Swiss Antibiotic Resistance Report 2026 - 1.0
17.11.2026 - Surveillance of antibiotic consumption and antimicrobial resistance in humans, livestock, companion animals and the environment is a central element of the Swiss Strategy on Antimicrobial Resistance (StAR). Since 2016, the results have been summarised every two years in the Swiss Antibiotic Resistance Report (SARR). The SARR 2026, published on 17. November 2026, provides an overview of the current situation in Switzerland. It highlights the most relevant developments in antibiotic consumption and antimicrobial resistance, explains their significance, and identifies areas that require continued attention. The findings are placed in the context of current StAR activities, including the One Health Action Plan StAR 2024–2027, with a focus on where further strengthening of measures may be needed.
Plüss-Suard Catherine¹, Friedli Olivier¹, Gottwalt Simon2 , Kronenberg Andreas1, Heinzpeter Schwermer3, Anaïs Léger3, Michael Gasser1, Tamara Habegger1, Gudrun Overesch4
Affiliations
1Swiss Centre for Antibiotic Resistance (ANRESIS), Institute for Infectious Diseases, University of Bern, Bern, Switzerland
2Federal Office of Public Health, Bern, Switzerland.
3Federal Food and Safety and Veterinary Office, Bern, Switzerland
4Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
1. Antimicrobial Consumption and Resistance in Switzerland
The surveillance of antibiotic consumption and antimicrobial resistance in humans, livestock, companion animals and the environment is a central element of the Swiss Strategy on Antimicrobial Resistance (StAR) and the One Health Action Plan StAR 2024–2027. Since 2016, the results of this surveillance have been summarised every two years in the Swiss Antibiotic Resistance Report (SARR).
This status report provides an assessment of the current situation in Switzerland. It summarises the most relevant developments in antibiotic consumption and antimicrobial resistance, and places them in context. The report does not aim to reproduce all available surveillance data. Instead, it highlights overarching trends, important changes, areas where the situation remains stable or favourable, and developments that require continued attention.
Surveillance is not an end in itself. Its purpose is to support action by providing relevant data as a basis for decision-making and response. This includes identifying where antibiotic prescription can be further optimised, where relevant resistant bacteria are emerging or spreading, and where existing measures in stewardship, infection prevention and control (IPC), animal health, food safety or environmental protection may need to be strengthened.
It also helps assess whether measures already implemented are reflected in more prudent antibiotic prescribing or in stabilising or declining resistance levels.
The report follows a One Health perspective. It brings together findings from human medicine, veterinary medicine and the environment, while recognising that data sources, indicators and interpretation differ between sectors. The aim is to support a shared understanding of where Switzerland stands today: where antibiotic prescribing has become more prudent, where resistance levels have stabilised or declined, where concerning signals are emerging, and where further stewardship, infection prevention, surveillance or research is needed.
2. Antibiotic consumption in human and veterinary medicine
Antibiotic consumption is one of the main drivers of antimicrobial resistance and therefore a central focus of surveillance and stewardship. The aim is not simply to reduce antibiotic prescribing in all situations, but to ensure that antibiotics are used appropriately: as broad as necessary, but as narrow as possible, and with the right substance, dose and duration.
This section summarises the most relevant developments in antibiotic consumption in human and veterinary medicine. It highlights what is changing, how these changes can be interpreted, and what they imply for antimicrobial stewardship programmes, surveillance strategies and further action. The focus is on overall trends, changes in the types of antibiotics used, and areas where targeted improvements remain possible, rather than on reproducing all available indicators.
The results are based on complementary surveillance sources and should be interpreted in the context of each sector. Human and veterinary medicine differ in populations, treatment contexts and reporting systems; the findings are therefore presented side by side to identify relevant developments and antimicrobial stewardship priorities. Detailed data are available in the corresponding dashboards.
2.1. Antibiotic use in human medicine
Switzerland remains one of the lower users of antibiotics in Europe. In 2024, total antibiotic consumption in human medicine reached a mean of 11.0 defined daily doses per 1,000 inhabitants per day (DID), which is below the reported European mean of 20.5 DID in 2024. In 2025, swiss antibiotic consumption reached a mean of 9.9 DID, and thereby surpasses the StAR Action Plan target of 10.1 DID for 2027, which aims to reduce total antibiotic consumption in human medicine by 4% from the 2019 baseline. Overall, antibiotic consumption has followed a downward trend since 2015, although this trend was temporarily interrupted by the COVID-19 pandemic. Antibiotic consumption showed a marked dip during the pandemic, mainly because respiratory infections became less frequent due to prevention measures such as mask-wearing and reduced social contact. As respiratory infections returned, including infections with Group A streptococci, Bordetella pertussis and Mycoplasma pneumoniae, antibiotic consumption rebounded temporarily, before declining again in the most recent data.
These observations place Switzerland in a favourable position in international comparison and suggests generally prudent prescribing. However, beyond overall consumption levels, further attention is needed to the quality of antibiotic prescribing, including the choice of antibiotic and the settings or indications where improvement may still be possible.
One important aspect of prescribing quality is the classification of antibiotics used. Because antibiotic classes differ in their role in treatment and in their potential to select for resistance, the WHO Access, Watch and Reserve classification provides antimicrobial stewardship guidance on their appropriate use. Access antibiotics are preferred for many common infections, Watch antibiotics should be used more restrictiv, and Reserve antibiotics are intended as last-resort options for serious infections caused by multidrug-resistant bacteria (MDRO/MDRB). In 2025, Access antibiotics accounted for 68.1% of total antibiotic use in Switzerland, a bit higher than the WHO GLASS estimate for high-income European countries. However, the UN General Assembly recently raised the global goal to 70%, and a recent assessment suggests that an even higher Access share of around 76% may be appropriate when infection burden, antimicrobial resistance, population demographics and healthcare provision in Switzerland are considered. At the same time, Watch antibiotic consumption decreased by 22.7% over the last decade, mainly due to reduced consumption of fluoroquinolones and cephalosporins. These changes reflect a shift in prescribing patterns, with increased use of Access antibiotics and reduced use of Watch antibiotics, although further improvement in antibiotic choice remains needed.
Most antibiotics are prescribed outside hospitals. In 2025, outpatient care accounted for 85.9% of total antibiotic consumption, indicating that this setting represents a major contributor to overall antibiotic use. For the first time, analyses of claims data allows outpatient prescribing to be described in more detail by specialty and canton. They show that general practitioners account for the largest share of prescriptions (36.5%; pediatricians 6.8%), while physicians in hospital-affiliated outpatient structures (21.0%), group practices (19.0%) and specialists (14.7%) also contribute substantially. These patterns suggest that efforts to improve outpatient prescribing should address high-prescribing providers and settings. In addition, this new analyses provides valuable insights for targeted measures and communication by medical societies and cantonal authorities. Tailored feedback and comparison with peers may support more appropriate prescribing across these settings. Two proposed law revisions would further strengthen this approach: dispensing antibiotics by unit, foreseen in the revision of the Therapeutic Products Act, and an audit-and-feedback system for antibiotic prescriptions, proposed in the revision of the Epidemics Act.
A closer look at outpatient prescribing helps identify regions, patient groups and indications where antibiotic use is concentrated. Outpatient antibiotic use varies strongly by linguistic region. In 2025, consumption was more than 1.5 times higher in French-speaking regions than in German-speaking regions, with the highest rates observed in Geneva (13.0 DID), Neuchâtel and Vaud and the lowest in Appenzell Innerrhoden (5.0 DID), Uri and Nidwalden. These differences may reflect several factors, including primary care physician density, access to healthcare, and cultural factors [1] Reducing regional disparities is one of the aims of the StAR Action Plan, which sets the target that all cantons should bring outpatient antibiotic use below 11.5 DID. In 2024, 5 of 26 cantons had not yet achieved this target. Since disparities between cantons have widened over the last five years, focused action in high-use cantons remains important.
Antibiotic consumption increases markedly with age, with higher prescribing among seniors (66+) than in younger age groups. This pattern likely reflects the higher burden of multimorbidity, recurrent infections, and healthcare contacts associated with ageing, which together increase both the clinical need for antibiotics and the opportunities for prescription.
Sex differences in antibiotic prescribing vary across the life course. In adults (16–65), antibiotic consumption is higher among women. This persists even after excluding antibiotics typically prescribed for urinary tract infections (UTI), suggesting that the difference is not solely driven by UTI incidence, but may also reflect broader differences in healthcare utilisation and consultation behaviour between men and women. In seniors, however, consumption becomes slightly higher among men, indicating a potential shift in sex-related healthcare use and prescribing patterns in older age groups.
Overall, these age- and sex-specific patterns highlight that antibiotic consumption is strongly shaped by demographic factors that influence both infection risk and healthcare-seeking behaviour. From a stewardship perspective, they suggest that interventions aiming to optimise prescribing may benefit from considering age- and sex-specific clinical contexts rather than relying on uniform strategies across the population.
Respiratory tract infections are the most common indication for antibiotic prescribing in primary care, although many are caused by viruses and do not benefit from antibiotic treatment [2]. In 2025, they accounted for almost half of antibiotic prescriptions by general practitioners; pneumonia, sinusitis, acute bronchitis and streptococcal laryngitis were the most frequent respiratory indications. The FOPH Sentinella surveillance system adds a quality perspective by showing how often consultations for infection-related symptoms result in an antibiotic prescription. Overall, 38.1% of such consultations resulted in an antibiotic prescription, and prescribing for sinusitis in adults (45.0%) and acute otitis media in children (61.4%) remained above ESAC quality targets of 20%. A cross-sectional study, also based on the Sentinella system, found that proportion of not-recommended antibiotic prescriptions was about 20% in adults and children. The proportion of antibiotics not recommended by clinical guidelines differed markedly by indicaton, from 8% in adult cases of lower UTI up to 39% for sinusitis, and from 5% in children with sinusitis up to 38% for pharyngitis. These findings indicate room for improvement through stronger guideline adherence, shared decision-making, use of point-of-care tests, and delayed prescribing strategies, as well as continued promotion of first-line prescribing with Access antibiotics and limiting unnecessary use of Watch antibiotics.
These improvement areas are supported by practical measures that help translate evidence and recommendations into outpatient care. The Antimicrobial Stewardship in Ambulatory Care Platform (ASAP) serves as a network and transfer platform, helping relevant knowledge, tools and messages reach general practitioners and other outpatient prescribers. Clinical guidelines of the Swiss Society for Infectious Diseases provide concrete recommendations for respiratory infections, including when to test, when not to test which antibiotic to use for how long, when to involve patients in shared decision-making, and how to weigh the benefits and risks of antibiotic treatment. Infection prevention and control (IPC) messages for population and patients, including good hand, respiratory and food hygiene, are also part of this broader approach.
Antibiotic consumption in the hospitals remained stable in 2025. Inpatient consumption was 1.4 DID, similar to 2024 and below the reported European mean of 1.7 DID in 2024, . Taking hospital activity into account, antibiotic consumption is measured per 100 patient days. Antibiotic consumption reached 53.7 DDD per 100 bed-days (DBD) in 2025, which was 3.4% higher than in 2016. In contrast to the outpatient setting, hospital antibiotic consumption was quite similar across the three linguistic regions.
While overall hospital consumption remained stable, surveillance data from ANRESIS provide important insights for interpreting prescribing practices and supporting stewardship efforts, including benchmarking across institutions and monitoring temporal trends. Aggregated consumption data allow benchmarking across institutions and regions, and the tracking of trends over time and among hospital departments. The use of electronic medical record data to calculate patient-level prescription quality indicators is still emerging, but holds considerable promise. Quantity indicators with aggregated consumption should be combined with complementary data sources such as point prevalence surveys (PPS), which are cross-sectional surveys that measure antimicrobial consumption and healthcare-associated infections in a hospital population at a single point in time, or clinical audits. In the nationwide PPS, coordinated in 2025 by Swissnoso, the proportion of patients receiving at least one antimicrobial (about 30%) that day in hospital remained broadly stable since 2022. However the proportion on surgical prophylaxis, which accounted for the largest share of antibiotic use, has increased slightly over X years. This could represent a concrete target for focused antimicrobial stewardship interventions.. A major success is the 50% reduction in fluoroquinolone consumption over the past ten years, an orally available broad spectrum antibiotic.The decline was attributed to heightened awareness of their side effects and their demotion in prescribing guidelines, especially for urinary tract infections.
Several hospital prescribing issues require continued attention. Carbapenem use is closely monitored as their broad spectrum of activity carries a high risk of selecting resistant pathogens. They are important treatment optio for severe infections caused by multidrug-resistant bacteria and should be restricted to this indication as much as possible. While hospitals in the German- and French-speaking regions have maintained stable carbapenem consumption levels in recent years, use in the Italian-speaking region was higher than in the other regions (3.5 DBD vs 2 DBD).
Despite higher rates of multi-drug resistant organisms, the consumption of Reserve antibiotics remained stable in whole hospitals in the last decade; however, the upward trend should be monitored closely in the intensive care units of the largest hospitals.
More generally, the rationaluse of antimicrobial, especially Watch and Reserve antibiotics, remains important. Antimicrobial stewardship measures include systematic re-evaluation of antimicrobial treatment at 48h- 72 hours aiming at evaluating possiblede-escalation from broad-spectrum antimicrobials or stop where appropriate, switching from iv to po, and careful limitation of treatment duration to what is clinically indicated . Furtherpore the duration of preoperative prophylaxis is one concrete area where prescribing can be optimised.
Hospital stewardship programs provide an important basis for these improvements. According to a Swissnoso survey [4], most hospitals report stewardship activities and around half have established a formal antimicrobial stewardship programme. Treatment guidelines and monitoring of antibiotic use are widely implemented, while dedicated staff resources for stewardship are available in fewer hospitals. The Swissnoso handbook on antimicrobial stewardship supports hospitals in implementing measures such as support from the hospital management, guideline adherence, training on best practice, which encourage de-escalation and reduction in the duration of treatment, diagnostic stewardship, audit and feedback, and restrictions for selected Watch and Reserve antibiotics.
2.2. Antibiotic consumption in veterinary medicine
While human antibiotic consumption is mainly interpreted through prescribing settings, regions and AWaRe categories, veterinary antibiotic use requires a parallel view of sales and prescription data because treatment patterns differ substantially between animal species and production systems.
Antibiotic consumption in veterinary medicine has continued to decline over the long term. Sales data show that the amount of antibiotic active substance sold has decreased for both livestock and companion animals. For livestock, however, the amount sold per population correction unit (PCU) has remained stable at around 30 mg/PCU over the past three years. This indicates that part of the recent decrease in total active substance may reflect changes in livestock numbers rather than a further reduction in treatment intensity.
For products intended only for companion animals, the annual trend is less clear, but the overall development also points downward, with a decrease of XX% between 2016 and 2025. This decline occurred despite a rising number of companion animals. However, sales data for companion animals should be interpreted with caution, because many products authorised for both farm and companion animals are classified under livestock in this analysis. The actual amount of active substances used in companion animals is therefore likely underestimated.In European comparison, Switzerland remains among the countries with the lowest antibiotic sales per PCU (8th position in Figure 2; ESUAvet 2024).
Sales data show that overall veterinary antibiotic use is declining, while prescription data show where further improvements are still needed. By providing more detailed information on use in veterinary practice, prescription data reveal that the overall favourable trend does not affect all animal species and production systems in the same way. They help identify where use remains concentrated, where reporting changes complicate interpretation, and where targeted improvements are most relevant.
Cattle remain the main area where targeted improvements are needed. They account for the largest absolute amount of active substances and for the largest amount of critical antibiotics used in veterinary medicine. The highest numbers of animal treatments per 1,000 animals were recorded for dairy cows, followed by rearing and fattening cattle. However, for the first time, there was no increase but a small decrease in most cattle categories.Overall, the data suggest that, albeit at a high level, there may be a slight downward trend for the first time. Nevertheless, the still high level makes cattle, particularly dairy cattle and calf fattening, a priority for targeted reduction strategies that preserve animal health and welfare.
In pigs, most categories showed a slight increase in active substance amounts, critical active substance amounts and treatment numbers. This is in contrast to the downward trend observed in previous years. Treatment numbers per 1,000 animals also increased in fattening pigs and breeding animals. The increase was particularly pronounced for penicillins (25.2%) and even more for macrolides (53%), classified as critical antibiotics. Treatments with and without critical active substances decreased overall, especially in piglets. This recent upwards signal should be monitored closely before being interpreted as a true reversal of the previous downward trend as the niveau, especially of the amount of active substances, remains lower than in previous years.
In poultry, the total amount of active substances remains low compared with cattle and pigs, but the proportion of critical antibiotics has historically been high. This proportion has declined substantially in recent years. The amount of critical active substances (-56% since 2021) and the number of treatments per 1,000 animals with critical active substances (-80% since 2021, broilers) continue to decrease, while total active substance amounts and overall treatment numbers fluctuate without a clear trend. Overall, antibiotic use is low in poultry. The main progress in poultry therefore concerns the reduced use of critical antibiotics rather than a general reduction across all antibiotic classes. This may partly reflect replacement by sulfonamides, which require higher active substance amounts for equivalent treatment. Poultry therefore illustrates why antibiotic choice, and not only total active substance amount, is important for interpreting progress.
In companion animals, active substance amounts and treatment numbers in dogs and equines remain stable or decline slightly overall. In equines, active substance amounts have increased due to higher quantities of sulfonamides, while treatment numbers remain stable. For dogs the amount of critical active substances and the number of treatments with critical active substances show a slight downward trend. For cats, the amount of active ingredients is increasing, while the number of treatments remains roughly constant. This is due to an increase in the amount of penicillins, coupled with a decline in the amount of critical active ingredients, particularly third- and fourth-generation cephalosporins. With the number of animal treatments remaining constant, this suggests that critical antibiotics are being replaced by penicillins. Since 2024, veterinary practices have received annual reports on their antibiotic use in companion animals, allowing them to understand their prescribing patterns and compare their use with other practices (Focus report pXX). This creates a basis for practice-level benchmarking and targeted improvement.
Overall, sales and prescription data indicate that antibiotic consumption in veterinary medicine continues to decline, including for critical antibiotics The ongoing decline suggests that the national measures developed in recent years are having an impact on veterinarians' use of antibiotics.. Further progress will depend on improvements in specific areas, enhanced by targeted and tailored interventions. Dairy cattle and calf fattening are particularly important because they combine high treatment numbers with large amounts of active substances. In other areas, like pigs and poultry, the goal must be to maintain the level that has been achieved..
Taken together, the human and veterinary consumption data show that Switzerland is in a favourable position, with low antibiotic use in international comparison and evidence of more prudent use over time. Further progress will depend less on broad, non-specific reduction and more on targeted improvements: improving antibiotic choice and reducing avoidable prescribing in human medicine, and addressing species-specific priorities in veterinary medicine, especially cattle and selected uses of critical antibiotics. Across both sectors, the central task is to preserve effective treatment options while maintaining patient safety, animal health and welfare.
3. Antimicrobial resistance in human and veterinary medicine
Antimicrobial resistance is monitored for specific combinations of bacteria and antibiotics. In the human sector, the relevance of a resistant pathogen depends not only on its resistance proportion against certain antibiotics, but also on how common the infection is, how severe it can be, whether treatment options are limited, and how easily the organism or its resistance genes can spread. Resistance data therefore need to be interpreted together with information on incidence, clinical relevance, reservoirs and transmission pathways. In the veterinary sector, the prevalence of resistance is assessed via the resistance rate in animal pathogens but also via the monitoring of resistance in commensal bacteria and zoonotic pathogens.
This section therefore focuses on the most relevant resistance patterns in human and veterinary medicine, their interpretation, and the implications for surveillance, infection prevention, prudent antibiotic use and One Health action.
3.1. Antimicrobial resistance in human
In human medicine, resistance trends differ substantially between distinct bacteria-antibiotic combinations. For several major pathogens, resistance proportions have stabilized in recent years and remain low compared with most other European countries. However, resistance proportions in clinical infections alone do not fully describe the public-health relevance of a resistant pathogen. Some resistant bacteria, such as broad-spectrum cephalosporin-resistant Escherichia coli, cause a high burden because the underlying infections are frequent. Others, such as carbapenemase-producing Enterobacterales or carbapenem-resistant Acinetobacter species, remain rare but are particularly important in healthcare settings because treatment options are limited and healthcare-associated transmission requires early containment. In addition, surveillance based mainly on invasive infections may not capture all relevant developments. It may underrepresent trends in the ambulatory setting, such as community-associated MRSA, and it may miss the burden and transmission relevance of colonisation, as seen for VRE.
Methicillin-resistant Staphylococcus aureus (MRSA) illustrates why resistance proportions should be interpreted together with incidence. S. aureus is a common cause of human infections, ranging from skin infections to invasive bloodstream infections. In Switzerland, MRSA proportions decreased from 13% in 2004 to around 4–5% in 2015 and have since stabilized. These proportions compare favorably with the EU/EEA average MRSA proportion of 14.2% in 2024, also declining since 2020 (ECDC, 2025). In Switzerland the decline was mainly driven by decreases in western Switzerland and Ticino, while proportions in German-speaking Switzerland remained more stable (Olearo et al., 2016). Intensified infection prevention efforts, including early screening and isolation as well as hand hygiene, probably contributed to this development. In Switzerland, the incidence of MRSA bloodstream infections also remained low, at 1.08 per 100,000 inhabitants in 2024, around 10% lower than the 2017–2021 average of 1.2 per 100,000 (Renggli et al., 2023, EU/EEA 4.43 in 2024). However, two caveats First, the overall incidence of (susceptible) S. aureus infections, including methicillin-susceptible infections, has increased over time, especially in German-speaking Switzerland. Second, increases have been observed in severe community-associated infections with toxin (VPL) -producing MRSA strains. Future monitoring should therefore consider resistance proportions and incidence together, and should distinguish between hospital-associated and community-associated when assessing the public-health relevance of MRSA.
Vancomycin-resistant enterococci (VRE) represent a different type of challenge. In Switzerland, the proportion of VRE among invasive Enterococcus faecium isolates remains relatively low at 3%, compared with an EU/EEA average of 16.5% in 2024. Resistance proportions differ essentially within European countries from 35% in Italy, to 11% in Germany, 3.2% in Austria and 1% in France, which is important in assessing the risk of importation of resistant isolates. Even when invasive infections remain uncommon, these organisms contribute substantially to the clinical burden as colonizers. They predominantly occur in nosocomial settings, are often identified as co-pathogens, and can complicate treatment decisions in mixed infections. In addition, their transmissibility necessitates extensive screening and infection control measures. Since a large outbreak detected in Switzerland at the end of 2017 (Piezzi et al., 2022), repeated, mostly regionally limited but sometimes long-lasting outbreaks have occurred (Vuichard-Gysin et al., 2025, Bosetti et al., 2025). Surveillance has therefore been intensified: ANRESIS included non-invasive and screening isolates into their surveillance, clusters of VRE became notifiable to the FOPH, and national recommendations for the prevention and control of multidrug-resistant organisms have been adapted. Specifically, swissnoso issued guidance to support containment of these strains and continues to monitor the situation. Continued monitoring, including at institutional level, remains important to detect and control outbreaks early.
Gram-negative bacteria, especially Enterobacterales such as Escherichia coli and Klebsiella pneumoniae, are among the most important causes of resistant infections in human medicine. E. coli is a natural intestinal bacterium in humans and animals, but it is also a frequent cause of urinary tract infections, including bladder and kidney infections, and can lead to bloodstream infections. Because E. coli causes around 75% of bladder infections, resistance in this species is highly relevant for empirical treatment decisions and for antibiotic prescribing in both outpatient and hospital care.
In Switzerland, quinolone resistance in E. coli increased markedly between 2004 and 2010, from 10% to 19%, but has since stabilized. In 2024, the resistance proportion was 17%, compared with an EU/EEA average of 22.5%. This stabilization may partly reflect efforts to restrict quinolone prescribing for bladder infections. The situation is less favorable for resistance to 3rd/4th generation cephalosporins, reported here as extended-spectrum cephalosporin resistance (ESCR). In E. coli, ESCR largely reflects extended-spectrum betalactamase (ESBL) production. ESCR – E. coli proportions increased continuously from 1% in 2004 to 14% in 2025. A similar increase has been observed in the EU/EEA, where the average reached 16% in 2024. Because E. coli infections are frequent, this increase contributes substantially to the overall burden of antimicrobial resistance. This is also reflected in incidence data: ESCR – E. coli bloodstream infections increased by 16% from an average of 7.9 infections per 100,000 inhabitants in 2017–2021 to 9.2 per 100,000 in 2024. Containment of ESCR – E. coli is challenging because they are already widely present not only in hospitals, but also in food chains and outpatient settings. Knowledge of local resistance data is therefore essential to guide empirical treatment decisions and support appropriate antibiotic use.
Increasing ESCR proportions are also observed in K. pneumonieae, but the public-health interpretation differs from that for E. coli. K. pneumoniae can cause pneumonia and accounts for about 7% of bloodstream infections. Compared with E. coli, these infections more often affect hospitalised patients and patients with underlying conditions. This makes ESCR K. pneumoniae particularly relevant for healthcare settings, where infection prevention and control and targeted surveillance can help reduce transmission.
Carbapenem-resistant Enterobacterales (CRE) remain rare in Switzerland, but they require particular attention because treatment options are limited and early containment is essential. Although resistance proportions remain low, they increased from 0.1% in 2015 to 0.5% in 2025. Their contribution to the overall AMR burden is therefore still limited compared with more frequent resistant pathogens, such as ESCR – E. coli. Nevertheless, even small increases are relevant because CRE are often difficult to treat and can signal a risk of healthcare-associated spread.
Among CRE, carbapenemase-producing Enterobacterales (CPE), are of particular concern. Carbapenemases are enzymes that can degrade carbapenem antibiotics, and the epidemiological situation needs to be interpreted by bacterial species and carbapenemase type. CPE are therefore subject to mandatory reporting to the FOPH since 2017, with molecular surveillance supported by the National Reference Centre for Emerging Antibiotic Resistance (NARA). Together, these structures support early detection, genomic characterisation and detailed interpretation of CPE epidemiology.
The number of Carbapenemases reported in Switzerland increased substantially, from 102 in 2017 to 835 in 2025.This increase should be interpreted with caution because awareness, screening and testing for these organisms have also increased during the same period. However, the change is not limited to higher reporting numbers: the distribution of bacterial species and carbapenemase types has also shifted. In 2017, K. pneumoniae producing OXA-48 was the most frequently reported combination, whereas in 2025 E. coli producing OXA-244 dominated. Ticino had previously shown an increased prevalence of KPC-producing isolates, comparable to the situation in Italy (Ramette et al., 2021); however, recent trends suggest increasing alignment with the carbapenemase distribution patterns observed across the rest of Switzerland.
This need for continued vigilance is reinforced by developments in the EU/EEA, where the incidence of carbapenem-resistant K. pneumoniae bloodstream infections increased in almost all countries between 2019 and 2023 (ECDC, 2025). Although carbapenem resistance in Enterobacterales remains rare in Switzerland, the increasing number of reported CPE and the shift in species and carbapenemase types call for sustained surveillance and coordinated containment. Detailed analysis of species, carbapenemase type, genotype and, where relevant, sequence-type distribution at institutional and national levels remains important to better understand transmission pathways and guide targeted control measures.
Other carbapenem-resistant Gram-negative bacteria also require continued attention. Carbapenem-resistant Pseudomonas aeruginosa (CRPA) and carbapenem-resistant Acinetobacter species (CRAB) are internationally important and included in the WHO Bacterial Priority Pathogens List 2024. These infections occur primarily in hospitals. In Switzerland, resistance proportions in 2025 remained low compared with EU/EEA averages in 2024: 7% versus 16% for CRPA and 5% versus 32% for CRAB. No relevant increase in resistance proportions has been observed over the last 20 years, but deadly outbreaks particularly involving CRAB are feared, because of the very limited treatment options.
Overall, carbapenem-resistant Gram-negative bacteria remain rare in Switzerland compared with many other European countries. The main current concern is the increase in CPE, even though absolute levels remain low. For CPE, CRPA and CRAB alike, early detection, detailed microbiological characterisation, timely and rigorous screening and infection-prevention measures are essential to identify transmission pathways and prevent healthcare-associated spread.
These pathogen-specific trends show why resistance needs to be interpreted not only by resistance proportions, but also by its contribution to infections, deaths and overall health impact. The estimated burden of antimicrobial resistance adds an important perspective beyond resistance rates (Cassini et al. 2019, and Gasser et al., 2023). Based on resistance data, ANRESIS estimated the number of infections and deaths attributable to resistance for 16 clinically relevant highly resistant pathogen–antibiotic combinations up to 2023. These data show that the estimated number of deaths attributable to these resistant pathogens increased from 135 in 2010 to 260 in 2023.
In 2023, the largest share of the estimated burden was attributable to 3rd generation cephalosporin resistant E. coli (31.1 infections per 100,000 inhabitants / 137 estimated number of attributable deaths). This reflects the combination of frequent E. coli infections and increasing ESCR resistance. MRSA and carbapenem-resistant P. aeruginosa were the next largest contributors. The estimated burden was higher in the French- and Italian-speaking regions of Switzerland than in the German-speaking region. It was also higher in university hospitals than in non-university hospitals, likely reflecting higher patient complexity, referral patterns and differences in the case mix. These differences show that the burden of AMR is driven not only by the level of resistance, but also by how frequent the underlying infections are and which patient groups are affected.
3.2. Antimicrobial resistance in veterinary medicine
Antimicrobial resistance in bacteria from animals is monitored from two complementary perspectives. Zoonotic and commensal bacteria from food-producing animals isolated from caecal content, nasal swabs and meat samples are monitored because resistant bacteria or resistance genes may be transmitted to humans through food or animal contact. Pathogenic bacteria from diseased animals are monitored because resistance directly affects treatment options in veterinary medicine.
As in human medicine, resistance findings in animals need to be interpreted in context. Their relevance depends not only on resistance levels, but also on the bacterial species, animal reservoir, possible transmission pathways, and consequences for treatment or food safety. This section therefore summarises the most relevant resistance patterns in bacteria from animals, focusing on interpretation and implications for surveillance, prevention and One Health action.
For zoonotic bacteria, the main concern remains Campylobacter jejuni. Campylobacteriosis is the most frequently reported food-borne zoonosis in the European Union (168’396 cases, 2024) and Switzerland, with 8,280 cases reported in Switzerland in 2024 (ref 1. 2). Human infections are mainly caused by C. jejuni, and contaminated broiler meat is considered an important source of exposure. It is therefore of interest to monitor the resistance levels of C. jejuni in poultry meat, to collect evidence on further risk of resistant infections in humans. Resistance to ciprofloxacin is very high in human C. jejuni isolates (6667% in 2025), and a comparable resistance pattern is observed in isolates from Swiss broilers at slaughter (48%, 2024) (ref 3, 4). ). By contrast, resistance to macrolides in Swiss broiler isolates remains very low (0% in 2024, maximum 3.6% in 2018 over the last 15 years). This is reassuring because macrolides are relevant treatment options for severe human infections such as campylobacteriosis. Despite existing measures, contamination of broiler carcasses remains a challenge, indicating that further efforts along the poultry production chain are needed.
The situation for Salmonella spp. differs from that of Campylobacter spp. Salmonellosis remains the second most common food-borne gastrointestinal zoonosis in Europe (79’703 cases, 2024); in Switzerland, human cases (2344 cases, 2024) are mostly associated with S. Enteritidis, S. Typhimurium and its monophasic variants (ref 1. 2). However, the main food sources of outbreaks in the EU, such as eggs, pork and meat products, are less important in Switzerland because Salmonella prevalence in Swiss livestock is low (<2%). Salmonella isolates from Swiss poultry and cattle continue to show high to very high rates of full susceptibility to the antimicrobials tested. This favourable situation suggests that current control measures in Swiss livestock remain effective, but continued monitoring is needed to detect changes early and preserve treatment options for severe human infections.
Resistance findings in animals can be relevant for human health through different pathways and are therefore captured by different monitoring programmes. After food-borne zoonotic bacteria, livestock-associated MRSA in pigs illustrates a second pathway: direct contact between animals and humans.
The prevalence of MRSA in nasal swabs from fattening pigs at slaughter has increased continuously and significantly since monitoring began, from 2% in 2009 to 69% in 2025 (ref 4). Nearly all MRSA isolates belong to the livestock-associated clonal complex CC398, and humans in close contact with livestock have a higher risk of carrying livestock-associated MRSA. However, current human hospital settings surveillance does not suggest that these strains have become broadly established in Swiss hospitals, as the MRSA prevalence is decreasing to 5% in 2025. Continued monitoring remains important to detect changes in transmission patterns between animals, exposed humans and healthcare settings. MRSA screening and infection prevention measures for risk patients, together with biosecurity measures in high-risk animal-contact settings, can help limit further spread. Reports of an increasing number of CC398 MRSA infections in humans with no contact to animals in Europe could point to new challenges for the future. To clarify the epidemiological situation in Switzerland, whole-genome sequencing of human and animal MRSA would help reducing the knowledge gap of MRSA transmission in the Swiss context. A lead to fill this gap would be to incorporate MRSA WGS analyses into a new integrated One Health surveillance programme (ref 5, 6).
Resistance monitoring in pathogenic bacteria from diseased animals supports empirical treatment decisions in veterinary practice, especially when treatment has to begin before susceptibility results are available. In bovine mastitis pathogens, methicillin resistance remains rare in S. aureus and coagulase-negative staphylococci (CoNS). Penicillin resistance was detected in 15% of S. aureus isolates and 3738% of CoNS in 2024, while overall trends in these two mastitis pathogen groups appear stable.
The interpretation of resistance patterns in bovine streptococci is more difficult because few clinical breakpoints are available. In Streptococcus uberis, the proportion of isolates with non-wildtype phenotypes to penicillin was clearly higher in 2025 than in 2021, and an increasing trend was also observed for Streptococcus dysgalactiae subsp. dysgalactiae. These findings should therefore be followed closely, but interpreted cautiously in relation to clinical treatment decisions.
In companion animals, canine Staphylococcus pseudintermedius requires attention. In 2025, 8.5% of isolates were methicillin-resistant. A marked increase in antimicrobial resistance was detected to marbofloxacin (49% in 2025), clindamycin (21% in 2025) and trimethoprim-sulfamethoxazole (18% in 2025). In parallel, resistance rates to penicillin (73% in 2025) and ampicillin (63% in 2025) decreased, but are still on a very high level (ref 4).Resistance to penicillin and ampicillin decreased but remained high, while resistance to amoxicillin-clavulanic acid remained low. These patterns are relevant for empirical treatment choices and support prudent antibiotic use and susceptibility-guided therapy where possible.
Gram-negative bacteria, especially Escherichia coli, are monitored because they can act as reservoirs of transferable resistance genes and because resistant strains may affect both animal and human health. In commensal E. coli from healthy broilers, pigs and calves under one year, the proportion of fully susceptible isolates has increased in recent years, reaching 49% in broilers, 60% in pigs and 65% in calves in 2024/2025. Resistance rates in Swiss livestock remain lower than the European average. However, resistance in commensal E. coli to ampicillin, sulfamethoxazole, trimethoprim and tetracycline is still frequently observed, with the highest levels observed for calves (tetracycline 28%, ampicillin 26%, sulfamethoxazole 25%(ref 4)). In commensal E. coli from broilers, ciprofloxacin resistance remains high at 31% in 2024, although a decreasing trend has been observed since 2018. These resistance patterns likely reflect the decreasing use of these antimicrobials in food-producing animals.
ESBL/AmpC-producing E. coli prevalence monitoring shows a differentiated picture across livestock species and food chain steps. In the past, broilers had the highest prevalence in Switzerland and Europe, but in Switzerland the prevalence in broilers has decreased strongly, from 52% in 2016 to 5% in 2024. This decline is an important positive development and is most likely linked to the use of ESBL/AmpC-free day-old breeding stock in European broiler production. In fattening pigs, prevalence also decreased between 2015 and 2025, reaching 7% in 2025. In contrast, the prevalence in calves under one year has remained high, at 33% in 2025, after already being around 38% in 2015. This makes calves an important reservoir that requires continued monitoring. At European level, the prevalence of ESBL/AmpC-producing E. coli is higher in many countries, reaching around 40% in fattening pigs and around 40% in calves under one year. Prevalences in beef and pork meat remain on a very low level since 2015 (<1%) and decreased in Swiss chicken meat to 4% in 2024. Several studies have shown that, despite high prevalences of ESBL/AmpC-producing E. coli in European livestock, no close epidemiological linkage of ESBL/AmpC genes and plasmid replicon types in humans could be found (ref 7). These studies highlight the fact that there is no clear direct evidence of livestock being the only reservoir for the human burden of ESCR E. coli. In the interest of a One Health understanding and potential targeted strategies, more focus should be broad to investigate the exposure pathways, understand the clinical settings in animals, and identify which resistance genes are potentially transfered.The current monitoring system could include WGS of animal commensal bacteria to enhance the One Health global understanding and support further studies in genome comparison between human and animals bacteria.
In diseased animals, ESBL/AmpC-producing E. coli remain rare in bovine mastitis cases and diseased hens (<1%), respectively. In companion animals, however, ESBL/AmpC was detected in 4.7% of E. coli from canine and feline urinary tract infections in 2025. The latter is relevant for empirical treatment choices in companion animals and prudent use of critically important antibiotics is essential.
Carbapenem-resistant Enterobacterales (CRE) require particular attention because they are often multidrug-resistant and treatment options are limited. In contrast to the situation in human medicine, where CRE prevalences (?) are increasing, these bacteria have not been detected in Swiss livestock or raw meat since specific monitoring began. This remains a favourable finding for food-producing animals and the food chain.
At European level, sporadic detections of carbapenem-resistantE. coli in food-producing animals have increased in recent years, although still at a low level. Positive findings have been reported by several countries, mainly in pigs, followed by calves under one year and, less frequently, poultry (ref 8). Continued monitoring is therefore important to detect possible introduction into Swiss livestock or food products early.
In Switzerland, carbapenemase-producing EnterobacteralesCRE have been detected in veterinary clinics for companion animals. This suggests that these hard-to-treat bacteria can enter veterinary healthcare settings, as observed in human medicine. Strict hygiene and infection prevention measures in veterinary clinics are therefore needed to prevent establishment and further spread. As part of the monitoring of animal pathogens in cats, dogs, pigs and poultry, no carbapenem-resistant E. coli were detected in 2025.
3.3. Antibiotics and antimicrobial resistance in the environment
The environment is an important part of the One Health perspective on antimicrobial resistance. Antibiotics used in human and veterinary medicine, as well as resistant bacteria and resistance genes, can enter the environment through different pathways. At StAR we focus with our current measures on the pathway from wastewater into the aquatic environment. The relevance of these emissions depends on several factors, including how much antibiotic is released, how persistent the substance is and how effectively it is removed during wastewater treatment.
In Switzerland, antibiotics are detected in treated municipal wastewater and at lower concentrations in surface water. Concentrations decrease from wastewater to surface water making wastewater treatment plants an important and effective barrier. Conventional wastewater treatment processes substantially reduce antimicrobial-resistant bacteria and resistance genes, while antibiotics are partly removed. Since 2016, Switzerland has been upgrading selected wastewater treatment plants with additional treatment steps to eliminate micropollutants, including antibiotics. These upgrades reduce antibiotic concentrations in wastewater effectively and contribute to lower concentrations in receiving waters. They therefore represent an important measure to reduce emissions from human antibiotic use into the environment.
The effectiveness of wastewater treatment also depends on whether contaminated wastewater reaches the treatment plant. During heavy rainfall, the wastewater infrastructure can reach its limits leading to combined sewer overflows discharging wastewater directly into surface waters without treatment. Such events can be relevant entry pathways for antibiotics, resistant bacteria and resistance genes. Reducing these discharges, for example through retention basins at hospitals or other sites with high loads of pharmaceuticals, can highly reduce the load entering the environment and at the same time ensure that wastewater is treated before being released into the environment.
The direct role of antibiotic concentrations measured in Swiss waters in selecting for antimicrobial resistance remains uncertain. Based on current knowledge, these concentrations are unlikely to be a major direct driver of resistance development in Swiss surface waters. However, antibiotics, resistant bacteria and resistance genes are present in the water cycle, and emissions should continue to be minimised according to the precautionary principle. The updgrade of Swiss wastewater plants with an elimination step for micropollutants is playing an important role on further preventing antibiotics from entering the surface waters. Environmental monitoring remains important to assess the effects of wastewater treatment upgrades, identify persistent substances and better understand how antibiotics, resistant bacteria and resistance genes move through the environment.
4. References
Adriaenssens, N., et al. (2011). European Surveillance of Antimicrobial Consumption (ESAC): disease-specific quality indicators for outpatient antibiotic prescribing. BMJ Qual Saf, 20(9), 764-772. https://doi.org/10.1136/bmjqs.2010.049049
Charton, L., et al. (2025). Factors influencing inappropriate antibiotic prescription in respiratory tract infections in general practice. Sci Rep, 15(1), 33365. https://doi.org/10.1038/s41598-025-17490-4
Cook, A., et al.(2026). Benchmarking AWaRe: estimating optimal levels of AWaRe antibiotic use in 186 countries, territories and areas based on clinical infection and resistance burden. https://doi.org/10.64898/2026.01.26.26344900
Eder, M., et al. (2025). Monitoring of antimicrobial stewardship implementation in Swiss hospitals: results from a national survey. Swiss Med Wkly, 155, 4860. https://doi.org/10.57187/s.4860