Canadian Antimicrobial Resistance Surveillance System (CARSS): Highlights

Established in 2015, the Canadian Antimicrobial Resistance Surveillance System (CARSS) serves as a national focal point for antimicrobial resistance (AMR) and antimicrobial use (AMU) surveillance, highlighting evidence and trends from PHAC and partners, and providing relevant, timely, accurate, and comprehensive information to stakeholders, to support research, policies and actions.

  • Last updated: 2026-01-28

This page features key findings, recent developments, and offers access to interactive platforms and resources that support national AMR and AMU surveillance efforts. The content is updated regularly as new data and insights emerge - ensuring stakeholders have access to the most current and relevant information on AMR and AMU trends nationwide.

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2025 highlights and integrated narrative: antimicrobial resistance (AMR) and antimicrobial use (AMU)

In 2023 the federal, provincial and territorial Ministers of Health and Agriculture released the Pan-Canadian Action Plan on Antimicrobial Resistance (PCAP). This 5-year action plan established FPT commitments on AMR (2023 to 2027). Ten priority actions are guiding Canada's multi-sectoral and multi-jurisdictional efforts across 5 pillars: research and innovation; surveillance; stewardship; infection prevention and control (IPC); and leadership. Surveillance underpins Canada's ability to detect, understand and take necessary action to respond to emerging public health threats.

Canada's One Health approach to AMR and AMU surveillance

Canada has a strong AMR and AMU surveillance foundation. This approach recognizes the interconnected nature of humans, animals, and the environment in the development, transmission and spread of resistance. Surveillance efforts across all One Health sectors support and inform action, reveal trends and gaps, and help measure the effect of interventions. This includes:

An effective pan-Canadian response to AMR rests on the ability to detect and understand current AMR and AMU trends throughout Canada. However, AMR is a complex issue that exists within and between One Health sectors. As such, surveillance initiatives inform, and benefit from, broader national multidisciplinary approaches like the Genomics Research and Development Initiative (GRDI), which contribute to a more sustainable and integrated One Health approach to monitor and mitigate AMR across all sectors. Under the first phase, the GRDI Antimicrobial Resistance Project (2016-2022) brought together 23 scientists and their teams from 5 federal departments and agencies to strengthen Canada's scientific capacity to address AMR through genomics.

This collaboration advanced understanding of the processes that contribute to AMR emergence in food production systems, provided perspective on the exposure pathways linking agricultural and human health, and developed tools and analytical infrastructure to study AMR transmission. It also explored alternatives to antibiotics to reduce selection pressure, informing public health and food production decisions and laying the foundation for coordinated One Health genomic surveillance. Building on this work, and to further address the complex issue of AMR, Canada launched the GRDI for Antimicrobial Resistance - One Health (GRDI-AMR-OH), a 5-year project (2022-2027) that brings together a diverse team of experts from various Canadian science-based departments and agencies.

This initiative uses cutting-edge methodologies, like metagenomics and whole-genome sequencing, to track how resistance moves between hospitals, farms, food (domestic and imported), water, wildlife, and communities. The GRDI-AMR-OH project is generating critical knowledge on the etiology of AMR across the One Health continuum, aiding in the development of impactful solutions to combat AMR in Canada and beyond. To date, this initiative has produced 88 new peer-reviewed publications, with 140 public communication activities, including conferences and publications, significantly contributing to Canada's evidence base on AMR within the One Health continuum.

AMR summary findings and importance

AMR is increasing in Canada, with multiple pathogens showing rising case counts, evolving resistance patterns, and greater impacts on healthcare and public health systems. Timely and accurate AMR surveillance is vital to detect emerging threats, preserve treatment effectiveness, inform public health and clinical decisions, and protect current and future population health. Supported by key national surveillance partners, CARSS tracks and reports on essential resistance data, patterns and trends across sectors.

Surveillance findings are presented according to pathogen priority (or tier) level, as defined in the most recent Canadian AMR Pathogen Prioritization Framework.

High-priority (Tier 1) threats include carbapenem-resistant organisms (CROs), Candida auris, and drug-resistant Neisseria gonorrhoeae. These pathogens are all characterized by limited treatment options coupled with rising resistance and case numbers, the need for strengthened national surveillance, as well as the need to reevaluate treatment guidelines and drug access. Extended-spectrum β-lactamase (ESBL)-producing Enterobacterales also fall within Tier 1, given their ongoing and rising prevalence in humans, animals and food.

Medium-high priority (Tier 2) threats such as drug-resistant Shigella, Mycoplasma genitalium, drug-resistant Streptococcus pneumoniae and community-associated methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSIs) are spreading in community settings, particularly affecting vulnerable and marginalized populations.

Other threats, including drug-resistant tuberculosis (TB) and clindamycin-resistant invasive Group A Streptococcus (iGAS), are also of growing concern. Rising resistance internationally (TB) and increasing case counts (iGAS) raise concerns for potential outbreaks

Together, these findings highlight the ongoing need to strengthen AMR surveillance, enhance infection prevention and control, promote antimicrobial stewardship, and support coordinated responses at local, provincial/territorial, national and global levels.

Showing ... of ... pathogens

Pathogens of high concern
Pathogens of moderate-high concern
Pathogens of low-moderate concern
Pathogens of low concern
Notes
  • *: Rare and/or emerging refers to increased detection of resistant cases, particularly within specific subpopulations, indicating a growing concern that may not yet be fully captured by existing enhanced national surveillance efforts.
  • **: Though Clostridioides difficile (CDI) is listed as an AMR pathogen, the organism is rarely resistant to the antimicrobials used to treat CDI; however, it often occurs in people who have taken antimicrobials and is a primary marker of prior antimicrobial use (AMU), a lead cause of AMR.
  • The table above highlights select key human AMR pathogens identified through national and provincial/territorial surveillance programs. It is not intended to be exhaustive, and the absence of a pathogen should not be interpreted as a lower public health concern. Where available, insights from provincial/territorial public health partners are included to provide additional context and nuance.

Monitoring AMU is essential to combatting AMR. The Government of Canada monitors AMU and/or antimicrobial sales and dispensing across the human, animal and plant/crop sectors to identify potential patterns of overuse or inappropriate prescribing (where data allow), monitor trends over time, and inform stewardship efforts (interventions designed to improve the appropriate use of antimicrobial drugs to limit the development of resistance and preserve their effectiveness for the future) and policy development. This integrated surveillance supports efforts to preserve the effectiveness of these critical drugs. Reducing unnecessary AMU supports public and animal health by ensuring that antimicrobials remain effective and available for both current and future generations.

Human sector: AMU in the community and hospital settings (2020-2024)

Across Canada, AMU presents both some progress and ongoing challenges in stewardship. After a notable decline during the pandemic, community antimicrobial prescribing rates rebounded by 24% between 2020 and 2024, returning to levels comparable to 2019. This rebound was the primary driver of the overall 23% national increase observed across all sectors during this period. Despite this, prescribing patterns continued to demonstrate positive stewardship trends, with over 70% of antimicrobial prescriptions in the community falling within the World Health Organization (WHO) “Access” category. In hospitals, AMU is more reliant on both “Access” and “Watch” category drugs, with over 25% of prescriptions deemed inappropriate or suboptimal. Expanding surveillance on the appropriateness of use could help strengthen local, regional and national stewardship strategies. Internationally, in per capita AMU, Canada ranks 23rd out of 65 countries, territories and areas participating in the WHO GLASS Antimicrobial Consumption (AMC) module (2024), and remains below the OECD average, a positive indicator of sustained stewardship progress.

🏘 Community

Highlights
  • 📈 Overall decline in prescribing rates from 2019 to 2021, followed by a 24% increase (2020 to 2024), returning to pre-pandemic levels.
  • 🌍 AWaRe Classification: Over 70% of prescribed drugs are from the Access category.
  • 💊 Most prescribed antibiotics: Penicillins (with or without) beta-lactamase inhibitors, macrolides, and tetracyclines.
Potential implication
  • 🛡 ️The Post-pandemic rebound suggests a return to pre-pandemic prescribing patterns, reinforcing the need to sustain and strengthen community stewardship initiatives.

🏥 Hospital

Highlights
  • ✖ Over 25% of prescriptions deemed inappropriate or suboptimal based on combined data from 2018 to 2024 in participating volunteer hospitals.
  • 🌍 AWaRe Classification: Most AMU falls within “Watch” (55%) and “Access” (~44%) category drugs. The “Reserve” group represented ~1% of hospital AMU (of which ~18% was deemed inappropriate).
  • Among inappropriate prescriptions, the most common indications reported were surgical prophylaxis (12.3%) cystitis (10.7%), and community-acquired pneumonia (9.3%).
  • Approximately 22% of inappropriate prescriptions were for indications that did not require any antimicrobial therapy. For prescriptions where an antimicrobial was indicated, the main reasons for inappropriate prescription were incorrect duration (34%), spectrum too broad (32%) and incorrect dose or frequency (17%).
  • 💊 Most prescribed antibiotics: 1st- and 3rd-generation cephalosporins (with a rise in 3rd-generation use). Broad spectrum quinolone use has dramatically declined over the years.
Potential implication
  • 🎯 Expanding surveillance on the appropriateness of use could help strengthen local, regional and national stewardship strategies.

🌍 International

Highlights
  • 🌍 Canada ranked 23rd out of 65 countries, territories and areas participating in the WHO GLASS AMC (2024) and lower than the OECD average.
Potential implication
  • 🌟 Canada’s relatively low per capital antimicrobial use is a positive indicator of ongoing stewardship efforts.

Integrated human, animal, food and environment surveillance: AMR and AMU across sectors (2019-2023)

Recognized globally as essential, integrated One Health surveillance is a cornerstone of efforts to address AMR, as it considers the interconnectedness of humans, animals, plants/crops, food and the environment. In Canada, data on AMU and/or antimicrobial sales across the human, animal and plant/crop sectors are integrated to assess usage patterns and understand selective pressure (which can allow certain AMR organisms to thrive and evolve). AMR data are also integrated from sources across the food chain and in humans. Where possible, there is integration of AMR and AMU data to enhance understanding of resistance trends and drivers.

Over the past several years, and continuing into 2023, the quantity of medically important antimicrobials (according to Health Canada's categorization system) sold for use in animals plateaued. Data from voluntary sentinel farm surveillance between 2019 and 2023 showed declining AMU on broiler chicken, turkey and grower-finisher pig farms, and beef cattle feedlots. AMU increased on sentinel dairy cattle farms between 2019 and 2022, which may be partly explained by improved reporting in 2021-2022. In aquaculture operations, AMU declined between 2019 and 2022 (data from Fisheries and Oceans Canada). Less than 2% of reported AMU on terrestrial farms involved Category I antimicrobials, which are of very high importance to human medicine. However, concerning trends of increasing resistance emerged throughout the food chain, including in ESBL-producing non-typhoidal Salmonella, nalidixic acid-resistant Salmonella Enteritiditis, and ciprofloxacin-resistant Campylobacter.

Category Highlight Potential Implication
Integrated AMR (human, animal and food)

Rising ESBL-producing non-typhoidal Salmonella:

ESBL-producing non-typhoidal Salmonella from humans, animals and food continued to increase in 2023.

Increasing nalidixic acid resistance in Salmonella Enteritidis:

Resistance in chickens (diagnostic isolates) and chicken meat continued to rise in 2023. Historically, S. Enteritidis from chickens showed almost full susceptibility to tested antimicrobials, but resistance to nalidixic acid emerged in 2018.

These ESBL-producing bacteria are resistant to third-generation cephalosporins, and are classified as a High Priority (Tier 1) pathogen in Canada and as critical group by the WHO. This raises concerns about treatment options and foodborne transmission.

Resistance to nalidixic acid signals reduced effectiveness of fluoroquinolones, a key treatment for serious human infections. This raises concerns about the progression to full resistance.
Integrated AMR (environmental and other sources)

Resistance to Category I antimicrobials was detected in isolates from both surface water and environments of sick animals in 2023.

In 2023, resistant non-typhoidal Salmonella capable of causing human disease were detected in animal feed ingredients and mixed feeds.

Raises concerns about environmental pathways contributing to the spread of resistant bacteria.

Surveillance of animal feed is important as it may serve as an entry point for resistant bacteria into the food chain, posing risks to human and animal health.
Integrated AMU/AMR (human, animal and food)

Increasing ciprofloxacin resistance in Campylobacter:

Ciprofloxacin resistance in Campylobacter from animals and food increased in 2023, despite relatively low fluoroquinolones sales for use in animals.

In humans, resistance remained high or very high from 2018 to 2022, despite a decrease in fluoroquinolone use in people (2019-2023).

Campylobacter is a major cause of foodborne illness in people. Fluoroquinolones are one of the main treatments (when needed), with macrolides as an alternative. Monitoring fluoroquinolone use and resistance in zoonotic and commensal bacteria from animals and food can help understand sources of resistant bacteria in humans.
Veterinary antimicrobial sales and sentinel terrestrial farm AMU surveillance

Between 2019 and 2023, the quantity of medically important antimicrobials sold for use in animals has plateaued in Canada.

In 2023, most antimicrobials sold for production animals were Category II and III. Less than 2% of reported AMU on sentinel farms were Category I antimicrobials (very high importance to human medicine).

Continued action is needed to ensure all antimicrobials are used prudently in Canada.

Category I antimicrobials are essential for treating serious human infections and have limited alternatives. Some Category I antimicrobials, like 3rd-generation cephalosporins and fluoroquinolones, are also “Veterinary Critically Important Antimicrobials” per the World Organisation for Animal Health (WOAH).

Shifts in the human AMR priority pathogen list

For nearly two decades, national and international health agencies have prioritized AMR pathogens to guide surveillance, prevention, and response. Building on earlier prioritization frameworks developed by the US Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO), PHAC conducted its first AMR prioritization exercise in 2015, laying the groundwork for CARSS. Since then, additional initiatives have refined global priorities, including the updated CDC threat list (2019) and the WHO's bacterial (2017, updated 2024) and fungal (2022) priority pathogen lists.

In 2025, building on enhanced surveillance data from CARSS and other national programs, PHAC updated Canada's AMR priority pathogen list. Of the 155 pathogens reviewed, 68 showed evidence of AMR. Following a rigorous screening by subject matter experts, 29 pathogens underwent detailed assessment using a multi-criteria decision analysis (MCDA) framework based on Canadian data, where available, from 2017 to 2022. Pathogens were ranked into tiers using 9 weighted criteria: trend, detection, morbidity, incidence, treatability, health equity, preventability, case fatality, and transmission mode. These criteria align with global best practices but were tailored to Canadian priorities. Canada is the first country to include health equity in such an exercise, reflecting a commitment to understanding and addressing disparities in AMR impact.

Carbapenem-resistant Enterobacterales (CRE) and ESBL-producing Enterobacterales maintained their High Priority Tier 1 group status. Notable upward shifts include drug-resistant Neisseria gonorrhoeae and carbapenem-resistant Acinetobacter spp., which moved from Tier 2 (Medium-High Priority), and carbapenem-resistant Pseudomonas aeruginosa, which moved from Tier 3 (Medium-Low Priority) to Tier 1. Candida auris is a significant new addition.

Tier 2 retained vancomycin-resistant Enterococcus spp., with upward shifts of drug-resistant Streptococcus pneumoniae, non-typhoidal drug-resistant Salmonella spp., and drug-resistant Shigella spp., while methicillin-resistant Staphylococcus aureus fell from Tier 1. Mycoplasma genitalium was newly recognized as Tier 2.

Tier 3 maintained drug-resistant Group B Streptococcus and drug-resistant Aspergillus spp., with upward shifts of drug-resistant Influenza A, drug-resistant HIV, and typhoidal drug-resistant Salmonella spp. Downward shifts included Clostridioides difficile from Tier 1 and clindamycin-resistant invasive Group A Streptococcus and multidrug-resistant Haemophilus influenzae, Treponema pallidum, Chlamydia trachomatis, and pulmonary non-tuberculosis Mycobacteria, while drug-resistant Campylobacter spp., Helicobacter pylori, non-auris Candida spp., and Bacteroides spp. fell from higher tiers. Ureaplasma spp. is newly added to Tier 4 (Low Priority).

Overall, Canada's AMR threat landscape has evolved over the past decade. Candida auris, gram-negative bacteria, including CRE, Pseudomonas, and Acinetobacter, and those causing drug-resistant sexually transmitted infections (STIs), such as Neisseria gonorrhoeae and Mycoplasma genitalium are emerging as increasingly urgent threats. Conversely, some pathogens previously considered higher priority, such as MRSA and C. difficile, have decreased in prioritization, though they continue to pose significant public health concerns. Tier 1 and Tier 2 pathogens represent the most critical threats, requiring focused resources for prevention, early detection, and enhanced surveillance. The inclusion of health equity underscores the need for targeted strategies to mitigate AMR's impact on marginalized populations, particularly in STIs, ensuring effective resource allocation and a strengthened national response to AMR.

Ongoing and emerging areas of exploration

Environmental surveillance

Environmental Surveillance Strategic Framework (ESSF)

A federal roadmap for addressing AMR in the environment

Antimicrobials are essential for protecting human, animal and plant/crop health. However, antimicrobial-resistant organisms (AROs) and resistance genes can be found in—and transmitted through—the environment, including water, air, soil, flora and fauna. Humans may be exposed through recreational and occupational activities, or via food, water, and air. Similarly, livestock, companion animals, wildlife, and plants/crops are also at risk of exposure from environmental sources.

While some level of AMR occurs naturally, environmental contamination with resistant microorganisms, resistance genes, antimicrobial residues, and other chemical pollutants can contribute to the development and spread of resistance.

To date, PHAC-led AMR surveillance in Canada has focused primarily on human and animal health. The Environmental Surveillance Strategic Framework (ESSF) provides guidance to advance surveillance into the environmental domain. Key objectives include:

National surface water and pilot wastewater AMR surveillance projects are ongoing and will help strengthen the evidence base for public health actions, policy development, and interventions to mitigate AMR risks across One Health sectors.

Note: Advancing AMR surveillance in the environment will require strong collaboration across FPT government departments to leverage complementary mandates, expertise, and monitoring networks. This aligns with federal commitments under the Pan-Canadian Action Plan on Antimicrobial Resistance.

Health, Attitudes and Behavioural Insights Tracker (HABIT) survey

The HABIT (Health, Attitudes and Behavioural Insights Tracker) survey, led by the Privy Council of Canada, collects data on Canadians' health, behaviours, attitudes and practices to inform public health policy and programs. The CARSS team conducted an analysis of the November 2023 survey data (n=2,036) to better understand patterns of antibiotic use and self-medication in Canada.

Key findings:

These results highlight the need for regular national data collection on AMU and self-medication, and targeted education about AMR and the risks of non-prescribed use, especially at the time antibiotics are prescribed.

Limitations: HABIT surveys do not include adults in healthcare facilities or long-term care facilities, and may under-represent frail home-dwelling adults.

Human AMU in primary care

Canadian Primary Care Sentinel Surveillance Network (CPCSSN)

CPCSSN is a pan-Canadian electronic medical record (EMR)-based surveillance system. It collects de-identified clinical data from more than 1,200 primary care providers across 8 provinces, representing approximately 2 million patients. Since nearly 90% of antibiotics in Canada are prescribed outside of hospitals, CPCSSN provides a unique opportunity to examine prescribing practices in the primary care setting, where national datasets have historically been limited. Urinary tract infections (UTIs) and skin and soft tissue infections (SSTIs) are among the most common bacterial infections managed in primary care, account for a substantial proportion of antibiotic prescriptions. Because first-line therapies for UTIs and SSTIs are increasingly affected by resistance, monitoring prescribing trends is essential to support stewardship and preserve treatment options.

Highlights Potential implication

UTIs 2017 to 2021:

227,154 UTIs were identified; 59% (134,425 cases) received at least 1 antibiotic, totaling 149,181 prescriptions.

Antibiotic prescribing was higher among female patients (66%).

Top antibiotics for UTIs (2021): nitrofurantoin (42%) (recommended first line therapy), ciprofloxacin (13%), sulfamethoxazole-trimethoprim (13%), fosfomycin (10%), and cefixime (5%).

Trends in UTI-associated antibiotic prescriptions show a decline in amoxicillin use (from 11% to 5%); slight increase in amoxicillin with β-lactamase inhibitor use (1.6% to 2.7%); slight decrease in ciprofloxacin use (14.3% to 12.7%) and a doubling in fosfomycin use (from 5% to 10%).

UTIs are a key driver of outpatient antibiotic prescribing and contribute to AMR selection pressure, reinforcing need for targeted stewardship and patient education on AMR and AMU

Shifts in antibiotic prescribing may reflect the use of guideline-recommended antibiotics and/or evolving AMR patterns for UTIs.

SSTIs 2017 to 2021:

155,277 SSTIs were identified, 47% (73,672 cases) received at least 1 antibiotic, totaling 82,997 prescriptions.

Antibiotic prescribing was similar between male (48%) and female (47%) patients.

Top antibiotics for SSTIs (2021): cephalexin (54%) (recommended first line therapy), amoxicillin with a β-lactamase inhibitor (9%), doxycycline (8%), sulfamethoxazole-trimethoprim (6%), and clindamycin (5%).

Trends in SSTI-associated antibiotic prescriptions show an increase in use of amoxicillin with a β-lactamase inhibitor (from 5.6% to 8.6%), and an increase in doxycycline use.

 Shifts in antibiotic prescribing may reflect the use of guideline-recommended antibiotics and/or evolving AMR patterns for SSTIs.

Exploratory antibiogram project

Sentinel laboratory surveillance of human pathogens – CANWARD

Antibiogram data are an important source of information for tracking AMR trends. However, collecting and integrating hospital laboratory data for national surveillance is complex due to data privacy and standardization challenges.

The Canadian Antimicrobial Resistance Alliance (CARA) Canadian Ward study (CANWARD) is a sentinel network of 10–15 hospitals (majority teaching) across 8 provinces. It has provided valuable, time-limited insight into into bloodstream infections (BSIs) and AMR trends, helping to fill important data gaps while PHAC develops more sustainable systems.

CANWARD provided interim insight into hospital antibiogram trends in Canada, filling key evidence gaps while AMRNet was being expanded. AMRNet is already operational, and some of its data have been included in this reporting. It is expected to become the primary source for both hospital and community antibiogram data, offering broader and more systematic coverage, integrated national datasets, and solutions to challenges related to privacy and data integration. This ongoing transition will help support a more comprehensive and coordinated national response to AMR.

Highlights Potential implication

2017 to 2021:

5,707 BSI isolates; 50% were caused by gram-negative bacteria, 47.6% by gram-positive bacteria, and 2.4% by fungal pathogens.

Key pathogens and resistance trends:

E. coli (27% of BSIs): 13% suspected ESBL (Tier 1—High Priority; resistant to ceftobiprole (newer antibiotic reserved for complex cases)).
S. aureus (17% of BSIs): 19% MRSA (Tier 2—Medium-High priority).
K. pneumoniae (10% of BSIs): <1% carbapenem-resistant (Tier 1—High priority.
P. aeruginosa (4% of BSIs): 15% resistant to meropenem (Tier 1—High priority).
E. faecium (3% of BSIs): 21% VRE (Tier 2—Medium-High priority).
E. faecalis (4% of BSIs): 0% VRE.

Gram-negative bacteria cause a significant share of BSIs in Canada and are associated with increased morbidity and mortality.

Highlights high-priority AMR threats; identifies pathogens where treatment options are limited or emerging resistance is a concern.

Emerging carbapenem-resistant infections pose serious clinical challenges and underscore the need for continued national surveillance and stewardship.

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