Clofazimine: A journey of a drug.

Among different strategies to develop novel therapies, drug repositioning (aka repurposing) aims at identifying new uses of an already approved or investigational drug. This approach has the advantages of availability of the extensive pre-existing knowledge of the drug's safety, pharmacology and toxicology, manufacturing and formulation. It provides advantages to the risk-versus-rewards trade-off as compared to the costly and time-consuming de novo drug discovery process. Clofazimine, a red-colored synthetic derivative of riminophenazines initially isolated from lichens, was first synthesized in the 1950 s, and passed through several phases of repositioning in its history as a drug. Being initially developed as an anti-tuberculosis treatment, it was repurposed for the treatment of leprosy, prior to re-repositioning for the treatment of multidrug-resistant tuberculosis and other infections. Since 1990 s, reports on the anticancer properties of clofazimine, both in vitro and in vivo, started to appear. Among the diverse mechanisms of action proposed, the activity of clofazimine as a specific inhibitor of the oncogenic Wnt signaling pathway has recently emerged as the promising targeting mechanism of the drug against breast, colon, liver, and other forms of cancer. Seventy years after the initial discovery, clofazimine's journey as a drug finding new applications continues, serving as a colorful illustration of drug repurposing in modern pharmacology.

Cocrystallizing and Codelivering Complementary Drugs to Multidrugresistant Tuberculosis Bacteria in Perfecting Multidrug Therapy.

Bacteria cells exhibit multidrug resistance in one of two ways: by raising the genetic expression of multidrug efflux pumps or by accumulating several drug-resistant components in many genes. Multidrug-resistive tuberculosis bacteria are treated by multidrug therapy, where a few certain antibacterial drugs are administered together to kill a bacterium jointly. A major drawback of conventional multidrug therapy is that the administration never ensures the reaching of different drug molecules to a particular bacterium cell at the same time, which promotes growing drug resistivity step-wise. As a result, it enhances the treatment time. With additional tabletability and plasticity, the formation of a cocrystal of multidrug can ensure administrating the multidrug chemically together to a target bacterium cell. With properly maintaining the basic philosophy of multidrug therapy here, the synergistic effects of drug molecules can ensure killing the bacteria, even before getting the option to raise the drug resistance against them. This can minimize the treatment span, expenditure and drug resistance. A potential threat of epidemic from tuberculosis has appeared after the Covid-19 outbreak. An unwanted loop of finding molecules with the potential to kill tuberculosis, getting their corresponding drug approvals, and abandoning the drug after facing drug resistance can be suppressed here. This perspective aims to develop the universal drug regimen by postulating the principles of drug molecule selection, cocrystallization, and subsequent harmonisation within a short period to address multidrug-resistant bacteria.

Shorter regimens improved treatment outcomes of multidrug-resistant tuberculosis patients in Tanzania in 2018 cohort.

OBJECTIVE: In 2018, shorter treatment regimens (STR) for people with drug-resistant tuberculosis (DR-TB) were introduced in Tanzania and included kanamycin, high-dose moxifloxacin, prothionamide, high-dose isoniazid, clofazimine, ethambutol and pyrazinamide. We describe treatment outcomes of people diagnosed with DR-TB in a cohort initiating treatment in 2018 in Tanzania. METHODS: This was a retrospective cohort study conducted at the National Centre of Excellence and decentralised DR-TB treatment sites for the 2018 cohort followed from January 2018 to August 2020. We reviewed data from the National Tuberculosis and Leprosy Program DR-TB database to assess clinical and demographic information. The association between different DR-TB regimens and treatment outcome was assessed using logistic regression analysis. Treatment outcomes were described as treatment complete, cure, death, failure or lost to follow-up. A successful treatment outcome was assigned when the patient achieved treatment completion or cure. RESULTS: A total of 449 people were diagnosed with DR-TB of whom 382 had final treatment outcomes: 268 (70%) cured; 36 (9%) treatment completed; 16 (4%) lost to follow-up; 62 (16%) died. There was no treatment failure. The treatment success rate was 79% (304 patients). The 2018 DR-TB treatment cohort was initiated on the following regimens: 140 (46%) received STR, 90 (30%) received the standard longer regimen (SLR), 74 (24%) received a new drug regimen. Normal nutritional status at baseline [adjusted odds ratio (aOR) = 6.57, 95% CI (3.33-12.94), p < 0.001] and the STR [aOR = 2.67, 95% CI (1.38-5.18), p = 0.004] were independently associated with successful DR-TB treatment outcome. CONCLUSION: The majority of DR-TB patients on STR in Tanzania achieved a better treatment outcome than on SLR. The acceptance and implementation of STR at decentralised sites promises greater treatment success. Assessing and improving nutritional status at baseline and introducing new shorter DR-TB treatment regimens may strengthen favourable treatment outcomes.

Implementation of the 'Removed Injectable modified Short-course regimens for EXpert Multidrug Resistant Tuberculosis' (RISE study) in Tanzania: a protocol for a mixed-methods process evaluation.

INTRODUCTION: Tanzania is adapting a shortened injectable-free multidrug resistant tuberculosis (MDR-TB) regimen, comprising new drugs such as bedaquiline and delamanid and repurposed drugs such as clofazimine and linezolid. The regimen is implemented using a pragmatic prospective cohort study within the National TB and Leprosy Programme and is accompanied by a process evaluation. The process evaluation aims to unpack the implementation processes, their outcomes and the moderating factors in order to understand the clinical effectiveness of the regimen. This protocol describes the methods employed in understanding the implementation processes of the new MDR-TB regimen in 15 regions of Tanzania. METHODS: This study adopts a concurrent mixed-methods design. Using multiple data collection tools, we capture information on: implementation outcomes, stakeholder response to the intervention and the influence of contextual factors. Data will be collected from the 22 health facilities categorised as dispensaries, health centres, district hospitals and referral hospitals. Health workers (n=132) and patients (n=220) will fill a structured questionnaire. For each category of health facility, we will conduct five focus group discussions and in-depth interviews (n=45) for health workers. Participant observations (n=9) and review documents (n=22) will be conducted using structured checklists. Data will be collected at two points over a period of 1 year. We will analyse quantitative data using descriptive and inferential statistical methods. Thematic analysis will be used for qualitative data. ETHICS AND DISSEMINATION: This study received ethical approval from National Institute of Medical research (NIMR), Ref. NIMR/HQ/R.8a/Vol.IX/3269 and from the Mbeya Medical Research and Ethics Review Committee, Ref. SZEC-2439/R.A/V.I/38. Our findings are expected to inform the wider implementation of the new MDR-TB regimen as it is rolled out countrywide. Dissemination of findings will be through publications, conferences, workshops and implementation manuals for scaling up MDR-TB treatments.

Telacebec: an investigational antibacterial for the treatment of tuberculosis (TB).

INTRODUCTION: Tuberculosis is an infectious disease that affected more than 50 million people and killed 6.7 million patients in the past 5 years alone. Additionally, rising incidence of treatment resistance threatens the global effort to eradicate this disease. With limited options available, additional novel antibiotics are needed for the treatment of multidrug-resistant tuberculosis (MDR-TB). Telacebec is a first-in-class antibiotic that targets the pathogen's energy metabolism. AREAS COVERED: This paper provides an overview of the recent progress in the development and testing of telacebec. We discuss published clinical data and examine the design and setup of its clinical trials. We also offer insights on the therapeutic potential of telacebec and aspects of which should be evaluated in the future. EXPERT OPINION: The first phase 2a trial showed a correlation between dosage and bacterial load in patient sputum, which should be confirmed using a direct measurement method such as colony-forming unit counting. Its clinical efficacy, favorable pharmacokinetic properties, low arrhythmogenic risk, and activity against MDR-TB strains make telacebec a suitable candidate for further development. Future clinical testing in combination with approved second-line drugs will reveal its full potential against MDR-TB. Considering recent preclinical studies, we also recommend initiating clinical trials for Buruli ulcer and leprosy.

Addressing the drug-resistant tuberculosis challenge through implementing a mixed model of care in Uganda.

Worldwide, Drug-resistant Tuberculosis (DR-TB) remains a big problem; the diagnostic capacity has superseded the clinical management capacity thereby causing ethical challenges. In Sub-Saharan Africa, treatment is either inadequate or lacking and some diagnosed patients are on treatment waiting lists. In Uganda, various health system challenges impeded scale-up of DR-TB care in 2012; only three treatment initiation facilities existed, with only 41 of the estimated 1010 RR-TB/MDR-TB cases enrolled on treatment yet 300 were on the waiting list and there was no DR-TB treatment scale-up plan. To scale up care, the National TB and leprosy Program (NTLP) with partners rolled out a DR-TB mixed model of care. In this paper, we share achievements and outcomes resulting from the implementation of this mixed Model of DR-TB care. Routine NTLP DR-TB program data on treatment initiation site, number of patients enrolled, their demographic characteristics, patient category, disease classification (based on disease site and human immunodeficiency virus (HIV) status), on co-trimoxazole preventive therapy (CPT) and antiretroviral therapy (ART) statuses, culture results, smear results and treatment outcomes (6, 12, and 24 months) from 2012 to 2017 RR-TB/MDR-TB cohorts were collected from all the 15 DR-TB treatment initiation sites and descriptive analysis was done using STATA version 14.2. We presented outcomes as the number of patient backlog cleared, DR-TB initiation sites, RR-TB/DR-TB cumulative patients enrolled, percentage of co-infected patients on the six, twelve interim and 24 months treatment outcomes as per the Uganda NTLP 2016 Programmatic Management of drug-resistant Tuberculosis (PMDT) guidelines (NTLP, 2016). Over the period 2013-2015, the RR-TB/MDR-TB Treatment success rate (TSR) was sustained between 70.1% and 74.1%, a performance that is well above the global TSR average rate of 50%. Additionally, the cure rate increased from 48.8% to 66.8% (P = 0.03). The Uganda DR-TB mixed model of care coupled with early application of continuous improvement approaches, enhanced cohort reviews and use of multi-disciplinary teams allowed for rapid DR-TB program expansion, rapid clearance of patient backlog, attainment of high cumulative enrollment and high treatment success rates. Sustainability of these achievements is needed to further reduce the DR-TB burden in the country. We highly recommend this mixed model of care in settings with similar challenges.

Adherence to the MDR-TB intensive phase treatment protocol amongst individuals followed up at central and peripheral health care facilities in Uganda - a descriptive study.

BACKGROUND: Following initiation of MDR-TB treatment, patients have a choice to receive follow up DOT supervision at either the central initiating facility or at a peripheral facility. OBJECTIVES: We describe the adherence patterns of MDR-TB patients undergoing DOT supervision at the two health facility categories during intensive phase of treatment. METHODS: We used a retrospective cohort of patients initiated on MDR TB treatment at Mulago National Referral Hospital between 2014 and 2016. We extracted data from the National Tuberculosis and Leprosy Program records and analysed these using STATA V14. RESULT: Majority (84.01%) of the patients received their DOT supervision from the peripheral facilities. Males made up 62.1% of patients, and 91.2% had had their household contacts screened for MDR-TB. 26.5% of the patients on peripheral DOT supervision had good adherence to treatment protocol compared to 0% among patients on central initiating health facility DOT supervision. Among the patients with good adherence, 24.1% had contacts screened for MDR-TB as compared to 3.6% with poor adherence. CONCLUSION: More patients preferred MDR-TB DOT supervision at peripheral facilities, which had better adherence to the treatment protocol compared to the central initiating facility. Younger people and those with household contacts screened had better adherence to the treatment protocol, highlighting areas for targeted interventional programs for MDR-TB in resource limited settingsMore patients preferred MDR-TB DOT supervision at peripheral facilities, which had better adherence to the treatment protocol compared to the central initiating facility. Younger people and those with household contacts screened had better adherence to the treatment protocol, highlighting areas for targeted interventional programs for MDR-TB in resource limited settings.

Validation of an indigenous assay for rapid molecular detection of rifampicin resistance in presumptive multidrug-resistant pulmonary tuberculosis patients.

BACKGROUND & OBJECTIVES: There is a need for an affordable, easy, high-sensitivity test usable at the peripheral health facility for diagnosis of drug-resistant (DR) tuberculosis (TB) to interrupt disease transmission. Nucleic acid amplification tests (NAATs) for early detection of DR-TB are ideal to bring testing near to the patient. TruenatTM MTB (Mycobacterium tuberculosis) and TruenatTM MTB-RIF (rifampicin) is an indigenous chip-based real-time polymerase chain reaction (PCR) based test for detection of multidrug-resistant (MDR) TB. The test involves extraction of DNA using automated, battery operated Trueprep instrument and real-time PCR performed on the Truelab analyzer. We report here multicentric validation of Truenat MTB-RIF for detection of DR-TB in suspected DR-TB patients. METHODS: Consecutive patients aged 18-65 yr, with symptoms suggestive of TB and with a history of previous treatment, reporting to the National TB Elimination Programme (NTEP) clinics under four national institutes, namely AIIMS (All India Institute of Medical Sciences, New Delhi), NITRD (National Institute of Tuberculosis and Respiratory Diseases, New Delhi), NIRT (National Institute for Research in Tuberculosis, Chennai) and ICMR-National JALMA Institute for Leprosy and other Mycobacterial Diseases, Agra, were included in the study. Two sputum samples (one spot and one morning) were collected from each patient, after obtaining informed written consent. The samples were subjected to smear, GeneXpert and MGIT 960 culture (and drug susceptibility testing to RIF) (surrogate for MDR-TB) to serve as reference tests. The samples were coded to ensure blinding and subjected to Truenat MTB-RIF. Truenat MTB-RIF Version 1.5 was used for testing 1084 samples for RIF resistance, while Version 2.0 was used to test another 1201 samples. RESULTS: Truenat MTB-RIF Version 1.5 in comparison with comprehensive laboratory reference standards yielded sensitivity and specificity of 76.2 and 94.7 per cent, respectively for the detection of RIF resistance in 1084 samples, collected across four sites. Based on the analysis of discordant samples, Version 2.0 of Truenat was developed by the manufacturer and this was further tested on additional 1201 samples, yielding a sensitivity of 87.5 per cent and specificity of 99.5 per cent. INTERPRETATION & CONCLUSIONS: Multicentric trial of TruenatTM MTB-RIF demonstrated a great potential of this point of care NAAT for detection of MDR-TB. The test would be useful in limited resource settings and inaccessible areas without need for any additional infrastructure.

Efeitos adversos no tratamento da tuberculose / Adverse effects in the treatment of tuberculosis

Objetivo: Analisar ocorrências de efeitos adversos relacionados a medicamentos no tratamento de tuberculose e sua associação com variáveis clínicas e desfecho. Método: Estudo transversal com 63 casos de tuberculose tratados no Ambulatório de Tuberculose e Hanseníase de São José do Rio Preto, São Paulo, no período de 2010 a 2015. Utilizou-se análise de frequência e teste qui-quadrado com correção de Monte Carlo. Resultados: Os efeitos adversos iniciaram-se antes do terceiro mês de tratamento; efeitos menores foram mais frequentes, com predomínio de irritação gástrica. Houve associação entre conduta médica e efeitos adversos (p = 0,009). Conclusão: Efeitos adversos causados pelos medicamentos podem prejudicar o desfecho clínico devido ao risco de abandono do tratamento. Profissionais de saúde devem estar atentos aos sinais e sintomas relacionados aos efeitos adversos, implementando condutas necessárias para neutralizar ou diminuir as queixas, visando adesão ao tratamento e cura da doença. (AU)

Objective: To analyze occurrences of drug-related adverse effects in treatment of tuberculosis and its association with clinical variables and outcome. Method: Cross-sectional study with 63 cases of tuberculosis treated at Tuberculosis and Leprosy Outpatient Clinic of São José do Rio Preto, São Paulo, from 2010 to 2015. We used frequency analysis and chi-square test with Monte Carlo correction. Results: Adverse effects started before the third month of treatment; effects were more frequent, with predominance of gastric irritation. There was association between medical conduct and adverse effects (p=0.009). Conclusion: Adverse effects caused by medications may impair the clinical outcome due to risk of treatment withdrawal. Health professionals should be alert to signs and symptoms related to adverse effects, implementing the necessary behaviors to neutralize or reduce complaints, aiming adherence to treatment and cure of the disease. (AU)

Objetivo: Analizar los efectos adversos relacionados con medicamentos en tratamiento de la tuberculosis y su asociación con variables clínicas y desenlace. Método: Estudio transversal con 63 casos de tuberculosis tratados en Ambulatorio de Tuberculosis y Hanseniasis de São José Rio Preto, São Paulo, en período de 2010 a 2015. Se utilizó análisis de frecuencia y prueba chi-cuadrado con corrección de Monte Carlo. Los efectos adversos se iniciaron antes del tercer mes de tratamiento; los efectos menores fueron más frecuentes, con predominio de irritación gástrica. Se observó asociación entre conducta médica y efectos adversos (p=0,009). Resultados: Los efectos adversos causados por medicamentos pueden perjudicar el resultado clínico debido al riesgo de abandono del tratamiento. Conclusiones: Los profesionales de salud deben estar atentos a los signos y síntomas relacionados con efectos adversos, implementando conductas necesarias para neutralizar o disminuir las quejas, visando adhesión al tratamiento y cura de la enfermedad. (AU)

Gridlock from diagnosis to treatment of multidrug-resistant tuberculosis in Tanzania: low accessibility of molecular diagnostic services and lack of healthcare worker empowerment in 28 districts of 5 high burden TB regions with mixed methods evaluation.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) outcomes are adversely impacted by delay in diagnosis and treatment. METHODS: Mixed qualitative and quantitative approaches were utilized to identify healthcare system related barriers to implementation of molecular diagnostics for MDR-TB. Randomly sampled districts from the 5 highest TB burden regions were enrolled during the 4th quarter of 2016. District TB & Leprosy Coordinators (DTLCs), and District AIDS Coordinators (DACs) were interviewed, along with staff from all laboratories within the selected districts where molecular diagnostics tests for MDR-TB were performed. Furthermore, the 2015 registers were audited for all drug-susceptible but retreatment TB cases and TB collaborative practices in HIV clinics, as these patients were in principal targeted for drug susceptibility testing by rapid molecular diagnostics. RESULTS: Twenty-eight TB districts from the 5 regions had 399 patients reviewed for retreatment with a drug-susceptible regimen. Only 160 (40%) had specimens collected for drug-susceptibility testing, and of those specimens only 120 (75%) had results communicated back to the clinic. MDR-TB was diagnosed in 16 (13.3%) of the 120 specimens but only 12 total patients were ultimately referred for treatment. Furthermore, among the HIV/AIDS clinics served in 2015, the median number of clients with TB diagnosis was 92 cases [IQR 32-157] yet only 2 people living with HIV were diagnosed with MDR-TB throughout the surveyed districts. Furthermore, the districts generated 53 front-line healthcare workers for interviews. DTLCs with intermediate or no knowledge on the clinical application of XpertMTB/RIF were 3 (11%), and 10 (39%), and DACs with intermediate or no knowledge were 0 (0%) and 2 (8%) respectively (p = 0.02). Additionally, 11 (100%) of the laboratories surveyed had only the 4-module XpertMTB/RIF equipment. The median time that XpertMTB/RIF was not functional in the 12 months prior to the investigation was 2 months (IQR 1-4). CONCLUSIONS: Underutilization of molecular diagnostics in high-risk groups was a function of a lack of front-line healthcare workforce empowerment and training, and a lack of equipment access, which likely contributed to the observed delay in MDR-TB diagnosis in Tanzania.

Cost of three models of care for drug-resistant tuberculosis patients in Nigeria.

BACKGROUND: Nigeria accounts for a significant proportion of the global drug-resistant tuberculosis (DR-TB) burden, a large proportion of which goes untreated. Different models for managing DR-TB treatment with varying levels of hospitalization are in use across Nigeria, however costing evidence is required to guide the scale up of DR-TB care. We aimed to estimate and compare the costs of different DR-TB treatment and care models in Nigeria. METHODS: We estimated the costs associated with three models of DR-TB treatment and care: Model (A) patients are hospitalized throughout the 8-month intensive phase, Model (B) patients are partially hospitalized during the intensive phase and Model (C) is entirely ambulatory. Costs of treatment, in-patient and outpatient care and diagnostic and monitoring tests were collected using a standardized data collection sheet from six sites through an ingredient's approach and cost models were based on the Nigerian National Tuberculosis, Leprosy and Buruli Ulcer Guideline - Sixth Edition (2014) and Guideline for programmatic and clinical management of drug-resistant tuberculosis in Nigeria (2015). RESULTS: Assuming adherence to the Nigerian DR-TB guidelines, the per patient cost of Model A was $18,528 USD, Model B $15,159 USD and Model C $9425 USD. Major drivers of cost included hospitalization (Models A and B) and costs of out-patient consultations and supervision (Model C). CONCLUSION: Utilizing a decentralized ambulatory model, is a more economically viable approach for the expansion of DR-TB care in Nigeria, given that patient beds for DR-TB treatment and care are limited and costs of hospitalized treatment are considerably more expensive than ambulatory models. Scale-up of less expensive ambulatory care models should be carefully considered in particular, when treatment efficacy is demonstrated to be similar across the different models to allow for patients not requiring hospitalization to be cared for in the least expensive way.

Drug-Resistant tuberculosis in Ethiopia: Characteristics of cases in a referral hospital and the implications.

Background: Tuberculosis (TB) programs should design intervention strategies based on the sound knowledge of the existing local epidemiology and sociodemographic characteristics of drug-resistant-TB (DR-TB) cases. The aim of the study was to characterize the pulmonary multidrug-resistant (MDR) and rifampicin-resistant (RR) TB cases enrolled in a referral hospital at Addis Ababa, Ethiopia, called All Africa Leprosy, Tuberculosis, Rehabilitation and Training (ALERT) Hospital. Methods: We conducted a descriptive study based on retrospective review of medical records of 340 pulmonary MDR/RR-TB cases enrolled in ALERT Hospital from November 2011 to December 2016. To characterize the cases, we described the distribution of demographic and clinical characteristics. To compare the distribution of demographic and clinical characteristics between male and female cases, we used Pearson's Chi-squared test. Results: Males accounted for 52.9% of the 340 cases. Nine out of ten cases were in the age group of 15-44 years. Sputum acid-fast bacilli smear-positive and human immunodeficiency virus-coinfected cases constituted 63.7% and 18.1% of cases, respectively. The proportion of new cases increased through the years from nil in 2011 to 21.4% in 2016. Adult males above 24 years constituted more than three quarters (77.2%) of the total male cases, while adult females in this age group constituted 56.9%. The age distribution between male and female cases showed significant differences (P < 0.001). Conclusion: There is age disparity between male and female cases with high impact of MDR/RR-TB on productive adult male population. The transmission potential for DR-TB is also high in the community.

Extended spectrum of antibiotic susceptibility for tuberculosis, Djibouti.

In the Horn of Africa, there is a high prevalence of tuberculosis that is reported to be partly driven by multidrug-resistant (MDR) Mycobacterium tuberculosis strictu sensu strains. We conducted a prospective study to investigate M. tuberculosis complex species causing tuberculosis in Djibouti, and their in vitro susceptibility to standard anti-tuberculous antibiotics in addition to clofazimine, minocycline, chloramphenicol and sulfadiazine. Among the 118 mycobacteria isolates from 118 successive patients with suspected pulmonary tuberculosis, 111 strains of M. tuberculosis, five Mycobacterium canettii, one 'Mycobacterium simulans' and one Mycobacterium kansasii were identified. Drug-susceptibility tests performed on the first 78 isolates yielded nine MDR M. tuberculosis isolates. All isolates were fully susceptible to clofazimine, minocycline and chloramphenicol, and 75 of 78 isolates were susceptible to sulfadiazine. In the Horn of Africa, patients with confirmed pulmonary tuberculosis caused by an in vitro susceptible strain may benefit from anti-leprosy drugs, sulfamides and phenicol antibiotics.

Susceptibilities of MDR Mycobacterium tuberculosis isolates to unconventional drugs compared with their reported pharmacokinetic/pharmacodynamic parameters.

Background: The second-line drugs recommended to treat drug-resistant TB are toxic, expensive and difficult to procure. Given increasing resistance, the need for additional anti-TB drugs has become more urgent. But new drugs take time to develop and are expensive. Some commercially available drugs have reported anti-mycobacterial activity but are not routinely used because supporting laboratory and clinical evidence is sparse. Methods: We analysed 217 MDR M. tuberculosis isolates including 153 initial isolates from unique patients and 64 isolates from follow-up specimens during the course of treatment. The resazurin microdilution assay was performed to determine MICs of trimethoprim/sulfamethoxazole, mefloquine, thioridazine, clofazimine, amoxicillin/clavulanate, meropenem/clavulanate, nitazoxanide, linezolid and oxyphenbutazone. Isoniazid was used for validation. We calculated the MIC 50 and MIC 90 as the MICs at which growth of 50% and 90% of isolates was inhibited, respectively. Results: The MIC 50 s, in mg/L, for initial isolates were as follows: trimethoprim/sulfamethoxazole, 0.2/4; mefloquine, 8; thioridazine, 4; clofazimine, 0.25; amoxicillin/clavulanate, 16/8; meropenem/clavulanate, 1/2.5; nitazoxanide, 16; linezolid, 0.25; and oxyphenbutazone, 40. The MIC 90 s, in mg/L, for initial isolates were as follows: trimethoprim/sulfamethoxazole, 0.4/8; mefloquine, 8; thioridazine, 8; clofazimine, 0.5; amoxicillin/clavulanate, 32/16; meropenem/clavulanate, 8/2.5; nitazoxanide, 16; linezolid, 0.25; and oxyphenbutazone, 60. By comparison, the MIC 90 of isoniazid was >4 mg/L, as expected. There was no evidence that previous treatment affected susceptibility to any drug. Conclusions: Most drugs demonstrated efficacy against M. tuberculosis . When these MICs are compared with the published pharmacokinetic/pharmacodynamic profiles of the respective drugs in humans, trimethoprim/sulfamethoxazole, meropenem/clavulanate, linezolid, clofazimine and nitazoxanide appear promising and warrant further clinical investigation.

Treatment outcomes of drug-resistant tuberculosis patients in Kenya.

SETTING: Successful treatment of drug-resistant tuberculosis (DR-TB) is crucial in preventing disease transmission and reducing related morbidity and mortality. A standardised DR-TB treatment regimen is used in Kenya. Although patients on treatment are monitored, no evaluation of factors affecting treatment outcomes has yet been performed. OBJECTIVE: To analyse treatment outcomes of DR-TB patients in Kenya and factors associated with successful outcome. DESIGN: Retrospective analysis of secondary data from Kenya's National Tuberculosis, Leprosy and Lung disease programme. DR-TB data from the national database for January to December 2012 were reviewed. RESULTS: Of 205 DR-TB patients included in the analysis, 169 (82.4%) had a successful treatment outcome, 18 (9%) died and 18 (9%) were lost to follow-up. Only sex (P = 0.006) and human immunodeficiency virus (HIV) status (P = 0.008) were predictors of successful treatment. Females were more likely to attain treatment success (OR 3.86, 95%CI 1.47-10.12), and HIV-negative status increased the likelihood of successful treatment (OR 3.53, 95%CI 1.4-8.9). CONCLUSION: Treatment success rates were higher than World Health Organization targets. Targeted policies for HIV-positive patients and males will improve treatment outcomes in these groups.

Negligible risk of inducing resistance in Mycobacterium tuberculosis with single-dose rifampicin as post-exposure prophylaxis for leprosy.

Post-exposure prophylaxis (PEP) for leprosy is administered as one single dose of rifampicin (SDR) to the contacts of newly diagnosed leprosy patients. SDR reduces the risk of developing leprosy among contacts by around 60 % in the first 2-3 years after receiving SDR. In countries where SDR is currently being implemented under routine programme conditions in defined areas, questions were raised by health authorities and professional bodies about the possible risk of inducing rifampicin resistance among the M. tuberculosis strains circulating in these areas. This issue has not been addressed in scientific literature to date. To produce an authoritative consensus statement about the risk that SDR would induce rifampicin-resistant tuberculosis, a meeting was convened with tuberculosis (TB) and leprosy experts. The experts carefully reviewed and discussed the available evidence regarding the mechanisms and risk factors for the development of (multi) drug-resistance in M. tuberculosis with a view to the special situation of the use of SDR as PEP for leprosy. They concluded that SDR given to contacts of leprosy patients, in the absence of symptoms of active TB, poses a negligible risk of generating resistance in M. tuberculosis in individuals and at the population level. Thus, the benefits of SDR prophylaxis in reducing the risk of developing leprosy in contacts of new leprosy patients far outweigh the risks of generating drug resistance in M. tuberculosis.

Strengthening the Tuberculosis Specimen Referral Network in Uganda: The Role of Public-Private Partnerships.

BACKGROUND: Diagnosis of multidrug-resistant tuberculosis and prompt initiation of effective treatment rely on access to rapid and reliable drug-susceptibility testing. Efficient specimen transport systems and appropriate training on specimen referral contribute to optimal and timely access to tuberculosis diagnostic services. METHODS: With support and technical assistance from a public-private partnership (PPP) between Becton Dickinson and the US President's Emergency Plan for AIDS Relief, the Uganda National TB Reference Laboratory (NTRL) and National TB and Leprosy Program redesigned the tuberculosis specimen transport network and trained healthcare workers with the goal of improving multidrug-resistant tuberculosis detection. RESULTS: Between 2008 and 2011, the PPP mapped 93% of health facilities and trained 724 healthcare and postal staff members covering 72% of districts. Strengthening the tuberculosis specimen referral system increased referrals from presumptive multidrug-resistant tuberculosis cases by >10-fold, with 94% of specimens reaching the NTRL within the established target transport time. CONCLUSIONS: This study demonstrates the potential of PPP collaborations with ministries of health to positively influence patient care by strengthening laboratory systems through increased access to drug-susceptibility testing in Uganda. Ongoing efforts to integrate specimen transport networks will maximize resources and improve patient management.

Elucidating the role of clofazimine for the treatment of tuberculosis.

Clofazimine (CFZ), a riminophenazine and a key component of the treatment regimen for lepromatous leprosy, has been rehabilitated clinically for the treatment of multidrug-resistant tuberculosis (MDR-TB). Observational studies and a randomized control trial suggest efficacy in the treatment of MDR-TB and the potential for treatment shortening. Animal and translational research have shown mixed results. In this article, we review key clinical, animal, and translational data to better understand the potential role of CFZ in the treatment of MDR-TB and in shortening anti-tuberculosis treatment.