Risk-based surveillance for meat-borne parasites.

There is a plethora of meat-borne hazards - including parasites - for which there may be a need for surveillance. However, veterinary services worldwide need to decide how to use their scarce resources and prioritise among the perceived hazards. Moreover, to remain competitive, food business operators - irrespective of whether they are farmers or abattoir operators - are preoccupied with maintaining a profit and minimizing costs. Still, customers and trade partners expect that meat products placed on the market are safe to consume and should not bear any risks of causing disease. Risk-based surveillance systems may offer a solution to this challenge by applying risk analysis principles; first to set priorities, and secondly to allocate resources effectively and efficiently. The latter is done through a focus on the cost-effectiveness ratio in sampling and prioritisation. Risk-based surveillance was originally introduced into veterinary public health in 2006. Since then, experience has been gathered, and the methodology has been further developed. Guidelines and tools have been developed, which can be used to set up appropriate surveillance programmes. In this paper, the basic principles are described, and by use of a surveillance design tool called SURVTOOLS (https://survtools.org/), examples are given covering three meat-borne parasites for which risk-based surveillance is 1) either in place in the European Union (EU) (Trichinella spp.), 2) to be officially implemented in December 2019 (Taenia saginata) or 3) only carried out by one abattoir company in the EU as there is no official EU requirement (Toxoplasma gondii). Moreover, advantages, requirements and limitations of risk-based surveillance for meat-borne parasites are discussed.

Transmission parameters estimated for Salmonella typhimurium in swine using susceptible-infectious-resistant models and a Bayesian approach.

BACKGROUND: Transmission models can aid understanding of disease dynamics and are useful in testing the efficiency of control measures. The aim of this study was to formulate an appropriate stochastic Susceptible-Infectious-Resistant/Carrier (SIR) model for Salmonella Typhimurium in pigs and thus estimate the transmission parameters between states. RESULTS: The transmission parameters were estimated using data from a longitudinal study of three Danish farrow-to-finish pig herds known to be infected. A Bayesian model framework was proposed, which comprised Binomial components for the transition from susceptible to infectious and from infectious to carrier; and a Poisson component for carrier to infectious. Cohort random effects were incorporated into these models to allow for unobserved cohort-specific variables as well as unobserved sources of transmission, thus enabling a more realistic estimation of the transmission parameters. In the case of the transition from susceptible to infectious, the cohort random effects were also time varying. The number of infectious pigs not detected by the parallel testing was treated as unknown, and the probability of non-detection was estimated using information about the sensitivity and specificity of the bacteriological and serological tests. The estimate of the transmission rate from susceptible to infectious was 0.33 [0.06, 1.52], from infectious to carrier was 0.18 [0.14, 0.23] and from carrier to infectious was 0.01 [0.0001, 0.04]. The estimate for the basic reproduction ration (R0) was 1.91 [0.78, 5.24]. The probability of non-detection was estimated to be 0.18 [0.12, 0.25]. CONCLUSIONS: The proposed framework for stochastic SIR models was successfully implemented to estimate transmission rate parameters for Salmonella Typhimurium in swine field data. R0 was 1.91, implying that there was dissemination of the infection within pigs of the same cohort. There was significant temporal-cohort variability, especially at the susceptible to infectious stage. The model adequately fitted the data, allowing for both observed and unobserved sources of uncertainty (cohort effects, diagnostic test sensitivity), so leading to more reliable estimates of transmission parameters.

Auditing of Danish pig herds for controlled housing requirements and Trichinella.

Trichinella is a zoonotic parasite, which historically has been of large concern for public health in Europe. Consequently, testing of all pigs for Trichinella has been mandatory in many European countries, even though Trichinella is almost exclusively found in outdoor or backyard production. The idea therefore emerged that auditing for biosecurity should replace testing in indoor production. In the European Union (EU), pigs raised under so-called controlled housing conditions are exempt from testing. The specific requirements for a pig production to be considered a controlled housing holding are described in Annex IV in the EU Trichinella Regulation No. 2015/1375. In Denmark, the controlled housing concept is used extensively, not to omit Trichinella testing but to allow visual-only post-mortem inspection at export-authorized abattoirs. The Danish pig industry has established a quality assurance scheme called DANISH Product Standard, which is used to assure that the pig production maintains specific standards. This paper describes how the control, including the auditing, is set up and shows how the EU requirements regarding controlled housing are controlled. Moreover, the EU requirements are compared with the recommendations issued by the International Commission on Trichinellosis and the World Organisation for Animal Health. Finally, strengths, weaknesses, opportunities and threats of the Danish way of documenting indoor finisher herds' compliance with controlled housing as specified by the EU are discussed. It is concluded that the validity of the system is high.

Estimating the impact of low temperature on African swine fever virus transmission through contaminated environments.

African Swine Fever Virus (ASFV) is the cause of an infectious disease in pigs, which is difficult to control. Long viability of ASFV has been shown for several contaminated materials, especially under low temperature. Therefore, when pigs are exposed to a contaminated environment, new infections could occur without the presence of infectious individuals. For example, a contaminated, poorly washed, empty livestock vehicle poses a risk to the next load of pigs. A quantitative stochastic environmental transmission model was applied to simulate the change in environmental contamination levels over time and calculate the epidemic parameters through exposure-based estimation. Due to the lack of experimental data on environmental transmission at low temperatures, we performed a non-linear fit of the decay rate parameter with temperature based on a literature review. Eventually, 16 scenarios were constructed for different temperature (at 20 °C, 10 °C, 0 °C, or -10 °C) and duration of empty periods (1, 3, 5, or 7 days) after the environment had been contaminated. We quantified the variation in the contamination level of the environment over time and the probability of newly added recipients getting infected when exposed to the environment after the empty period. As a result, the transmission rate parameter for ASFV in pigs was estimated to be 1.53 (0.90, 2.45) day-1, the decay rate parameter to be 1.02 (0.73, 1.47) day-1 (at 21 °C), and the excretion rate parameter to be 2.70 (2.51, 3.02) day-1. Without washing and disinfecting, the environment required 9, 14, 24, 54 days to reach a low probability of causing at least one new case (<0.005) at 20 °C, 10 °C, 0 °C, -10 °C, respectively. In addition, the method proposed in this paper enables assessment of the effect of washing and disinfecting on ASFV environmental transmission. We conducted this study to better understand how the viability of ASFV at different temperatures could affect the infectivity in environmental transmission and to improve risk assessment and disease control strategies.

Characterisation of antimicrobial usage in Danish pigs in 2020.

Introduction: Denmark is one of the world's largest exporters of pigs and pig meat, so the sector plays an important role in the national antimicrobial use (AMU). The Danish government has run antimicrobial stewardship programs in collaboration with the pig industry for more than 25 years. These have resulted in substantial overall reductions in total AMU and limiting the use of fluoroquinolones, the 3rd and 4th generation cephalosporines and the polymyxin colistin. To understand where further reductions in AMU could take place, it is necessary to investigate which antimicrobials are being used, how, and for which reasons. Materials and methods: We characterized the AMU in the Danish pig sector in 2020, providing new analytical insights based on data retrieved from the VetStat database. The AMU data were segmented into classes, routes of administration, treatment indications and age groups, and interpreted as an outcome of the interventions taken. We evaluated the current AMU regarding choice of antimicrobial class. Moreover, we discussed how to further improve the antimicrobial stewardship in Danish pig production to achieve additional reductions without jeopardizing animal welfare. Where relevant, two pig veterinary specialists were consulted. Results: In 2020, 43.3 mg antimicrobials per population correction unit (PCU) were ascribed to the Danish pig sector. There was practically no use of fluoroquinolones, 3rd and 4th generation cephalosporins and polymyxins. Weaners related to 45% of the total AMU in pigs when measured in tonnes and 81% when measured in defined animal daily doses, of these 76% were ascribed to gastrointestinal indications and overall, 83% were administered perorally. Conclusion: To enable further reductions in AMU, it should be investigated how and when to replace group treatments (e.g., all animals in section or a pen) with individual treatments. Moreover, prevention of disease and promotion of animal health should be prioritized, e.g., through focus on feed, vaccination, biosecurity, and disease eradication.

Evaluating the OH-EpiCap tool using the Danish integrated surveillance program for AMU and AMR as a case study.

Antimicrobial resistance (AMR) is considered a One Health (OH) challenge, ideally demanding concerted efforts from the animal, human and environmental side. DANMAP, the Danish Integrated Antimicrobial Resistance Monitoring and Research Program, is monitoring AMR and antimicrobial use in animals and humans. OH-EpiCap is an evaluation tool, developed to address essential elements in OH surveillance systems, such as the dimensions of the organization, operational activities and the impact of the surveillance activities. We aimed to evaluate DANMAP using OH-EpiCap and hereby assessed the suitability of OH-EpiCap to evaluate integrated AMR surveillance systems. During the evaluation, the strengths and weaknesses of DANMAP concerning the "OH-ness" of the program were discussed. Furthermore, possible adaptations of the standard operating procedures and governance structure were addressed. Attention was paid to the ability and easiness of DANMAP to cope with current and future challenges connected to integrated AMR surveillance. It was concluded that DANMAP has a strong OH approach covering relevant aspects for humans and animals, whereas environmental aspects are missing. OH-EpiCap proved to be straightforward to use and provided valuable insights. The authors recommend OH-EpiCap to be used by health authorities and stakeholders. It is not suitable for the technical evaluation of a surveillance program.

Assessment of human exposure risk related to contamination of Danish sow carcasses with bile containing Salmonella.

In 2020, the Danish competent authority (CA) raised questions about the Salmonella exposure risk to consumers from bile-contaminated pig carcasses. This study assesses this risk related to sow carcasses. A total of 300 bile samples were collected aseptically at a large Danish sow abattoir. A selective method and medium, RAPID'Salmonella, was used to detect Salmonella and other family members. MALDI-TOF was used to identify bacterial species. None of the 300 bile samples were positive for Salmonella. A simulation model was set up to estimate the number of bile-contaminated carcasses with Salmonella that would go unnoticed on the market if the food business operator (FBO) had full responsibility for handling bile contamination. Data originated from our own and previous data collection, the Danish Meat Inspection Database and expert opinion from the CA and FBO. The FBO-scenario showed that a median of one (90% C.I. 0 - 7) carcasses carrying bile contamination with Salmonella would go unnoticed out of 281,000 in one year, whereas the CA-scenario showed a median of 14 (90% C.I. 1 - 63) such carcasses. Hence, the role of bile contamination on sow carcasses for the exposure of consumers to Salmonella seems to be negligible. Still, the FBO should be encouraged to prevent bile contamination.

Pilot study of the productivity and Salmonella seroprevalence in pigs administered organic acids.

Control of Salmonella in pig/pork production is important to protect public health because pork is one of the main sources of human infection. Moreover, antimicrobial use in pig farms should be kept low to minimize development and transmission of antimicrobial resistance. This pilot study evaluated the productivity and Salmonella seroprevalence in pigs administered organic acids (OA) compared to pigs given growth promoters in one farm in Antioquia, Colombia. Two groups each consisting of 60 pigs of 6-weeks of age were studied for 4 months. One group was provided feed and water with OA (Selko pH® and Selacid®), whereas the other group (control) received antimicrobial growth promoters according to routine feeding practices (tylosin and zinc bacitracin). Blood samples were taken three times (T1-T3) and pigs were weighted five times to calculate daily weight gain (DWG) and feed conversion ratio (FCR). Initially when the pigs were 6 weeks old (T1), the Salmonella seroprevalence was 1.7% in both groups. When the pigs were 11 weeks old (T2), the seroprevalence was significantly lower in pigs provided OA compared to the control group (19 vs. 47%, P < 0.001), whereas when the pigs were 23 weeks old (T3), the seroprevalence did not differ between the groups (62 vs. 77%; P = 0.075). The cumulative DWG was significantly higher in the intervention group than in the control group (713 vs. 667 g/day; P < 0.001). The cumulative FCR did not differ between groups (2.80 vs. 2.77; P = 0.144). The pilot study indicates that cleaning the water pipes and administrating OA improve productivity in pigs and delay exposure to Salmonella spp. when compared with growth promoters. Thus, OA could replace antimicrobial growth promoters and reduce antimicrobial use and resistance. However, the study should be repeated before firmer conclusions can be drawn.

Users' perception of the OH-EpiCap evaluation tool based on its application to nine national antimicrobial resistance surveillance systems.

Introduction: Antimicrobial resistance (AMR) is a One Health (OH) challenge. To achieve or maintain an effective and efficient AMR surveillance system, it is crucial to evaluate its performance in meeting the proposed objectives, while complying with resource restrictions. The OH-EpiCap tool was created to evaluate the degree of compliance of hazard surveillance activities with essential OH concepts across the following dimensions: organization, operational activities, and impact of the surveillance system. We present feedback on the application of the OH-EpiCap tool from a user's perspective, based on the use of the tool to evaluate nine national AMR surveillance systems, each with different contexts and objectives. Methods: The OH-EpiCap was assessed using the updated CoEvalAMR methodology. This methodology allows the evaluation of the content themes and functional aspects of the tool and captures the user's subjective experiences via a strengths, weaknesses, opportunities, and threats (SWOT) approach. Results and Discussion: The results of the evaluation of the OH-EpiCap are presented and discussed. The OH-EpiCap is an easy-to-use tool, which can facilitate a fast macro-overview of the application of the OH concept to AMR surveillance. When used by specialists in the matter, an evaluation using OH-EpiCap can serve as a basis for the discussion of possible adaptations of AMR surveillance activities or targeting areas that may be further investigated using other evaluation tools.

Capturing systematically users' experience of evaluation tools for integrated AMU and AMR surveillance.

Tackling antimicrobial resistance (AMR) is a goal for many countries. Integrated surveillance of antimicrobial use (AMU) and resistance is a prerequisite for effective risk mitigation. Regular evaluation of any surveillance is needed to ensure its effectiveness and efficiency. The question is how to evaluate specifically integrated surveillance for AMU and AMR. In an international network called CoEvalAMR, we have developed guidelines for selection of the most appropriate tools for such an evaluation. Moreover, we have assessed different evaluation tools as examples using a country case format and a methodology with a focus on the user's experience. This paper describes the updated methodology, which consists of a brief introduction to the case and to the tool separately. Moreover, there are 12 functional aspects and nine content themes which should be scored using a 4-tiered scale. Additionally, four Strengths, Weaknesses, Opportunities, Threats (SWOT) questions should be addressed. Results are illustrated using radar diagrams. An example of application of the updated methodology is given using the ECoSur evaluation tool. No tool can cover all evaluation aspects comprehensively in a user-friendly manner, so the choice of tool must be based upon the specific evaluation purpose. Moreover, adequate resources, time and training are needed to obtain useful outputs from the evaluation. Our updated methodology can be used by tool users to share their experience with available tools, and hereby assist other users in identifying the most suited tool for their evaluation purpose. Additionally, tool developers can get valuable information for further improvements of their tool.

SWOT analysis of risk factors associated with introduction of African Swine Fever through vehicles returning after export of pigs.

Denmark is a major pig exporter and applies a high level of biosecurity, with washing and disinfecting stations for returning livestock vehicles. The introduction of African Swine Fever (ASF) would have significant economic consequences related to loss of export of live pigs and products thereof. In this study, we focused on the role of empty livestock vehicles returning after exports of pigs for the introduction of ASF. Initially, the current components and measures related to export of livestock were described. Next, analyses of strengths, weaknesses, opportunities, and threats (SWOT) were conducted, covering the components and measures identified. Then, export of pigs was described either through assembly centers or directly from farms. Washing and disinfection, as required and undertaken at the designated stations, constitutes the most important among all risk-reducing measures identified. Recommendations are to: (1) ensure the quality of washing and disinfection through staff training; (2) find new, safe, and more efficient disinfectants; (3) ensure the required temperature, and therefore effect, of the disinfectant and water. It was impossible to assess, the influence of export through assembly centers compared to direct transport. However, through SWOT analyses we identified the strengths and weaknesses of the two pathways. Moreover, components/measures with risks of unknown sizes are also discussed, such as vehicles undertaking cabotage and the current vehicle quarantine periods.

Determination of an optimal ELISA cut-off for the diagnosis of Toxoplasma gondii infection in pigs using Bayesian latent class modelling of data from multiple diagnostic tests.

Toxoplasma gondii infection in pigs is commonly diagnosed using serological tests that detect IgG antibodies targeted against the parasite. Such tests include enzyme-linked immunosorbent assay (ELISA), modified agglutination test (MAT), and western blot (WB), which are commercially available as rapid test kits. In this study, we evaluated the manufacturer recommended cut-off of ELISA-PrioCHECK test kit and determined a new optimal cut-off for identifying T. gondii infections in pigs. Assessment of the commercial ELISA kit was done by including data from two additional serological tests, MAT, and WB, applied to seven pig population categories with varying prevalences. A total of 233 plasma samples that were previously used in other studies for investigating T. gondii seroprevalence in pigs in Denmark were randomly selected for inclusion, including 95 samples that had previously been analysed with all three tests and an additional 138 samples that were analysed using the three serological tests for this study. In the absence of a gold standard test, a latent class model was fit to the data to obtain estimates of sensitivity and specificity for each of the tests along with prevalence in each of the populations. A cut-off that maximized the sensitivity and specificity of the ELISA test was then selected. The optimal cut-off value for percent of positive control (PP) in ELISA-PrioCHECK was estimated to be 27.7 PP, which is higher than the cut-off value of 20 PP that is recommended by the manufacturer. At this cut-off, the estimated sensitivities of ELISA, MAT and WB were 99.2% (96.3-100.0%), 96.3% (88.0-100.0%), and 89.8% (80.0-98.0%), respectively. The estimated specificities of ELISA, MAT and WB were 95.2% (92.5-97.6%), 99.6% (97.5-100.0%), and 98.2% (95.9-100.0%), respectively. Our findings have broad relevance to the use of the ELISA-PrioCHECK test kit for detecting Toxoplasma gondii infection in pigs.

A European survey on post-mortem inspection of finishing pigs: Total condemnation criteria to declare meat unfit for human consumption.

Meat inspection (MI) is essential to verify compliance with legal requirements related to human and animal health and animal welfare protections. Judgement criteria applied during MI, resulting in condemnation data of importance, among other things, for livestock producers and for benchmarking reasons. However, although the Meat Inspection Regulation sets out judgement criteria, most are generic, favouring flexibility, but also subjectivity. To address the degree of variation on total condemnation (TC) criteria applied during post-mortem inspection (PMI) of finishing pigs, an online survey was prepared aiming to collect this information from several European countries. The focus was on TC criteria regarding the following PMI findings: abscesses, arthritis, cachexia, erysipelas, icterus, Mycobacterium-like lesions, osteomyelitis, peritonitis, pleuritis and pneumonia. From September to November 2020, a total of 44 completed questionnaires were obtained from 26 European countries. The results showed a substantial variation in the TC criteria in place in the participating countries. One of the main reasons for the variability seen in the respondents' reported answers was related to the indicators used to define a generalised condition related to the 10 PMI findings addressed, making harmonisation a challenge and avoiding to draw conclusions when comparing condemnation causes between abattoirs. This implies that it would make sense to look into how a generalised condition can be identified/described and how it should be judged. The results should be used as inspiration towards possible harmonisation, improving decision-making, and permitting comparative analysis between different reports to allow trend analyses and benchmarking.

A longitudinal study of Toxoplasma gondii seroconversion on four large Danish sow farms.

Serological tests are routinely used to detect Toxoplasma gondii specific IgG antibodies in serum. Serological surveys of T. gondii show a medium to high prevalence in Danish indoor sows at the time of slaughter. However, little is known about when sows acquire T. gondii, and for how long they remain seropositive. Our focus was on quantifying the incidence rates in different age-cohorts and on investigating the T. gondii IgG antibody dynamics in sows. Four large Danish sow farms were longitudinally surveyed for 1 year. A total of 320 animals from 6, 12, 18, and 24-months age-cohorts were sampled at 5-week intervals. In total, 2989 plasma samples were tested using commercial enzyme linked immunosorbent assay (ELISA). The incidence rate in each of the four age-cohorts was calculated, and a time-to-event analysis was applied to the interval censored data to investigate the relationship between age and probability of T. gondii seroconversion. In the initial ELISA testing, eight sows tested positive for T. gondii at first survey, of which seven remained seropositive throughout the follow-up period. Additionally, 16 sows seroconverted, but only five of these remained seropositive. Weekly incidence rates in the 6, 12, 18, and 24-month age-cohorts were 0.0017 (95% CI = 0.0008 - 0.0037), 0.0009 (95% CI = 0.0003 - 0.0027), 0.0003 (95% CI = 0.0000 - 0.0018), and 0.0023 (95% CI = 0.0010 - 0.0051), respectively. Time-to-event analysis suggested that the incidence rate increased with age but could not conclude this definitively. The retesting of a subsample of the sows (n = 200) with the same ELISA and with modified direct agglutination test (MAT), and western blot (WB) assays suggested that 12 out of the 24 initial ELISA seropositive sows may have been false positive. These 12 sows also showed fluctuating antibody dynamics in ELISA. Hence, the unstable antibody dynamics in ELISA may pose a challenge for serological surveys of T. gondii in sows.

Assessing the value of bacteriological examination as a diagnostic tool in relation to meat inspection in cattle.

In Denmark, lesions indicating acute generalised infection identified at meat inspection will result in total condemnation. An official bacteriological examination (BU) protocol can be used for slaughtered animals with lesions such as endocarditis and endophlebitis as an assisting diagnostic tool to confirm whether the condition is local or generalised. If local, the carcass can be approved after condemnation of the relevant organs. The BU involves cultivating samples from the spleen and muscle. The aim of this study was to assess the value of the BU protocol. The study was conducted from February to May 2019 at a Danish cattle abattoir. Three groups of slaughtered cattle were included: 24 cases consisting of cattle with endocarditis and endophlebitis, 25 control animals consisting of cattle fully approved at inspection and 16 animals condemned at inspection due to endocarditis and endophlebitis with complications. Samples were taken from the heart, liver, kidney, lung, spleen and muscles of each animal. The BU protocol was used for cultivation. Different types of colonies were identified using MALDI-TOF-MS analysis. One or more samples with bacterial growth were found in all condemned animals - in 16 out of the 24 case animals and in two out of 25 control animals. In all three groups, Trueperella pyogenes was the most frequently isolated bacterium (60%) followed by Fusobacterium necrophorum (10%). For the case animals, the organ most commonly found with bacterial growth was the liver (46%), followed by the lung (38%) and the kidney (38%), while 96% of the muscle samples were negative. For the condemned group, bacterial growth was found in 75% of the spleen samples, 56% of liver and lung samples, and 50% of the muscle samples. A statistical analysis of the samples from cases and controls showed strong pair-wise associations for the presence of bacteria between organs, but no pair-wise associations between presence of bacteria in the muscle and any of the organs. Hence, if bacteria are found e.g. in the liver, they are likely to be found in other organs, but not in the muscle. In total, 20 of the 24 case animals were fully or partly approved in accordance with the current rules for judgement. It was concluded that the BU protocol using spleen and muscle samples would be suitable as a diagnostic tool for the judgement of slaughtered animals in cases where there is doubt about the stage of the lesions observed.

Assessment of Evaluation Tools for Integrated Surveillance of Antimicrobial Use and Resistance Based on Selected Case Studies.

Regular evaluation of integrated surveillance for antimicrobial use (AMU) and resistance (AMR) in animals, humans, and the environment is needed to ensure system effectiveness, but the question is how. In this study, six different evaluation tools were assessed after being applied to AMU and AMR surveillance in eight countries: (1) ATLASS: the Assessment Tool for Laboratories and AMR Surveillance Systems developed by the Food and Agriculture Organization (FAO) of the United Nations, (2) ECoSur: Evaluation of Collaboration for Surveillance tool, (3) ISSEP: Integrated Surveillance System Evaluation Project, (4) NEOH: developed by the EU COST Action "Network for Evaluation of One Health," (5) PMP-AMR: The Progressive Management Pathway tool on AMR developed by the FAO, and (6) SURVTOOLS: developed in the FP7-EU project "RISKSUR." Each tool was scored using (i) 11 pre-defined functional aspects (e.g., workability concerning the need for data, time, and people); (ii) a strengths, weaknesses, opportunities, and threats (SWOT)-like approach of user experiences (e.g., things that I liked or that the tool covered well); and (iii) eight predefined content themes related to scope (e.g., development purpose and collaboration). PMP-AMR, ATLASS, ECoSur, and NEOH are evaluation tools that provide a scoring system to obtain semi-quantitative results, whereas ISSEP and SURVTOOLS will result in a plan for how to conduct evaluation(s). ISSEP, ECoSur, NEOH, and SURVTOOLS allow for in-depth analyses and therefore require more complex data, information, and specific training of evaluator(s). PMP-AMR, ATLASS, and ISSEP were developed specifically for AMR-related activities-only ISSEP included production of a direct measure for "integration" and "impact on decision making." NEOH and ISSEP were perceived as the best tools for evaluation of One Health (OH) aspects, and ECoSur as best for evaluation of the quality of collaboration. PMP-AMR and ATLASS seemed to be the most user-friendly tools, particularly designed for risk managers. ATLASS was the only tool focusing specifically on laboratory activities. Our experience is that adequate resources are needed to perform evaluation(s). In most cases, evaluation would require involvement of several assessors and/or stakeholders, taking from weeks to months to complete. This study can help direct future evaluators of integrated AMU and AMR surveillance toward the most adequate tool for their specific evaluation purpose.

Herd typologies based on multivariate analysis of biosecurity, productivity, antimicrobial and vaccine use data from Danish sow herds.

The use of antimicrobials in livestock constitutes an increasing global concern, and many countries pursue approaches to reduce the amount used, particularly in the pig production industry. The EU Commission has decided, due to environmental concerns, to phase out use of zinc oxide in pigs by 2022. This poses an additional challenge to efforts to reduce antimicrobial use (AMU) in European pig production. The pig production sector needs further information about how to comply with official AMU requirements without losing competitiveness. The most efficient approaches are likely to involve a combination of multiple factors. Therefore, the objective of this study was to explore multidimensional associations between biosecurity, productivity, vaccination and AMU. A cross sectional study was conducted using data from 160 Danish sow herds in 2014-2015. Biosecurity data were collected through computer-assisted telephone interviews using a pre-developed questionnaire (Biocheck.UGent®) supplemented with additional country-specific questions and translated into Danish. Herd-specific data, consisting of antimicrobial prescriptions, purchase of vaccines against five endemic infections, herd health status and one productivity measure (i.e. number of weaned piglets per sow per year) were extracted from various databases. Factor analysis was conducted on a subset of the data from 152 herds with sufficiently complete data. The identified factors were explained by evaluating data from herds with extreme loadings on the respective factor. The results were further discussed based on plots combining herd factor loadings on two factors at a time. Four factors were selected based on the break-point in the scree-plot. Factor 1 included herd type, herd size, and age of farm buildings. Factor 2 covered general biosecurity, including several internal and external biosecurity measures. Factor 3 represented preventive measures implying specific focus on avoiding introduction of ASF by foreign employees. Lastly, Factor 4 covered vaccination status, specifically regarding vaccination against Mycoplasma hyopneumoniae and Porcine Reproductive and Respiratory Syndrome virus. These factors were used to group the 152 sow herds into herd typologies. Feasible strategies aimed at improving health by reducing AMU without hampering animal welfare were identified and discussed for each typology. AMU and productivity correlated only weakly with other variables. This is probably due to limited variability in both these variables in study herds, which might be attributed to official restrictions on AMU, and a general high level of health and biosecurity in Danish sow herds.

Evaluating integrated surveillance of antimicrobial resistance: experiences from use of three evaluation tools.

BACKGROUND: Integrated antimicrobial resistance (AMR) surveillance programmes require regular evaluation to ensure they are fit for purpose and that all actors understand their responsibilities. This will strengthen their relevance for the clinical setting, which depends heavily on continued access to effective treatment options. Several evaluation tools addressing different surveillance aspects are available. OBJECTIVES: The aim was to understand the strengths and weaknesses of three evaluation tools, and to improve guidance on how to choose a fit-for-purpose tool. SOURCES: Three tools were assessed: (a) AMR-PMP-the Progressive Management Pathway tool on AMR developed by the Food and Agriculture Organization (FAO) of the United Nations, (b) NEOH developed by the EU COST Action 'Network for Evaluation of One Health' and (c) SURVTOOLS developed in an FP7-EU project 'RISKSUR'. Each tool was assessed with regard to contents, required evaluation processes including stakeholder engagement and resource demands, integration coverage across relevant sectors and applicability. They were compared using a predefined scoring scheme and a strengths-weaknesses-opportunities-threats (SWOT)-like format for commenting. CONTENT: All three tools address multiple decision-making levels and aspects of stakeholder engagement. NEOH focuses on system features, learning, sharing, leadership and infrastructure, and requires a description of the underlying system in which AMR develops. AMR-PMP focuses on four areas: awareness, evidence, governance and practices and assesses the implementation degree of pre-chosen aspects within these areas. This requires less of the evaluator, but warrants participation of multiple stakeholders. SURVTOOL provides information and references on how to evaluate effectiveness, process and comprehensiveness of surveillance programmes. All three tools require veterinary epidemiology expertise and varying levels of evaluation methodology training to use appropriately. IMPLICATIONS: The tools covered AMR surveillance and One Health aspects to varying degrees. This study provides guidance on aspects to consider when choosing between available tools and embarking on an evaluation of integrated surveillance.

Classification of Vertebral Osteomyelitis and Associated Judgment Applied during Post-Mortem Inspection of Swine Carcasses in Portugal.

Vertebral osteomyelitis (VO) it is often a suppurative lesion that, in Portugal, represents the main cause of total condemnation of slaughtered finishing pigs. Based on the EU Meat Inspection legislation, meat from generalized VO cases presenting signs of pyemia should be declared unfit for human consumption. For that reason, the main objective of this study is to establish a classification scheme to differentiate between localized and generalized VO cases using macroscopic findings and validate it based on the presence of pyemia. To assist in, a combination of macroscopic characteristics of gross lesions (e.g., presence of pyaemia-related lesions (PRL), acute/chronic characteristics of VO) was used to create a classification scheme to differentiate between localized and generalized VO cases. The scheme was applied to 40 VO cases that had been totally condemned in an undifferentiated way. In those 40 cases, histopathological analysis was used to validate acute/chronic macro-criteria, and microbiological analysis was performed to identify the pyemia cases. From the 40 selected VO cases, 20 were macroscopically classified as chronic and 20 as acute. Cohen's kappa coefficient (κ = 0.80; p < 0.001), revealed a substantial agreement between macroscopic and histopathology classification. Microbiological analyses identified 13 pyemia cases (13/40; 32.5%). Among those, 12 were macroscopically classified as acute, this association being highly significant (p < 0.001). By using the proposed VO classification scheme, 14 possible cases out of 40 could have been spared from total condemnation. This scheme can be used to harmonize the classification of VO and meat inspection decisions in Portuguese abattoirs. The output would lead to avoidance of unnecessary carcasses condemnation (food waste/economic losses), under an evidence-based approach, without compromising food safety and public health as demanded by the EU Meat Inspection legislation.

Seroprevalence of Toxoplasma gondii infection in sows and finishers from conventional and organic herds in Denmark: Implications for potential future serological surveillance.

Pigs are one of several host species for Toxoplasma gondii parasites, and consumption of infected pork may lead to toxoplasmosis in humans. We estimated seroprevalence in sows and finishers from conventional and organic herds in Denmark and discussed the strategies for reducing the risk from pork. We collected 447 blood samples from 59 herds, and additional meat-juice samples from 212 of the same pigs. Using a T. gondii IgG commercial ELISA test, we found 2% (95% CI = 0.4%-5%) apparent seroprevalence of T. gondii in conventional finishers, 11% (95% CI = 6%-17%) in organic finishers, 19% (95% CI = 11%-30%) in conventional sows and 60% (95% CI = 47%-72%) in organic sows. The odds of an animal testing positive for T. gondii was 16 times higher (95% CI = 4.6-74.3) in organic compared to conventional herds. The odds were 22 times higher (95% CI = 6.5-88.3) if the animal was a sow compared to a finisher. Meat-juice ELISA values were significantly correlated with plasma results (P < 0.001), but on average 64% of the blood-plasma ELISA values. Lowering the recommended cut-off from 20 to 13 percent positive values of the positive control for meat-juice ELISA, resulted in the meat-juice ELISA identifying 93% of the plasma positives as positive and 99% of the plasma negatives as negative. The time taken to detect one or more infected pigs from a T. gondii positive herd at slaughter was estimated using abattoir data on pigs (17,195,996) and batches (165,569) delivered to Danish abattoirs in 2018. The time to detection was affected by the seroprevalence, frequency at which the pigs were delivered, the number of samples tested per batch delivery and the batch sizes. Time to detection was long in conventional finisher herds due to low prevalence, and in sow herds because of intermittent delivery of a low number of sows. In organic finisher herds, time to detection was short due to medium prevalence and frequent delivery of a high number of finishers. Conventional finisher herds may be classified as low-risk, organic finisher herds as medium-risk, and conventional and organic sow herds as high-risk herds. Risk-mitigation strategies at processing plants (freezing or curing) or at the consumer level (heat treatment) for meat originating from high-risk herds, surveillance of medium-risk herds, and auditing for controlled housing (high biosecurity) in low-risk herds may be cost-effective alternatives to serological surveillance of all Danish pig herds.