The plasma kynurenine-to-tryptophan ratio as a biomarker of tuberculosis disease in people living with HIV on antiretroviral therapy: an exploratory nested case-control study.

BACKGROUND: Non-sputum-based tests are needed to predict or diagnose tuberculosis (TB) disease in people living with HIV (PWH). The enzyme indoleamine 2, 3-dioxygenase-1 (IDO1) is expressed in tuberculoid granuloma and catabolizes tryptophan (Trp) to kynurenine (Kyn). IDO1 activity compromises innate and adaptive immune responses, promoting mycobacterial survival. The plasma Kyn-to-Trp (K/T) ratio is a potential TB diagnostic and/or predictive biomarker in PWH on long-term antiretroviral therapy (ART). METHODS: We compared plasma K/T ratios in samples from PWH, who were followed up prospectively and developed TB disease after ART initiation. Controls were matched for age and duration of ART. Kyn and Trp were measured at 3 timepoints; at TB diagnosis, 6 months before TB diagnosis and 6 months after TB diagnosis, using ultra performance liquid chromatography combined with mass spectrometry. RESULTS: The K/T ratios were higher for patients with TB disease at time of diagnosis (median, 0.086; IQR, 0.069-0.123) compared to controls (0.055; IQR 0.045-0.064; p = 0.006), but not before or after TB diagnosis. K/T ratios significantly declined after successful TB treatment, but increased upon treatment failure. The K/T ratios showed a parabolic correlation with CD4 cell counts in participants with TB (p = 0.005), but there was no correlation in controls. CONCLUSIONS: The plasma K/T ratio helped identify TB disease and may serve as an adjunctive biomarker for for monitoring TB treatment in PWH. Validation studies to ascertain these findings and evaluate the optimum cut-off for diagnosis of TB disease in PWH should be undertaken in well-designed prospective cohorts. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00411983.

Reasons for, and factors associated with, positive HIV retesting: a cross-sectional study in Eswatini.

Eswatini has a high HIV prevalence but has made progress towards improving HIV-status awareness, ART uptake and viral suppression. However, there is still a delay in ART initiation, which could partly be attributed to positive HIV-retesting. This study examines reasons for, and factors associated with, positive HIV-retesting among MaxART participants in Eswatini. Data from 601 participants is included in this cross-sectional study. Descriptive statistics and logistic regressions were used. Of the participants, 32.8% has ever retested after a previous positive result. Most participants who retested did this because they could not accept their results (61.9% of all retesters). Other main reasons are related to external influences, gender or the progression of their HIV infection (respectively 18.3%, 10.2%, and 6.1% of all retesters). Participants without a current partner and participants with less time since their first positive test have lower odds of retesting. To decrease retesting and reduce the delay in ART initiation resulting from it, efforts could be made on increasing the acceptance of positive HIV results. Providing more information on the process of testing and importance of early ART initiation, could be part of the solution.

Incidence and factors associated with active tuberculosis among people living with HIV after long-term antiretroviral therapy in Thailand: a competing risk model.

BACKGROUND: Antiretroviral therapy (ART) is known to reduce tuberculosis (TB) incidence among people living with HIV (PLWH). However, studies describing the impact of long-term ART and CD4 count recovery on TB incidence remain scarce due to limited follow up in previous studies. We evaluated TB incidence in a long-term cohort of PLWH on ART in Thailand. METHODS: We conducted an analysis of PLWH aged ≥ 18 years who started ART between 1996 and December 2020. Participants were followed up every 6 months for routine HIV care. TB risk factors, body mass index (BMI), physical examination and full differential blood counts were evaluated at each clinic visit, and CD4 cell counts and HIV RNA every 12 months. Participants diagnosed with TB > 3 months after starting ART were classified as incident cases. Time to event models with death as a competing risk, were used to derive the TB cumulative incidence function (CIF) after ART initiation, and assess time-updated factors associated with incident TB using a six month lag. RESULTS: A total of 2,636 PLWH contributing 24,229 person years (PY) of follow-up on ART were analysed. Median age was 32.0 (IQR 27.4-37.6) years; 67.5% were male. Median CD4 cell count at ART initiation was 264 (IQR 167-379) cells/mm3 and median follow-up duration was 7.6 (IQR 1.9-15.7) years. During follow-up, 113 PLWH developed TB. The probability of incident TB was 0.7%, 1.7%, 3.3% and 4.3%, at 1, 2, 5 and 7 years after ART initiation, respectively. TB CIF was highest among participants with CD4 < 50 cells/mm3. The overall crude incidence of TB was 4.66 (95% CI 3.87-5.60) per 1000 PY. Low CD4 count, BMI < 18 kg/m2, and substance use in the previous six months were significantly associated with incident TB. Incidence declined with time on suppressive ART, but remained higher than the Thai general population 7 years after ART initiation (2.2 vs 1.5/1000 PY, respectively). CONCLUSION: Despite a marked reduction in TB incidence following ART, ongoing TB risk remains high among PLWH, despite long-term suppressive ART. Those with low CD4 cell counts, who are underweight, or currently having substance abuse should be carefully monitored.

Prediction of anti-tuberculosis treatment duration based on a 22-gene transcriptomic model.

BACKGROUND: The World Health Organization recommends standardised treatment durations for patients with tuberculosis (TB). We identified and validated a host-RNA signature as a biomarker for individualised therapy durations for patients with drug-susceptible (DS)- and multidrug-resistant (MDR)-TB. METHODS: Adult patients with pulmonary TB were prospectively enrolled into five independent cohorts in Germany and Romania. Clinical and microbiological data and whole blood for RNA transcriptomic analysis were collected at pre-defined time points throughout therapy. Treatment outcomes were ascertained by TBnet criteria (6-month culture status/1-year follow-up). A whole-blood RNA therapy-end model was developed in a multistep process involving a machine-learning algorithm to identify hypothetical individual end-of-treatment time points. RESULTS: 50 patients with DS-TB and 30 patients with MDR-TB were recruited in the German identification cohorts (DS-GIC and MDR-GIC, respectively); 28 patients with DS-TB and 32 patients with MDR-TB in the German validation cohorts (DS-GVC and MDR-GVC, respectively); and 52 patients with MDR-TB in the Romanian validation cohort (MDR-RVC). A 22-gene RNA model (TB22) that defined cure-associated end-of-therapy time points was derived from the DS- and MDR-GIC data. The TB22 model was superior to other published signatures to accurately predict clinical outcomes for patients in the DS-GVC (area under the curve 0.94, 95% CI 0.9-0.98) and suggests that cure may be achieved with shorter treatment durations for TB patients in the MDR-GIC (mean reduction 218.0 days, 34.2%; p<0.001), the MDR-GVC (mean reduction 211.0 days, 32.9%; p<0.001) and the MDR-RVC (mean reduction of 161.0 days, 23.4%; p=0.001). CONCLUSION: Biomarker-guided management may substantially shorten the duration of therapy for many patients with MDR-TB.

Defining Outcomes of Tuberculosis (Treatment): From the Past to the Future.

Untreated active tuberculosis (TB) has a very high long-term mortality. Treatment of TB reduces mortality dramatically and should maximize cure, preventing ongoing transmission and TB sequelae. However, predicting the risk of failure and relapse is crucial for the management of individual patients and for the evaluation of effectiveness of programs. Various outcome definitions for drug-sensitive and drug-resistant TB were developed, implemented, and endorsed since introduction of TB chemotherapy by the World Health Organization (WHO), mostly based on culture and smear results. They should be applicable for individual patient care, surveillance, and research. Definitions with focus on program evaluation differ from definitions to evaluate the efficacy and effectiveness of regimens. Lack of sputum production at the later stage of treatment reduces the easy applicability of current definitions. Definitions of failure and cure are sometimes difficult to apply. Alternative approaches suggest culture positivity at 6 months or more of treatment as an indicator for failure. New definitions for cure including a relapse-free period posttreatment and reduced number of culture and smear results are considered. Increasing variation and individualization of treatment and its duration urgently require new approaches using pathogen- or host-specific biomarkers, which indicate risk of failure and define cure. Such biomarkers are under evaluation but still far from translation in clinical routine practice.

Correction to: The use of ultrasensitive quantitative-PCR to assess the impact of primaquine on asymptomatic relapse of Plasmodium vivax infections: a randomized, controlled trial in Lao PDR.

Following publication of the original article [1], it was brought to the authors' attention that one of the names in the author list had been provided with the incorrect spelling.

The use of ultrasensitive quantitative-PCR to assess the impact of primaquine on asymptomatic relapse of Plasmodium vivax infections: a randomized, controlled trial in Lao PDR.

BACKGROUND: Trials to assess the efficacy of the radical cure of Plasmodium vivax malaria with 8-aminoquinolines require that most post-treatment relapses are identified, but there is no consensus on the optimal duration of follow-up in either symptomatic or asymptomatic vivax malaria. The efficacy of a 14-day course of primaquine on the cumulative incidence of recurrent asymptomatic P. vivax infections detected by ultrasensitive quantitative PCR (uPCR) as a primary endpoint was assessed. METHODS: A randomized, placebo-controlled, single-blind trial was conducted in four villages of the Lao PDR during 2016-2018 nested in a larger project evaluating mass drug administrations (MDA) with dihydroartemisinin-piperaquine (DP) and a single low-dose primaquine to clear Plasmodium falciparum infections. In the nested sub-study, eligible participants with mono- or mixed P. vivax infections detected by uPCR were randomized to receive either 14 days of primaquine (0.5 mg/kg/day) or placebo during the last round of MDA (round 3) through directly observed therapy. Participants were checked monthly for 12 months for parasitaemia using uPCR. The primary outcome was cumulative incidence of participants with at least one recurrent episode of P. vivax infection. RESULTS: 20 G6PD-normal participants were randomized in each arm. 5 (29%) of 20 participants in the placebo arm experienced asymptomatic, recurrent P. vivax infections, resulting in a cumulative incidence at month 12 of 29%. None of the 20 participants in the intervention arm had recurrent infections (p = 0.047 Fisher's exact test). Participants with recurrent P. vivax infections were found to be parasitaemic for between one and five sequential monthly tests. The median time to recurrence of P. vivax parasitaemia was 178 days (range 62-243 days). CONCLUSIONS: A 14-day course of primaquine in addition to a DP-MDA was safe, well-tolerated, and prevented recurrent asymptomatic P. vivax infections. Long follow-up for up to 12 months is required to capture all recurrences following the treatment of asymptomatic vivax infection. To eliminate all malarias in settings where P. vivax is endemic, a full-course of an 8-aminoquinolines should be added to MDA to eliminate all malarias. Trial registration This study was registered with ClinicalTrials.gov under NCT02802813 on 16th June 2016. https://clinicaltrials.gov/ct2/show/NCT02802813.

Rethinking Antimicrobial Resistance Surveillance: A Role for Lot Quality Assurance Sampling.

Global surveillance of antimicrobial resistance (AMR) is a key component of the 68th World Health Assembly Global Action Plan on AMR. Laboratory-based surveillance is inherently biased and lacks local relevance due to aggregation of data. We assessed the feasibility, sensitivity, and affordability of a population-based AMR survey using lot quality assurance sampling (LQAS), which classifies a population as having a high or low prevalence of AMR based on a priori defined criteria. Three studies were carried out in Medan and Bandung, Indonesia, between April 2014 and June 2017. LQAS classifications for 15 antibiotics were compared with AMR estimates from a conventional population-based survey, with an assessment of the cost of a single LQAS classification using microcosting methodology, among patients suspected of urinary tract infection at 11 sites in Indonesia. The sensitivity of LQAS was above 98%. The approach detected local variation in the prevalence of AMR across sites. Time to reach LQAS results ranged from 47 to 138 days. The average cost of an LQAS classification in a single facility was US$466. The findings indicate that LQAS-based AMR survey is a feasible, sensitive, and affordable strategy for population-based AMR surveys, providing essential data to inform local empirical treatment guidelines and antimicrobial stewardship efforts.

Changes in disclosure, adherence and healthcare interactions after the introduction of immediate ART initiation: an analysis of patient experiences in Swaziland.

INTRODUCTION: There are concerns that immediate ART initiation (regardless of CD4 count) negatively affects HIV status disclosure, ART adherence and healthcare interactions. We assessed changes in these factors after the 'Early access to ART for all' intervention, a universal test-and-treat study in Swaziland. METHODS: We recruited two samples of participants between 2014 and 2017. The first group was interviewed before the intervention (control); the second group at the implementation and 6 months thereafter (intervention). RESULTS: High levels of disclosure to partners (controls and intervention: 94%) and family members (controls: 78%, intervention: 79%) were reported, and high levels of adherence (85% did not miss a dose among the controls, 84% in the intervention group). There were no changes in patients reporting feeling pressured to initiate ART (controls: 10%, intervention: 11%). The quality of interaction with healthcare workers improved after the intervention; healthcare workers explained more often the choice of ART initiation (controls: 88%, intervention: 93%) and the meaning of both CD4 and viral load test results (controls: 15%, intervention: 47%). More patients in the intervention group reported receiving test results (controls: 13%, intervention: 46%). We observed no changes in disclosure, adherence or patient experiences 6 months into the intervention compared to its start. CONCLUSION: Our results suggest that both reported adherence and disclosure levels remain high after the introduction of immediate ART in Swaziland. We observed an improvement in the healthcare interactions, possibly due to training at participating facilities, which will be an important element for a successful roll-out of immediate ART.

OBJECTIF: Il y a des craintes que l'initiation de l'ART immédiat (quel que soit la numération des CD4) affecte négativement la divulgation du statut VIH, l'adhésion au traitement et les interactions avec les soins de santé. Nous avons évalué les modifications de ces facteurs après l'intervention «Accès précoce à l'ART pour tous¼, une étude universelle de dépistage et traitement au Swaziland. MÉTHODES: Nous avons recruté deux échantillons de participants entre 2014 et 2017. Le premier groupe a été interviewé avant l'intervention (témoins), le deuxième groupe lors de l'implémentation et six mois après (intervention). RÉSULTATS: Des niveaux élevés de divulgation aux partenaires (témoin et intervention: 94%) et aux membres de la famille (témoins: 78%, intervention: 79%) ont été rapportés, ainsi que des taux élevés d'adhésion (85% n'ont pas oublié une dose chez les témoins, 84% dans le groupe d'intervention). Aucun changement n'a été observé chez les patients déclarant se sentir poussés à commencer l'ART (témoins: 10%, intervention: 11%). La qualité de l'interaction avec les agents de la santé s'est améliorée après l'intervention; les agents de santé expliquent plus souvent le choix de l'initiation de l'ART (témoins: 88%, intervention: 93%) et la signification des résultats des tests de CD4 et de la charge virale (témoins: 15%, intervention: 47%). Plus de patients du groupe d'intervention ont déclaré avoir reçu les résultats des tests (témoins: 13%, intervention: 46%). Nous n'avons observé aucun changement dans la divulgation, l'adhésion ou l'expérience des patients six mois après le début de l'intervention par rapport à son début. CONCLUSION: Nos résultats suggèrent que les taux d'adhésion et de divulgation rapportés restent élevés après l'introduction de l'ART immédiat au Swaziland. Nous avons observé une amélioration des interactions avec les soins de santé, probablement due à la formation dispensée dans les établissements participants, ce qui constituera un élément important pour le succès du déploiement de l'ART immédiat.

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.

Pharmacy-based hypertension care employing mHealth in Lagos, Nigeria - a mixed methods feasibility study.

BACKGROUND: Access to quality hypertension care is often poor in sub-Saharan Africa. Some community pharmacies offer hypertension monitoring services, with and without involvement of medical doctors. To directly connect pharmacy staff and cardiologists a care model including a mobile application (mHealth) for remote patient monitoring was implemented and pilot tested in Lagos, Nigeria. Pharmacists provided blood pressure measurements and counselling. Cardiologists enrolled patients in the pilot program and remotely monitored them, for which patients paid a monthly fee. We evaluated the feasibility of this care model at five private community pharmacies. Outcome measures were retention in care, blood pressure change, quality of care, and patients' and healthcare providers' satisfaction with the care model. METHODS: Patients participated in the care model's pilot at one of the five pharmacies for approximately 6-8 months from February 2016. We conducted structured patient interviews and blood pressure measurements at pilot entry and exit, and used exports of the mHealth-application, in-depth interviews and focus group discussions with patients, pharmacists and cardiologists. RESULTS: Of 336 enrolled patients, 236 (72%) were interviewed at pilot entry and exit. According to the mHealth data 71% returned to the pharmacy after enrollment, with 3.3 months (IQR: 2.2-5.4) median duration of activity in the mHealth-application. Patients self-reported more visits than recorded in the mHealth data. Pharmacists mentioned use of paper records, understaffing, the application not being user-friendly, and patients' unwillingness to pay as reasons for underreporting. Mean systolic blood pressure decreased 9.9 mmHg (SD: 18). Blood pressure on target increased from 24 to 56% and an additional 10% had an improved blood pressure at endline, however this was not associated with duration of mHealth activity. Patients were satisfied because of accessibility, attention, adherence and information provision. CONCLUSION: Patients, pharmacists and cardiologists adopted the care model, albeit with gaps in mHealth data. Most patients were satisfied, and their mean blood pressure significantly reduced. Usage of the mHealth application, pharmacy incentives, and a modified financing model are opportunities for improvement. In addition, costs of implementation and availability of involved healthcare providers need to be investigated before such a care model can be further implemented.

Antimicrobial resistance in uropathogens and appropriateness of empirical treatment: a population-based surveillance study in Indonesia.

Objectives: Urinary tract infections (UTIs) are a common reason for empirical treatment with broad-spectrum antibiotics worldwide. However, population-based antimicrobial resistance (AMR) prevalence data to inform empirical treatment choice are lacking in many regions, because of limited surveillance capacity. We aimed to assess the prevalence of AMR to commonly used antimicrobial drugs in Escherichia coli and Klebsiella pneumoniae isolated from patients with community- or healthcare-associated UTIs on two islands of Indonesia. Methods: We performed a cross-sectional patient-based study in public and private hospitals and clinics between April 2014 and May 2015. We screened patients for symptoms of UTIs and through urine dipstick analysis. Urine culture and susceptibility testing were supported by telemicrobiology and interactive virtual laboratory rounds. Surveillance data were entered in forms on mobile phones. Results: Of 3424 eligible patients, 3380 (98.7%) were included in the final analysis, and yielded 840 positive cultures and antimicrobial susceptibility data for 657 E. coli and K. pneumoniae isolates. Fosfomycin was the single oral treatment option with resistance prevalence <20% in both E. coli and K. pneumoniae in community settings. Tigecycline and fosfomycin were the only options for treatment of catheter-associated UTIs with resistance prevalence <20%, whilst the prevalence of resistance to meropenem was 21.3% in K. pneumoniae . Conclusions: Patient-based surveillance of AMR in E. coli and K. pneumoniae causing UTIs indicates that resistance to the commonly available empirical treatment options is high in Indonesia. Smart AMR surveillance strategies are needed to inform policy makers and to guide interventions.

An easy tool to assess ventilation in health facilities as part of air-borne transmission prevention: a cross-sectional survey from Uganda.

BACKGROUND: No guidelines exist on assessing ventilation through air changes per hour (ACH) using a vaneometer. The objective of the study was to evaluate the position and frequency for measuring air velocity using a vaneometer to assess ventilation with ACH; and to assess influence of ambient temperature and weather on ACH. METHODS: Cross-sectional survey in six urban health facilities in Kampala, Uganda. Measurements consisted of taking air velocity on nine separate moments in five positions in each opening of the TB clinic, laboratory, outpatient consultation and outpatient waiting room using a vaneometer. We assessed in addition the ventilation with the "20% rule", and compared this estimation with the ventilation in ACH assessed using the vaneometer. RESULTS: A total of 189 measurements showed no influence on air velocity of the position and moment of the measurement. No significant influence existed of ambient temperature and a small but significant influence of sunny weather. Ventilation was adequate in 17/24 (71%) of all measurements. Using the "20% rule", ventilation was adequate in 50% of rooms assessed. Agreement between both methods existed in 13/23 (56%) of the rooms assessed. CONCLUSION: Most rooms had adequate ventilation when assessed using a vaneometer for measuring air velocity. A single vaneometer measurement of air velocity is adequate to assess ventilation in this setting. These findings provide practical input for clear guidelines on assessing ventilation using a vaneometer. Assessing ventilation with a vaneometer differs substantially from applying the "20% rule".

Intention of physicians to implement guidelines for screening and treatment of latent tuberculosis infection in HIV-infected patients in The Netherlands: a mixed-method design.

BACKGOUND: All newly diagnosed HIV-infected patients in the Netherlands should be screened for latent tuberculosis infection (LTBI) and offered preventive therapy if infected without evidence of active tuberculosis. This guideline, endorsed by the national professional body of HIV physicians is in line with international recommendations, and based on the increased risk of progression from LTBI to active tuberculosis in HIV-infected patients. The objective of the study is to assess the intention of HIV physicians to implement this national guideline. METHODS: A mixed method design triangulating results from two surveys among all (n = 80) HIV physicians in The Netherlands and qualitative interviews among 11 Dutch HIV physicians performed in 2014. RESULTS: The majority of physicians used a risk-stratification approach based on individual a priori risk of tuberculosis to identify HIV-infected patients for LTBI screening, rather than screening all new HIV-infected patients. The intended and actual provision of preventive treatment was low, due to expressed doubts on the accuracy of diagnostic tools for LTBI. Interviewees reported that the guidelines did not match their clinical experience and lacked evidence for the recommendations. Screening for and treatment of LTBI was approached at a patient-level only. None of the interviewees referred to potential public health implications of the guidelines. CONCLUSIONS: Intended implementation of the national HIV-TB guidelines in the Netherlands is poor, due to a disconnect between clinical practice and evidence-based recommendations in the guideline. There is an urgent need to reconcile the views of HIV-physicians, public health experts, and guideline committee members, regarding the best strategy to address HIV-TB co-infection in the Netherlands.

Multidrug-resistant tuberculosis in Europe, 2010-2011.

Drug-resistant Mycobacterium tuberculosis is challenging elimination of tuberculosis (TB). We evaluated risk factors for TB and levels of second-line drug resistance in M. tuberculosis in patients in Europe with multidrug-resistant (MDR) TB. A total of 380 patients with MDR TB and 376 patients with non-MDR TB were enrolled at 23 centers in 16 countries in Europe during 2010-2011. A total of 52.4% of MDR TB patients had never been treated for TB, which suggests primary transmission of MDR M. tuberculosis. At initiation of treatment for MDR TB, 59.7% of M. tuberculosis strains tested were resistant to pyrazinamide, 51.1% were resistant to ≥1 second-line drug, 26.6% were resistant to second-line injectable drugs, 17.6% were resistant to fluoroquinolones, and 6.8% were extensively drug resistant. Previous treatment for TB was the strongest risk factor for MDR TB. High levels of primary transmission and advanced resistance to second-line drugs characterize MDR TB cases in Europe.

Availability, price and affordability of anti-tuberculosis drugs in Europe: a TBNET survey.

Data on availability and cost of anti-tuberculosis (TB) drugs in relation to affordability at national level are scarce. We performed a cross-sectional study on availability and cost of anti-TB drugs at major TB-reference centres in 37 European countries. Costs of standardised treatment regimens used for pan-sensitive TB, multidrug-resistant (MDR) TB, pre-extensively drug-resistant (XDR) TB, and XDR-TB were compared using a purchasing power analysis. Affordability was evaluated in relation to monthly national gross domestic products per capita (GDP). At least one second-line injectable and either moxifloxacin or levofloxacin were available in all countries. Linezolid and clofazimine were available in 79% and 46% of the countries, respectively. Drug cost for XDR-TB was three-times more expensive than those for MDR-TB. The average price of treatment for pan-sensitive TB represented a maximum of 8.5% of the monthly GDP across countries, while for standard MDR-TB treatment this was <30% in only six countries and more than 100% in four countries. Treatment of XDR-TB represented more than 100% of a month's GDP in all countries where the regimen was available. High cost and limited availability of drugs for treatment of drug-resistant TB, particularly beyond resistance to first-line drugs, are a major impediment to successful TB control in Europe.

Risk assessment of tuberculosis in immunocompromised patients. A TBNET study.

RATIONALE: In the absence of active tuberculosis, a positive tuberculin skin test (TST) or interferon-γ release assay (IGRA) result defines latent infection with Mycobacterium tuberculosis, although test results may vary depending on immunodeficiency. OBJECTIVES: This study compared the performance of TST and IGRAs in five different groups of immunocompromised patients, and evaluated their ability to identify those at risk for development of tuberculosis. METHODS: Immunocompromised patients with HIV infection, chronic renal failure, rheumatoid arthritis, solid-organ or stem-cell transplantation, and healthy control subjects were evaluated head-to-head by the TST, QuantiFERON-TB-Gold in-tube test (ELISA), and T-SPOT.TB test (enzyme-linked immunospot) at 17 centers in 11 European countries. Development of tuberculosis was assessed during follow-up. MEASUREMENTS AND MAIN RESULTS: Frequencies of positive test results varied from 8.7 to 15.9% in HIV infection (n = 768), 25.3 to 30.6% in chronic renal failure (n = 270), 25.0% to 37.2% in rheumatoid arthritis (n = 199), 9.0 to 20.0% in solid-organ transplant recipients (n = 197), 0% to 5.8% in stem-cell transplant recipients (n = 103), and 11.2 to 15.2% in immunocompetent control subjects (n = 211). Eleven patients (10 with HIV infection and one solid-organ transplant recipient) developed tuberculosis during a median follow-up of 1.8 (interquartile range, 0.2-3.0) years. Six of the 11 patients had a negative or indeterminate test result in all three tests at the time of screening. Tuberculosis incidence was generally low, but higher in HIV-infected individuals with a positive TST (3.25 cases per 100 person-years) than with a positive ELISA (1.31 cases per 100 person-years) or enzyme-linked immunospot result (1.78 cases per 100 person-years). No cases of tuberculosis occurred in patients who received preventive chemotherapy. CONCLUSIONS: Among immunocompromised patients evaluated in this study, progression toward tuberculosis was highest in HIV-infected individuals and was poorly predicted by TST or IGRAs. Clinical trial registered with www.clinicaltrials.gov (NCT 00707317).