Assessing potential drug-drug interactions between clofazimine and other frequently used agents to treat drug-resistant tuberculosis.

Clofazimine is included in drug regimens to treat rifampicin/drug-resistant tuberculosis (DR-TB), but there is little information about its interaction with other drugs in DR-TB regimens. We evaluated the pharmacokinetic interaction between clofazimine and isoniazid, linezolid, levofloxacin, and cycloserine, dosed as terizidone. Newly diagnosed adults with DR-TB at Klerksdorp/Tshepong Hospital, South Africa, were started on the then-standard treatment with clofazimine temporarily excluded for the initial 2 weeks. Pharmacokinetic sampling was done immediately before and 3 weeks after starting clofazimine, and drug concentrations were determined using validated liquid chromatography-tandem mass spectrometry assays. The data were interpreted with population pharmacokinetics in NONMEM v7.5.1 to explore the impact of clofazimine co-administration and other relevant covariates on the pharmacokinetics of isoniazid, linezolid, levofloxacin, and cycloserine. Clofazimine, isoniazid, linezolid, levofloxacin, and cycloserine data were available for 16, 27, 21, 21, and 6 participants, respectively. The median age and weight for the full cohort were 39 years and 52 kg, respectively. Clofazimine exposures were in the expected range, and its addition to the regimen did not significantly affect the pharmacokinetics of the other drugs except levofloxacin, for which it caused a 15% reduction in clearance. A posteriori power size calculations predicted that our sample sizes had 97%, 90%, and 87% power at P < 0.05 to detect a 30% change in clearance of isoniazid, linezolid, and cycloserine, respectively. Although clofazimine increased the area under the curve of levofloxacin by 19%, this is unlikely to be of great clinical significance, and the lack of interaction with other drugs tested is reassuring.

Diagnostic accuracy of the Xpert® MTB/XDR assay for detection of Isoniazid and second-line antituberculosis drugs resistance at central TB reference laboratory in Tanzania.

INTRODUCTION: Early diagnosis of tuberculosis (TB) and universal access to drug-susceptibility testing (DST) are critical elements of the WHO End TB Strategy. Current rapid tests (e.g., Xpert® MTB/RIF and Ultra-assays) can detect rifampicin resistance-conferring mutations, but cannot detect resistance to Isoniazid and second-line anti-TB agents. Although Line Probe Assay is capable of detecting resistance to second-line anti-TB agents, it requires sophisticated laboratory infrastructure and advanced skills which are often not readily available in settings replete with TB. A rapid test capable of detecting Isoniazid and second-line anti-TB drug resistance is highly needed. METHODS: We conducted a diagnostic accuracy study to evaluate a new automated Xpert MTB/XDR 10-colour assay for rapid detection of Isoniazid and second-line drugs, including ethionamide, fluoroquinolones, and injectable drugs (Amikacin, Kanamycin, and Capreomycin). Positive Xpert MTB/RIF respiratory specimens were prospectively collected through routine diagnosis and surveillance of drug resistance at the Central TB Reference Laboratory in Tanzania. Specimens were tested by both Xpert XDR assay and LPA against culture-based phenotypic DST as the reference standard. FINDINGS: We analysed specimens from 151 TB patients with a mean age (SD) of 36.2 (12.7) years. The majority (n = 109, 72.2%) were males. The sensitivity for Xpert MTB/XDR was 93.5% (95% CI, 87.4-96.7); for Isoniazid, 96.6 (95% CI, 92.1-98.6); for Fluoroquinolone, 98.7% (95% Cl 94.8-99.7); for Amikacin, 96.6%; and (95% CI 92.1-98.6) for Ethionamide. Ethionamide had the lowest specificity of 50% and the highest was 100% for Fluoroquinolone. The diagnostic performance was generally comparable to that of LPA with slight variations between the two assays. The non-determinate rate (i.e., invalid M. tuberculosis complex detection) of Xpert MTB/XDR was 2·96%. CONCLUSION: The Xpert MTB/XDR demonstrated high sensitivity and specificity for detecting resistance to Isoniazid, Fluoroquinolones, and injectable agents. This assay can be used in clinical settings to facilitate rapid diagnosis of mono-isoniazid and extensively drug-resistant TB.

The introduction of video-enabled directly observed therapy (video-DOT) for patients with drug-resistant TB disease in Eswatini amid the COVID-19 pandemic - a retrospective cohort study.

BACKGROUND: Video-enabled directly observed therapy (video-DOT) has been proposed as an additional option for treatment provision besides in-person DOT for patients with drug-resistant TB (DRTB) disease. However, evidence and implementation experience mainly originate from well-resourced contexts. This study describes the operationalization of video-DOT in a low-resourced setting in Eswatini facing a high burden of HIV and TB amid the emergence of the COVID-19 pandemic. METHODS: This is a retrospectively established cohort of patients receiving DRTB treatment during the implementation of video-DOT in Shiselweni from May 2020 to March 2022. We described intervention uptake (vs. in-person DOT) and assessed unfavorable DRTB treatment outcome (death, loss to care) using Kaplan-Meier statistics and multivariable Cox-regression models. Video-related statistics were described with frequencies and medians. We calculated the fraction of expected doses observed (FEDO) under video-DOT and assessed associations with missed video uploads using multivariable Poisson regression analysis. RESULTS: Of 71 DRTB patients eligible for video-DOT, the median age was 39 (IQR 30-54) years, 31.0% (n = 22) were women, 67.1% (n = 47/70) were HIV-positive, and 42.3% (n = 30) were already receiving DRTB treatment when video-DOT became available. About half of the patients (n = 37; 52.1%) chose video-DOT, mostly during the time when COVID-19 appeared in Eswatini. Video-DOT initiations were lower in new DRTB patients (aHR 0.24, 95% CI 0.12-0.48) and those aged ≥ 60 years (aHR 0.27, 95% CI 0.08-0.89). Overall, 20,634 videos were uploaded with a median number of 553 (IQR 309-748) videos per patient and a median FEDO of 92% (IQR 84-97%). Patients aged ≥ 60 years were less likely to miss video uploads (aIRR 0.07, 95% CI 0.01-0.51). The cumulative Kaplan-Meier estimate of an unfavorable treatment outcome among all patients was 0.08 (95% CI 0.03-0.19), with no differences detected by DOT approach and other baseline factors in multivariable analysis. CONCLUSIONS: Implementing video-DOT for monitoring of DRTB care provision amid the intersection of the HIV and COVID-19 pandemics seemed feasible. Digital health technologies provide additional options for patients to choose their preferred way to support treatment taking, thus possibly increasing patient-centered health care while sustaining favorable treatment outcomes.

Multi-drug resistant and rifampin-resistant tuberculosis in transplant recipients.

BACKGROUND: Management of multidrug-resistant (MDR) and rifampin-resistant (RR) tuberculosis is challenging. Data on transplant recipients is limited. We reviewed published literature to examine treatment choices, outcomes, and adverse effects from MDR-TB/RR-TB treatment in transplant recipients. METHODS: Multiple databases from inception to 12/2022 were reviewed using the keywords "drug-resistant TB" or "drug-resistant tuberculosis" or "multidrug-resistant TB" or "multidrug-resistant tuberculosis". MDR-TB was defined as resistance to isoniazid (H) and rifampin (R), and RR if resistant to rifampin alone. Cases without patient-level data and reports which did not describe treatment and/or outcomes for MDR-TB were excluded. RESULTS: A total of 12 patients (10 solid organ transplants and two hematopoietic cell transplants) were included. Of these, 11 were MDR-TB and one was RR-TB. Seven recipients were male. The median age was 41.5 (range 16-60) years. Pre-transplant evaluation for the majority (8/12, 66.7%) did not reveal a prior history of TB or TB treatment, but 9/12 were from TB intermediate or high-burden countries. Seven patients were initially treated with the quadruple first-line anti-TB regimen. Those who had early RR confirmation (5/12) via Xpert MTB/RIF assay were initiated on alternative therapies. Final regimens were individualized based on susceptibility profiles and tolerability. Adverse events were reported in seven recipients, including acute kidney injury (n = 3), cytopenias (n = 3), and jaundice (n = 2). Four recipients died, with two deaths attributable to TB. The remaining eight patients who survived had functioning allografts at the last follow-up. CONCLUSIONS: MDR-TB treatment in transplant recipients is associated with many complications. Xpert MTB/RIF detected RR early and guided early empiric therapy.

Determining the risk-factors for molecular clustering of drug-resistant tuberculosis in South Africa.

BACKGROUND: Drug-resistant tuberculosis (DR-TB) epidemic is driven mainly by the effect of ongoing transmission. In high-burden settings such as South Africa (SA), considerable demographic and geographic heterogeneity in DR-TB transmission exists. Thus, a better understanding of risk-factors for clustering can help to prioritise resources to specifically targeted high-risk groups as well as areas that contribute disproportionately to transmission. METHODS: The study analyzed potential risk-factors for recent transmission in SA, using data collected from a sentinel molecular surveillance of DR-TB, by comparing demographic, clinical and epidemiologic characteristics with clustering and cluster sizes. A genotypic cluster was defined as two or more patients having identical patterns by the two genotyping methods used. Clustering was used as a proxy for recent transmission. Descriptive statistics and multinomial logistic regression were used. RESULT: The study identified 277 clusters, with cluster size ranging between 2 and 259 cases. The majority (81.6%) of the clusters were small (2-5 cases) with few large (11-25 cases) and very large (≥ 26 cases) clusters identified mainly in Western Cape (WC), Eastern Cape (EC) and Mpumalanga (MP). In a multivariable model, patients in clusters including 11-25 and ≥ 26 individuals were more likely to be infected by Beijing family, have XDR-TB, living in Nelson Mandela Metro in EC or Umgungunglovo in Kwa-Zulu Natal (KZN) provinces, and having history of imprisonment. Individuals belonging in a small genotypic cluster were more likely to infected with Rifampicin resistant TB (RR-TB) and more likely to reside in Frances Baard in Northern Cape (NC). CONCLUSION: Sociodemographic, clinical and bacterial risk-factors influenced rate of Mycobacterium tuberculosis (M. tuberculosis) genotypic clustering. Hence, high-risk groups and hotspot areas for clustering in EC, WC, KZN and MP should be prioritized for targeted intervention to prevent ongoing DR-TB transmission.

Community-based directly observed therapy is effective and results in better treatment outcomes for patients with multi-drug resistant tuberculosis in Uganda.

BACKGROUND: Health facility-based directly observed therapy (HF DOT) is the main strategy for the management of patients with drug-resistant tuberculosis (DR TB) in Uganda, however, this still yields sub-optimal treatment outcomes. We set out to assess the effectiveness of community-based directly observed therapy (CB DOT) for the treatment of DR TB in Uganda. METHODS: Using a previously developed patient-centered model for CB DOT, we assigned community health workers (CHWs) as primary caregivers to patients diagnosed with DR TB. CHWs administered daily DOT to patients in their homes. Once a month, patients received travel vouchers to attend clinic visits for treatment monitoring. We assessed the effectiveness of this model using a quasi-experimental pre and post-study. From December 2020 to March 2022, we enrolled adult DR-TB patients on the CB DOT model. We collected retrospective data from patients who had received care using the HF DOT model during the year before the study started. The adjusted effect of CB DOT versus HF DOT on DR TB treatment success was estimated using modified Poisson regression model with robust cluster variance estimator. RESULTS: We analyzed data from 264 DR TB patients (152 HF DOT, 112 CB DOT). The majority were males (67.8%) with a median age of 36 years (IQR 29 to 44 years). Baseline characteristics were similar across the comparison groups, except for educational level, regimen type, and organizational unit with age being borderline. The treatment success rate in the CB DOT group was 12% higher than that in the HF DOT (adjusted prevalence ratio (aPR)= 1.12 [95%CI 1.01, 1.24], P-value=0.03). Males were less likely to achieve treatment success compared to their female counterparts (aPR=0.87 [95% CI 0.78, 0.98], P-value=0.02). A total of 126 (47.7%) of 264 patients reported at least one adverse event. The HF DOT group had a higher proportion of patients with at least one adverse event compared to the CB DOT group (90/152 [59.2%] versus 36/112 [32.1], P-value<0.01). The model was acceptable among patients (93.6%) and health workers (94.1%). CONCLUSIONS: CB DOT for DR-TB care is effective and results in better treatment outcomes than HF DOT. The cost-effectiveness of this model of care should be further evaluated.

Electronic Dose Monitoring Identifies a High-Risk Subpopulation in the Treatment of Drug-resistant Tuberculosis and Human Immunodeficiency Virus.

BACKGROUND: In generalized drug-resistant tuberculosis (DR-TB) human immunodeficiency virus (HIV) epidemics, identifying subpopulations at high risk for treatment failure and loss to care is critically important to improve treatment outcomes and prevent amplification of drug resistance. We hypothesized that an electronic dose-monitoring (EDM) device could empirically identify adherence-challenged patients and that a mixed-methods approach would characterize treatment challenges. METHODS: A prospective study of patients with DR-TB HIV on antiretroviral therapy (ART) initiating bedaquiline-containing regimens in KwaZulu-Natal, South Africa. Separate EDM devices measured adherence for bedaquiline and ART. Patients with low adherence (<85%) to both bedaquiline and ART were identified as high risk for poor outcomes. Baseline survey, study visit notes, and focus group discussions characterized treatment challenges. RESULTS: From December 2016-February 2018, 32 of 198 (16%) enrolled patients with DR-TB HIV were identified as dual-adherence challenged. In a multivariate model including baseline characteristics, only receiving a disability grant was significantly associated with dual nonadherence at 6 months. Mixed-methods identified treatment barriers including alcohol abuse, family conflicts, and mental health issues. Compared with adherent patients, dual-adherence-challenged patients struggled to prioritize treatment and lacked support, and dual-adherence-challenged patients experienced higher rates of detectable HIV viral load and mortality than more adherent patients. CONCLUSIONS: EDM empirically identified a subpopulation of patients with DR-TB HIV with dual-adherence challenges early in treatment. Mixed-methods revealed intense psychosocial, behavioral, and structural barriers to care in this subpopulation. Our data support developing differential, patient-centered, adherence support interventions focused on psychosocial and structural challenges for subpopulations of at-risk DR-TB HIV patients.

Mycobacterium enoyl acyl carrier protein reductase (InhA): A key target for antitubercular drug discovery.

Enoyl acyl carrier protein reductase (InhA) is a key enzyme involved in fatty acid synthesis mainly mycolic acid biosynthesis that is a part of NADH dependent acyl carrier protein reductase family. The aim of the present literature is to underline the different scaffolds or enzyme inhibitors that inhibit mycolic acid biosynthesis mainly cell wall synthesis by inhibiting enzyme InhA. Various scaffolds were identified based on the screening technologies like high throughput screening, encoded library technology, fragment-based screening. The compounds studied include indirect inhibitors (Isoniazid, Ethionamide, Prothionamide) and direct inhibitors (Triclosan/Diphenyl ethers, Pyrrolidine Carboxamides, Pyrroles, Acetamides, Thiadiazoles, Triazoles) with better efficacy against drug resistance. Out of the several scaffolds studied, pyrrolidine carboxamides were found to be the best molecules targeting InhA having good bioavailability properties and better MIC. This review provides with a detailed information, analysis, structure activity relationship and useful insight on various scaffolds as InhA inhibitors.

Epidemiological profile of multidrug-resistant and extensively drug-resistant Mycobacterium Tubrculosis among Congolese patients.

BACKGROUND: There is paucity of data on the prevalence and distribution of multidrug- Resistant-Tuberculosis (MDR-TB) in the Republic of Congo. Among the challenges resides the implementation of a robust TB resistance diagnostic program using molecular tools. In resource limited settings there is a need to gather data to enable prioritization of actions. The objective of this study was is to implement molecular tools as a best of diagnosing MDR and XDR-TB among presumptive tuberculosis patients referred to reference hospital of Makelekele in Brazzaville, Republic of the Congo. METHODS: We have conducted a cross-sectional study, including a total of 92 presumptive pulmonary tuberculosis patients and who had never received treatment recruited at the reference hospital of Makelekele from October 2018 to October 2019. The socio-demographic and clinical data were collected as well as sputum samples. Rifampicin resistance was investigated using Xpert (Cepheid) and second-line TB drugs Susceptibility testing were performed by the Brucker HAIN Line Probe Assay (GenoType MTBDRsl VER 2.0 assay) method. RESULTS: From the 92 recruited patients, 57 (62%) were found positive for the Mycobacterium tuberculosis complex. The prevalence of rifampicin-resistant tuberculosis (RR-TB) was 9.8% (9/92) and importantly 2.2% were pre-XDR/XDR. CONCLUSION: This study showed a high rate of rifampicin resistance and the presence of extensively drug-resistant tuberculosis in the study area in new patients. This study highlights the need for further studies of TB drug resistance in the country.

Socio-economic drivers of drug-resistant tuberculosis in Africa: a scoping review.

BACKGROUND: Drug-resistant TB (DR-TB) remains a public health concern due to the high morbidity and mortality rates from the disease. The DR-TB is a multifaceted illness with expensive treatment regimens, toxic medications and most often the long duration of treatment constitutes a substantial financial burden on both infected patients and the health system. Despite significant research advances in the diagnosis and treatment, there is a paucity of synthesized evidence on how socio-economic factors are associated with DR-TB. This review aims to address this gap by synthesizing available evidence and data on the common socio-economic drivers of DR-TB infection in Africa. METHODS: A systematic search was conducted on PUBMED and Google Scholar databases from January 2011 to January 2020 using Joanna Briggs Institute's scoping review approach. An updated search was conducted on 21 September 2020. The eligibility criteria only included systematic reviews and studies with quantitative research methods (cross-sectional, case-control, cohort, and randomized-control trials). Studies conducted in Africa and focusing on socio-economic factors influencing DR-TB burden in African countries were also considered. Data was extracted from all the studies that met the eligibility criteria based on the study's objectives. RESULTS: Out of the 154 articles that were retrieved for review, 20 abstracts of these articles met all the eligibility criteria. Of the 20 articles, 17 quantitative and 3 reviews. Two additional articles were found eligible, following the updated search. The following themes were identified as major findings: Social and economic drivers associated with DR-TB. Substance abuse of which, stigma and discrimination were the prominent social drivers. Economic drivers included poverty, financial constraints because of job loss, loss of productive time during hospital admission and treatment costs. CONCLUSION: This review has highlighted which socio-economic factors contribute to DR- TB This is relevant to assist DR-TB management program and TB stakeholders in different settings to address identified socio-economic gaps and to reduce its negative impact on the programmatic management of DR TB. Therefore, redirecting strategies with more focus on socio-economic empowerment of DR-TB patients could be one of the innovative solutions to reduce the spread and eliminate DR-TB in Africa.

Delivery of long-term-injectable agents for TB by lay carers: pragmatic randomised trial.

BACKGROUND: People with recurrent or drug-resistant TB require long courses of intramuscular injections. We evaluate a novel system in which patient-nominated lay carers were trained to deliver intramuscular injections to patients in their own homes. METHODS: A pragmatic, individually randomised non-inferiority trial was conducted at two hospitals in Malawi. Adults starting TB retreatment were recruited. Patients randomised to the intervention received home-based care from patient-nominated lay people trained to deliver intramuscular streptomycin. Patients receiving standard care were admitted to hospital for 2 months of streptomycin. The primary outcome was successful treatment (alive and on treatment) at the end of the intervention. RESULTS: Of 456 patients screened, 204 participants were randomised. The trial was terminated early due to futility. At the end of the intervention, 97/101 (96.0%) in the hospital arm were still alive and on treatment compared with 96/103 (93.2%) in the home-based arm (risk difference -0.03 (95% CI -0.09 to 0.03); p value 0.538). There were no differences in the proportion completing 8 months of anti-TB treatment; or the proportion experiencing 2-month sputum culture conversion. The mean cost of hospital-based management was US$1546.3 per person, compared to US$729.2 for home-based management. Home-based care reduced risk of catastrophic household costs by 84%. CONCLUSIONS: Although this trial failed to meet target recruitment, the available data demonstrate that training patient-nominated lay people has potential to provide a feasible solution to the operational challenges associated with delivering long-term-injectable drugs to people with recurrent or drug-resistant TB in resource-limited settings, and substantially reduce costs. Further data under operational conditions are required. TRIAL REGISTRATION NUMBER: ISRCTN05815615.

Targeted-Sequencing Workflows for Comprehensive Drug Resistance Profiling of Mycobacterium tuberculosis Cultures Using Two Commercial Sequencing Platforms: Comparison of Analytical and Diagnostic Performance, Turnaround Time, and Cost.

BACKGROUND: The emergence of Mycobacterium tuberculosis with complex drug resistance profiles necessitates a rapid and comprehensive drug susceptibility test for guidance of patient treatment. We developed two targeted-sequencing workflows based on Illumina MiSeq and Nanopore MinION for the prediction of drug resistance in M. tuberculosis toward 12 antibiotics. METHODS: A total of 163 M. tuberculosis isolates collected from Hong Kong and Ethiopia were subjected to a multiplex PCR for simultaneous amplification of 19 drug resistance-associated genetic regions. The amplicons were then barcoded and sequenced in parallel on MiSeq and MinION in respective batch sizes of 24 and 12 samples. A web-based bioinformatics pipeline, BacterioChek-TB, was developed to translate the raw datasets into clinician-friendly reports. RESULTS: Both platforms successfully sequenced all samples with mean read depths of 1,127× and 1,649×, respectively. The variant calling by MiSeq and MinION could achieve 100% agreement if variants with an allele frequency of <40% reported by MinION were excluded. Both workflows achieved a mean clinical sensitivity of 94.8% and clinical specificity of 98.0% when compared with phenotypic drug susceptibility test (pDST). Turnaround times for the MiSeq and MinION workflows were 38 and 15 h, facilitating the delivery of treatment guidance at least 17-18 days earlier than pDST, respectively. The higher cost per sample on the MinION platform ($71.56) versus the MiSeq platform ($67.83) was attributed to differences in batching capabilities. CONCLUSION: Our study demonstrates the interchangeability of MiSeq and MinION platforms for generation of accurate and actionable results for the treatment of tuberculosis.

Detection of Beijing strains of MDR M. tuberculosis and their association with drug resistance mutations in katG, rpoB, and embB genes.

BACKGROUND: Molecular epidemiological studies of Mycobacterium tuberculosis (MTB) are the core of current research to find out the association of the M. tuberculosis genotypes with its outbreak and transmission. The high prevalence of the Beijing genotype strain among multidrug resistance (MDR) TB has already been reported in various studies around India. The overall objective of this study was to detect the prevalence of Beijing genotype strains of MDR M. tuberculosis and their association with the clinical characteristics of TB patients. METHODS: In this study 381 M. tuberculosis clinical isolates were obtained from sputum samples from 2008 to 2014. The multiplex-PCR and Spoligotyping (n = 131) methods were used to investigate the prevalence of the Beijing genotype strain by targeting the Rv2820 gene and their association with drug resistance and clinical characteristics of TB patients. The drug susceptibility testing of first-line anti-TB drugs was performed by using the proportion method and MGIT960. A collection of isolates having Beijing and non-Beijing strains were also characterized to see if Beijing genotype strains had a higher rate of mutations at codons 516, 526 and 531 of the 81-bp region of the rpoB gene, codon 315 of the katG gene, and codon 306 of the embB gene. RESULTS: The sensitivities and specificities of multiplex-PCR assay compared to that of standard Spoligotyping was detected to be 100%. Further, we observe that the multi drug-resistance was significantly associated with Beijing genotype strains (p = 0.03) and a strong correlation between Beijing genotype strains and specific resistance mutations at the katG315, rpoB531, and embB306 codons (p = < 0.0001, < 0.0001 & 0.0014 respectively) was also found. CONCLUSIONS: This rapid, simple, and cost-effective multiplex PCR assay can effectively be used for monitoring the prevalence of Beijing genotype strains in low resource settings. Findings of this study may provide a scientific basis for the development of new diagnostic tools for detection and effective management of DR-TB in countries with a higher incidence rate of Beijing genotype strains.

Tuberculosis in Poland in 2018.

AIM OF THE STUDY: To evaluate the main features of tuberculosis (TB) epidemiology in 2018 in Poland and to compare with the situation in the EU/EEA countries. METHODS: Analysis of case- based data on TB patients from National TB Register, data on anti-TB drug susceptibility testing results in cases notified in 2018, data from National Institute of Public Health- National Institute of Hygiene on HIV-positive subjects for whom TB was an AIDS-defining disease, data from Central Statistical Office on deaths from tuberculosis based on death certificates, data from the report " European Centre for Disease Prevention and Control/WHO Regional Office for Europe. Tuberculosis surveillance and monitoring in Europe 2020- 2018 data. Stockholm: European Centre for Disease Prevention and Control, 2020". RESULTS: In 2018, 5487 TB cases were reported in Poland. The incidence rate was 14.3 cases per 100000, with large variability between voivodeships from 7.3 to 23.4 per 100 000. The mean annual decrease of TB incidence in 2014- 2018 was 3.8%. In 2018, 4852 cases were newly diagnosed with no history of previous treatment i.e. 12.6 per 100 000. 635 cases i.e. 1.7 per 100 000 - 11.6% of all registered subjects were previously treated for tuberculosis. In 2018, the number of all pulmonary tuberculosis cases was 5224 i.e. 13.7 per 100000. Pulmonary cases represented 95.2% of all TB cases. In 2018, 243 extrapulmonary TB cases were found i.e. 0.6 per 100 000. In the whole country there were 52 pediatric cases of tuberculosis. TB in children represented 0.9% of all cases notified in Poland in 2018. The incidence rates of tuberculosis were growing along with the age group from 0.9 per 100 000 among children to 24.7 per 100 000 among subjects in the age group 45-64 years (the highest incidence rate). In 2018, the incidence rate in the age group ≥65 years was 21.3 per 100 000. The TB incidence among men i.e. 21.0 per 100 000 was 2.6 times higher than among women i.e. 8.0 per 100 000. The biggest difference in the TB incidence between the two sex groups occurred in persons aged 55 to 59 years - 44.9 vs. 9.8 and in age group 60- 64 years - 43.7 vs. 10.2. The TB incidence in rural population was lower than in urban, respectively 13.4 per 100 000 and 14.9 per 100 000. The number of all registered culture positive TB cases was 4075. Pulmonary tuberculosis was bacteriologically confirmed in 3935 subjects. Cases confirmed by culture represented 74.3% of all TB cases and 75.3% of all pulmonary TB cases. The number of smear-positive pulmonary TB cases reported in 2018 was 2324 i.e. 6.1 per 100 000 accounting for 44.3% of all pulmonary TB cases and 59.1% of pulmonary TB cases confirmed by culture. In all patients with tuberculosis in Poland in 2018 there were 48 cases with MDR-TB (among them 14 foreigners) and 83 patients with resistance to isoniazid only, representing respectively 1.3% and 2.2% of cases with known DST results (DSTs were available in 90.7% of all culture-confirmed TB cases). In 2018, there were 97 patients of foreign origin among all cases of tuberculosis in Poland. TB was AIDS-indicative disease in 14 subjects with HIV co-infection. There were 490 deaths due to tuberculosis reported in 2017 - 1.3 per 100 000; 468 people died from pulmonary and 22 from extrapulmonary tuberculosis. Mortality among males - 2.1 per 100 000 - was 3.6 X higher than among females - 0.5. 40.2% of all TB deaths were cases 65 years old and older - 3.1 per 100 000. In 2017, there was no death from tuberculosis in children and no deaths in adolescents. In 2017, tuberculosis represented 0.1% of total mortality in Poland and 25.4% of mortality from infectious and parasitic diseases. CONCLUSIONS: In 2018, the incidence of tuberculosis in Poland was lower than in 2017. Despite a continuous decline it is still higher than the average in the EU/EEA countries. The highest incidence rates were observed in older age groups. The participation of pediatric cases is smaller than average in the EU/EEA countries. The incidence in males was more than 2 times higher than in females. The impact of migration on the characteristics of tuberculosis in Poland is not substantial. In Poland, MDR-TB is less common than the average in the EU/EEA countries.

Direct Detection of Pyrazinamide Resistance in Mycobacterium tuberculosis by Use of pncA PCR Sequencing.

An in-house-developed pncA sequencing assay for analysis of pyrazinamide (PZA) resistance was evaluated using 162 archived Mycobacterium tuberculosis complex (MTBC) isolates with phenotypic PZA susceptibility profiles that were well defined by analysis of Bactec MGIT 960 PZA kit and PZase activity data. Preliminary results showed 100% concordance between pncA sequencing and phenotypic PZA drug susceptibility test (DST) results among archived isolates. Also, 637 respiratory specimens were prospectively collected, and 158 were reported as MTBC positive by the Abbott Realtime MTB assay (96.3% sensitivity [95% confidence interval {CI}: 92.2% to 98.7%]; 100% specificity [95% CI: 99.2% to 100.0%]). Genotypic and phenotypic PZA resistance profiles of these 158 MTBC-positive specimens were analyzed by pncA sequencing and Bactec MGIT 960 PZA kit, respectively. For analysis of PZA resistance, pncA sequencing detected pncA mutations in 5/5 (100%) phenotypic PZA-resistant respiratory specimens within 4 working days. No pncA mutations were detected among PZA-susceptible specimens. Combining archived isolates with prospective specimens, 27 were identified as phenotypic PZA resistant with pncA mutation. Among these 27 samples, 6/27 (22.2%) phenotypic PZA-resistant strains carried novel pncA mutations without rpsA and panD mutations. These included 5 with mutations (a deletion [Del] at 383T [Del383T], Del 380 to 390, insertion of A [A Ins] at position 127, A Ins at position 407, and G Ins at position 508) in pncA structural genes and 1 with a mutation (T-12C) at the pncA promoter region. All six of these strains had no or reduced PZase activities, indicating that the novel mutations might confer PZA resistance. Additionally, 25/27 phenotypic PZA-resistant strains were confirmed multidrug-resistant tuberculosis (MDR-TB) strains. As PZA is commonly used in MDR-TB treatment regimens, direct pncA sequencing will rapidly detect PZA resistance and facilitate judicious use of PZA in treating PZA-susceptible MDR-TB.

Low prevalence of MDR-TB in Lao PDR: results from the first national anti-tuberculosis drug resistance survey.

OBJECTIVE: To present results of the first national anti-tuberculosis (TB) drug resistance survey conducted in Lao PDR between May 2016 and August 2017 to determine the prevalence of resistance to first-line anti-TB drugs among new and previously treated pulmonary TB cases in the country. METHODS: Patients with sputum smear-positive pulmonary TB were enrolled from 42 TB laboratories distributed in 40 clusters throughout the country. Survey sites were selected using probability-proportional-to-size sampling among all diagnostic centres in the country. In addition to smear microscopy, all patients underwent Xpert MTB/RIF testing and those found positive to Mycobacterium tuberculosis underwent sputum culture and drug susceptibility testing using the proportion method on solid Löwenstein-Jensen medium. RESULTS: Among 1006 eligible patients, 946 sputum smear-positive and Xpert MTB/RIF positive (Mycobacterium tuberculosis detected) patients were included in the survey, comprising 897 new and 49 previously treated TB cases. The prevalence of rifampicin-resistant TB was 1.2% (95% CI: 0.5-2.0%, n = 11/897) among new cases and 4.1% (95% CI: 0-9.6%, n = 2/49) among previously treated cases. Among the 946 TB cases confirmed by Xpert MTB/RIF, phenotypic drug sensitivity testing was available for 820 (776 new and 44 previously treated). The prevalence of multidrug-resistant TB (MDR-TB) was 0.5% (95% CI: 0-1.0%, n = 4/776) among new cases and 2.3% (95% CI: 0-6.7%, n = 1/44) among previously treated cases. No resistance to second-line injectable agents nor to fluoroquinolones was detected among MDR-TB patients. CONCLUSIONS: The first national anti-TB drug resistance survey in Lao PDR demonstrated an encouragingly low prevalence of MDR-TB. The results appear lower than previous WHO estimates, and in line with the routine surveillance based on Xpert MTB/RIF testing (conducted among 50% of presumptive TB patients in 2017). The country should continue to expand its Xpert MTB/RIF network and strive to achieve universal drug susceptibility testing.

OBJECTIF: Présenter les résultats de la première surveillance nationale de la résistance aux médicaments antituberculeux, menée en République Démocratique Populaire (RDP) Lao entre mai 2016 et août 2017 afin de déterminer la prévalence de la résistance aux médicaments antituberculeux de première intention chez les nouveaux cas et les cas déjà traités de tuberculose (TB) pulmonaire dans le pays. MÉTHODES: Les patients atteints de TB pulmonaire à frottis d'expectoration positif ont été recrutés dans 42 laboratoires TB répartis dans 40 groupes à travers tout le pays. Les sites de surveillance ont été sélectionnés sur la base d'un échantillon probabiliste proportionnel à la taille parmi tous les centres de diagnostic du pays. Outre l'examen microscopique des frottis, tous les patients ont subi un test Xpert MTB/RIF et ceux trouvés positifs pour Mycobacterium tuberculosis ont subi une culture d'expectorations et un test de sensibilité aux médicaments en utilisant la méthode des proportions sur un milieu solide de Löwenstein-Jensen. RÉSULTATS: Parmi les 1.006 patients éligibles, 946 patients à frottis positif et Xpert MTB/RIF positif (Mycobacterium tuberculosis détecté) ont été inclus dans la surveillance, comprenant 897 nouveaux cas et 49 cas de TB déjà traités. La prévalence de la TB résistante à la rifampicine était de 1,2% (IC95%: 0,5-2,0%, n = 11/897) chez les nouveaux cas et de 4,1% (IC95%: 0-9,6%, n = 2/49) chez les cas traités. Parmi les 946 cas de TB confirmés par Xpert MTB/RIF, des tests de sensibilité phénotypique aux médicaments étaient disponibles pour 820 (776 nouveaux cas et 44 cas traités antérieurement). La prévalence de la TB multirésistante (TB-MDR) était de 0,5% (IC95%: 0-1,0%, n = 4/776) chez les nouveaux cas et de 2,3% (IC95%: 0 à 6,7%, n = 1/44) parmi les cas précédemment traités. Aucune résistance aux agents injectables de deuxième intention ni aux fluoroquinolones n'a été détectée chez les patients atteints de TB-MDR. CONCLUSIONS: La première surveillance nationale de la résistance aux médicaments antituberculeux menée en RDP Lao a révélé une prévalence rassurante de la TB-MDR. Les résultats apparaissent inférieurs aux estimations précédentes de l'OMS et conformes à la surveillance de routine basée sur le test Xpert MTB/RIF (menée auprès de 50% des patients atteints de TB présumée en 2017). Le pays devrait continuer à élargir son réseau Xpert MTB/RIF et s'efforcer d'atteindre des tests universels de sensibilité aux médicaments.

Design, synthesis, and bioevaluation of a novel class of (E)-4-oxo-crotonamide derivatives as potent antituberculosis agents.

A series of novel (E)-4-oxo-2-crotonamide derivatives were designed and synthesized to find potent antituberculosis agents. All the target compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv(MTB). Results reveal that 4-phenyl moiety at part A and short methyl group at part C were found to be favorable. Most of the derivatives displayed promising activity against MTB with MIC ranging from 0.125 to 4 µg/mL. Especially, compound IIIa16 was found to have the best activity with MIC of 0.125 µg/mL against MTB and with MIC in the range of 0.05-0.48 µg/mL against drug-resistant clinical MTB isolates.

Adverse drug reactions in South African patients receiving bedaquiline-containing tuberculosis treatment: an evaluation of spontaneously reported cases.

BACKGROUND: Bedaquiline was recently introduced into World Health Organization (WHO)-recommended regimens for treatment of drug resistant tuberculosis. There is limited data on the long-term safety of bedaquiline. Because bedaquiline prolongs the QT interval, there are concerns regarding cardiovascular safety. The Western Cape Province in South Africa has an established pharmacovigilance programme: a targeted spontaneous reporting system which solicits reports of suspected adverse drug reactions (ADRs) in patients with HIV-1 and/or tuberculosis infection. Since 2015, bedaquiline has been included in the treatment regimens recommended for resistant tuberculosis in South Africa. We describe ADRs in patients on bedaquiline-containing tuberculosis treatment that were reported to the Western Cape Pharmacovigilance programme. METHODS: We reviewed reports of suspected ADRs and deaths received between March 2015 and June 2016 involving patients receiving bedaquiline-containing tuberculosis treatment. A multidisciplinary panel assessed causality, and categorised suspected ADRs using World Health Organisation-Uppsala Monitoring Centre system categories. "Confirmed ADRs" included all ADRs categorised as definite, probable or possible. Preventability was assessed using Schumock and Thornton criteria. Where a confirmed ADR occurred in a patient who died, the panel categorised the extent to which the ADR contributed to the patient's death as follows: major contributor, contributor or non-contributor. RESULTS: Thirty-five suspected ADRs were reported in 32 patients, including 13 deaths. There were 30 confirmed ADRs, of which 23 were classified as "possible" and seven as "probable". Bedaquiline was implicated in 22 confirmed ADRs in 22 patients. The most common confirmed ADR in patients receiving bedaquiline was QT prolongation (8 cases, 7 of which were severe). A fatal arrhythmia was suspected in 4 sudden deaths. These 4 patients were all taking bedaquiline together with other QT-prolonging drugs. There were 8 non-bedaquiline-associated ADRs, of which 7 contributed to deaths. CONCLUSIONS: Confirmed ADRs in patients receiving bedaquiline reflect the known safety profile of bedaquiline. Quantifying the incidence and clinical consequences of severe QT-prolongation in patients receiving bedaquiline-containing regimens is a research priority to inform recommendations for patient monitoring in treatment programmes for drug resistant tuberculosis. Pharmacovigilance systems within tuberculosis treatment programmes should be supported and encouraged, to provide ongoing monitoring of treatment-limiting drug toxicity.

Comparison of GeneXpert and line probe assay for detection of Mycobacterium tuberculosis and rifampicin-mono resistance at the National Tuberculosis Reference Laboratory, Kenya.

BACKGROUND: The dual challenge of low diagnostic sensitivity of microscopy test and technical challenge of performing a TB culture test poses a problem for case detection and initiation of Tuberculosis (TB) second-line treatment. There is thus need for a rapid, reliable and easily accessible assay. This comparative analysis was performed to assess diagnostic performance characteristics of GeneXpert MTB/RIF and Line Probe Assay (LPA). METHODS: Three hundred twenty nine sputum samples of patients across the 47 counties in Kenya suspected to have drug resistant TB were picked and subjected to GeneXpert, LPA and Culture MGIT at the National TB Reference Laboratory. Sensitivity, specificity and predictive values were then determined to assess the performance characteristics of the various assays. RESULTS: Against culture MGIT as the gold standard for TB diagnosis, GeneXpert had a sensitivity, specificity, positive predictive value, and negative predictive value of 78.5, 64.9, 59.4 and 82.2% respectively while LPA had 98.4, 66.0, 65.4 and 98.4%. For diagnosis of rifampicin mono-resistance GeneXpert had a moderate agreement (Kappa 0.59, P < 0.01) (sensitivity 62.50%, specificity 96.50%) while LPA that had almost perfect agreement (Kappa = 0.89, p < 0.01) with a (sensitivity 90.0% and specificity 99.1%). CONCLUSION: LPA has a better performance characteristic to GeneXpert and an alternative to culture with regards to detection of RIF's mono-resistance.

Clinical Management of Multidrug-Resistant Tuberculosis in 16 European Countries.

RATIONALE: Multidrug-resistant tuberculosis (MDR-TB) is a major burden to public health in Europe. Reported treatment success rates are around 50% or less, and cure rates are even lower. OBJECTIVES: To document the management and treatment outcome in patients with MDR-TB in Europe. METHODS: We performed a prospective cohort study, analyzing management and treatment outcomes stratified by incidence of patients with MDR-TB in Europe. Treatment outcomes were compared by World Health Organization and alternative simplified definitions by the Tuberculosis Network European Trialsgroup (TBNET). MEASUREMENTS AND MAIN RESULTS: A total of 380 patients with MDR-TB were recruited and followed up between 2010 and 2014 in 16 European countries. Patients in high-incidence countries compared with low-incidence countries were treated more frequently with standardized regimen (83.2% vs. 9.9%), had delayed treatment initiation (median, 111 vs. 28 d), developed more additional drug resistance (23% vs. 5.8%), and had increased mortality (9.4% vs. 1.9%). Only 20.1% of patients using pyrazinamide had proven susceptibility to the drug. Applying World Health Organization outcome definitions, frequency of cure (38.7% vs. 9.7%) was higher in high-incidence countries. Simplified outcome definitions that include 1 year of follow-up after the end of treatment showed similar frequency of relapse-free cure in low- (58.3%), intermediate- (55.8%), and high-incidence (57.1%) countries, but highest frequency of failure in high-incidence countries (24.1% vs. 14.6%). CONCLUSIONS: Conventional standard MDR-TB treatment regimens resulted in a higher frequency of failure compared with individualized treatments. Overall, cure from MDR-TB is substantially more frequent than previously anticipated, and poorly reflected by World Health Organization outcome definitions.