Measuring antimicrobial use on dairy farms: A method comparison cohort study.

Antimicrobial use on UK dairy farms is measured for surveillance purposes, with veterinary sales data as a proxy for use. Two other methods of recording use have been used commonly on-farm: medicine waste bins and farm medicine records. However, none of these methods has been validated to measure antimicrobial use. The objective of this research was to assess agreement between the 3 most common methods for measuring on-farm antimicrobial use with a predetermined reference method on UK dairy farms. Antimicrobial use was measured prospectively on 26 UK dairy farms using medicine waste bins into which participants placed all discarded medicine packaging for a 12-mo period. At the end of 12 mo, farm medicine records and veterinary sales data were obtained retrospectively for participating farms. The reference method used was based on pre- and poststudy inventories combined with veterinary sales data. We investigated the systematic difference between the mean on-farm antimicrobial use measured by each of the 3 methods and a reference method, using one-way repeated-measures ANOVA models. Reliability and clinical relevance of the agreement between each pair of methods was quantified using the concordance correlation coefficient (CCC) and the Bland-Altman method, respectively. When compared with the reference method, veterinary sales data had excellent reliability for injectable antimicrobials and intramammary antimicrobials [95% confidence interval (CI) of CCC > 0.90] and moderate to excellent reliability for other antimicrobials (95% CI of CCC: 0.68-0.97). Medicine waste bins had good to excellent reliability for injectable (95% CI of CCC: 0.84-0.99), and intramammary products (95% CI of CCC: 0.78-0.94) and no agreement for other forms of antimicrobial. Farm medicine records did not agree for any form of antimicrobial when compared with the reference method. The use of veterinary sales data as a proxy for on-farm antimicrobial use in the UK represented excellent statistical reliability and offered clinically good agreement with the reference method when used to measure injectable antimicrobials. This study applies to the UK context and included a relatively small number of farms. However, these results have research and policy implications, both nationally and internationally, and are essential in accurately quantifying agricultural antimicrobial use to inform both animal and human health.

New approaches to pharmacosurveillance for monitoring prescription frequency, diversity, and co-prescription in a large sentinel network of companion animal veterinary practices in the United Kingdom, 2014-2016.

Pharmaceutical agents (PAs) are commonly prescribed in companion animal practice in the United Kingdom. However, little is known about PA prescription on a population-level, particularly with respect to PAs authorised for human use alone prescribed via the veterinary cascade; this raises important questions regarding the efficacy and safety of PAs prescribed to companion animals. This study explored new approaches for describing PA prescription, diversity and co-prescription in dogs, cats and rabbits utilising electronic health records (EHRs) from a sentinel network of 457 companion animal-treating veterinary sites throughout the UK over a 2-year period (2014-2016). A novel text mining-based identification and classification methodology was utilised to semi-automatically map practitioner-defined product descriptions recorded in 918,333 EHRs from 413,870 dogs encompassing 1,242,270 prescriptions; 352,730 EHRs from 200,541 cats encompassing 491,554 prescriptions, and 22,526 EHRS from 13,398 rabbits encompassing 18,490 prescriptions respectively. PA prescription as a percentage of booked consultations was 65.4% (95% confidence interval, CI, 64.6-66.3) in dogs; in cats it was 69.1% (95% CI, 67.9-70.2) and in rabbits, 56.3% (95% CI, 54.7-57.8). Vaccines were the most commonly prescribed PAs in all three species, with antibiotics, antimycotics, and parasiticides also commonly prescribed. PA prescription utilising products authorised for human use only (hence, 'human-authorised') comprised 5.1% (95% CI, 4.7-5.5) of total canine prescription events; in cats it was 2.8% (95% CI, 2.6-3.0), and in rabbits, 7.8% (95% CI, 6.5-9.0). The most commonly prescribed human-authorised PA in dogs was metronidazole (antibiotic); in cats and rabbits it was ranitidine (H2 histamine receptor antagonist). Using a new approach utilising the Simpson's Diversity Index (an ecological measure of relative animal, plant etc. species abundance), we identified differences in prescription based on presenting complaint and species, with rabbits generally exposed to a less diverse range of PAs than dogs or cats, potentially reflecting the paucity of authorised PAs for use in rabbits. Finally, through a novel application of network analysis, we demonstrated the existence of three major co-prescription groups (preventive health; treatment of disease, and euthanasia); a trend commonly observed in practice. This study represents the first time PA prescription has been described across all pharmaceutical families in a large population of companion animals, encompassing PAs authorised for both veterinary and human-only use. These data form a baseline against which future studies could be compared, and provides some useful tools for understanding PA comparative efficacy and risks when prescribed in the varied setting of clinical practice.

Use of vaccines and factors associated with their uptake variability in dogs, cats and rabbits attending a large sentinel network of veterinary practices across Great Britain.

Vaccination remains a mainstay of companion animal population health. However, how vaccine use at a population level complies with existing guidelines is unknown. Here we use electronic health records to describe vaccination in dogs, cats and rabbits attending a large sentinel network of UK veterinary practices. In total, 77.9% (95% CI: 77.6-78.1) of animals had recorded vaccinations. The percentage of animals with recorded vaccinations was higher in dogs, neutered animals, in insured dogs and cats and in purebred dogs. Vaccination rates varied in different regions of Great Britain in all species. Dogs and cats belonging to owners living in less deprived areas of England and Scotland were more likely to be recorded as vaccinated. In the vaccinated population, cats received more core vaccines per year of life (0.86) than dogs (0.75), with feline leukaemia vaccines almost as frequent as core vaccines. In dogs, leptospira vaccines were more frequent than core vaccines. This descriptive study suggests a substantial proportion of animals are not benefiting from vaccine protection. For the first time, we identify potential factors associated with variations in recorded vaccination frequency, providing a critical baseline against which to monitor future changes in companion animal vaccination and evidence to inform future targeted health interventions.

Patterns of antimicrobial agent prescription in a sentinel population of canine and feline veterinary practices in the United Kingdom.

Antimicrobial resistance is an increasingly important global health threat and the use of antimicrobial agents is a key risk factor in its development. This study describes antimicrobial agent prescription (AAP) patterns over a 2year period using electronic health records (EHRs) from booked consultations in a network of 457 sentinel veterinary premises in the United Kingdom. A semi-automated classification methodology was used to map practitioner defined product codes in 918,333 EHRs from 413,870 dogs and 352,730 EHRs from 200,541 cats, including 289,789 AAPs. AAP as a proportion of total booked consultations was more frequent in dogs (18.8%, 95% confidence interval, CI, 18.2-19.4) than cats (17.5%, 95% CI 16.9-18.1). Prescription of topical antimicrobial agents was more frequent in dogs (7.4%, 95% CI 7.2-7.7) than cats (3.2%, 95% CI 3.1-3.3), whilst prescription of systemic antimicrobial agents was more frequent in cats (14.8%, 95% CI 14.2-15.4) than dogs (12.2%, 95% CI 11.7-12.7). A decreasing temporal pattern was identified for prescription of systemic antimicrobial agents in dogs and cats. Premises which prescribed antimicrobial agents frequently for dogs also prescribed frequently for cats. AAP was most frequent during pruritus consultations in dogs and trauma consultations in cats. Clavulanic acid potentiated amoxicillin was the most frequently prescribed antimicrobial agent in dogs (28.6% of prescriptions, 95% CI 27.4-29.8), whereas cefovecin, a third generation cephalosporin, was the most frequently prescribed antimicrobial agent in cats (36.2%, 95% CI 33.9-38.5). This study demonstrated patterns in AAP over time and for different conditions in a population of companion animals in the United Kingdom.

The passive surveillance of ticks using companion animal electronic health records.

Ticks represent a large global reservoir of zoonotic disease. Current surveillance systems can be time and labour intensive. We propose that the passive surveillance of companion animal electronic health records (EHRs) could provide a novel methodology for describing temporal and spatial tick activity. A total of 16 58 857 EHRs were collected over a 2-year period (31 March 2014 and 29 May 2016) from companion animals attending a large sentinel network of 192 veterinary clinics across Great Britain (the Small Animal Veterinary Surveillance Network - SAVSNET). In total, 2180 EHRs were identified where a tick was recorded on an animal. The relative risk of dogs presenting with a tick compared with cats was 0·73 (95% confidence intervals 0·67-0·80). The highest number of tick records were in the south central regions of England. The presence of ticks showed marked seasonality with summer peaks, and a secondary smaller peak in autumn for cats; ticks were still being found throughout most of Great Britain during the winter. This suggests that passive surveillance of companion animal EHRs can describe tick activity temporally and spatially in a large cohort of veterinary clinics across Great Britain. These results and methodology could help inform veterinary and public health messages as well as increase awareness of ticks and tick-borne diseases in the general population.

Canine babesiosis and tick activity monitored using companion animal electronic health records in the UK.

Recent publications highlighting autochthonous Babesia canis infection in dogs from Essex that have not travelled outside the UK are a powerful reminder of the potential for pathogen emergence in new populations. Here the authors use electronic health data collected from two diagnostic laboratories and a network of 392 veterinary premises to describe canine Babesia cases and levels of Babesia concern from January 2015 to March 2016, and the activity of ticks during December 2015-March 2016. In most areas of the UK, Babesia diagnosis in this population was rare and sporadic. In addition, there was a clear focus of Babesia cases in the affected area in Essex. Until February 2016, analysis of health records indicated only sporadic interest in Babesia largely in animals coming from overseas. Following media coverage in March 2016, there was a spike in owner concern that was geographically dispersed beyond the at-risk area. Tick activity (identified as ticks being removed from animals in veterinary consultations) was consistent but low during the period preceding the infections (<5 ticks/10,000 consultations), but increased in March. This highlights the use of electronic health data to describe rapidly evolving risk and concern that follows the emergence of a pathogen.

European molecular epidemiology and strain diversity of feline calicivirus.

Feline calicivirus (FCV) causes a variable syndrome of upper respiratory tract disease, mouth ulcers and lameness. A convenience-based prospective sample of oropharyngeal swabs (n=426) was obtained from five countries (France, Germany, Greece, Portugal and the UK). The prevalence of FCV by virus isolation was 22.2 per cent. Multivariable analysis found that animals presenting with lymphoplasmacytic gingivitis stomatitis complex were more likely to test positive for FCV infection. Furthermore, vaccinated cats up to 48 months of age were significantly less likely to be infected with FCV than unvaccinated animals of similar ages. Phylogenetic analysis based on consensus sequences for the immunodominant region of the capsid gene from 72 FCV isolates identified 46 strains. Thirteen of the 14 strains with more than one sequence were restricted to individual regions or sites in individual countries; the exception was a strain present in two sites close to each other in France. Four strains were present in more than one household. Five colonies, four of which were rescue shelters, had multiple strains within them. Polymerase sequence suggested possible rare recombination events. These locally, nationally and internationally diverse FCV populations maintain a continuous challenge to the control of FCV infection and disease.

The impact of a specific blend of essential oil components and sodium butyrate in feed on growth performance and Salmonella counts in experimentally challenged broilers.

Essential oils (EO) and short-chain fatty acids have potential antimicrobial activity in broilers. This study aimed to investigate the effect of a specific blend of EO and a combination of this blend of EO with sodium-butyrate on growth performance and Salmonella colonization in broilers. A total of 480 one-day-old male broilers were distributed into 5 treatments (8 pens per treatment and 12 birds per pen) and reared during 42 d in experimental conditions. Dietary treatments consisted of the addition of different doses of EO (0 mg/kg, control; 50 mg/kg, EO50 and 100 mg/kg, EO100) or a combination of EO with 1 g/kg of sodium-butyrate (B; EO50 + B, EOB50 and EO100 + B, EOB100) to a basal diet. All birds were orally infected with 10(8) cfu of Salmonella Enteritidis on d 7 of study. Individual BW and feed intake per pen were measured at arrival and on a weekly basis. The prevalence and enumeration of Salmonella in feces was determined per treatment at 72 h postinfection and on d 23 and 37 of study. At slaughter, cecal content and liver samples from 16 birds per treatment were cultured for Salmonella and cecal pH was measured. No differences were observed on growth performance among treatments. All fecal samples analyzed were positive for Salmonella from d 10 to the end of the rearing period. At slaughter, Salmonella contamination (positive samples) in cecum was lower in birds fed EOB50 compared with the other treatments (P < 0.05), whereas birds fed the control diet showed the highest colonization rates. The pH of the cecal content was not different among treatments. Thus, EO or its combination with sodium-butyrate did not affect growth performance. However, a clear effectiveness of these products was observed in Salmonella control, especially when low doses of EO were combined with sodium-butyrate (EOB50).

A multi-analysis approach for space-time and economic evaluation of risks related with livestock diseases: the example of FMD in Peru.

This study presents a multi-disciplinary decision-support tool, which integrates geo-statistics, social network analysis (SNA), spatial-stochastic spread model, economic analysis and mapping/visualization capabilities for the evaluation of the sanitary and socio-economic impact of livestock diseases under diverse epidemiologic scenarios. We illustrate the applicability of this tool using foot-and-mouth disease (FMD) in Peru as an example. The approach consisted on a flexible, multistep process that may be easily adapted based on data availability. The first module (mI) uses a geo-statistical approach for the estimation (if needed) of the distribution and abundance of susceptible population (in the example here, cattle, swine, sheep, goats, and camelids) at farm-level in the region or country of interest (Peru). The second module (mII) applies SNA for evaluating the farm-to-farm contact patterns and for exploring the structure and frequency of between-farm animal movements as a proxy for potential disease introduction or spread. The third module (mIII) integrates mI-II outputs into a spatial-stochastic model that simulates within- and between-farm FMD-transmission. The economic module (mIV) connects outputs from mI-III to provide an estimate of associated direct and indirect costs. A visualization module (mV) is also implemented to graph and map the outputs of module I-IV. After 1000 simulated epidemics, the mean (95% probability interval) number of outbreaks, infected animals, epidemic duration, and direct costs were 37 (1, 1164), 2152 (1, 13, 250), 63 days (0, 442), and US$ 1.2 million (1072, 9.5 million), respectively. Spread of disease was primarily local (<4.5km), but geolocation and type of index farm strongly influenced the extent and spatial patterns of an epidemic. The approach is intended to support decisions in the last phase of the FMD eradication program in Peru, in particular to inform and support the implementation of risk-based surveillance and livestock insurance systems that may help to prevent and control potential FMD virus incursions into Peru.

A new approach for rapidly assessing the risk of Aujeszky's disease reintroduction into a disease-free Spanish territory by analysing the movement of live pigs and potential contacts with wild boar.

Aujeszky's disease (AD) causes significant economic losses in the Spanish pig sector due to import trade restrictions imposed by disease-free countries. Most regions of Spain have achieved 'low AD prevalence' status as a result of an intensive national AD eradication programme involving vaccination and other measures. However, to achieve AD-free status that would eliminate trade restrictions, vaccination must be stopped. For this final stage of eradication, up to date and reliable estimates of the risk of AD reintroduction are essential. Here, we propose an approach based on spatio-temporal scan statistics that the assesses risk of AD reintroduction in a disease-free territory by analysing the two most frequent risk pathways: movement of live domestic pigs and contact with wildlife reservoirs. The approach is illustrated using the case of Navarre, one of the first Spanish regions which plan to stop vaccination. Moreover, direct contacts among pig farms in Navarre were used to evaluate the potential spread of AD in the event of reintroduction. Areas at highest risk of AD reintroduction were in the southern part of the region during the second half of the year through pig movements and in the western and east-central parts of Navarre through contact with wild boars. Northern Navarre, despite having the highest density of pig farms, seems to be at low risk of AD reintroduction. Analysing the network of pig movements within Navarre revealed distinct northern and southern compartments that may be used in preventive compartmentalization strategies to reduce potential risk of AD re-infection in the scenario without vaccination. The approach described here may be extended to other regions and may be useful for guiding risk-based measures that reduce the risk of AD re-infection in a more cost-effective manner. Such analysis in Spain may allow authorities to stop vaccination in the safest possible way.

Social network analysis of Equidae movements and its application to risk-based surveillance and to control of spread of potential Equidae diseases.

Movements of animals and animal products are one of the most important ways of disease introduction and spread between regions and countries. Maybe one of the most complex animal species in terms of diversity of uses, nature and extent of movements are equidae, for which animal movement records are usually not available. The study presented here is the first characterization of a complete and reliable network of equidae movements in Castile and Leon, which is one of the most important equidae production regions of Spain. Social network analysis and space-time cluster analysis were used to describe the contact patterns of the equidae network and to identify the most important premises, areas and time periods for potential disease introduction or spread into the region. The studied network was complex, with very heterogeneous types of premises and diverse nature and extent of the movements compared with other livestock species, which have important implications for prevention and control of equidae diseases. Centrality measures revealed that production and reproduction farms and centres of livestock competition were the most important type of premises in the studied network. Cluster analyses allowed to identify seventeen significant spatio-temporal clusters of premises at high risk of dispatching or receiving equidae, which formed four interconnected compartments. These clusters were mainly located in the north-west region and in the second part of the year. The results of this study may be useful to design risk-based surveillance and control programmes of equidae diseases and increase the speed of detection and control of potential secondary outbreaks in future epidemics. Consequently, these results will help to minimize the great economic and sanitary impact of equidae diseases. The analytical approach used here may be easily extended to characterize the equidae movement patterns in other countries and regions of the world.