Successful Prevention of Antimicrobial Resistance in Animals-A Retrospective Country Case Study of Sweden

Why prescribe antibiotics? A systematic review of knowledge, tension, and motivation among clinicians in low-, middle- and high-income countries

Medical professionals such as physicians and veterinarians are responsible for appropriate antimicrobial prescription (AMP) and use. Although seemingly straightforward, the factors influencing antibiotic prescription, a category of antimicrobials, are complex. Many studies have been conducted in the past two decades on this subject. As a result, there is a plethora of empirical evidence regarding the factors influencing clinicians' AMP practices.

AIM

A systematic review of AMR studies on AMP was conducted, condensing findings according to a combination of the Knowledge, Attitude, and Practice (KAP) and Capacity, Opportunity, Motivation-Behavior (COM-B) models. Review findings were then synthesized and analyzed for policy implementation according to the Consolidated Framework for Implementation Research (CFIR).

DESIGN AND METHODOLOGY

A systematic literature review was conducted according to PRISMA guidelines to identify peer-reviewed papers indexed in pre-determined medical science, social sciences, and humanities databases that apply the KAP model in their investigations. Antimicrobial prescription factors were compared and contrasted among low- and middle-income countries (LMICs) and high-income countries (HICs).

FINDINGS

The KAP model is a heuristic and structured framework for identifying and classifying respondents' knowledge. However, other than medical knowledge, factors that influence prescription decision-making can be expanded to include attitudes, perception, personal affinities, professional circumstances, relational pressure, and social norms.

The Importance of Hazard Analysis by Critical Control Point for Effective Pathogen Control in Animal Feed: Assessment of Salmonella Control in Feed Production in Sweden, 1982-2005

This study is the first to show that Hazard Analysis by Critical Control Point (HACCP)-based monitoring can be an effective tool for ensuring Salmonella-safe feed, by virtually eliminating feedborne Salmonella infection even in broiler production. Data from the control of Salmonella in feed and food animal production during 1982-2005, showed that conventional endpoint testing in feed mills did not ensure a Salmonella-safe feed, and in one feed mill failed to detect Salmonella contamination, resulting in the feed infecting 80 out of 197 (40.6%) recipient broiler flocks. Following implementation in 1991 of a HACCP-based control in feed mills, the annual number of samples tested at specified critical control points during a 15-year period increased from ∼4400 to 10,000, while the proportion of Salmonella-contaminated samples decreased from 2.0% to 0.3%. Thus, introduction of HACCP was followed by a dramatic decrease, from 40 to <5, in the annual number of Salmonella-infected broiler flocks identified by preslaughter monitoring. Incidence has generally remained at that low level, despite production since 1980 increasing from 39 to 112 million chickens per year. Feed mills start using soymeal with an unsafe Salmonella status and possibly with a suboptimal HACCP control, increased their level of Salmonella-contaminated HACCP samples, and their feed subsequently infected 78 swine-producing herds. The results also show that the HACCP concept can be an effective tool to supply feed mills with Salmonella-safe feed ingredients as demonstrated for a soybean crushing plant, which produced Salmonella-safe soymeal over a 19-year period despite frequent (34%) and highly varied (92 different serovars) Salmonella contamination in samples from incoming soybean. Similar results are reported for a plant producing rapeseed meal. It is emphasized that the achievements described through use of the HACCP required interventions of relevant preventive biosecurity measures and corrective actions when the HACCP-based monitoring identified Salmonella contamination.

Interventions to change antimicrobial use in livestock: A scoping review and an impact pathway analysis of what works, how, for whom and why

Antimicrobial resistance (AMR) is a public health threat responsible for 700,000 deaths per year worldwide. Antimicrobial use (AMU) in livestock contributes to AMR in animal and public health. Therefore, it is essential to implement effective interventions towards better AMU in livestock. However, there is a lack of evidence to inform decision-makers of what works, how, for whom and why and how effective interventions can be adapted to different contexts. We conducted a scoping review and an impact pathway analysis to systematically map the research done in this area and to inform evidence-based and context-appropriate policies. We followed the PRISMA-ScR requirements and searched Web of Science, PubMed and Scopus databases to identify studies in English or French languages, in open access and published between 2000 and 2022. We selected thirty references addressing twenty-eight different interventions that were successful in changing AMU in livestock. We used an impact pathway logic model as an analytic framework to guide the technical aspects of the scoping review process and to identify the complex relationships between outputs, outcomes, impacts and contextual factors. A majority of interventions managed to improve AMU by changing herd and health management practices (ni=18). We identified intermediate outcomes including change in the veterinarian-farmer relationship (ni=7), in knowledge and perception (ni=6), and in motivation and confidence (ni=1). Twenty-two studies recorded positive impacts on animal health and welfare (ni=11), technical performances (ni=9), economic performances (ni=4) and AMR reduction (ni=4). Interventions implemented different strategies including herd and health management support (ni=20), norms and standards (ni=11), informational and educational measures (ni=10), economic support (ni=5). Studies were mainly in European countries and in pig and large ruminants farming. Most interventions targeted farmers or veterinarians but we identified other major and influential actors including authority and governmental organizations, academics and research, organization of producers or veterinarians, herd advisors and technicians, laboratories, and public opinion. Key success factors were knowledge and perception (ni=14), social factors (ni=13), intervention characteristics (ni=11), trajectory and ecosystem of change (ni=11), economic factors (ni=9), herd and health status (ni=8), data access and monitoring (ni=4). This review describes a paucity of impact assessment of interventions towards better AMU in livestock. There is no one-size-fits-all transition pathway but we inform decision-makers about the most successful interventions that work, how, for whom and why. The impact pathway analysis provided a holistic view of the successful change processes and the complex relationships between outputs, outcomes, impacts and contexts.

Exposure Assessment of Nitrofuran Metabolites in Fish and Honey Produced in Armenia: A Pilot Investigation

In Armenia, the presence of nitrofuran residues in food products is unacceptable for both domestic sales and export. However, food may contain nitrofuran metabolites (NMs) due to the illegal use of these drugs in the agrofarming practice. This study aimed to identify NMs as the marker residues for nitrofurans in fish and honey produced in Armenia and assess the potential health risks associated with consuming these foods. The commodities studied were natural honey and three species of farmed fish produced by various regions nationwide. Concentrations of the marker metabolites (3-amino-2-oxazolidinone (AOZ), 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ), 1-aminohydantoin (AHD), and semicarbazide (SEM)) were determined through an enzyme-linked immunosorbent assay (ELISA) and verified using liquid chromatography-mass spectrometry (LC-MS/MS). Consumer groups were identified based on their average daily intake of foods. Health risk was assessed by calculating the margin of exposure (MOE). Reference values for health risk assessment were obtained from the European Food Safety Authority (EFSA). Results showed that 33.3% of fish samples and 44.4% of honey samples contained NMs, the mean concentrations ranging from 0.05 μg/kg to 0.52 μg/kg. All MOE values obtained were over 10,000, indicating that the detected concentrations of NMs in fish and honey produced in Armenia pose no health risk to consumers. However, these results highlight the illicit use of highly toxic substances and the need for improved control of farming practices.

Is scientific evidence enough? Using expert opinion to fill gaps in data in antimicrobial resistance research

BACKGROUND

Antimicrobial Resistance (AMR) is a global problem with large health and economic consequences. Current gaps in quantitative data are a major limitation for creating models intended to simulate the drivers of AMR. As an intermediate step, expert knowledge and opinion could be utilized to fill gaps in knowledge for areas of the system where quantitative data does not yet exist or are hard to quantify. Therefore, the objective of this study was to identify quantifiable data about the current state of the factors that drive AMR and the strengths and directions of relationships between the factors from statements made by a group of experts from the One Health system that drives AMR development and transmission in a European context.

METHODS

This study builds upon previous work that developed a causal loop diagram of AMR using input from two workshops conducted in 2019 in Sweden with experts within the European food system context. A secondary analysis of the workshop transcripts was conducted to identify semi-quantitative data to parameterize drivers in a model of AMR.

MAIN FINDINGS

Participants spoke about AMR by combining their personal experiences with professional expertise within their fields. The analysis of participants' statements provided semi-quantitative data that can help inform a future of AMR emergence and transmission based on a causal loop diagram of AMR in a Swedish One Health system context.

CONCLUSION

Using transcripts of a workshop including participants with diverse expertise across the system that drives AMR, we gained invaluable insight into the past, current, and potential future states of the major drivers of AMR, particularly where quantitative data are lacking.

Co-created community contracts support biosecurity changes in a region where African swine fever is endemic – Part II: Implementation of biosecurity measures

Smallholder subsistence pig production is common in Uganda and African swine fever (ASF) is endemic in the country, with its spread driven by human activities along the smallholder value chain. Previous research in the study area has revealed that many stakeholders are aware of how ASF is spread, its prevention and control, and have a generally positive attitude towards biosecurity. Despite this, even basic biosecurity is largely lacking. Costs, as well as a lack of adaptation to the local context, culture and traditions have been identified as factors hindering biosecurity implementation. Community engagement and local ownership of disease problems are increasingly recognised as important for improving disease prevention and control. The objective of this study was to investigate the capacity of participatory action at community level with broad inclusion of stakeholders to improve biosecurity in the smallholder pig value chain. Specific attention was paid to participants' perceptions and experiences of implementing the biosecurity measures included in their co-created community contracts. The study was conducted in Northern Uganda in villages purposively selected on the basis of previous occurrences of ASF. In each village, farmers and traders were also purposively selected. At a first meeting, basic information about ASF was shared and participants presented with a list of biosecurity measures adapted for farmers and traders respectively. Participants discussed each measure in farmer and trader subgroups, decided on the measures to implement for one year, and signed a community contract to this effect. The following year, interviews were again undertaken and implementation support given. Interview data were coded and thematically analysed. Each subgroup chose a minimum of three and a maximum of nine measures, with wide variations between villages in their selection of measures. At the follow-ups, none of the subgroups had fully implemented what had been agreed in their contract, but all had changed some of their biosecurity routines. Some frequently recommended biosecurity measures, such as not borrowing breeding boars, were not considered feasible. Relatively simple and cheap biosecurity measures were rejected for reasons of cost, highlighting the participants' general level of poverty and the relevance of poverty as a specific factor governing disease control results. The participatory methodology allowing for discussions, co-creation and the option to refuse measures seemed to facilitate the implementation of measures that had initially been thought to be controversial. The broad community approach was deemed to be positive for strengthening community identity, cooperation and implementation.

The rise of antibiotic resistance in Campylobacter

PURPOSE OF REVIEW

Campylobacter is a major foodborne pathogen that infects the human intestinal tract. This review discusses the current status of antibiotic resistance, transmission of antibiotic resistance genes, and strategies to combat the global Campylobacter epidemic.

RECENT FINDINGS

Over the past 18 months, articles on Campylobacter antibiotic resistance have been published in ∼39 countries. Antibiotic-resistant Campylobacter have been detected in humans, livestock, poultry, wild animals, the environment, and food. Campylobacter spp. are resistant to a wide spectrum of antimicrobial agents, including the antibiotics quinolones, macrolides, tetracyclines, aminoglycosides, and chloramphenicols. Multidrug resistance is a globally emerging problem. Continuous antibiotic pressure promotes the spread of drug-resistant Campylobacter spp. Additionally, Campylobacter is well adapted to acquiring foreign drug resistance genes, including ermB, optrA, fexA, and cfrC, which are usually acquired from gram-positive bacteria.

SUMMARY

The widespread use of antibiotics has caused a global epidemic of drug-resistant Campylobacter infections. Many countries are actively reducing the use of antibiotics and adopting alternatives in the livestock and poultry industries to control the spread of drug-resistant Campylobacter spp.

Trust, agreements, and occasional breakdowns: Veterinarians' perspectives on farmer-veterinarian relationships and use of antimicrobials for Swedish dairy cattle

Studies have shown that farmer-veterinarian relationships influence antimicrobial use (AMU) in livestock, though how they do so is unclear. On the one hand, research shows that well-established veterinarian-farmer relationships are positive for implementation of antibiotic stewardship and restrictive AMU. On the other hand, studies also show that farmer demands can increase antimicrobial prescribing and that prescribing antimicrobials can strengthen the veterinarian's relationship with farmer clients. In the present study, we focus on veterinarians' perspectives on the relationships between dairy cattle farmers and veterinarians in Sweden and explore what characterizes these relationships when restrictive AMU is described as unproblematic and when AMU becomes a matter of tension or conflict. The study draws on semistructured interviews with 21 veterinarians working with livestock in Sweden. Interviews were analyzed thematically. The study shows that from the perspectives of veterinarians, well-established veterinarian-farmer relationships generally facilitate restrictive AMU in 3 slightly different but related ways: (1) they create trust in the veterinarian and their prescribing decisions; (2) they create shared understanding concerning when antimicrobials are needed and not needed; and (3) they facilitate constructive discussions between veterinarians and farmers on AMU. To make the farmer feel listened to and to come to an agreement on AMU was described as central for the veterinarians. However, the veterinarians described agreements on restrictive AMU as sometimes requiring strategic work, such as discussions to motivate the farmer and leave the door open for antimicrobials later if needed. Such work takes time and energy and is easier within well-established relationships according to the veterinarians. We also identified examples where veterinarians explained that they occasionally make compromises with farmers concerning antimicrobials-compromises that, according to the veterinarians, facilitate the relationship with the farmer, which in turn facilities restrictive AMU in the longer term. The examples in our interviews where antimicrobials became a matter of tension and even conflict between veterinarians and farmers could, with a few exceptions, be traced to absence of well-established relationships. However, some veterinarians also described AMU as a matter of tension within well-established relationships, especially with older farmers who do not trust new treatment strategies. We also found a small number of examples where disagreements on antimicrobials made a relationship with specific farmers impossible. Thus, even though the interviewed veterinarians generally meant that their restrictive antimicrobial prescribing did not threaten the relationship with the farmer, our study also, to some extent, confirms research showing that restrictive AMU can harm the relationship with some clients who simply choose another, less restrictive, veterinarian. In summary, our study supports that decisions on AMU cannot be reduced to the individual prescriber's behavior, nor to a strict medical judgment. Antimicrobial use for dairy cattle needs to be understood as taking form in relationships in which both veterinarians and farmers are active parts.

Governing Antimicrobial Resistance (AMR) in a Changing Climate: A Participatory Scenario Planning Approach Applied to Sweden in 2050

Background

Antimicrobial resistance (AMR) is a growing global crisis with long-term and unpredictable health, social and economic impacts, with which climate change is likely to interact. Understanding how to govern AMR amidst evolving climatic changes is critical. Scenario planning offers a suitable approach. By envisioning alternative futures, stakeholders more effectively can identify consequences, anticipate problems, and better determine how to intervene. This study explored future worlds and actions that may successfully address AMR in a changing climate in a high-income country, using Sweden as the case.

Methods

We conducted online scenario-building workshops and interviews with eight experts who explored: (1) how promising interventions (taxation of antimicrobials at point of sale, and infection prevention measures) could each combat AMR in 2050 in Sweden given our changing climate; and (2) actions to take starting in 2030 to ensure success in 2050. Transcripts were thematically analyzed to produce a narrative of participant validated alternative futures.

Results

Recognizing AMR to be a global problem requiring global solutions, participants looked beyond Sweden to construct three alternative futures: (1) "Tax Burn Out" revealed taxation of antimicrobials as a low-impact intervention that creates inequities and thus would fail to address AMR without other interventions, such as infection prevention measures. (2) "Addressing the Basics" identified infection prevention measures as highly impactful at containing AMR in 2050 because they would contribute to achieving the Sustainable Development Goals (SDGs), which would be essential to tackling inequities underpinning AMR and climate change, and help to stabilize climate-induced mass migration and conflicts; and (3) "Siloed Nations" described a movement toward nationalism and protectionism that would derail the "Addressing the Basics" scenario, threatening health and wellbeing of all. Several urgent actions were identified to combat AMR long-term regardless which future un-folds, such as global collaboration, and a holistic approach where AMR and climate change are addressed as interlinked issues.

Conclusion

Our participatory scenario planning approach enabled participants from different sectors to create shared future visions and identify urgent actions to take that hinge on global collaboration, addressing AMR and climate change together, and achieving the SDGs to combat AMR under a changing climate.

Differences in Genotype and Antimicrobial Resistance between Campylobacter spp. Isolated from Organic and Conventionally Produced Chickens in Sweden

Antibiotic resistance is a major challenge worldwide and increased resistance to quinolones in Campylobacter is being reported. Analysis of antibiotic resistance was performed on 157 Campylobacter strains (123 C. jejuni and 34 C. coli) from conventional and organic chickens produced in Sweden. Susceptibility for tetracycline, ciprofloxacin, erythromycin, nalidixic acid, streptomycin, and gentamycin was determined by microdilution. All 77 isolates from organic chickens were sensitive to all antibiotics, except two C. jejuni that were resistant to tetracycline. Of the 80 isolates from conventional chickens, 22.5% of C. jejuni and 11.1% of C. coli were resistant to quinolones and 5.6% of C. jejuni were resistant to tetracycline. Whole-genome sequencing resulted in 50 different sequence types of C. jejuni and six of C. coli. Nine sequence types were found in both organic and conventional chickens. Two of these (ST-19 and ST-257) included isolates from conventional broilers with different resistance phenotypes to the remaining isolates from conventional and organic broilers. There are management differences between the production systems, such as feed, breed, use of coccidiostats, and access to outdoor area. It is unlikely that quinolone resistance has arisen due to use of antimicrobials, since fluoroquinolones are not permitted in Swedish broiler production.

The oral microbiota of wild bears in Sweden reflects the history of antibiotic use by humans

Following the advent of industrial-scale antibiotic production in the 1940s,¹ antimicrobial resistance (AMR) has been on the rise and now poses a major global health threat in terms of mortality, morbidity, and economic burden.^2,3 Because AMR can be exchanged between humans, livestock, and wildlife, wild animals can be used as indicators of human-associated AMR contamination of the environment.⁴ However, AMR is a normal function of natural environments and is present in host-associated microbiomes, which makes it challenging to distinguish between anthropogenic and natural sources.^4,5 One way to overcome this difficulty is to use historical samples that span the period from before the mass production of antibiotics to today. We used shotgun metagenomic sequencing of dental calculus, the calcified form of the oral microbial biofilm, to determine the abundance and repertoire of AMR genes in the oral microbiome of Swedish brown bears collected over the last 180 years. Our temporal metagenomics approach allowed us to establish a baseline of natural AMR in the pre-antibiotics era and to quantify a significant increase in total AMR load and diversity of AMR genes that is consistent with patterns of national human antibiotic use. We also demonstrated a significant decrease in total AMR load in bears in the last two decades, which coincides with Swedish strategies to mitigate AMR. Our study suggests that public health policies can be effective in limiting human-associated AMR contamination of the environment and wildlife.

Exploring the One Health Perspective in Sweden's Policies for Containing Antibiotic Resistance

Antibiotic resistance is considered to be a major threat to global health. The main driver of antibiotic resistance is antibiotic use. Antibiotics are used in humans, animals, and food production and are released into the environment. Therefore, it is imperative to include all relevant sectors in the work to contain antibiotic resistance, i.e., a One Health approach. In this study, we aimed to describe and analyse Sweden’s policies related to containing antibiotic resistance, from a One Health perspective. Twenty-three key policy documents related to containment of antibiotic resistance in Sweden were selected and analysed according to the policy triangle framework. Sweden started early to introduce policies for containing antibiotic resistance from an international perspective. Systematic measures against antibiotic resistance were implemented in the 1980s, strengthened by the creation of Strama in 1995. The policies involve agencies and organisations from human and veterinary medicine, the environment, and food production. All actors have clear responsibilities in the work to contain antibiotic resistance with a focus on international collaboration, research, and innovation. Sweden aims to be a model country in the work to contain antibiotic resistance and has a strategy for achieving this through international cooperation through various fora, such as the EU, the UN system, and OECD.