Mortality and sequelae of tuberculous meningitis in a high-resource setting: A cohort study, 1990–2017 / Mortalidad y secuelas de la meningitis tuberculosa en Barcelona (España): Estudio de cohortes, 1990-2017

Introduction: Tuberculous meningitis (TBM), the most serious form of tuberculosis, results in high mortality and long-term disability in low-resource countries. We investigated temporal trends in mortality and sequelae in a high-resource low-incidence country. Methods: We performed a retrospective cohort study of all adult patients with TBM at two third-level teaching hospitals in Barcelona (Spain), between January 1990 and December 2017, assessing temporal trends in mortality and sequelae after 12 months over four consecutive 7-year time windows. Rates observed across the four periods were adjusted for covariates. Results: Of the 135 cases included, all but one started tuberculosis (TB) treatment and 120 (89.6%) received rifampicin, isoniazid, and pyrazinamide, with or without ethambutol. The probability of being alive at month 12 was 81.8%, with no differences among the four periods: in comparison with the 1990–1996 period, the adjusted hazard ratios and 95% confidence intervals (CI) were 2.55 (0.71–9.25), 0.70 (0.13–3.85), and 1.29 (0.28–5.91) for the 1997–2003, 2004–2010, and 2011–2017 periods respectively. Sequelae were present in 28.3% at month 12, with no differences across the four periods in the adjusted analysis: in comparison with the 1990–1996 period, the odds ratios and 95% CIs were 0.80 (0.09–7.22); 1.94 (0.21–17.96), and 2.42 (0.25–23.07) for the 1997–2003, 2004–2010, and 2011–2017 periods respectively. Conclusion: This study shows that TBM still causes high mortality and disability even in a high-resource low-incidence TB setting and without improvement over time.(AU)

Introducción: La meningitis tuberculosa (TBM), la forma más grave de tuberculosis, provoca una alta mortalidad y discapacidad a largo plazo en países con bajos recursos. Nuestro objetivo es investigar la tendencia temporal de la mortalidad y las secuelas en un país con recursos elevados y baja incidencia. Métodos: Hemos realizado un estudio de cohortes retrospectivo de los pacientes adultos con TBM en dos hospitales universitarios de tercer nivel en Barcelona (España), entre 1990 y 2017, evaluando las tendencias temporales de mortalidad y secuelas a los 12 meses, comparando cuatro periodos consecutivos de siete años. Las tasas observadas en los cuatro periodos se han ajustado por covariables. Resultados: De los 135 casos incluidos, todos menos uno inició tratamiento antituberculoso y 120 (89,6%) recibieron rifampicina, isoniazida y pirazinamida, con o sin etambutol. La probabilidad de estar vivo a los 12 meses fue de 81,8%, sin diferencias entre los cuatro periodos: en comparación con el periodo 1990-1996, los coeficientes de riesgo ajustados y los intervalos de confianza (IC) del 95% fueron 2,55 (0,71-9,25), 0,70 (0,13-3,85) y 1,29 (0,28-5,91) para los periodos 1997-2003, 2004-2010 y 2011-2017, respectivamente. Las secuelas estaban presentes en 28,3% en el mes 12, sin diferencias entre los cuatro periodos en el análisis ajustado: en comparación con el periodo 1990-1996, los coeficientes de probabilidad y los IC 95% fueron 0,80 (0,09-7,22); 1,94 (0,21-17,96) y 2,42 (0,25-23,07) para los periodos 1997-2003, 2004-2010 y 2011-2017, respectivamente. Conclusión: Este estudio muestra que la TBM todavía causa una alta mortalidad y discapacidad sin mejoría con el tiempo, incluso en un entorno con baja incidencia de tuberculosis y con elevados recursos.(AU)

Mortality and sequelae of tuberculous meningitis in a high-resource setting: A cohort study, 1990-2017.

INTRODUCTION: Tuberculous meningitis (TBM), the most serious form of tuberculosis, results in high mortality and long-term disability in low-resource countries. We investigated temporal trends in mortality and sequelae in a high-resource low-incidence country. METHODS: We performed a retrospective cohort study of all adult patients with TBM at two third-level teaching hospitals in Barcelona (Spain), between January 1990 and December 2017, assessing temporal trends in mortality and sequelae after 12 months over four consecutive 7-year time windows. Rates observed across the four periods were adjusted for covariates. RESULTS: Of the 135 cases included, all but one started tuberculosis (TB) treatment and 120 (89.6%) received rifampicin, isoniazid, and pyrazinamide, with or without ethambutol. The probability of being alive at month 12 was 81.8%, with no differences among the four periods: in comparison with the 1990-1996 period, the adjusted hazard ratios and 95% confidence intervals (CI) were 2.55 (0.71-9.25), 0.70 (0.13-3.85), and 1.29 (0.28-5.91) for the 1997-2003, 2004-2010, and 2011-2017 periods respectively. Sequelae were present in 28.3% at month 12, with no differences across the four periods in the adjusted analysis: in comparison with the 1990-1996 period, the odds ratios and 95% CIs were 0.80 (0.09-7.22); 1.94 (0.21-17.96), and 2.42 (0.25-23.07) for the 1997-2003, 2004-2010, and 2011-2017 periods respectively. CONCLUSION: This study shows that TBM still causes high mortality and disability even in a high-resource low-incidence TB setting and without improvement over time.

Reversions of QuantiFERON-TB Gold Plus in tuberculosis contact investigation: A prospective multicentre cohort study.

BACKGROUND: Interferon-y Release Assays (IGRA) reversions have been reported in different clinical scenarios for the diagnosis of tuberculosis (TB) infection. This study aimed to determine the rate of QuantiFERON-TB Gold Plus (QFT-Plus) reversions during contact investigation as a potential strategy to reduce the number of preventive treatments. METHODS: Prospective, multicentre cohort study of immunocompetent adult contacts of patients with pulmonary TB tested with QFT-Plus. Contacts with an initial positive QFT-Plus (QFT-i) underwent a second test within 4 weeks (QFT-1), and if negative, underwent a repeat test 4 weeks later (QFT-2). Based on the QFT-2 result, we classified cases as sustained reversion if they remained negative and as temporary reversion if they turned positive. RESULTS: We included 415 contacts, of whom 96 (23.1%) had an initial positive test (QFT-i). Following this, 10 had negative QFT-1 results and 4 (4.2%) of these persisted with a negative result in the QFT-2 (sustained reversions). All four sustained reversions occurred in contacts with IFN-γ concentrations between ≥0.35 and ≤0.99 IU•mL-1 in one or both QFT-i tubes. CONCLUSION: In this study, TB contact investigations rarely reveal QFT-Plus reversion. These results do not support retesting cases with an initial positive result to reduce the number of preventive treatments.

Time to sputum conversion in patients with pulmonary tuberculosis: A score to estimate the infectious period.

Introduction: Patients with pulmonary tuberculosis (PTB) disease and positive sputum cultures are the main source of infection. Culture conversion time is inconsistent and defining the length of respiratory isolation is challenging. The objective of this study is to develop a score to predict the length of isolation period. Methods: A retrospective study was carried out to evaluated risk factors associated with persistent positive sputum cultures after 4 weeks of treatment in 229 patients with PTB. A multivariable logistic regression model was used to determinate predictors for positive culture and a scoring system was created based on the coefficients of the final model. Results: Sputum culture was persistently positive in 40.6%. Fever at consultation (1.87, 95% CI:1.02-3.41), smoking (2.44, 95% CI:1.36-4.37), >2 affected lung lobes (1.95, 95% CI:1.08-3.54), and neutrophil-to-lymphocyte ratio > 3.5 (2.22, 95% CI:1.24-3.99), were significantly associated with delayed culture conversion. Therefore, we assembled a severity score that achieved an area under the curve of 0.71 (95% CI:0.64-0.78). Conclusions: In patients with smear positive PTB, a score with clinical, radiological and analytical parameters can be used as a supplemental tool to assist clinical decisions in isolation period.

Lessons learned in aortoenteric fistula repair: a multidisciplinary team approach and diagnostic-therapeutic algorithm matter.

Aortoenteric fistula (AEF) is a low-prevalence, life-threatening condition regardless of treatment, with a 30-50% postoperative (≤60 days) mortality. This study aimed to estimate our postoperative cumulative mortality incidence and assess the feasibility of the diagnostic-therapeutic algorithm used in our clinical practice. We performed a retrospective cohort study of patients treated for AEF at a fully-equipped tertiary healthcare center between January 2008 and December 2020.

Comparison of three short-course rifamycin-based regimens for the prevention of tuberculosis in patients with end-stage kidney disease: Study protocol for a randomised clinical trial (RIFAKiD-TB trial).

BACKGROUND AND PURPOSE: Screening for and treatment of latent tuberculosis (TB) in patients with end-stage kidney disease (ESKD) are recommended. However, there is limited evidence on safety and treatment completion in this population. The objective of the study is to evaluate three short-course rifamycin-based regimens for the treatment of latent TB in ESKD patients. METHODS: Study design and setting. This is a prospective, open label, randomized clinical trial, that will be conducted at seven teaching hospitals in Spain. Study population, randomization, and interventions. Consecutive adult patients with ESKD requiring treatment for a latent TB infection will be randomly allocated (1:1:1) to receive one of the three treatment regimens of the study: three months of daily isoniazid plus rifampicin (3HR); three months of once-weekly isoniazid plus rifapentine (3HP); or four months of daily rifampicin (4R). Participants will be followed regularly through pre-established visits and a blood test schedule from enrolment to a month after finishing the assigned treatment. Outcomes. The primary outcome will be treatment completion, while the secondary outcomes will be discontinuation of the assigned treatment due to adverse events, related or unrelated to the study treatment; definitive discontinuation of the assigned treatment because of adverse events related to the treatment of the study, and death. Sample size. Two hundred and twenty-five subjects (75 per arm) will be enrolled, which will enable the demonstration, if it exists, of an increase of 0.16 in treatment completion rates either in the 3HP or 4R arm with respect to the 3HR arm. DISCUSSION: Results of this clinical trial will contribute to evidence-based recommendations on the management of latent TB infection in ESKD patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05021731.

Consensus management recommendations for less common non-tuberculous mycobacterial pulmonary diseases.

The 2020 clinical practice guideline for the treatment of non-tuberculous mycobacterial pulmonary disease (NTM-PD) by the American Thoracic Society, European Respiratory Society, European Society of Clinical Microbiology and Infectious Diseases, and Infectious Diseases Society of America; and the 2017 management guideline by the British Thoracic Society covered pulmonary diseases in adults caused by Mycobacterium avium complex, Mycobacterium kansasii, Mycobacterium xenopi, and Mycobacterium abscessus. In order to provide evidence-based recommendations for the treatment of less common non-tuberculous mycobacterial (NTM) species in adult patients without cystic fibrosis or HIV infection, our expert panel group performed systematic literature searches to provide management guidance for pulmonary diseases caused by seven additional organisms: Mycobacterium chelonae, Mycobacterium fortuitum, Mycobacterium genavense, Mycobacterium gordonae, Mycobacterium malmoense, Mycobacterium simiae, and Mycobacterium szulgai. Treatment recommendations were developed by a structured consensus process. The evidence from the scientific literature published in English for treatment recommendations for pulmonary diseases caused by other NTM species was of very low quality, with the exception of M malmoense, and based on the evaluation of case reports and case series. For M malmoense, results from two randomised controlled trials and three retrospective cohort studies provided a better evidence base for treatment recommendations, although the evidence was still of low quality.

Identification of Recent Tuberculosis Exposure Using QuantiFERON-TB Gold Plus, a Multicenter Study.

We investigated whether the difference of antigen tube 2 (TB2) minus antigen tube 1 (TB1) (TB2-TB1) of the QuantiFERON-TB gold plus test, which has been postulated as a surrogate for the CD8+ T-cell response, could be useful in identifying recent tuberculosis (TB) exposure. We looked at the interferon gamma (IFN-γ) responses and differences in TB2 and TB1 tubes for 686 adults with QFT-plus positive test results. These results were compared among groups with high (368 TB contacts), low (229 patients with immune-mediated inflammatory diseases [IMID]), and indeterminate (89 asylum seekers or people from abroad [ASPFA]) risks of recent TB exposure. A TB2-TB1 value >0.6 IU·ml-1 was deemed to indicate a true difference between tubes. In the whole cohort, 13.6%, 10.9%, and 11.2% of cases had a TB2>TB1 result in the contact, IMID, and ASPFA groups, respectively (P = 0.591). The adjusted odds ratios (aORs) for an association between a TB2-TB1 result of >0.6 IU·ml-1 and risk of recent exposure versus contacts were 0.71 (95% confidence interval [CI], 0.31 to 1.61) for the IMID group and 0.86 (95% CI, 0.49 to 1.52) for the ASPFA group. In TB contact subgroups, 11.4%, 15.4%, and 17.7% with close, frequent, and sporadic contact had a TB2>TB1 result (P = 0.362). The aORs versus the close subgroup were 1.29 (95% CI, 0.63 to 2.62) for the frequent subgroup and 1.55 (95% CI, 0.67 to 3.60) for the sporadic subgroup. A TB2-TB1 difference of >0.6 IU·ml-1 was not associated with increased risk of recent TB exposure, which puts into question the clinical potential as a proxy marker for recently acquired TB infection. IMPORTANCE Contact tuberculosis tracing is essential to identify recently infected people, who therefore merit preventive treatment. However, there are no diagnostic tests that can determine whether the infection is a result of a recent exposure or not. It has been suggested that by using the QuantiFERON-TB gold plus, an interferon gamma (IFN-γ) release assay, a difference in IFN-γ production between the two antigen tubes (TB2 minus TB1) of >0.6 IU·ml-1 could serve as a proxy marker for recent infection. In this large multinational study, infected individuals could not be classified according to the risk of recent exposure based on differences in IFN-γ in TB1 and TB2 tubes that were higher than 0.6 IU·ml-1. QuantiFERON-TB gold plus is not able to distinguish between recent and remotely acquired tuberculosis infection, and it should not be used for that purpose in contact tuberculosis tracing.

Evaluation of the Fully Automated Chemiluminescence Analyzer Liaison XL for the Performance of the QuantiFERON-TB Gold Plus Assay in an Area with a Low Incidence of Tuberculosis.

Diagnosis of latent tuberculosis infection (LTBI) is considered key in the control of tuberculosis. Interferon gamma (IFN-γ) release assays, such as the QuantiFERON-TB Gold Plus test (QFT-Plus), are now widely implemented for the in vitro diagnosis of LTBI. To date, the detection and quantification of IFN-γ has been mostly performed with semiautomated enzyme-linked immunosorbent assays (ELISAs), but several limitations currently exist. The study aims to evaluate the chemiluminescence immunoassay (CLIA) analyzer Liaison XL compared to ELISA for the performance of the QFT-Plus test. Between February and April 2020, 333 heparin blood samples from 323 adult patients were collected at a tertiary teaching hospital in Barcelona, Spain. Overall, the CLIA analyzer Liaison XL performed well for the detection of IFN-γ compared to the ELISA method, demonstrating substantial agreement (κ, 0.872) and great correlation between assays (r, >0.950). CLIA produced significantly higher values of IFN-γ IU per milliliter than the ELISA (P = 0.004 for the TB1 tube and P = 0.010 for the TB2 tube). Many discrepant cases (8/15, 53.3%) corresponded to indeterminate results with ELISA (NIL-corrected mitogen value of <0.5 IU/ml), which, when analyzed with the CLIA analyzer Liaison XL, reverted to interpretable results. In conclusion, this analysis suggests that CLIA presents a greater sensitivity for the identification of LTBI, especially among immunocompromised patients. Furthermore, the analytical variability reported between both ELISA and CLIA methods, especially around the standardized 0.35-IU/ml positivity threshold, suggests the need to refine the interpretative algorithm.

Clinical Significance of Indeterminate QuantiFERON-TB Gold Plus Assay Results in Hospitalized COVID-19 Patients with Severe Hyperinflammatory Syndrome.

Performance of the QuantiFERON-TB Gold Plus (QFT-Plus) assay could be affected by conditions of immune dysregulation. Little is known about the reliability of QTF-Plus in COVID-19 patients. Our aim was to determine the prevalence and the factors related to an indeterminate QFT-Plus test in COVID-19 hospitalized patients, and to analyze its relationship with in-hospital mortality. A retrospective analysis of all hospitalized COVID-19 patients on whom a QTF-Plus assay was performed in a tertiary care public hospital during the first epidemic wave in Spain (March-April 2020). Out of a total of 96 patients included, 34 (35.4%) had an indeterminate result, in all cases due to a lack of response in the mitogen control. Factors related to COVID-19 severity, such as higher lactate dehydrogenase (LDH) (odds ratio [OR] 1.005 [95% confidence interval [CI] 1.002-1.008]) and previous administration of corticosteroids (OR 4.477 [95% CI 1.397-14.345]), were independent predictors for indeterminate QFT-Plus assay. Furthermore, indeterminate results were more frequent among COVID-19 patients who died during hospitalization (29.1% vs. 64.7%; p = 0.005). We conclude that QFT-Plus assay yielded an unexpected, high prevalence of indeterminate results in severe COVID-19 patients. Factors related to worse COVID-19 outcome, such as LDH, as well as corticosteroid use before the QFT-Plus assay, seem to be predictors for an indeterminate result. The role of an indeterminate QFT-Plus result in predicting COVID-19 severity and mortality should be evaluated.

Tuberculosis prevention in patients undergoing kidney transplantation: A nurse-led program for screening and treatment.

BACKGROUND: Systematic screening for, and treatment of, latent tuberculosis (TB) infection is recommended prior to kidney transplant. However, little is known about patient compliance with, or the safety profile of, preventive therapies used in clinical practice. METHODS: This was a retrospective observational study of patients who were eligible for kidney transplant and were evaluated for TB infection between January 2013 and June 2019 at the TB clinic of a tertiary care teaching hospital. All patient data were registered prospectively as part of our nurse-led program before kidney transplant. We assessed completion rates, tolerance with therapy, development of TB, and associated workload. RESULTS: In total, 1568 patients were referred to our TB clinic for evaluation. Preventive therapy was given to 385 patients and completed by 340 (88.3%). Of these, 89 (23.1%) experienced some intolerance, with 27 requiring full discontinuation. After a median follow-up of 45 months (1426 patient-years), 206 (53.5%) of the treated patients received a kidney transplant; only one patient, who failed to complete treatment, developed post-transplant TB (7.01 cases per 10 000 patient-years; 95% confidence interval, 0.35-34.59). Extra nurse or medical visits were required by 268 (69.6%) patients. CONCLUSION: Despite the complexity and workload generated by patients with ESRD awaiting kidney transplant, preventive therapy for TB is effective in most cases. Our experience provides important evidence on the feasibility of preventive therapy for TB before kidney transplant when delivered as part of a comprehensive nurse-led program.

Management of Drug Toxicity in Mycobacterium avium Complex Pulmonary Disease: An Expert Panel Survey.

Adverse events are frequent in nontuberculous mycobacteria pulmonary disease treatment, but evidence to support their management is scarce. An expert panel survey on management of adverse events shows consistent opinions on management of hepatoxicity, ocular toxicity, ototoxicity, tinnitus, and gastrointestinal upset. These opinions can provide assistance in individual patient management decisions.

Multicentre testing of the EUCAST broth microdilution reference method for MIC determination on Mycobacterium tuberculosis.

OBJECTIVES: The first objective of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) subcommittee for antimycobacterial susceptibility testing (AMST), launched in 2016, was to set a reference method for determining the MICs of antituberculous agents, since many protocols are used worldwide and a consensus one is needed for the determination of microbiological breakpoints. METHODS: During 2017 and 2018, MIC determination protocols were evaluated prospectively in a multicentre study within the four AMST laboratories. MIC results were obtained for isoniazid, levofloxacin and amikacin on the reference strain Mycobacterium tuberculosis H37Rv ATCC 27294. Broth microdilution (BMD) in Middlebrook 7H9 and solid medium dilution (SMD) in Middlebrook 7H10 were performed using two inoculum concentrations. MICs were interpreted with regard to visual and 99% inhibition after 7, 14 or 21 days of incubation for BMD and 21 days for SMD. RESULTS: Following the EUCAST reference protocol, intra- and inter-assay agreements were within ±1 MIC dilution for >95% of the observations for the three drugs in both methods. MIC values, presented as MIC mode (range) for BMD and SMD respectively, were: 0.03 (0.015-0.06) mg/L and 0.12 (0.06-0.25) mg/L for isoniazid, 0.25 mg/L (0.25-0.5) and 0.5 mg/L (0.12-0.5) for levofloxacin, and 0.5 mg/L (0.5-1.0) and 0.5 mg/L (0.5-1.0) for amikacin. CONCLUSIONS: Both SMD and BMD were reproducible and eligible as a reference method for MIC determination of the Mycobacterium tuberculosis complex (MTBC). BMD was finally selected as the EUCAST reference method. From now on it will be used to set epidemiological cut-off values and clinical breakpoints of new and old antituberculous agents.

Tumor necrosis factor antagonists for paradoxical inflammatory reactions in the central nervous system tuberculosis: Case report and review.

RATIONALE: Paradoxical reaction/immune reconstitution inflammatory syndrome is common in patients with central nervous system tuberculosis. Management relies on high-dose corticosteroids and surgery when feasible. PATIENT CONCERN: We describe 2 cases of HIV-negative patients with corticosteroid-refractory paradoxical reactions of central nervous system tuberculosis. DIAGNOSES: The 2 patients experienced clinical impairment shortly after starting therapy for TB, and magnetic resonance imaging showed the presence of tuberculomas, leading to the diagnosis of a paradoxical reaction. INTERVENTIONS: We added infliximab, an anti-tumor necrosis factor (TNF)-alpha monoclonal antibody, to the dexamethasone. OUTCOMES: Both patients had favorable outcomes, 1 achieving full recovery but 1 suffering neurologic sequelae. LESSONS: Clinicians should be aware of the risk of paradoxical reactions/immune reconstitution inflammatory syndrome when treating patients with tuberculosis of the central nervous system and should consider the prompt anti-TNF-α agents in cases not responding to corticosteroids.

Management of Tuberculosis: Are the Practices Homogeneous in High-Income Countries?

Objectives: To evaluate and compare practices regarding the diagnosis, isolation measures, and treatment of tuberculosis (TB) in high-income countries and mainly in Europe. Materials and Methods: A survey was conducted from November 2018 to April 2019 within the European Society of Clinical Microbiology and Infectious Diseases Study Group for Mycobacterial Infections (ESGMYC). The practices observed were compared to the main international guidelines. Results: Among 136 ESGMYC members, 64 (17 countries) responded to the questionnaire. In their practice, two (20.7%) or three sputum samples (79.3%) were collected for the diagnosis of pulmonary TB, alternatively induced sputum (n = 37, 67.2%), bronchoscopy (34, 58.6%), and gastric aspirates (15, 25.9%). Nucleic acid amplification tests (NAATs) were performed by 41 (64%) respondents whatever the smear result and by 47 (73%) in case of smear-positive specimens. NAAT and adenosine deaminase measurement were used for extrapulmonary TB diagnosis in 83.6 and 40.4% of cases, respectively. For isolation duration, 21 respondents (42.9%) were keeping isolation until smear negativity. An initial treatment without ethambutol was offered by 14% (n = 9) of respondents. Corticosteroid therapy, cerebrospinal fluid opening pressure testing, and repeated lumbar puncture were carried out for central nervous system TB by 79.6, 51.9, and 46.3% of the respondents, respectively. For patients with human immunodeficiency virus-TB coinfection, the preferred antiretroviral therapy included dolutegravir 50 mg twice a day (56.8%). Comparing with the recommendations of the main guidelines, the practices are not totally consistent. Conclusion: This study shows heterogeneous practices, particularly for diagnosis, and isolation, although rapid molecular testing is implemented in most centers. More standardization might be needed.

Treatment of Nontuberculous Mycobacterial Pulmonary Disease: An Official ATS/ERS/ESCMID/IDSA Clinical Practice Guideline.

Nontuberculous mycobacteria (NTM) represent over 190 species and subspecies, some of which can produce disease in humans of all ages and can affect both pulmonary and extrapulmonary sites. This guideline focuses on pulmonary disease in adults (without cystic fibrosis or human immunodeficiency virus infection) caused by the most common NTM pathogens such as Mycobacterium avium complex, Mycobacterium kansasii, and Mycobacterium xenopi among the slowly growing NTM and Mycobacterium abscessus among the rapidly growing NTM. A panel of experts was carefully selected by leading international respiratory medicine and infectious diseases societies (ATS, ERS, ESCMID, IDSA) and included specialists in pulmonary medicine, infectious diseases and clinical microbiology, laboratory medicine, and patient advocacy. Systematic reviews were conducted around each of 22 PICO (Population, Intervention, Comparator, Outcome) questions and the recommendations were formulated, written, and graded using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Thirty-one evidence-based recommendations about treatment of NTM pulmonary disease are provided. This guideline is intended for use by healthcare professionals who care for patients with NTM pulmonary disease, including specialists in infectious diseases and pulmonary diseases.

Antimicrobial susceptibility testing of Mycobacterium tuberculosis complex isolates - the EUCAST broth microdilution reference method for MIC determination.

SCOPE: Several methods are used worldwide for antibiotic susceptibility testing (AST) for the Mycobacterium tuberculosis complex (MTBC). The variability in the results obtained with these methods hampers setting epidemiological cut-off (ECOFF) values and clinical breakpoints according to EUCAST guidelines. Methods for susceptibility testing and determination of the minimal inhibitory concentrations (MICs) need to be standardized for MTBC isolates for old and new agents. Our objective was to establish a standardized reference method for MIC determination for MTBC. METHODS: The EUCAST antimycobacterial susceptibility testing subcommittee (AMST) compared protocols of MIC determination with regard to medium, inoculum preparation, antituberculous agent preparation, incubation, reading of the results and interpretation. RECOMMENDATIONS: The EUCAST reference method of MIC determination for MTBC is the broth microdilution method in Middlebrook 7H9-10% OADC medium. The final inoculum is a 105 CFU/mL suspension, obtained from a 10-2 dilution of a 0.5 McFarland suspension prepared after vortexing bacterial colonies with glass beads before suspending them in sterile water. The culture is maintained in a U-shaped 96-well polystyrene microtitre sterile plate with a lid incubated at 36° ± 1°C. Reading is done using an inverted mirror as soon as the 1:100 diluted control (i.e. 103 CFU/mL suspension) shows visual growth. The MIC, expressed in mg/L, is the lowest concentration that inhibits visual growth. Mycobacterium tuberculosis H37Rv ATCC 27294 is used as the reference strain and its targeted MIC values are within the range 0.03-0.12 for isoniazid, 0.12-0.5 for levofloxacin and 0.25-1 mg/L for amikacin. CONCLUSIONS: The EUCAST reference method for MTBC was endorsed by EUCAST after public consultation and will from now on be used to define EUCAST ECOFFs and clinical breakpoints. This reference method is not primarily intended to be used under routine conditions and the AST methods will need to be calibrated against this reference method to be used with EUCAST breakpoints.