97.14% and 100%; 100%, respectively for rifampicin, isoniazid, fluoroquinolones and bedaquiline. Against LPA, all Truenat chips detected resistant isolates with 100% sensitivity; but 2 cases each of false-rifampicin and false-isoniazid resistance and 1 case of false-fluoroquinolone resistance was reported. Truenat drug chips gave indeterminate results in ∼25% cases, which were excluded. All cases reported indeterminate were found to be susceptible by pDST/LPA.

CONCLUSION

The strategic drug resistance chips of Truenat Plus assay can contribute greatly to TB elimination by providing rapid and reliable detection of drug resistance pattern in TBM. Cases reported indeterminate require confirmation by other phenotypic and genotypic methods.

Concomitant bedaquiline and delamanid therapy in patients with drug-resistant extra-pulmonary tuberculosis in Mumbai, India

Background

World Health Organization suggests concurrent bedaquiline-delamanid (BDQ-DLM) as part of individualised regimens for eligible patients with pulmonary drug-resistant tuberculosis (DR-TB); however, data for patients with drug-resistant extrapulmonary tuberculosis (EPTB) is extremely limited. This study documents the treatment outcomes and adverse events associated with concurrent BDQ-DLM-based regimens in patients with drug-resistant EPTB at a Médecins Sans Frontières clinic in Mumbai, India.

Methods

Retrospective cohort study based on routinely collected programmatic data. Individualised regimens were based on drug-susceptibility testing and previous drug exposure. Drug-resistant EPTB patients initiated on regimens containing concurrent BDQ and DLM from April 2016 to October 2019 were included. Patients who completed treatment were followed up at 12 months.

Results

Of 17 patients, median age was 23 years (IQR = 21-30 years) and 12/17 (71 %) were female. Pre-extensively drug-resistant tuberculosis and extensively drug-resistant TB was reported in 13/17 (76.4 %) and 2/17 (11.7 %) patients respectively. Microbiological reports were unavailable for two patients with central nervous system TB. Lymph node TB was the commonest form of EPTB in 9/17 (53 %) of patients. Median duration of treatment was 18.9 months. At least one grade three or four severe adverse event (SAE) was reported by 13/17 (76.4 %) patients. Thirteen (76.4 %) patients had favourable outcomes. None of the patients relapsed or died in the one-year period of post-treatment follow-up.

Conclusion

Concurrent BDQ-DLM-based regimens in drug-resistant EPTB were effective and associated with manageable adverse events.

Pediatric Multidrug-Resistant Disseminated Tuberculosis Presenting as Small Finger Tuberculous Osteomyelitis: A Case Report

CASE

We report a case in the United States of a 12-year-old girl with multidrug-resistant tuberculous (MDR-TB) osteomyelitis of the hand managed with surgical debridement and second-line anti-TB therapy. The disease course was complicated by dissemination and multifocal progression.

CONCLUSION

Despite early intervention, multidrug resistance makes TB treatment challenging and facilitated progression to disseminated disease in this case. We review the difficulties in diagnosis and treatment of pediatric MDR-TB.

Clinical features, resistance patterns and treatment outcomes of drug-resistant extra-pulmonary tuberculosis: A scoping review

Background

Drug-resistant tuberculosis (DR-TB) is a threat to tuberculosis (TB) control. Extra-pulmonary forms of DR-TB (DR-epTB) are not well characterized. This review summarizes the clinical features, resistance patterns and treatment outcomes of DR-epTB.

Methods

We searched EMBASE to identify studies that reported drug-resistance among extra-pulmonary TB sites. All age groups were included in this review. Studies which did not describe drug-resistance patterns at extra-pulmonary TB sites were excluded. We summarized the proportion of resistance to individual anti-TB drugs as well as multi-drug resistant (MDR), pre-extensively drug resistant (pre-XDR) and extensively drug-resistant (XDR) TB.

Results

Eighteen studies with a total of 10,222 patients with extra-pulmonary TB of whom 1,236 (12.0%) had DR-epTB, were included in this review. DR-epTB was mostly reported in young people aged 28 to 46 years. While TB meningitis is the most commonly studied form, adenitis is the commonest form of DR-epTB reported in 21% to 47%. Central nervous system TB (3.8% to 51.6%), pleural TB (11.3% to 25.9%), skeletal TB (9.4% to 18.1%), abdominal TB (4.3% to 6.5%), and disseminated TB (3.8%) are also encountered. The HIV co-infection rate is reported to be 5.0% to 81.3% while 2.6% to 25.4 % have diabetes mellitus. Clinical symptoms of DR-epTB are consistent with morbidity in the affected body system. Among patients with DR-epTB, the proportion of MDR TB was 5% to 53% while that for pre-XDR TB and XDR TB was 3% to 40% and 4% to 33%, respectively. Treatment success is achieved in 26% to 83% of patients with DR-epTB while death, treatment loss-to-follow up, and treatment failure occur in 2% to 76%, 7% to 15%, and 0% to 4% respectively. Patients with DR-epTB were reported to have poorer outcomes than those with pulmonary DR-TB and extra-pulmonary drug-susceptible TB.

Conclusion

Clinical features of DR-epTB are similar to those observed among people with drug-susceptible EPTB but patients with DR-epTB post worse treatment outcomes.

Distribution of common and rare drug resistance patterns in Mycobacterium tuberculosis clinical isolates revealed by GenoType MTBDRplus and MTBDRsl assay

Background

Tuberculosis (TB) remains a significant global health emergency caused by Mycobacterium tuberculosis (Mtb). The epidemiology, transmission, genotypes, mutational patterns, and clinical consequences of TB have been extensively studied worldwide, however, there is a lack of information regarding the epidemiology and mutational patterns of Mtb in Pakistan, specifically concerning the prevalence of multi-drug resistant TB (MDR-TB).

Methods

This study aimed to investigate the incidence of Mtb and associated mutational patterns using the line probe assay (LPA). Previous studies have reported a high frequency of mutations in the rpoB, inhA, and katG genes, which are associated with resistance to rifampicin (RIF) and isoniazid (INH). Therefore, the current study utilized LPA to detect mutations in the rpoB, katG, and inhA genes to identify multi-drug resistant Mtb.

Results

LPA analysis of a large pool of Mtb isolates, including samples from 241 sputum-positive patients, revealed that 34.85% of isolates were identified as MDR-TB, consistent with reports from various regions worldwide. The most prevalent mutations observed were rpoB S531L and inhA promoter C15T, which were associated with resistance to RIF and INH, respectively.

Conclusions

This study highlights the effectiveness of GenoType MTBDRplus and MTBDRsl assays as valuable tools for TB management. These assays enable rapid detection of resistance to RIF, INH, and fluoroquinolones (FQs) in Mtb clinical isolates, surpassing the limitations of solid and liquid media-based methods. The findings contribute to our understanding of MDR-TB epidemiology and provide insights into the genetic profiles of Mtb in Pakistan, which are essential for effective TB control strategies.

Case Report: Ocular Tissue Diagnosis of Previously Undiagnosed, Extensively Drug-Resistant Pulmonary Tuberculosis

We describe a patient with concurrent ocular and pulmonary tuberculosis (TB) in whom the diagnosis of extensively drug-resistant TB was made through phenotypic drug-sensitivity testing of an ocular fluid sample after sputum testing yielded incomplete results. Our results are remarkable, because culture-based diagnosis of TB in ocular fluid is unusual. We not only overcame this limitation, but also were able to create a complete drug-sensitivity testing profile from ocular samples, which led to effecting appropriate therapy for the patient.

Adapting Clofazimine for Treatment of Cutaneous Tuberculosis by Using Self-Double-Emulsifying Drug Delivery Systems

Although chemotherapeutic treatment regimens are currently available, and considerable effort has been lavished on the development of new drugs for the treatment of tuberculosis (TB), the disease remains deeply intractable and widespread. This is due not only to the nature of the life cycle and extraordinarily disseminated habitat of the causative pathogen, principally Mycobacterium tuberculosis (Mtb), in humans and the multi-drug resistance of Mtb to current drugs, but especially also to the difficulty of enabling universal treatment of individuals, immunocompromised or otherwise, in widely differing socio-economic environments. For the purpose of globally eliminating TB by 2035, the World Health Organization (WHO) introduced the "End-TB" initiative by employing interventions focusing on high impact, integrated and patient-centered approaches, such as individualized therapy. However, the extraordinary shortfall in stipulated aims, for example in actual treatment and in TB preventative treatments during the period 2018-2022, latterly and greatly exacerbated by the COVID-19 pandemic, means that even greater pressure is now placed on enhancing our scientific understanding of the disease, repurposing or repositioning old drugs and developing new drugs as well as evolving innovative treatment methods. In the specific context of multidrug resistant Mtb, it is furthermore noted that the incidence of extra-pulmonary TB (EPTB) has significantly increased. This review focusses on the potential of utilizing self-double-emulsifying drug delivery systems (SDEDDSs) as topical drug delivery systems for the dermal route of administration to aid in treatment of cutaneous TB (CTB) and other mycobacterial infections as a prelude to evaluating related systems for more effective treatment of CTB and other mycobacterial infections at large. As a starting point, we consider here the possibility of adapting the highly lipophilic riminophenazine clofazimine, with its potential for treatment of multi-drug resistant TB, for this purpose. Additionally, recently reported synergism achieved by adding clofazimine to first-line TB regimens signifies the need to consider clofazimine. Thus, the biological effects and pharmacology of clofazimine are reviewed. The potential of plant-based oils acting as emulsifiers, skin penetration enhancers as well as these materials behaving as anti-microbial components for transporting the incorporated drug are also discussed.

Agreement between CBNAAT, liquid culture and line probe assay for detection of Mycobacterium tuberculosis and anti-tubercular drug resistance in extrapulmonary samples

PURPOSE

Cartridge based nucleic acid amplification test (CBNAAT) has been endorsed by the WHO as the screening test for diagnosing extrapulmonary tuberculosis (EPTB). In the present study we report the agreement between CBNAAT (Xpert MTB/RIF), liquid culture (LC) and line probe assay (LPA) for diagnosis of Mycobacterium tuberculosis and detection of drug resistance among EPTB cases.

METHODS

The EP samples were subjected to CBNAAT (Xpert MTB/RIF, Cepheid, USA) and wherever possible, to LC (MGIT 960, Becton Dickinson, USA) followed sequentially by first line and second line-LPA (FL-LPA, SL-LPA, Hain Lifescience, Germany) on the isolates.

RESULTS

Total 566/4080 (13.9%) EP samples were detected positive for M. tuberculosis on CBNAAT. Aspirates from lymph nodes were most often positive (11/30; 36.6%), followed by pus (240/873; 27.5%) and CSF samples (166/104; 15.8%). The detection of M. tuberculosis was more in adults than children except in tissue biopsy samples. Rifampicin resistance was also higher among adults except CSF in which resistance was more in children. Total 185 of 566 (32.7%) CBNAAT positive and 770 of 3510 (21.9%) CBNAAT negative samples could be cultured of which 110/185 (59.4%) and 33/770 (4.3%) respectively turned positive. FL-LPA and SL-LPA of 143 culture isolates showed that 27 isolates had drug resistance, of which 3 (2.1%) were XDR, 11 (7.7%) were Pre-XDR (FQ) and 13 (9.1%) were MDR. Of these 27 resistant isolates, 12 were negative by CBNAAT and two were mislabeled as Rifampicin sensitive or indeterminate based on the unique RpoB gene mutation patterns on LPA. The positive and negative agreements between LC and CBNAAT for detection of M. tuberculosis were 67.1% and 92.7% respectively and between LPA and CBNAAT for rifampicin resistance detection were 98.9% and 92.9% respectively.

CONCLUSIONS

For EPTB, CBNAAT should be accompanied with LC wherever possible irrespective of the CBNAAT result.

Extrapulmonary Tuberculosis—An Update on the Diagnosis, Treatment and Drug Resistance

Pathogenic Mycobacterium tuberculosis complex organisms (MTBC) primarily cause pulmonary tuberculosis (PTB); however, MTBC are also capable of causing disease in extrapulmonary (EP) organs, which pose a significant threat to human health worldwide. Extrapulmonary tuberculosis (EPTB) accounts for about 20–30% of all active TB cases and affects mainly children and adults with compromised immune systems. EPTB can occur through hematogenous, lymphatic, or localized bacillary dissemination from a primary source, such as PTB, and affects the brain, eye, mouth, tongue, lymph nodes of neck, spine, bones, muscles, skin, pleura, pericardium, gastrointestinal, peritoneum, and the genitourinary system as primary and/or disseminated disease. EPTB diagnosis involves clinical, radiological, microbiological, histopathological, biochemical/immunological, and molecular methods. However, only culture and molecular techniques are considered confirmatory to differentiate MTBC from any non-tuberculous mycobacteria (NTM) species. While EPTB due to MTBC responds to first-line anti-TB drugs (ATD), drug susceptibility profiling is an essential criterion for addressing drug-resistant EPTB cases (DR-EPTB). Besides antibiotics, adjuvant therapy with corticosteroids has also been used to treat specific EPTB cases. Occasionally, surgical intervention is recommended, mainly when organ damage is debilitating to the patient. Recent epidemiological studies show a striking increase in DR-EPTB cases ranging from 10–15% across various reports. As a neglected disease, significant developments in rapid and accurate diagnosis and better therapeutic interventions are urgently needed to control the emerging EPTB situation globally. In this review, we discuss the recent advances in the clinical diagnosis, treatment, and drug resistance of EPTB.

Drug-Resistant Tuberculosis Presenting as a Testicular Mass: A Case Report

Background

Extrapulmonary drug-resistant tuberculosis is extremely rare and is almost always associated with poor treatment outcomes. This is partly due to the difficulty in confirming the diagnosis.

Case Presentation

A 40-year-old HIV-negative male presented with a painless scrotal mass, low-grade fever, general malaise, night sweats, and no pulmonary symptoms. He was initially treated for malaria with no improvement. His final diagnosis was rifampicin-resistant tuberculosis following Xpert^® MTB/RIF Ultra (Xpert-Ultra) assay performed on a fine needle aspirate of the scrotal mass. Second-line anti-tuberculosis medication was initiated, and the patient is being followed up with directly observed therapy.

Conclusion

With the scale-up of Gene-Xpert technology, this case raises awareness about tuberculosis masquerading as a testicular mass and the possibility of extrapulmonary drug-resistant tuberculosis in high endemic areas.

Molecular characterization and drug resistance patterns of Mycobacterium tuberculosis complex in extrapulmonary tuberculosis patients in Addis Ababa, Ethiopia

Background

Molecular characterization of Mycobacterium tuberculosis (MTB) is important to understand the pathogenesis, diagnosis, treatment, and prevention of tuberculosis (TB). However, there is limited information on molecular characteristics and drug-resistant patterns of MTB in patients with extra-pulmonary tuberculosis (EPTB) in Ethiopia. Thus, this study aimed to determine the molecular characteristics and drug resistance patterns of MTB in patients with EPTB in Addis Ababa, Ethiopia.

Methods

This study was conducted on frozen stored isolates of EPTB survey conducted in Addis Ababa, Ethiopia. A drug susceptibility test was performed using BACTEC-MGIT 960. Species and strain identification were performed using the Geno-Type MTBC and spoligotyping technique, respectively. Data were entered into the MIRU-VNTRplus database to assess the spoligotype patterns of MTB. Analysis was performed using SPSS version 23, and participants’ characteristics were presented by numbers and proportions.

Results

Of 151 MTB isolates, 29 (19.2%) were resistant to at least one drug. The highest proportion of isolates was resistant to Isoniazid (14.6%) and Pyrazinamide (14.6%). Nine percent of isolates had multidrug-resistant TB (MDR-TB), and 21.4% of them had pre-extensively drug-resistant TB (pre-XDR-TB). Among the 151 MTB isolates characterized by spoligotyping, 142 (94.6%) had known patterns, while 9 (6.0%) isolates were not matched with the MIRU-VNTRplus spoligotype database. Of the isolates which had known patterns, 2% was M.bovis while 98% M. tuberculosis. Forty-one different spoligotype patterns were identified. The most frequently identified SpolDB4 (SIT) wereSIT149 (21.2%), SIT53 (14.6%) and SIT26 (9.6%). The predominant genotypes identified were T (53.6%), Central Asia Strain (19.2%) and Haarlem (9.9%).

Conclusion

The present study showed a high proportion of MDR-TB and pre-XDR-TB among EPTB patients. The strains were mostly grouped into SIT149, SIT53, and SIT26. The T family lineage was the most prevalent genotype. MDR-TB and pre-XDR-TB prevention is required to combat these strains in EPTB. A large scale study is required to describe the molecular characteristics and drug resistance patterns of MTB isolates in EPTB patients.

Does Drug-Resistant Extrapulmonary Tuberculosis Hinder TB Elimination Plans? A Case from Delhi, India

Extrapulmonary drug-resistant tuberculosis (DR-EPTB) poses a formidable diagnostic and therapeutic challenge.Besides associated with high morbidity, it is a major financial burden for the patient and the health system. In spite of this, it has often been neglected as it does not “pose” a visible public health threat. We study clinical profiles, treatment outcomes, and factors associated with unfavourable outcomes among DR-EPTB patients under programmatic settings in New Delhi, India, and evaluate how this could impact TB elimination. A retrospective analysis of all DR-EPTB patients registered at three nodal DR-TB centres in Delhi in 2016 was carried out. Of the 1261 DR-TB patients registered, 203 (16%) were DR-EPTB, with lymph nodes (118, 58%) being the most common site, followed by bone (69, 34%). Nearly 29% (n = 58) experienced adverse drug reactions with severe vomiting (26, 13 %), joint pain (21, 10%) and behavioral disorder (15, 7%). History of previous TB treatment was observed in a majority of the cases (87.7%). Nearly one-third of DR-EPTB cases (33%) had unfavourable treatment outcomes, with loss-to-follow-up (n = 40, 58%) or death (n = 14, 20%) being the most common unfavourable outcomes. In the adjusted analysis, weight band 31–50 kilograms (aRR = 1.8, 1.2–3.4) and h/o previous TB (aRR = 2.1, 1.1–4.8) were mainly associated with unfavourable outcomes. TB elimination efforts need to focus on all forms of TB, including DR-EPTB, leaving no one behind, in order to realise the dream of ending TB.

Fluoroquinolone resistance and mutational profile of gyrA in pulmonary MDR tuberculosis patients

BACKGROUND

Fluoroquinolones (FQs) are potential drugs that inhibit DNA synthesis and are used in the treatment of multidrug-resistant tuberculosis (TB) and short-term anti-TB regimens. In recent years, a high proportion of FQ resistance has been observed in Mycobacterium tuberculosis isolates. The development of FQ resistance in multidrug-resistant TB negatively impacts patient treatment outcome and is a serious threat to control of TB.

METHODS

The study included a total of 562 samples from patients with pulmonary TB that had been on anti-tuberculosis therapy. MTBDRsl assays were performed for the molecular detection of mutations. Sequence analysis was performed for the characterization and mutational profiling of FQ-resistant isolates.

RESULTS

FQ resistance was observed in 104 samples (18.5%), most of which were previously treated and treatment failure cases. A total of 102 isolates had mutations in DNA gyrase subunit A (gyrA), while mutations in gyrB were observed in only two isolates. Mutational analysis revealed that the mutations mostly alter codons 94 (replacing aspartic acid with glycine, D94G) and 90 (replacing alanine with valine, A90V). In MDR and treatment failure cases, resistance to FQs was most commonly associated with the D94G mutation. In contract, a high proportion of A90V mutations were observed in isolates that were newly diagnosed.

CONCLUSION

The findings suggest that genotypic assays for FQ resistance should be carried out at the time of initial diagnosis, before starting treatment, in order to rule out mutations that impact the potential use of FQs in treatment and to control drug resistance.

Multidrug resistance in tubercular mediastinal adenopathy diagnosed by endobronchial ultrasound-transbronchial needle aspiration

Background

Drug resistance in tuberculosis (TB) is a major public health problem. It is easy to assess for drug resistance in pulmonary samples, but the resistance pattern of TB in the mediastinal nodes has not been studied. The aim of this study is to assess the incidence of multidrug resistance in tubercular mediastinal adenopathy with the help of endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration.

Materials and Methods

This was a prospective study at a tertiary care teaching hospital in New Delhi where 102 patients with positive mycobacterial cultures from mediastinal lymph node aspirates taken with the help of EBUS were enrolled over 24 months and their drug sensitivity to the first-line antitubercular drugs analyzed.

Results

There were 30 cases of drug resistance of 102 culture-positive cases. Of them, 8 patients had multidrug resistant TB (MDR-TB), 16 cases had only single drug resistance, and the remaining 6 cases had more than one drug resistance pattern but not MDR. In our study, the overall incidence of MDR-TB is 7.8% (8/102), although the incidence of MDR-TB in new and re-treatment cases is 2.2% (2/89) and 46.1% (6/13), respectively.

Conclusion

Such a high percentage of drug-resistant patients is common in tertiary care hospitals; however, similar percentages may be found in other settings as well. Therefore, all efforts should be made to take samples for Mycobacterium tuberculosis culture from the involved nodes before commencing therapy to avoid treatment failures.

Drug-resistant spinal tuberculosis - Current concepts, challenges, and controversies

The alarming global increase in drug-resistant strains plagues the global fight to end tuberculosis (TB), especially in developing countries. The often reported poor treatment outcomes, sequelae, and lack of best practice guidelines in drug-resistant spinal TB poses a significant challenge in its efficient management. While multi-drug chemotherapy is still the primary modality of treatment, surgical intervention is essential in specific scenarios. With limited data on management and outcomes in drug-resistant spinal TB, there is no consensus on the appropriate therapy regarding the number and duration of drugs and therapeutic endpoints of this conundrum. In this light of limited evidence, we have performed a systematic computerized search using the Cochrane Database of Systematic Reviews, Scopus, Embase, Web of Science, and PubMed databases and studies published over the past 30 years on drug-resistance in spinal TB have been analyzed. This systematic review aims to review the current epidemiology, clinical features, updates in clinical diagnostics and chemotherapy, surgical management, and outcomes in drug-resistant spinal TB. We also consolidate potential areas of action and emphasize the need for research and large scale trials in the management of drug-resistant spinal TB.

Such a long journey: What health seeking pathways of patients with drug resistant tuberculosis in Mumbai tell us

INTRODUCTION

The Indian Tuberculosis (TB) Programme currently faces the dual challenges of tackling increasing numbers of drug resistant (DR) TB cases and regulating practices of a pluralistic private sector catering to TB patients. A study of health seeking behaviour of DR-TB patients in such a situation, offers an opportunity to understand the problems patients face while interacting with health systems.

METHODOLOGY

Forty-six DR-TB patients drawn from 15 high TB burden wards in Mumbai were interviewed using an open ended interview tool. Interviews were audio recorded and transcribed. Pathway schematics developed from analysis of patient records, were linked to transcripts. Open coding was used to analyse these units and themes were derived after collating the codes.

RESULTS AND DISCUSSION

The paper presents themes interwoven with narratives in the discussions. These include awareness-action gap among patients, role of neighbourhood providers, responsiveness of health systems, the not-such a 'merry go round' that patients go/are made to go on while seeking care, costs of diagnostics and treatment, and how DR-TB is viewed as the 'big TB'.

CONCLUSION

The recommendations are based on a preventative ethos which is sustainable, compared to interventions with top-down approaches, which get piloted, but fail to sustain impact when scaled up.