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Highlights
• Open pulmonary tuberculosis patient discharge policy was not reviewed for decades.
• After smear-negativity conversion, substantial cultural positivity may remain.
• It remains unclear, whether smear-negative patients still may be infective.
• The clinical relevance of this finding warrants further investigation.
Abstract
Objectives: Patients with open pulmonary tuberculosis (opTB) are subject to strict isolation rules. Sputum smear microscopy is used to determine infectivity, but sensitivity is lower than for culture. This study aimed to investigate the clinical relevance of this mismatch in contemporary settings.
Methods: Differential results between microscopy and culture were determined at the time of microscopic sputum conversion, from all patients with opTB between 01/2013 and 12/2017. In addition, data on HIV, multi/extensive drug-resistant TB status, time to smear- and cultural-negativity conversion were analyzed; and a Kaplan-Meier curve was developed.
Results: Of 118 patients with opTB, 58 had demographic data available for microbiological and clinical follow-up analysis; among these, 26 (44.8%) had still at least one positive culture result. Median time from opTB-treatment initiation to full microscopic sputum- or culture conversion, was 16.5 days (range 2-105), and 20 days (1-105), respectively (median difference: +3.5 days). Sixteen days after de-isolation, >90% had converted culturally. HIV- or multi/extensive drug-resistant TB status did not impact conversion time.
Conclusion: When patients with opTB were de-isolated after 3 negative sputum smear microscopy tests, a substantial part still revealed cultural growth of Mycobacterium tuberculosis complex, but it remains unclear, whether smear-negative and culturally-positive individuals on therapy are really infective. Thus, the clinical relevance of this finding warrants further investigation.
Hintergrund: Ab Frühjahr 2020 kam es zur weltweiten Verbreitung von SARS-CoV‑2 mit der heute als erste Welle der Pandemie bezeichneten Phase ab März 2020. Diese resultierte an vielen Kliniken in Umstrukturierungen und Ressourcenverschiebungen. Ziel unserer Arbeit war die Erfassung der Auswirkungen der Pandemie auf die universitäre Hals-Nasen-Ohren(HNO)-Heilkunde für die Forschung, Lehre und Weiterbildung. Material und Methoden: Die Direktorinnen und Direktoren der 39 Universitäts-HNO-Kliniken in Deutschland wurden mithilfe einer strukturierten Online-Befragung zu den Auswirkungen der Pandemie im Zeitraum von März bis April 2020 auf die Forschung, Lehre und die Weiterbildung befragt. Ergebnisse: Alle 39 Direktorinnen und Direktoren beteiligten sich an der Umfrage. Hiervon gaben 74,4 % (29/39) an, dass es zu einer Verschlechterung ihrer Forschungstätigkeit infolge der Pandemie gekommen sei. Von 61,5 % (24/39) wurde berichtet, dass pandemiebezogene Forschungsaspekte aufgegriffen wurden. Von allen Kliniken wurde eine Einschränkung der Präsenzlehre berichtet und 97,5 % (38/39) führten neue digitale Lehrformate ein. Im Beobachtungszeitraum sahen 74,4 % der Klinikdirektoren die Weiterbildung der Assistenten nicht gefährdet. Schlussfolgerung: Die Ergebnisse geben einen Einblick in die heterogenen Auswirkungen der Pandemie. Die kurzfristige Bearbeitung pandemiebezogener Forschungsthemen und die Einführung innovativer digitaler Konzepte für die studentische Lehre belegt eindrücklich das große innovative Potenzial und die schnelle Reaktionsfähigkeit der HNO-Universitätskliniken, um auch während der Pandemie ihre Aufgaben in der Forschung, Lehre und Weiterbildung bestmöglich zu erfüllen.
The electron-capture process was studied for Xe54+ colliding with H2 molecules at the internal gas target of the Experimental Storage Ring (ESR) at GSI, Darmstadt. Cross-section values for electron capture into excited projectile states were deduced from the observed emission cross section of Lyman radiation, being emitted by the hydrogenlike ions subsequent to the capture of a target electron. The ion beam energy range was varied between 5.5 and 30.9 MeV/u by applying the deceleration mode of the ESR. Thus, electron-capture data were recorded at the intermediate and, in particular, the low-collision-energy regime, well below the beam energy necessary to produce bare xenon ions. The obtained data are found to be in reasonable qualitative agreement with theoretical approaches, while a commonly applied empirical formula significantly overestimates the experimental findings.
We report the first measurement of low-energy proton-capture cross sections of 124Xe in a heavy-ion storage ring. 124Xe54+ ions of five different beam energies between 5.5 and 8 AMeV were stored to collide with a windowless hydrogen target. The 125Cs reaction products were directly detected. The interaction energies are located on the high energy tail of the Gamow window for hot, explosive scenarios such as supernovae and x-ray binaries. The results serve as an important test of predicted astrophysical reaction rates in this mass range. Good agreement in the prediction of the astrophysically important proton width at low energy is found, with only a 30% difference between measurement and theory. Larger deviations are found above the neutron emission threshold, where also neutron and γ widths significantly impact the cross sections. The newly established experimental method is a very powerful tool to investigate nuclear reactions on rare ion beams at low center-of-mass energies.