Medicamentos para Tuberculosis Resistente/Latente ISSS / Medications for resistant/latent tuberculosis ISSS

INTRODUCCIÓN: El presente documento muestra el resultado de la evaluación de la solicitud de incorporación de los medicamentos Delamanid 50 mg tableta, Pretomanid 200 mg tabletas y Rifapentina 150 mg tabletas como parte de la terapia para Tuberculosis Multidrogorresistente (TB-MDR), Tuberculosis Extensamente Drogorrresistente (TB -XDR) y Tuberculosis Latente (ILTB). TECNOLOGÍA: Delamanid 50 mg tableta, Pretomanid 200 mg tabletas, Rifapentina 150 mg tabletas. OBJETIVO: Evaluar la incorporación de las tecnologías en el esquema de tratamiento de Tuberculosis Farmacorresistente y Tuberculosis Latente. OBJETIVO Evaluar la incorporación de las tecnologías en el esquema de tratamiento de Tuberculosis Farmacorresistente y Tuberculosis Latente. MÉTODOS: l. Verificación de disponibilidad local en la Dirección Nacional de Medicamentos (DNM). 2. Investigación en Agencias Reguladoras (AEMPS/EMA/FDA) para verificación de la indicación. 3. Informe Técnico Revisión de la evidencia científica/ Revisión de directrices de la Organización Mundial de la Salud OMS y Guías Clínicas del Ministerio de Salud de El Salvador (MINSAL). 4. Costos de los medicamentos. 5. Conclusiones 6. Recomendaciones. RESULTADOS: Se evaluó información científica disponible, como guías, lineamientos y Evaluaciones de Tecnología Sanitaria, de acuerdo a la evidencia científica disponible, los medicamentos solicitados se encuentran dentro de las directrices para el manejo de Tuberculosis Farmacorresistente y Tuberculosis Latente de la Organización Mundial de la Salud (OMS) y Ministerio de Salud de El Salvador (MINSAL). CONCLUSIONES: Actualmente, los medicamentos solicitados no están comercializados en el país, pero forman parte del Lista de Medicamentos Fondo Estratégico OPS Las Agencias Reguladoras consultadas muestran que los fármacos cuentan con autorización uso para las indicaciones solicitadas Así mismo, las directrices emitidas por la OMS, los fármacos Delamanid 50 mg tableta y Pretornanid 200 mg tabletas están aprobados para el tratamiento de tuberculosis Tuberculosis Multidrogorresistente (TB-MDR) y Tuberculosis Extensamente Drogorrresistente (TB -XDR) Según lo establecido por la OMS y por MINSAL, Rifapentina se puede utilizar como tratamiento preventivo en Tuberculosis Latente (ILTB), tanto en países de incidencia alta como incidencia baja.

Pooling sputum testing to diagnose tuberculosis using xpert MTB/RIF and xpert ultra: a cost-effectiveness analysis.

BACKGROUND: The World Health Organization (WHO) recommends the diagnosis of tuberculosis (TB) using molecular tests, such as Xpert MTB/RIF (MTB/RIF) or Xpert Ultra (Ultra). These tests are expensive and resource-consuming, and cost-effective approaches are needed for greater coverage. METHODS: We evaluated the cost-effectiveness of pooling sputum samples for TB testing by using a fixed amount of 1,000 MTB/RIF or Ultra cartridges. We used the number of people with TB detected as the indicator for cost-effectiveness. Cost-minimization analysis was conducted from the healthcare system perspective and included the costs to the healthcare system using pooled and individual testing. RESULTS: There was no significant difference in the overall performance of the pooled testing using MTB/RIF or Ultra (sensitivity, 93.9% vs. 97.6%, specificity 98% vs. 97%, p-value > 0.1 for both). The mean unit cost across all studies to test one person was 34.10 international dollars for the individual testing and 21.95 international dollars for the pooled testing, resulting in a savings of 12.15 international dollars per test performed (35.6% decrease). The mean unit cost per bacteriologically confirmed TB case was 249.64 international dollars for the individual testing and 162.44 international dollars for the pooled testing (34.9% decrease). Cost-minimization analysis indicates savings are directly associated with the proportion of samples that are positive. If the TB prevalence is ≥ 30%, pooled testing is not cost-effective. CONCLUSION: Pooled sputum testing can be a cost-effective strategy for diagnosis of TB, resulting in significant resource savings. This approach could increase testing capacity and affordability in resource-limited settings and support increased testing towards achievement of WHO End TB strategy.

Performance Assessment of Xpert MTB/RIF Assay for Detecting Pulmonary Tuberculosis and Rifampin Resistance in a Tertiary Care Hospital in Korea.

In this study, we aimed to assess the performance of the Xpert MTB/RIF assay for the detection of pulmonary tuberculosis compared to the acid-fast bacilli (AFB) smear and culture analysis, and the incidence of rifampin resistance using the drug susceptibility test. The specimens referred for AFB smear and culture analysis and Xpert MTB/RIF assay from April 2015 to March 2018 were retrospectively reviewed. The sensitivity, specificity, and mean cycle threshold (Ct) values obtained in Xpert MTB/RIF assay and for rifampin resistance were analyzed. The results of Xpert MTB/RIF assay for pulmonary tuberculosis were evaluated based on the AFB smear grade. Among 3,840 specimens, 491 were positive in Xpert MTB/RIF assay and 626 in culture analysis. The sensitivity and specificity of Xpert MTB/RIF assay were 75.6% and 99.4%, respectively. The sensitivity of Xpert MTB/RIF assay for smear-positive/culture-positive specimens was 98.6% and that of smear-negative and -trace/culture-positive specimens was 63.1%. The positivity of Xpert MTB/RIF assay for culture-positive specimens was 89.9%, 98.6%, 95.7%, 100.0%, and 100.0% for the smear grades trace, 1+, 2+, 3+, 4+, respectively. The Ct values of 491 specimens significantly decreased as the AFB smear grade increased (P < 0.0001). The Ct values of smear-positive, -trace, and -negative specimens were 21.7 ± 4.2, 26.5 ± 3.9, and 27.4 ± 3.6, respectively. Rifampin resistance evaluated using Xpert MTB/RIF assay and culture analysis exhibited a correlation of 98.3%. The region covered by probe E was the most frequently mutated region (50.0%). Xpert MTB/RIF assay demonstrated reliable performance in detecting pulmonary tuberculosis from smear-positive and culture-positive specimens; however, further improvements are still required to detect smear-negative and culture-positive specimens.

Coverage and fidelity of the Xpert MTB/RIF™ implementation in a high-burden area for pulmonary tuberculosis in Colombia / [Cobertura y fidelidad de la prueba Xpert MTB/RIF™ en un área de alta carga de tuberculosis pulmonar en Colombia].

Introduction: The Xpert MTB/RIF™ is a rapid molecular test that diagnoses tuberculosis and rifampin resistance. Since 2010, it is recommended by the World Health Organization (WHO) and although it was introduced in Colombia since 2012, the results of its implementation are unknown. Objective: To describe the coverage and fidelity in the implementation of the Xpert MTB/RIF™ in patients with pulmonary tuberculosis in a city with a high burden for the disease in Colombia. Materials and methods: We conducted a retrospective, descriptive study of cases from a tuberculosis program in Cali between 2013 and 2019. We estimated the coverage as the total number of tests used compared to the cases registered in the program and the fidelity based on international Xpert MTB/RIF™ implementation protocols. We performed a multivariate analysis of multiple correspondences between the test and the sociodemographic variables. Results: We included 6,328 patients with pulmonary tuberculosis of whom 181 were drugresistant. The Xpert MTB/RIF™ coverage was 10,3% (n=655) with an annual variation between 0.2% and 23%. Loyalty among the highest risk groups of MDR-TB was 46.8%. The use of the test was related to being an Afro-Colombian man between 41 and 60 years of age. Conclusions: The coverage of the Xpert MTB/RIF in Cali is low and its use does not follow the recommended prioritization for its implementation. Implementation strategies are required for its proper use to contribute to the goal of ending tuberculosis.

Introducción. La prueba Xpert MTB/RIF™ es una prueba molecular rápida para el diagnóstico de la tuberculosis y la resistencia a la rifampicina. Desde el 2010 es la recomendada por la Organización Mundial de la Salud (OMS) y, aunque fue introducida en Colombia en el 2012, se desconocen los resultados de su uso. Objetivo. Describir la cobertura y la fidelidad en el uso de la prueba Xpert MTB/RIF™ en pacientes con tuberculosis pulmonar en una ciudad con alta carga de la enfermedad en Colombia. Materiales y métodos. Se hizo un estudio retrospectivo descriptivo de casos del programa de tuberculosis en Cali entre el 2013 y el 2019. La cobertura se estimó como el total de pruebas empleadas en los casos registrados en el programa. La fidelidad se midió con base en los protocolos internacionales de uso de la Xpert MTB/RIF™. Además, se hizo un análisis de correspondencias múltiples entre la prueba y las variables sociodemográficas. Resultados. Se incluyeron 6.328 pacientes con tuberculosis pulmonar, de los cuales 181 eran resistentes a los fármacos. La cobertura total de la Xpert MTB/RIF™ durante el periodo de estudio fue de 10,3 % (n=655), con una variación anual entre 0,2 y 23 %. La fidelidad fue de 46,8 % para los grupos de mayor riesgo de tuberculosis multirresistente (TB-MDR). El uso de la prueba se relacionó con la condición de ser hombre, afrocolombiano, y tener entre 41 y 60 años de edad. Conclusiones. La cobertura de la prueba Xpert MTB/RIF™ en Cali es baja y su uso no responde a la priorización recomendada para su implementación. Se requieren estrategias para promover su uso adecuado, de manera que contribuya a la meta de poner fin a la tuberculosis.

Factors associated with catastrophic total costs due to tuberculosis under a designated hospital service model: a cross-sectional study in China.

BACKGROUND: Certain districts and counties in China designated local general hospital as the designated hospital for tuberculosis (TB) management after the promulgation of the Law of Practicing Physicians in 2009. To our knowledge, there is limited research on catastrophic payments of TB patients under this service model, often with inconsistent conclusions. In addition, there has been no published studies from China using the updated 2018 World Health Organization (WHO) definition of catastrophic total costs due to TB. This study used the latest criterion recommended by the WHO to analyze the incidence of catastrophic total costs for households affected by TB under the designated hospital model and explore its influencing factors. METHODS: A cross-sectional analysis was carried out in all ten designated hospitals in Ningbo, China. Eligible pulmonary TB cases confirmed by sputum culture of Mycobacterium tuberculosis were recruited and surveyed from September 2018 to October 2018. We evaluated catastrophic total costs using total costs for TB treatment exceeding 20% of the household's annual pre-TB income. A sensitivity analysis was performed while varying the thresholds. The least absolute shrinkage and selection operator (LASSO) regression were applied to select variables, and multiple logistic regression analysis were used to identify the determinants of catastrophic total costs. RESULTS: A total of 672 patients were included, with a median age of 41 years old. The rate of catastrophic total costs of surveyed households was 37.1%, and that of households affected by MDR was 69.6%. Medical cost accounted for more than 60% of the total cost. 57.7% cases were hospitalized. The hospitalization rates of patients with no comorbidities, no severe adverse drug reactions, and rifampin-sensitive TB were 53.9, 54.9, and 55.3%, respectively. Patients in the poorest households had the highest hospitalization rates (Q1:54.8%, Q2:61.4%, Q3:52.2%, Q4:49.5%, Q5:69.7%, P = 0.011) and the highest incidence of severe adverse drug reactions (Q1:29.6%, Q2:19.6%, Q3:28.0%, Q4:33.7%, Q5:35.3%, P = 0.034). Factors such as elderly, minimum living security, unemployed before or after illness, poor economic status, seeking medical care outside the city, hospitalization, absence of local basic medical insurance coverage and MDR were positively associated with catastrophic costs. CONCLUSION: Substantial proportions of patients and households affected by pulmonary TB faced catastrophic economic risks in Ningbo, China. The existing policies that focus on expanding the coverage of basic medical insurance and economic protection measures (such as cash transfers to compensate low-income households for direct non-medical costs and income loss) might be insufficient. Tailored program that mitigate inappropriate healthcare and address equity of care delivery are worthy of attention.

Tuberculosis treatment in the private healthcare sector in India: an analysis of recent trends and volumes using drug sales data.

BACKGROUND: There is a pressing need for systematic approaches for monitoring how much TB treatment is ongoing in the private sector in India: both to cast light on the true scale of the problem, and to help monitor the progress of interventions currently being planned to address this problem. METHODS: We used commercially available data on the sales of rifampicin-containing drugs in the private sector, adjusted for data coverage and indication of use. We examined temporal, statewise trends in volumes (patient-months) of TB treatment from 2013 to 2016. We additionally analysed the proportion of drugs that were sold in combination packaging (designed to simplify TB treatment), or as loose pills. RESULTS: Drug sales suggest a steady trend of TB treatment dispensed by the private sector, from 18.4 million patient-months (95% CI 17.3-20.5) in 2013 to 16.8 patient-months (95% CI 15.5-19.0) in 2016. Overall, seven of 29 states in India accounted for more than 70% of national-level TB treatment volumes, including Uttar Pradesh, Maharashtra and Bihar. The overwhelming majority of TB treatment was dispensed not as loose pills, but in combination packaging with other TB drugs, accounting for over 96% of private sector TB treatment in 2017. CONCLUSIONS: Our findings suggest consistent levels of TB treatment in the private sector over the past 4 years, while highlighting specific states that should be prioritized for intervention. Drug sales data can be helpful for monitoring a system as large, disorganised and opaque as India's private sector.

Pathways and associated costs of care in patients with confirmed and presumptive tuberculosis in Tanzania: A cross-sectional study.

OBJECTIVE: To assess pathways and associated costs of seeking care from the onset of symptoms to diagnosis in patients with confirmed and presumptive tuberculosis (TB). DESIGN: Cross-sectional study. SETTING: District hospital in Dar es Salaam, Tanzania. PARTICIPANTS: Bacteriologically confirmed TB and presumptive TB patients. PRIMARY AND SECONDARY OUTCOME MEASURES: We calculated distance in metres and visualised pathways to healthcare up to five visits for the current episode of sickness. Costs were described by medians and IQRs, with comparisons by gender and poverty status. RESULTS: Of 100 confirmed and 100 presumptive TB patients, 44% of confirmed patients sought care first at pharmacies after the onset of symptoms, and 42% of presumptive patients did so at hospitals. The median visits made by confirmed patients was 2 (range 1-5) and 2 (range 1-3) by presumptive patients. Patients spent a median of 31% of their monthly household income on health expenditures for all visits. The median total direct costs were higher in confirmed compared with presumptive patients (USD 27.4 [IQR 18.7-48.4] vs USD 19.8 [IQR 13.8-34.0], p=0.02), as were the indirect costs (USD 66.9 [IQR 35.5-150.0] vs USD 46.8 [IQR 20.1-115.3], p<0.001). The indirect costs were higher in men compared with women (USD 64.6 [IQR 31.8-159.1] vs USD 55.6 [IQR 25.1-141.1], p<0.001). The median total distance from patients' household to healthcare facilities for patients with confirmed and presumptive TB was 2338 m (IQR 1373-4122) and 2009 m (IQR 986-2976) respectively. CONCLUSIONS: Patients with confirmed TB have complex pathways and higher costs of care compared with patients with presumptive TB, but the costs of the latter are also substantial. Improving access to healthcare and ensuring integration of different healthcare providers including private, public health practitioners and patients themselves could help in reducing the complex pathways during healthcare seeking and optimal healthcare utilisation.

Household contact investigation for the detection of tuberculosis in Vietnam: economic evaluation of a cluster-randomised trial.

BACKGROUND: Active case finding is recommended as an important strategy to control tuberculosis, particularly in low-income and middle-income countries with a high prevalence of the disease. However, the costs and cost-effectiveness of active case finding are unclear due to the absence of evidence from randomised trials. We assessed the costs and cost-effectiveness of an active case finding strategy in Vietnam, where there is a high prevalence of tuberculosis. METHODS: We conducted an economic evaluation alongside the Active Case Finding in Tuberculosis (ACT2) trial-a pragmatic cluster-randomised controlled trial in 70 districts across eight provinces of Vietnam. Patients aged 15 years and older with smear-positive pulmonary tuberculosis were recruited to the trial if they lived with one or more other household members. Household contacts were verbally invited to the clinic by the index patient with tuberculosis. ACT2 compared a combination of active and passive case finding with usual care (passive case finding) of household contacts of patients with tuberculosis from a health system perspective. Clustering occurred at the district and household level. Districts were the unit of randomisation, and we used minimisation to ensure balance of intervention and control districts within each province. In the intervention group, participants were invited to attend screening at baseline, 6 months, 12 months, and 24 months. We determined health-care costs with a standardised national costing survey and reported results in 2017 $US. The primary outcome of our study was disability-adjusted life years (DALYs) averted over a 24-month period. ACT2 was registered prospectively with the Australian and New Zealand Clinical Trials Registry, number ACTRN126.100.00600044. FINDINGS: Between Aug 11, 2010, and Aug 11, 2015, 10 964 index patients and 25 707 household contacts completed the ACT2 study. There were 10 069 household contacts in the intervention group and 15 638 household contacts in the control group. The incremental cost-effectiveness ratio per DALY averted was $544 (330-1375). INTERPRETATION: Active case finding was shown to be highly cost-effective in a setting with a high prevalence of tuberculosis. Investment in the wide-scale implementation of this programme in Vietnam should be strongly supported. FUNDING: Australian National Health and Medical Research Council.

Improving rifampicin-resistant tuberculosis diagnosis using Xpert® MTB/RIF: modelling interventions and costs.

SETTING: Cape Town, South Africa. OBJECTIVE: To model the diagnosis of rifampicin-resistant tuberculosis (RR-TB) and laboratory costs of smear/culture and Xpert-based algorithms and the effect of varying adherence and human immunodeficiency virus (HIV) testing in the Xpert-based algorithm. METHODS: We used a validated operational model (100 000 population) and published laboratory cost data. We estimated the number and cost of RR-TB cases identified using the smear/culture- and Xpert-based algorithms. We modelled varying adherence and different levels of known HIV status against the Xpert-based algorithm. RESULTS: The number of RR-TB cases identified increased from 603 with smear/culture to 1178 with the Xpert-based algorithm (100% adherence; 60% knew their HIV status). The overall laboratory cost increased from US$1 073 858 to US$2 430 050 and the cost per RR-TB case identified increased from US$1781 to US$2063 in the respective algorithms. When adherence to the Xpert-based algorithm was increased from 50% to 100% (60% knew their HIV status), the number of RR-TB cases identified increased from 721 to 1178. CONCLUSION: The Xpert-based algorithm is efficient in identifying RR-TB, as the increase in costs is offset by the increase in the number of cases identified. Adherence to the Xpert-based algorithm is important to ensure that all presumptive TB cases receive the benefit of simultaneous TB and RR-TB testing.

How has the Zimbabwe mycobacterial culture and drug sensitivity testing system among re-treatment tuberculosis patients functioned during the scale-up of the Xpert MTB/RIF assay?

Background: In Zimbabwe, while the Xpert MTB/RIF assay is being used for diagnosing tuberculosis and rifampicin-resistance, re-treatment tuberculosis (TB) patients are still expected to have culture and drug sensitivity testing (CDST) performed at national reference laboratories for confirmation. The study aim was to document the Xpert MTB/RIF assay scale-up and assess how the CDST system functioned for re-treatment TB patients. Methods: We performed an ecologic study using national aggregate data. Results: Use of the Xpert MTB/RIF assay increased from 11 829 to 68 153 between 2012 and 2016. Xpert assays worked well, with successful tests in more than 90% of cases, TB detection rates at 15-17% and rifampicin resistance in <10%. During Xpert scale-up, the number of sputum specimens from re-treatment TB patients reaching national reference laboratories for CDST increased from 12% to 51%. In terms of laboratory performance, culture contamination increased from 3% to 17%, positive cultures from 13% to 17% and successful CDST from 6% to 14%: the proportion of CDST showing any resistance to rifampicin averaged 44%. From 2009 to 2016, the proportion of notified re-treatment TB patients with successful CDST increased from <1% to 7%. Conclusions: While components of Zimbabwe's CDST system for re-treatment TB patients showed some changes during the scale-up of the Xpert MTB/RIF assay, overall performance was poor. The country must either invest in improving CDST performance or in advanced molecular diagnostic technology.

The South African Tuberculosis Care Cascade: Estimated Losses and Methodological Challenges.

Background: While tuberculosis incidence and mortality are declining in South Africa, meeting the goals of the End TB Strategy requires an invigorated programmatic response informed by accurate data. Enumerating the losses at each step in the care cascade enables appropriate targeting of interventions and resources. Methods: We estimated the tuberculosis burden; the number and proportion of individuals with tuberculosis who accessed tests, had tuberculosis diagnosed, initiated treatment, and successfully completed treatment for all tuberculosis cases, for those with drug-susceptible tuberculosis (including human immunodeficiency virus (HIV)-coinfected cases) and rifampicin-resistant tuberculosis. Estimates were derived from national electronic tuberculosis register data, laboratory data, and published studies. Results: The overall tuberculosis burden was estimated to be 532005 cases (range, 333760-764480 cases), with successful completion of treatment in 53% of cases. Losses occurred at multiple steps: 5% at test access, 13% at diagnosis, 12% at treatment initiation, and 17% at successful treatment completion. Overall losses were similar among all drug-susceptible cases and those with HIV coinfection (54% and 52%, respectively, successfully completed treatment). Losses were substantially higher among rifampicin- resistant cases, with only 22% successfully completing treatment. Conclusion: Although the vast majority of individuals with tuberculosis engaged the public health system, just over half were successfully treated. Urgent efforts are required to improve implementation of existing policies and protocols to close gaps in tuberculosis diagnosis, treatment initiation, and successful treatment completion.

Scaling-up the Xpert MTB/RIF assay for the detection of tuberculosis and rifampicin resistance in India: An economic analysis.

BACKGROUND: India is considering the scale-up of the Xpert MTB/RIF assay for detection of tuberculosis (TB) and rifampicin resistance. We conducted an economic analysis to estimate the costs of different strategies of Xpert implementation in India. METHODS: Using a decision analytical model, we compared four diagnostic strategies for TB patients: (i) sputum smear microscopy (SSM) only; (ii) Xpert as a replacement for the rapid diagnostic test currently used for SSM-positive patients at risk of drug resistance (i.e. line probe assay (LPA)); (iii) Upfront Xpert testing for patients at risk of drug resistance; and (iv) Xpert as a replacement for SSM for all patients. RESULTS: The total costs associated with diagnosis for 100,000 presumptive TB cases were: (i) US$ 619,042 for SSM-only; (ii) US$ 575,377 in the LPA replacement scenario; (iii) US$ 720,523 in the SSM replacement scenario; and (iv) US$ 1,639,643 in the Xpert-for-all scenario. Total cohort costs, including treatment costs, increased by 46% from the SSM-only to the Xpert-for-all strategy, largely due to the costs associated with second-line treatment of a higher number of rifampicin-resistant patients due to increased drug-resistant TB (DR-TB) case detection. The diagnostic costs for an estimated 7.64 million presumptive TB patients would comprise (i) 19%, (ii) 17%, (iii) 22% and (iv) 50% of the annual TB control budget. Mean total costs, expressed per DR-TB case initiated on treatment, were lowest in the Xpert-for-all scenario (US$ 11,099). CONCLUSIONS: The Xpert-for-all strategy would result in the greatest increase of TB and DR-TB case detection, but would also have the highest associated costs. The strategy of using Xpert only for patients at risk for DR-TB would be more affordable, but would miss DR-TB cases and the cost per true DR-TB case detected would be higher compared to the Xpert-for-all strategy. As such expanded Xpert strategy would require significant increased TB control budget to ensure that increased case detection is followed by appropriate care.

Cost-effectiveness study of the microbiological diagnosis of tuberculosis using geneXpert MTB/RIF®. / Estudio de coste-efectividad del diagnóstico microbiológico de tuberculosis mediante geneXpert MTB/RIF®.

INTRODUCTION/OBJECTIVE: To perform a cost-effectiveness analysis of a molecular biology technique for the diagnosis of tuberculosis compared to the classical diagnostic alternative. METHODS: A cost-effectiveness analysis was performed to evaluate the theoretical implementation of a molecular biology method including two alternative techniques for early detection of Mycobacterium tuberculosis Complex, and resistance to rifampicin (alternative1: one determination in selected patients; alternative2: two determinations in all the patients). Both alternatives were compared with the usual procedure for microbiological diagnosis of tuberculosis (staining and microbiological culture), and was accomplished on 1,972 patients in the period in 2008-2012. The effectiveness was measured in QALYs, and the uncertainty was assessed by univariate, multivariate and probabilistic analysis of sensitivity. RESULTS: A value of €8,588/QALYs was obtained by the usual method. Total expenditure with the alternative1 was €8,487/QALYs, whereas with alternative2, the cost-effectiveness ratio amounted to €2,960/QALYs. Greater diagnostic efficiency was observed by applying the alternative2, reaching a 75% reduction in the number of days that a patient with tuberculosis remains without an adequate treatment, and a 70% reduction in the number of days that a patient without tuberculosis remains in hospital. CONCLUSION: The implementation of a molecular microbiological technique in the diagnosis of tuberculosis is extremely cost-effective compared to the usual method. Its introduction into the routine diagnostic procedure could lead to an improvement in quality care for patients, given that it would avoid both unnecessary hospitalisations and treatments, and reflected in economic savings to the hospital.

Development, roll-out and impact of Xpert MTB/RIF for tuberculosis: what lessons have we learnt and how can we do better?

The global roll-out of Xpert MTB/RIF (Cepheid Inc., Sunnyvale, CA, USA) has changed the diagnostic landscape of tuberculosis (TB). More than 16 million tests have been performed in 122 countries since 2011, and detection of multidrug-resistant TB has increased three- to eight-fold compared to conventional testing. The roll-out has galvanised stakeholders, from donors to civil society, and paved the way for universal drug susceptibility testing. It has attracted new product developers to TB, resulting in a robust molecular diagnostics pipeline. However, the roll-out has also highlighted gaps that have constrained scale-up and limited impact on patient outcomes. The roll-out has been hampered by high costs for under-funded programmes, unavailability of a complete solution package (notably comprehensive training, quality assurance, implementation plans, inadequate service and maintenance support) and lack of impact assessment. Insufficient focus has been afforded to effective linkage to care of diagnosed patients, and clinical impact has been blunted by weak health systems. In many countries the private sector plays a dominant role in TB control, yet this sector has limited access to subsidised pricing. In light of these lessons, we advocate for a comprehensive diagnostics implementation approach, including increased engagement of in-country stakeholders for product launch and roll-out, broader systems strengthening in preparation for new technologies, as well as quality impact data from programmatic settings.

A call to action: Addressing the reproductive health needs of women with drug-resistant tuberculosis.

Although there is substantial risk to maternal and neonatal health in the situation of pregnancy during treatment for rifampicin-resistant tuberculosis (RR-TB), there is little evidence to guide clinicians as to how to manage this complexity. Of the 49 680 patients initiated on RR-TB treatment from 2009 to 2014 in South Africa, 47% were women and 80% of them were in their reproductive years (15 - 44). There is an urgent need for increased evidence of the safety of RR-TB treatment during pregnancy, increased access to contraception during RR-TB treatment, and inclusion of reproductive health in research on the prevention and treatment of TB.

Cost-effectiveness of the Xpert® MTB/RIF assay for tuberculosis diagnosis in Brazil.

INTRODUCTION: The Xpert® MTB/RIF assay is being implemented as a substitute for sputum smear microscopy (SSM) in many low and high tuberculosis (TB) burden countries, including Brazil, a country with low multidrug resistance and moderate human immunodeficiency virus co-infection rates. SETTING: Brazilian National TB Programme (NTP). OBJECTIVE AND DESIGN: We estimated the incremental cost-effectiveness ratio (ICER) of Xpert as a substitute for two SSM tests in the diagnosis of drug-susceptible TB. The costs for confirming each additional case and for avoiding treatment due to false-positive empirical diagnoses were estimated. RESULTS: The ICER was US$943 for each additional TB diagnosis and US$356 for each additional TB diagnosis with bacteriological confirmation, assuming 80% specificity of clinical diagnosis using both strategies. For every 100 000 patients with suspected TB, the NTP would spend an additional US$1.2 million per year to confirm 3344 more TB patients. The model was highly sensitive to specificity of clinical diagnosis after a negative test. CONCLUSION: Although the NTP has no threshold for cost-effectiveness, our model can provide support for decision makers in Brazil and other countries with a low prevalence of drug resistance among TB patients. Financial benefit can potentially be expected if physicians rely more on a negative Xpert result and empirical treatment is reduced.

Analysis of the Molecular Evolution of the Mycobacterium Tuberculosis Drug-Resistant Gene rpoB in Asia Using a Bayesian Evolutionary Method.

BACKGROUND: Tuberculosis (TB) is a serious communicable disease throughout the world. Re-emergence of the TB epidemic is aggravated by the circulation of multidrug-resistant Mycobacterium tuberculosis strains, and more than half of new cases have occurred in Asia. Therefore, it is important to understand the gene mutations underlying the development of rifampicin resistance in Asia. METHODS: In this study, we classified the rifampicin-resistant Mycobacterium tuberculosis (MTB) rpoB data downloaded from Genbank, based on 12 mutation points. The relationship between the mutation sites and regional information was analyzed, after which the mutation dates and mutation trends of the rpoB gene were predicted by the Markov Chain Monte Carlo (MCMC) method. RESULTS: We discovered that the mutation sites of the rpoB gene were disparate in different regions of Asia. The results of this study clearly showed that drug-resistant gene mutations in Asia started to increase in 2000 and peaked in 2006, indicating the relationship between drug resistance and outbreak trends of TB. CONCLUSIONS: From our analysis, it was not difficult to see the relationship between the mutation rates of the rpoB gene and the outbreak of TB. Hence, to some degree, outbreak trends of TB can be predicted through genotyping based on the rpoB gene.

Routine use of Xpert® MTB/RIF in areas with different prevalences of HIV and drug-resistant tuberculosis.

SETTING: Despite the widespread introduction of Xpert(®) MTB/RIF in developing countries, reports of its use and value in routine conditions remain limited. OBJECTIVE: To describe Xpert results in relation to microscopy, treatment initiation, cost and workload under routine conditions at four sites in Cambodia, Georgia, Kenya and Swaziland. DESIGN: Laboratory and clinical information on presumed TB patients were obtained from routine registers over a period of at least 6 months between March and November 2012. RESULTS: Among the 6086 presumed TB patients included in the analysis, Xpert testing increased the number of biologically confirmed cases by 15% to 67% compared to microscopy. Up to 12% of the initial Xpert results were inconclusive. Between 56% and 83% of patients were started on treatment based on microscopy and/or Xpert results, with median delays of 1-16 days. Rifampicin resistance was detected in 3-19% of Xpert-positive patients. CONCLUSION: Despite the additional numbers of cases detected by Xpert compared to microscopy, large proportions of patients are still started on treatment empirically in routine practice. Patient and specimen flow should be optimised to reduce delays in treatment initiation. Simple, non-sputum-based point-of-care tests with high sensitivity are needed to improve TB diagnosis and management.

Computational pharmacokinetics/pharmacodynamics of rifampin in a mouse tuberculosis infection model.

One critical approach to preclinical evaluation of anti-tuberculosis (anti-TB) drugs is the study of correlations between drug exposure and efficacy in animal TB infection models. While such pharmacokinetic/pharmacodynamic (PK/PD) studies are useful for the identification of optimal clinical dosing regimens, they are resource intensive and are not routinely performed. A mathematical model capable of simulating the PK/PD properties of drug therapy for experimental TB offers a way to mitigate some of the practical obstacles to determining the PK/PD index that best correlates with efficacy. Here, we present a preliminary physiologically based PK/PD model of rifampin therapy in a mouse TB infection model. The computational framework integrates whole-body rifampin PKs, cell population dynamics for the host immune response to Mycobacterium tuberculosis infection, drug-bacteria interactions, and a Bayesian method for parameter estimation. As an initial application, we calibrated the model to a set of available rifampin PK/PD data and simulated a separate dose fractionation experiment for bacterial killing kinetics in the lungs of TB-infected mice. The simulation results qualitatively agreed with the experimentally observed PK/PD correlations, including the identification of area under the concentration-time curve as best correlating with efficacy. This single-drug framework is aimed toward extension to multiple anti-TB drugs in order to facilitate development of optimal combination regimens.