W e read with great interest the mathematical model presented by Fofana et al. (1) on the role of pyrazinamide (PZA) in the emergence of multidrug-resistant tuberculosis (MDR TB), particularly as the results of their model mirror our concerns regarding the amplification of PZA resistance during inappropriate first-line therapy and the dramatic negative consequences that this can have on the subsequent response to second-line therapy. Indeed recent data from Belarus suggest that approximately 50% of PZA resistance is acquired de novo (2). Fofana et al. (1) propose that this problem, a result of using the same important agent in first-and second-line therapy, might be circumvented by using an as-yet-unidentified new agent with characteristics similar to those of PZA in a new second-line regimen. Although considerable effort is being applied to the development of new targets for such agents (3), it is far from certain when or even if these miraculous drugs will be available for routine use. Consequently, PZA is currently a uniquely valuable agent, which we speculate will be very difficult to replace (4, 5). We therefore suggest that in settings where the a priori risk of MDR TB due to transmission is above a certain level, such as in Belarus, prescribing PZA to new patients before they have been screened for rifampin and isoniazid resistance is likely counterproductive. Screening for PZA resistance is still complicated and not in reach for many laboratories. Of course, in an ideal world, a full drug susceptibility test (DST) profile would be available for all patients before TB therapy is prescribed. Unfortunately, in reality, this is seldom the case; at best, there is a considerable delay before DST results are communicated to the physician, and at worst, DST is not performed at all until there is evidence of treatment failure, which may be between 2 and 6 months after starting the patient on first-line agents. As this scenario appears to account for 50% of the PZA resistance seen in MDR-TB cases in many settings (5), action is required now to prevent transmissible PZA-resistant mutants from becoming widely established (6, 7). Thus, we propose that, in settings with a high proportion of MDR-TB patients, PZA be withheld until there is evidence of susceptibility to other first-line agents, because of either a clinical response (acid-fast bacillus [AFB] smear conversion) or a solid laboratory diagnosis. Modeling the exact proportion of primary MDR-TB patients in whom PZA resistance was prevented, a population benefitting from this change, and discussion of the ethics of this approach would be highly informative. Delaying action Citation Anthony RM, Cynamon M, Hoffner S, Werngren J, den Hertog AL, van Soolingen D. 2017. Protecting pyrazinamide, a priority for improving outcomes in multidrug-resistant tuberculosis treatment. Antimicrob Agents Chemother 61:e00258-17. https://doi.

BackgroundLittle is known about immunovirological treatment outcomes and adherence in HIV/AIDS patients on antiretroviral therapy (ART) treated using a simplified management approach in rural areas of developing countries, or about the main factors influencing those outcomes in clinical practice.MethodsCross-sectional immunovirological, pharmacological, and adherence outcomes were evaluated in all patients alive and on fixed-dose ART combinations for 24 months, and in a random sample of those treated for 12 months. Risk factors for virological failure (>1,000 copies/ml) and subtherapeutic antiretroviral (ARV) concentrations were investigated with multiple logistic regression.ResultsAt 12 and 24 months of ART, 72% (n = 701) and 70% (n = 369) of patients, respectively, were alive and in care. About 8% and 38% of patients, respectively, were diagnosed with immunological failure; and 75% and 72% of patients, respectively, had undetectable HIV RNA (<400 copies/ml). Risk factors for virological failure (>1,000 copies/ml) were poor adherence, tuberculosis diagnosed after ART initiation, subtherapeutic NNRTI concentrations, general clinical symptoms, and lower weight than at baseline. About 14% of patients had low ARV plasma concentrations. Digestive symptoms and poor adherence to ART were risk factors for low ARV plasma concentrations.ConclusionEfforts to improve both access to care and patient management to achieve better immunological and virological outcomes on ART are necessary to maximize the duration of first-line therapy.

In spite of the growing awareness of emerging drug-resistant Mycobacterium tuberculosis, the extent of inappropriate tuberculosis (TB) case management may be underestimated, even in Europe. We evaluated TB case management in the European Union/ European Economic Area countries, with special focus on multidrug-resistant (MDR) and extensively drug-resistant (XDR)-TB, using a purposely developed, standardised survey tool.National reference centres in five countries representing different geographical, socioeconomic and epidemiological patterns of TB in Europe were surveyed. 40 consecutive, original clinical TB case records (30 MDR/XDR-TB cases) were reviewed in each of the five countries. The findings were recorded and, through the survey tool, compared with previously agreed and identified international standards.Deviations from international standards of TB care were observed in the following areas: surveillance (no information available on patient outcomes); infection control (lack of respiratory isolation rooms/procedures and negative-pressure ventilation rooms); clinical management of TB, MDR-TB and HIV co-infection (inadequate bacteriological diagnosis, regimen selection and treatment duration); laboratory support; and diagnostic/treatment algorithms.Gaps between present international standards of care and the management of MDR/XDR-TB patients were identified. Training, increased awareness, promotion of standards and allocation of appropriate resources are necessary to ensure appropriate care and management as well as to prevent further emergence of drug resistance.

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