Communicable E41: Diagnostic stewardship

In this episode of Communicable, Emily McDonald returns for another ‘Quarterly catch-up’ and is joined by Angela Huttner as co-host. Together, they review four recent randomised clinical trials, focusing on antibiotic treatment duration and different treatment approaches across a range of infections and patient populations [1–4]. They discuss the results and weigh in on their implications for clinical practice. References Johnson, et al. Vancomycin Taper and Pulse or Fidaxomicin for Recurrent C. difficile Infection. NEJM Evid. DOI: 10.1056/EVIDoa2600016 Bundgaard, et al. Response-Tailored or Standard-Duration Antibiotic Treatment for Infective Endocarditis (POET II). NEJM. DOI: 10.1056/NEJMoa2607887 Bielicki, et al. Oral step-down, optimal drug, and total duration of antibiotic treatment in African children hospitalised with severe community-acquired pneumonia (PediCAP): a factorial randomised controlled trial. Lancet 2026. DOI: 10.1016/S0140-6736(26)00879-2 Carlsen, et al. Individualized Duration of Antibiotic Treatment in Culture-Negative Early-Onset Sepsis in Late Preterm and Term-Born Neonates in Denmark: A Multicenter, Open-Label, Randomised, Controlled Non-Inferiority Trial. Lancet Child Adolesc Health. DOI: 10.1016/S2352-4642(26)00118-5

In this episode of Communicable, hosts Emily McDonald and Marc Bonten are joined by Sylvain Lother and Valentijn Schweitzer for a discussion on the use of macrolides in community-acquired pneumonia. Together, they examine the evidence for adding a macrolide to beta-lactam therapy, which patients may benefit from combination treatment, and how available evidence can inform clinical practice. Resources: AMMI Canada, https://ammi.ca/en/home/ Further reading Postma DF, et al. Antibiotic Treatment Strategies for Community-Acquired Pneumonia in Adults (CAP-START). NEJM 2015. DOI: 10.1056/NEJMoa1406330 Qian ET, et al. Cefepime vs Piperacillin-Tazobactam in Adults Hospitalized With Acute Infection: the ACORN Randomized Clinical Trial. JAMA 2023. DOI: 10.1001/jama.2023.20583 Schweitzer VA, et al. Narrow-spectrum antibiotics for community-acquired pneumonia in Dutch adults (CAP-PACT): a cross-sectional, stepped-wedge, cluster-randomised, non-inferiority, antimicrobial stewardship intervention trial. Lancet Infect Dis 2022. DOI: 10.1016/S1473-3099(21)00255-3 van Daalen FV, et al. Management of community-acquired pneumonia in adults: Practice Guideline from The Dutch Working Party on Antibiotic Policy and Dutch Association of Chest Physicians. CMI Comms 2026. DOI: 10.1016/j.cmicom.2026.105206

At the Critical Care Reviews meeting in Belfast in June this year, REMAP-CAP investigators presented results suggesting that oseltamivir may be harmful in critically ill patients with influenza, upending a long-standing clinical practice in intensive care [1]. In this fourth collaboration between SIDP’s Breakpoints and ESCMID’s Communicable podcasts, hosts Erin McCreary and Josh Davis are joined by Steve Webb (Monash University), senior REMAP-CAP investigator and 'godfather of adaptive trial design', and Steve Tong (University of Melbourne), esteemed clinical trialist and friend of both podcasts. Together, they walk through the trial domain’s design, outcomes and results, also highlighting how these findings demonstrate the importance and clinical impact of randomised clinical trials. At the time of this episode recording in August, the results discussed were available as a preprint version [1]. Resources REMAP-CAP: A Randomised, Embedded, Multi-factorial, Adaptive Platform Trial for Community-Acquired Pneumonia, https://www.remapcap.org/ References Murthy S, et al. Oseltamivir for Critically Ill Patients with Influenza: A Randomised Trial. Lancet 2026. Preprint http://dx.doi.org/10.2139/ssrn.7172531

In this episode of Communicable, Emily McDonald and Josh Davis host Henning Bundgaard and Sami El-Dalati for a discussion on early oral antibiotic switch for endocarditis, focusing on the POET trial, led by Bundgaard, and its clinical impact seven years after the results were first published in 2019 [1]. The episode also covers the ‘prose’ and cons of early oral switch therapy, as well as broader challenges of implementing new evidence in practice when it goes against long-standing dogma. References Iversen K, et al. Partial Oral versus Intravenous Antibiotic Treatment of Endocarditis, NEJM 2018. DOI: 10.1056/NEJMoa1808312 Further reading: Pries-Heje MM, et al. Five-Year Outcomes of the Partial Oral Treatment of Endocarditis (POET) Trial, NEJM 2022. DOI: 10.1056/NEJMc2114046 El-Dalati S, et al. Partial Oral Versus Intravenous Antibiotic Therapy for Endocarditis With Management by a Multidisciplinary Team: A Retrospective Cohort Study, OFID 2025. DOI: 10.1093/ofid/ofaf625 McDonald EM, et al. Guidelines for Diagnosis and Management of Infective Endocarditis in Adults: A WikiGuidelines Group Consensus Statement, JAMA Netw Open 2023. DOI: 10.1001/jamanetworkopen.2023.26366 European Society of Cardiology (ESC). 2023 ESC Guidelines for the management of endocarditis, 2023.

In this episode of Communicable, Amy Legg (Brisbane, Australia), Rekha Pai Mangalore (Melbourne, Australia) & Angela Huttner (Geneva, Switzerland) return for the third part of the ‘We will make you love PK/PD’ series. The hosts are joined by two experts, Amanda Gwee (Melbourne, Australia) & Sebastian Wicha (Hamburg, Germany), to dive into an important application of PK/PD: model-informed precision dosing (MIPD), and how it allows for more informed, individualised dosing decisions. The episode also covers the open-access educational tools, KidsCalc and TDMx, developed by Gwee and Wicha respectively, and the steps clinicians can take to put MIPD into practice, keeping the individual patient at the centre of dosing decisions. Resources TDMx, https://www.tdmx.eu/ KidsCalc, https://www.kidscalc.org/ Further reading Broeker A, et al. Towards precision dosing of vancomycin: a systematic evaluation of pharmacometric models for Bayesian forecasting. CMI 2019. DOI: 10.1016/j.cmi.2019.02.029 Brusamarello C, et al. How important are MIC determination methods when targeting vancomycin levels in patients with Staphylococcus aureus infections? J Antimicrob Chemother 2021. DOI: 10.1093/jac/dkab065 De Cock PA, et al. Bedside model-informed precision dosing of vancomycin in severely ill neonates and children in Belgium (the BENEFICIAL trial): a multicentre, randomised controlled trial. Lancet Child Adolesc Health 2026. DOI: 10.1016/S2352-4642(25)00385-2 Gwee A, et al. Identifying a therapeutic target for vancomycin against staphylococci in young infants. J Antimicrob Chemother 2022. DOI: 10.1093/jac/dkab469 Haiping X, et al. Model-informed precision dosing of vancomycin in children 3 months to 18 years of age using Australia-wide data. Antimicrob Agents Chemother 2026. DOI: 10.1128/aac.01840-25 Harwood K, et al. Refining Absolute GFR Estimation in Children: Development and Validation of the GROW-GFR Equation. Front Pharmacol 2026. Minichmayr IK, et al. Model-informed precision dosing: State of the art and future perspectives. Adv Drug Deliv Rev 2024. DOI: 10.1016/j.addr.2024.115421 Starp J, et al. Towards model-informed precision dosing of intravenous linezolid: a multicentre external evaluation of pharmacokinetic models in critically ill adults. CMI 2026. DOI: 10.1016/j.cmi.2025.08.032 Wilkins AL, et al. Individualized vancomycin dosing in infants: prospective evaluation of an online dose calculator. Int J Antimicrob Agents 2023. DOI: 10.1016/j.ijantimicag.2023.106728 US National Kidney Foundation for different equations for kidney function estimates as related to drug dosing – estimating kidney function for medication related decisions: Frequently Asked Questions | National Kidney Foundation