Catherine Plüss-Suard

Antimicrobial resistance—partly driven by inappropriate antibiotic consumption—is a major public health threat. Point-of-care (POC) procalcitonin testing can reduce antibiotic prescribing safely. Within an implementation-effectiveness trial, we conducted a two-phase participatory context analysis to identify and prioritise determinants of POC procalcitonin adoption, implementation and continued use in Swiss primary care. First, we conducted 32 semi-structured interviews with 34 participants, including physicians, representatives of medical organisations, patient representatives and other stakeholders. By coding transcripts deductively using the Consolidated Framework for Implementation Research and inductively, we identified 86 potential determinants. Second, in a focus group with ten ImpPro research team members, 15 determinants were identified as ‘not requiring change’, and ten were considered ‘unchangeable’. Among the remaining 61 determinants, 41 were prioritised through dot-voting and group discussion. These key implementation determinants were inductively grouped into eight themes. The themes with the highest priority were: (1) physicians’ awareness, knowledge, and access to education regarding POC procalcitonin, (2) scientific evidence supporting POC procalcitonin-guided antibiotic prescribing, (3) physician motivation and (4) endorsement of POC procalcitonin by credible organisations and experts. Addressing these determinants will likely require a tailored, multifaceted (combining several unique strategies), and multilevel (targeting different levels of the system) implementation strategy.

Antimicrobial resistance (AMR) surveillance requires approaches that monitor both clinical and community-level dynamics. We monitored antibiotic-resistant bacteria in Swiss wastewater and compared these results with human resistance and antibiotic consumption data from the national surveillance network ANRESIS. Between 2021 and 2024, 772 samples from six wastewater treatment plants were analyzed for Escherichia coli , extended-spectrum β-lactamase-producing (ESBL)- E.coli , carbapenem-resistant E. coli (CR- E.coli ), Enterococcus faecium/faecalis , and vancomycin-resistant enterococci (VRE). The rank order of the proportion of resistance was conserved between wastewater and clinical data. Mean (±standard deviation) wastewater resistance percentages were 2.2±0.8 for ESBL- E.coli , 0.4±0.6 for VRE, and 0.1±0.1 for CR- E.coli . Clinical resistance percentages were 9.8±0.8 for ESBL- E.coli , 2.9±1.4 for VRE, and 0.3±0.1 for CR- E.coli . Both datasets showed similar rising trends for ESBL- E. coli and VRE, while CR- E. coli remained stable in wastewater but increased slightly in clinics. No consistent lead-lag relationships were observed between wastewater resistance, clinical resistance, or antibiotic use, indicating independent short-term dynamics. Resistance percentages in wastewater were not associated with antibiotic use data for either the antibiotics used for treatment or the ones that are selective for the target. These results suggest that wastewater monitoring reflects long-term population-level AMR dynamics, aligning with clinical trends over years but not months. Graphical Synopsis: Antibiotic-resistant bacteria in Swiss wastewater alongside hospital resistance and antibiotic use data reveal increasing community resistance and show how environmental surveillance can complement clinical surveillance in understanding antibiotic resistance spread.

Objectives: To evaluate the trend in macrolide ambulatory use among children in Switzerland following a global surge in Mycoplasma pneumoniae infections in late 2023. Methods: We conducted a population-based interrupted time-series analysis of macrolide use in Swiss children aged 0 to 11 years from 2018 to 2023 using national ambulatory antibiotic claims data. The main outcome was the evolution of macrolide use in ambulatory setting, expressed as monthly defined daily doses (DDD) per 1000 children. We defined two time periods: (i) the pre-autumn 2023 period, before M. pneumoniae detections increased in Switzerland (1 January 2018 to 30 September 2023) and (ii) the autumn 2023 period, after M. pneumoniae detections increased in Switzerland (1 October 2023 to 31 December 2023). We built a quasi-Poisson regression model to estimate the changes in macrolide monthly DDD per 1000 children from October 2023 in Switzerland. The model accounted for temporal trends before the WHO alert and for the seasonal pattern of macrolide prescriptions. We analysed amoxicillin use as a control outcome. Results: We found a significant increase in macrolides use expressed in monthly DDD per 1000 children aged 0 to 11 years from October 2023 in Switzerland [+235% (95%CI +139%–+368%), P value < 0.001]. The use of amoxicillin remained stable in both age groups after October 2023. Conclusions: We found a 3-fold increase in macrolide monthly DDD per 1000 children in autumn 2023 in the context of a global increase in M. pneumoniae infections. Monitoring macrolide resistance and promoting appropriate prescription practices are essential.

INTRODUCTION: Inappropriate antibiotic prescribing drives antimicrobial resistance. Although the Swiss Society of Infectious Diseases has introduced national guidelines for common infectious diseases starting from 2019, it remains unclear whether family physicians and paediatricians adhere to them and what factors influence their prescriptions. The aims of this study were to assess whether Swiss family physicians and paediatricians make appropriate antibiotic choices in accordance with national guidelines and to identify physician- and patient-related factors associated with the prescribing of not-recommended antibiotic choices for specific indications. METHODS: A cross-sectional study analysed the choice of antibiotics (2017–2022) by indication from a sentinel physician surveillance network, comparing them to adult (16+) and paediatric national guidelines. Indications included pharyngitis, sinusitis, otitis media, pneumonia, chronic obstructive pulmonary disease exacerbation (adults only) and upper and lower urinary tract infections (adult females only). Descriptive analysis and pre- and post-guideline comparisons were conducted. A multilevel logistic regression model assessed factors influencing prescribing of not-recommended antibiotics across several clinical indications. RESULTS: A total of 52,098 observations were analysed. The overall proportion of not-recommended antibiotic prescriptions was 18% for adults and 19% for children. The proportion of not-recommended antibiotics ranged from 8% (lower urinary tract infection) to 39% (sinusitis) in adults, and from 5% (sinusitis) to 38% (pharyngitis) in children. The proportion of not-recommended antibiotics decreased following guideline implementation for all indications for children and for sinusitis (48% vs 39%) and pneumonia (19% vs 15%) for adults. A multilevel model revealed that certain clinical indications – such as pharyngitis – were associated with higher odds of prescribing not-recommended antibiotics. Additionally, family physicians (compared to paediatricians), older physician age and physicians’ perception of a favourable patient attitude to the antibiotic were also linked to increased prescribing of not-recommended antibiotics. CONCLUSIONS: Swiss family physicians and paediatricians show high levels of non-adherence to national guidelines across several indications, with limited change post-guideline implementation. Certain demographic characteristics of physicians and patient behaviour exacerbate these inappropriate prescribing habits. These insights indicate the need to enhance guideline dissemination and adoption by considering physicians’ needs.

Antimicrobial resistance (AMR) is directly driven by inappropriate use of antibiotics. Although the majority of antibiotics (an estimated 80%) are consumed in primary care settings, antimicrobial stewardship (AMS) activities in primary care remain underdeveloped and factors influencing their implementation are poorly understood. This can result in promising stewardship activities having little-to-no real-world impact. With this narrative review, we aim to identify and summarize peer-reviewed literature reporting on (1) the nature and impact of AMS interventions in primary care and (2) the individual and contextual factors influencing their implementation. Reported activities included AMS at different contextual levels (individual, collective and policy). AMS activities being often combined, it is difficult to evaluate them as stand-alone interventions. While some important individual and contextual factors were reported (difficulty to reach physicians leading to a low uptake of interventions, tight workflow of physicians requiring implementation of flexible and brief interventions and AMS as a unique opportunity to strengthen physician-patients relationship), this review identified a paucity of information in the literature about the factors that support or hinder implementation of AMS in primary care settings. In conclusion, identifying multilevel barriers and facilitators for AMS uptake is an essential step to explore before implementing primary care AMS interventions.

The aim of this study was to analyze inpatient antibiotic consumption during the first 16 months of the COVID-19 pandemic in Switzerland. The entire period (January 2018–June 2021) was divided into the prepandemic period, the first and second waves, and the intermediate period. In the first year of the pandemic, total overall inpatient antibiotic consumption measured in defined daily doses (DDD) per 100 bed-days remained stable (+1.7%), with a slight increase in ICUs of +4.2%. The increase in consumption of broad-spectrum antibiotics was +12.3% overall and 17.3% in ICUs. The segmented regression model of monthly data revealed an increase in overall antibiotic consumption during the first wave but not during the second wave. In the correlation analysis performed in a subset of the data, a significant positive association was found between broad-spectrum antibiotic consumption and an increasing number of hospitalized COVID-19 patients (p = 0.018). Restricting this dataset to ICUs, we found significant positive correlations between the number of hospitalized COVID-19 patients and total antibiotic consumption (p = 0.007) and broad-spectrum antibiotic consumption (p < 0.001). In conclusion, inpatient antibiotic use during the different periods of the COVID-19 pandemic varied greatly and was predominantly notable for broad-spectrum antibiotics.

Background: Monitoring antimicrobial use and resistance in hospitals are important tools of antimicrobial stewardship programs. We aimed to determine the association between the use of frequently prescribed antibiotics and the corresponding resistance rates in Escherichia coli and Klebsiella pneumoniae among the clinical departments of a tertiary care hospital. Methods: We performed a retrospective observational study to analyse the use of nine frequently prescribed antibiotics and the corresponding antimicrobial resistance rates in hospital acquired E. coli and K. pneumoniae isolates from 18 departments of our institution over 9 years (2008–2016). The main cross-sectional analysis assessed the hypothetical influence of antibiotic consumption on resistance by mixed logistic regression models. Results: We found an association between antibiotic use and resistance rates in E. coli for amoxicillin-clavulanic acid (OR per each step of 5 defined daily dose/100 bed-days 1.07, 95% CI 1.02–1.12; p = 0.004), piperacillin-tazobactam (OR 2.11, 95% CI 1.45–3.07; p < 0.001), quinolones (OR 1.52, 95% CI 1.25–1.86; p < 0.001) and trimethoprim-sulfamethoxazole (OR 1.59, 95% CI 1.19–2.13; p = 0.002). Additionally, we found a significant association when all nine antibiotics were combined in one analysis. The association between consumption and resistance rates was stronger for nosocomial than for community strains. In K. pneumoniae, we found an association for amoxicillin-clavulanic acid (OR 1.07, 95% CI 1.01–1.14; p = 0.025) and for trimethoprim-sulfamethoxazole (OR 2.02, 95% CI 1.44–2.84; p < 0.001). The combined analysis did not show an association between consumption and resistance (OR 1.06, 95% CI 0.99–1.14; p = 0.07). Conclusions: We documented an association between antibiotic use and resistance rate for amoxicillin-clavulanic acid, piperacillin-tazobactam, quinolones and trimethoprim-sulfamethoxazole in E. coli and for amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole in K. pneumoniae across different hospital departments. Our data will support stewardship interventions to optimize antibiotic prescribing at a department level.